diff options
Diffstat (limited to 'ANDROID_3.4.5/fs/ext4/mballoc.c')
| -rw-r--r-- | ANDROID_3.4.5/fs/ext4/mballoc.c | 5047 |
1 files changed, 0 insertions, 5047 deletions
diff --git a/ANDROID_3.4.5/fs/ext4/mballoc.c b/ANDROID_3.4.5/fs/ext4/mballoc.c deleted file mode 100644 index 6b0a57ea..00000000 --- a/ANDROID_3.4.5/fs/ext4/mballoc.c +++ /dev/null @@ -1,5047 +0,0 @@ -/* - * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com - * Written by Alex Tomas <alex@clusterfs.com> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public Licens - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- - */ - - -/* - * mballoc.c contains the multiblocks allocation routines - */ - -#include "ext4_jbd2.h" -#include "mballoc.h" -#include <linux/debugfs.h> -#include <linux/slab.h> -#include <trace/events/ext4.h> - -/* - * MUSTDO: - * - test ext4_ext_search_left() and ext4_ext_search_right() - * - search for metadata in few groups - * - * TODO v4: - * - normalization should take into account whether file is still open - * - discard preallocations if no free space left (policy?) - * - don't normalize tails - * - quota - * - reservation for superuser - * - * TODO v3: - * - bitmap read-ahead (proposed by Oleg Drokin aka green) - * - track min/max extents in each group for better group selection - * - mb_mark_used() may allocate chunk right after splitting buddy - * - tree of groups sorted by number of free blocks - * - error handling - */ - -/* - * The allocation request involve request for multiple number of blocks - * near to the goal(block) value specified. - * - * During initialization phase of the allocator we decide to use the - * group preallocation or inode preallocation depending on the size of - * the file. The size of the file could be the resulting file size we - * would have after allocation, or the current file size, which ever - * is larger. If the size is less than sbi->s_mb_stream_request we - * select to use the group preallocation. The default value of - * s_mb_stream_request is 16 blocks. This can also be tuned via - * /sys/fs/ext4/<partition>/mb_stream_req. The value is represented in - * terms of number of blocks. - * - * The main motivation for having small file use group preallocation is to - * ensure that we have small files closer together on the disk. - * - * First stage the allocator looks at the inode prealloc list, - * ext4_inode_info->i_prealloc_list, which contains list of prealloc - * spaces for this particular inode. The inode prealloc space is - * represented as: - * - * pa_lstart -> the logical start block for this prealloc space - * pa_pstart -> the physical start block for this prealloc space - * pa_len -> length for this prealloc space (in clusters) - * pa_free -> free space available in this prealloc space (in clusters) - * - * The inode preallocation space is used looking at the _logical_ start - * block. If only the logical file block falls within the range of prealloc - * space we will consume the particular prealloc space. This makes sure that - * we have contiguous physical blocks representing the file blocks - * - * The important thing to be noted in case of inode prealloc space is that - * we don't modify the values associated to inode prealloc space except - * pa_free. - * - * If we are not able to find blocks in the inode prealloc space and if we - * have the group allocation flag set then we look at the locality group - * prealloc space. These are per CPU prealloc list represented as - * - * ext4_sb_info.s_locality_groups[smp_processor_id()] - * - * The reason for having a per cpu locality group is to reduce the contention - * between CPUs. It is possible to get scheduled at this point. - * - * The locality group prealloc space is used looking at whether we have - * enough free space (pa_free) within the prealloc space. - * - * If we can't allocate blocks via inode prealloc or/and locality group - * prealloc then we look at the buddy cache. The buddy cache is represented - * by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets - * mapped to the buddy and bitmap information regarding different - * groups. The buddy information is attached to buddy cache inode so that - * we can access them through the page cache. The information regarding - * each group is loaded via ext4_mb_load_buddy. The information involve - * block bitmap and buddy information. The information are stored in the - * inode as: - * - * { page } - * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]... - * - * - * one block each for bitmap and buddy information. So for each group we - * take up 2 blocks. A page can contain blocks_per_page (PAGE_CACHE_SIZE / - * blocksize) blocks. So it can have information regarding groups_per_page - * which is blocks_per_page/2 - * - * The buddy cache inode is not stored on disk. The inode is thrown - * away when the filesystem is unmounted. - * - * We look for count number of blocks in the buddy cache. If we were able - * to locate that many free blocks we return with additional information - * regarding rest of the contiguous physical block available - * - * Before allocating blocks via buddy cache we normalize the request - * blocks. This ensure we ask for more blocks that we needed. The extra - * blocks that we get after allocation is added to the respective prealloc - * list. In case of inode preallocation we follow a list of heuristics - * based on file size. This can be found in ext4_mb_normalize_request. If - * we are doing a group prealloc we try to normalize the request to - * sbi->s_mb_group_prealloc. The default value of s_mb_group_prealloc is - * dependent on the cluster size; for non-bigalloc file systems, it is - * 512 blocks. This can be tuned via - * /sys/fs/ext4/<partition>/mb_group_prealloc. The value is represented in - * terms of number of blocks. If we have mounted the file system with -O - * stripe=<value> option the group prealloc request is normalized to the - * the smallest multiple of the stripe value (sbi->s_stripe) which is - * greater than the default mb_group_prealloc. - * - * The regular allocator (using the buddy cache) supports a few tunables. - * - * /sys/fs/ext4/<partition>/mb_min_to_scan - * /sys/fs/ext4/<partition>/mb_max_to_scan - * /sys/fs/ext4/<partition>/mb_order2_req - * - * The regular allocator uses buddy scan only if the request len is power of - * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The - * value of s_mb_order2_reqs can be tuned via - * /sys/fs/ext4/<partition>/mb_order2_req. If the request len is equal to - * stripe size (sbi->s_stripe), we try to search for contiguous block in - * stripe size. This should result in better allocation on RAID setups. If - * not, we search in the specific group using bitmap for best extents. The - * tunable min_to_scan and max_to_scan control the behaviour here. - * min_to_scan indicate how long the mballoc __must__ look for a best - * extent and max_to_scan indicates how long the mballoc __can__ look for a - * best extent in the found extents. Searching for the blocks starts with - * the group specified as the goal value in allocation context via - * ac_g_ex. Each group is first checked based on the criteria whether it - * can be used for allocation. ext4_mb_good_group explains how the groups are - * checked. - * - * Both the prealloc space are getting populated as above. So for the first - * request we will hit the buddy cache which will result in this prealloc - * space getting filled. The prealloc space is then later used for the - * subsequent request. - */ - -/* - * mballoc operates on the following data: - * - on-disk bitmap - * - in-core buddy (actually includes buddy and bitmap) - * - preallocation descriptors (PAs) - * - * there are two types of preallocations: - * - inode - * assiged to specific inode and can be used for this inode only. - * it describes part of inode's space preallocated to specific - * physical blocks. any block from that preallocated can be used - * independent. the descriptor just tracks number of blocks left - * unused. so, before taking some block from descriptor, one must - * make sure corresponded logical block isn't allocated yet. this - * also means that freeing any block within descriptor's range - * must discard all preallocated blocks. - * - locality group - * assigned to specific locality group which does not translate to - * permanent set of inodes: inode can join and leave group. space - * from this type of preallocation can be used for any inode. thus - * it's consumed from the beginning to the end. - * - * relation between them can be expressed as: - * in-core buddy = on-disk bitmap + preallocation descriptors - * - * this mean blocks mballoc considers used are: - * - allocated blocks (persistent) - * - preallocated blocks (non-persistent) - * - * consistency in mballoc world means that at any time a block is either - * free or used in ALL structures. notice: "any time" should not be read - * literally -- time is discrete and delimited by locks. - * - * to keep it simple, we don't use block numbers, instead we count number of - * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA. - * - * all operations can be expressed as: - * - init buddy: buddy = on-disk + PAs - * - new PA: buddy += N; PA = N - * - use inode PA: on-disk += N; PA -= N - * - discard inode PA buddy -= on-disk - PA; PA = 0 - * - use locality group PA on-disk += N; PA -= N - * - discard locality group PA buddy -= PA; PA = 0 - * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap - * is used in real operation because we can't know actual used - * bits from PA, only from on-disk bitmap - * - * if we follow this strict logic, then all operations above should be atomic. - * given some of them can block, we'd have to use something like semaphores - * killing performance on high-end SMP hardware. let's try to relax it using - * the following knowledge: - * 1) if buddy is referenced, it's already initialized - * 2) while block is used in buddy and the buddy is referenced, - * nobody can re-allocate that block - * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has - * bit set and PA claims same block, it's OK. IOW, one can set bit in - * on-disk bitmap if buddy has same bit set or/and PA covers corresponded - * block - * - * so, now we're building a concurrency table: - * - init buddy vs. - * - new PA - * blocks for PA are allocated in the buddy, buddy must be referenced - * until PA is linked to allocation group to avoid concurrent buddy init - * - use inode PA - * we need to make sure that either on-disk bitmap or PA has uptodate data - * given (3) we care that PA-=N operation doesn't interfere with init - * - discard inode PA - * the simplest way would be to have buddy initialized by the discard - * - use locality group PA - * again PA-=N must be serialized with init - * - discard locality group PA - * the simplest way would be to have buddy initialized by the discard - * - new PA vs. - * - use inode PA - * i_data_sem serializes them - * - discard inode PA - * discard process must wait until PA isn't used by another process - * - use locality group PA - * some mutex should serialize them - * - discard locality group PA - * discard process must wait until PA isn't used by another process - * - use inode PA - * - use inode PA - * i_data_sem or another mutex should serializes them - * - discard inode PA - * discard process must wait until PA isn't used by another process - * - use locality group PA - * nothing wrong here -- they're different PAs covering different blocks - * - discard locality group PA - * discard process must wait until PA isn't used by another process - * - * now we're ready to make few consequences: - * - PA is referenced and while it is no discard is possible - * - PA is referenced until block isn't marked in on-disk bitmap - * - PA changes only after on-disk bitmap - * - discard must not compete with init. either init is done before - * any discard or they're serialized somehow - * - buddy init as sum of on-disk bitmap and PAs is done atomically - * - * a special case when we've used PA to emptiness. no need to modify buddy - * in this case, but we should care about concurrent init - * - */ - - /* - * Logic in few words: - * - * - allocation: - * load group - * find blocks - * mark bits in on-disk bitmap - * release group - * - * - use preallocation: - * find proper PA (per-inode or group) - * load group - * mark bits in on-disk bitmap - * release group - * release PA - * - * - free: - * load group - * mark bits in on-disk bitmap - * release group - * - * - discard preallocations in group: - * mark PAs deleted - * move them onto local list - * load on-disk bitmap - * load group - * remove PA from object (inode or locality group) - * mark free blocks in-core - * - * - discard inode's preallocations: - */ - -/* - * Locking rules - * - * Locks: - * - bitlock on a group (group) - * - object (inode/locality) (object) - * - per-pa lock (pa) - * - * Paths: - * - new pa - * object - * group - * - * - find and use pa: - * pa - * - * - release consumed pa: - * pa - * group - * object - * - * - generate in-core bitmap: - * group - * pa - * - * - discard all for given object (inode, locality group): - * object - * pa - * group - * - * - discard all for given group: - * group - * pa - * group - * object - * - */ -static struct kmem_cache *ext4_pspace_cachep; -static struct kmem_cache *ext4_ac_cachep; -static struct kmem_cache *ext4_free_data_cachep; - -/* We create slab caches for groupinfo data structures based on the - * superblock block size. There will be one per mounted filesystem for - * each unique s_blocksize_bits */ -#define NR_GRPINFO_CACHES 8 -static struct kmem_cache *ext4_groupinfo_caches[NR_GRPINFO_CACHES]; - -static const char *ext4_groupinfo_slab_names[NR_GRPINFO_CACHES] = { - "ext4_groupinfo_1k", "ext4_groupinfo_2k", "ext4_groupinfo_4k", - "ext4_groupinfo_8k", "ext4_groupinfo_16k", "ext4_groupinfo_32k", - "ext4_groupinfo_64k", "ext4_groupinfo_128k" -}; - -static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap, - ext4_group_t group); -static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap, - ext4_group_t group); -static void ext4_free_data_callback(struct super_block *sb, - struct ext4_journal_cb_entry *jce, int rc); - -static inline void *mb_correct_addr_and_bit(int *bit, void *addr) -{ -#if BITS_PER_LONG == 64 - *bit += ((unsigned long) addr & 7UL) << 3; - addr = (void *) ((unsigned long) addr & ~7UL); -#elif BITS_PER_LONG == 32 - *bit += ((unsigned long) addr & 3UL) << 3; - addr = (void *) ((unsigned long) addr & ~3UL); -#else -#error "how many bits you are?!" -#endif - return addr; -} - -static inline int mb_test_bit(int bit, void *addr) -{ - /* - * ext4_test_bit on architecture like powerpc - * needs unsigned long aligned address - */ - addr = mb_correct_addr_and_bit(&bit, addr); - return ext4_test_bit(bit, addr); -} - -static inline void mb_set_bit(int bit, void *addr) -{ - addr = mb_correct_addr_and_bit(&bit, addr); - ext4_set_bit(bit, addr); -} - -static inline void mb_clear_bit(int bit, void *addr) -{ - addr = mb_correct_addr_and_bit(&bit, addr); - ext4_clear_bit(bit, addr); -} - -static inline int mb_find_next_zero_bit(void *addr, int max, int start) -{ - int fix = 0, ret, tmpmax; - addr = mb_correct_addr_and_bit(&fix, addr); - tmpmax = max + fix; - start += fix; - - ret = ext4_find_next_zero_bit(addr, tmpmax, start) - fix; - if (ret > max) - return max; - return ret; -} - -static inline int mb_find_next_bit(void *addr, int max, int start) -{ - int fix = 0, ret, tmpmax; - addr = mb_correct_addr_and_bit(&fix, addr); - tmpmax = max + fix; - start += fix; - - ret = ext4_find_next_bit(addr, tmpmax, start) - fix; - if (ret > max) - return max; - return ret; -} - -static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max) -{ - char *bb; - - BUG_ON(e4b->bd_bitmap == e4b->bd_buddy); - BUG_ON(max == NULL); - - if (order > e4b->bd_blkbits + 1) { - *max = 0; - return NULL; - } - - /* at order 0 we see each particular block */ - if (order == 0) { - *max = 1 << (e4b->bd_blkbits + 3); - return e4b->bd_bitmap; - } - - bb = e4b->bd_buddy + EXT4_SB(e4b->bd_sb)->s_mb_offsets[order]; - *max = EXT4_SB(e4b->bd_sb)->s_mb_maxs[order]; - - return bb; -} - -#ifdef DOUBLE_CHECK -static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b, - int first, int count) -{ - int i; - struct super_block *sb = e4b->bd_sb; - - if (unlikely(e4b->bd_info->bb_bitmap == NULL)) - return; - assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group)); - for (i = 0; i < count; i++) { - if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) { - ext4_fsblk_t blocknr; - - blocknr = ext4_group_first_block_no(sb, e4b->bd_group); - blocknr += EXT4_C2B(EXT4_SB(sb), first + i); - ext4_grp_locked_error(sb, e4b->bd_group, - inode ? inode->i_ino : 0, - blocknr, - "freeing block already freed " - "(bit %u)", - first + i); - } - mb_clear_bit(first + i, e4b->bd_info->bb_bitmap); - } -} - -static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count) -{ - int i; - - if (unlikely(e4b->bd_info->bb_bitmap == NULL)) - return; - assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group)); - for (i = 0; i < count; i++) { - BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap)); - mb_set_bit(first + i, e4b->bd_info->bb_bitmap); - } -} - -static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap) -{ - if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) { - unsigned char *b1, *b2; - int i; - b1 = (unsigned char *) e4b->bd_info->bb_bitmap; - b2 = (unsigned char *) bitmap; - for (i = 0; i < e4b->bd_sb->s_blocksize; i++) { - if (b1[i] != b2[i]) { - ext4_msg(e4b->bd_sb, KERN_ERR, - "corruption in group %u " - "at byte %u(%u): %x in copy != %x " - "on disk/prealloc", - e4b->bd_group, i, i * 8, b1[i], b2[i]); - BUG(); - } - } - } -} - -#else -static inline void mb_free_blocks_double(struct inode *inode, - struct ext4_buddy *e4b, int first, int count) -{ - return; -} -static inline void mb_mark_used_double(struct ext4_buddy *e4b, - int first, int count) -{ - return; -} -static inline void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap) -{ - return; -} -#endif - -#ifdef AGGRESSIVE_CHECK - -#define MB_CHECK_ASSERT(assert) \ -do { \ - if (!(assert)) { \ - printk(KERN_EMERG \ - "Assertion failure in %s() at %s:%d: \"%s\"\n", \ - function, file, line, # assert); \ - BUG(); \ - } \ -} while (0) - -static int __mb_check_buddy(struct ext4_buddy *e4b, char *file, - const char *function, int line) -{ - struct super_block *sb = e4b->bd_sb; - int order = e4b->bd_blkbits + 1; - int max; - int max2; - int i; - int j; - int k; - int count; - struct ext4_group_info *grp; - int fragments = 0; - int fstart; - struct list_head *cur; - void *buddy; - void *buddy2; - - { - static int mb_check_counter; - if (mb_check_counter++ % 100 != 0) - return 0; - } - - while (order > 1) { - buddy = mb_find_buddy(e4b, order, &max); - MB_CHECK_ASSERT(buddy); - buddy2 = mb_find_buddy(e4b, order - 1, &max2); - MB_CHECK_ASSERT(buddy2); - MB_CHECK_ASSERT(buddy != buddy2); - MB_CHECK_ASSERT(max * 2 == max2); - - count = 0; - for (i = 0; i < max; i++) { - - if (mb_test_bit(i, buddy)) { - /* only single bit in buddy2 may be 1 */ - if (!mb_test_bit(i << 1, buddy2)) { - MB_CHECK_ASSERT( - mb_test_bit((i<<1)+1, buddy2)); - } else if (!mb_test_bit((i << 1) + 1, buddy2)) { - MB_CHECK_ASSERT( - mb_test_bit(i << 1, buddy2)); - } - continue; - } - - /* both bits in buddy2 must be 1 */ - MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2)); - MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2)); - - for (j = 0; j < (1 << order); j++) { - k = (i * (1 << order)) + j; - MB_CHECK_ASSERT( - !mb_test_bit(k, e4b->bd_bitmap)); - } - count++; - } - MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count); - order--; - } - - fstart = -1; - buddy = mb_find_buddy(e4b, 0, &max); - for (i = 0; i < max; i++) { - if (!mb_test_bit(i, buddy)) { - MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free); - if (fstart == -1) { - fragments++; - fstart = i; - } - continue; - } - fstart = -1; - /* check used bits only */ - for (j = 0; j < e4b->bd_blkbits + 1; j++) { - buddy2 = mb_find_buddy(e4b, j, &max2); - k = i >> j; - MB_CHECK_ASSERT(k < max2); - MB_CHECK_ASSERT(mb_test_bit(k, buddy2)); - } - } - MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info)); - MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments); - - grp = ext4_get_group_info(sb, e4b->bd_group); - list_for_each(cur, &grp->bb_prealloc_list) { - ext4_group_t groupnr; - struct ext4_prealloc_space *pa; - pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list); - ext4_get_group_no_and_offset(sb, pa->pa_pstart, &groupnr, &k); - MB_CHECK_ASSERT(groupnr == e4b->bd_group); - for (i = 0; i < pa->pa_len; i++) - MB_CHECK_ASSERT(mb_test_bit(k + i, buddy)); - } - return 0; -} -#undef MB_CHECK_ASSERT -#define mb_check_buddy(e4b) __mb_check_buddy(e4b, \ - __FILE__, __func__, __LINE__) -#else -#define mb_check_buddy(e4b) -#endif - -/* - * Divide blocks started from @first with length @len into - * smaller chunks with power of 2 blocks. - * Clear the bits in bitmap which the blocks of the chunk(s) covered, - * then increase bb_counters[] for corresponded chunk size. - */ -static void ext4_mb_mark_free_simple(struct super_block *sb, - void *buddy, ext4_grpblk_t first, ext4_grpblk_t len, - struct ext4_group_info *grp) -{ - struct ext4_sb_info *sbi = EXT4_SB(sb); - ext4_grpblk_t min; - ext4_grpblk_t max; - ext4_grpblk_t chunk; - unsigned short border; - - BUG_ON(len > EXT4_CLUSTERS_PER_GROUP(sb)); - - border = 2 << sb->s_blocksize_bits; - - while (len > 0) { - /* find how many blocks can be covered since this position */ - max = ffs(first | border) - 1; - - /* find how many blocks of power 2 we need to mark */ - min = fls(len) - 1; - - if (max < min) - min = max; - chunk = 1 << min; - - /* mark multiblock chunks only */ - grp->bb_counters[min]++; - if (min > 0) - mb_clear_bit(first >> min, - buddy + sbi->s_mb_offsets[min]); - - len -= chunk; - first += chunk; - } -} - -/* - * Cache the order of the largest free extent we have available in this block - * group. - */ -static void -mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp) -{ - int i; - int bits; - - grp->bb_largest_free_order = -1; /* uninit */ - - bits = sb->s_blocksize_bits + 1; - for (i = bits; i >= 0; i--) { - if (grp->bb_counters[i] > 0) { - grp->bb_largest_free_order = i; - break; - } - } -} - -static noinline_for_stack -void ext4_mb_generate_buddy(struct super_block *sb, - void *buddy, void *bitmap, ext4_group_t group) -{ - struct ext4_group_info *grp = ext4_get_group_info(sb, group); - ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb); - ext4_grpblk_t i = 0; - ext4_grpblk_t first; - ext4_grpblk_t len; - unsigned free = 0; - unsigned fragments = 0; - unsigned long long period = get_cycles(); - - /* initialize buddy from bitmap which is aggregation - * of on-disk bitmap and preallocations */ - i = mb_find_next_zero_bit(bitmap, max, 0); - grp->bb_first_free = i; - while (i < max) { - fragments++; - first = i; - i = mb_find_next_bit(bitmap, max, i); - len = i - first; - free += len; - if (len > 1) - ext4_mb_mark_free_simple(sb, buddy, first, len, grp); - else - grp->bb_counters[0]++; - if (i < max) - i = mb_find_next_zero_bit(bitmap, max, i); - } - grp->bb_fragments = fragments; - - if (free != grp->bb_free) { - ext4_grp_locked_error(sb, group, 0, 0, - "%u clusters in bitmap, %u in gd", - free, grp->bb_free); - /* - * If we intent to continue, we consider group descritor - * corrupt and update bb_free using bitmap value - */ - grp->bb_free = free; - } - mb_set_largest_free_order(sb, grp); - - clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state)); - - period = get_cycles() - period; - spin_lock(&EXT4_SB(sb)->s_bal_lock); - EXT4_SB(sb)->s_mb_buddies_generated++; - EXT4_SB(sb)->s_mb_generation_time += period; - spin_unlock(&EXT4_SB(sb)->s_bal_lock); -} - -/* The buddy information is attached the buddy cache inode - * for convenience. The information regarding each group - * is loaded via ext4_mb_load_buddy. The information involve - * block bitmap and buddy information. The information are - * stored in the inode as - * - * { page } - * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]... - * - * - * one block each for bitmap and buddy information. - * So for each group we take up 2 blocks. A page can - * contain blocks_per_page (PAGE_CACHE_SIZE / blocksize) blocks. - * So it can have information regarding groups_per_page which - * is blocks_per_page/2 - * - * Locking note: This routine takes the block group lock of all groups - * for this page; do not hold this lock when calling this routine! - */ - -static int ext4_mb_init_cache(struct page *page, char *incore) -{ - ext4_group_t ngroups; - int blocksize; - int blocks_per_page; - int groups_per_page; - int err = 0; - int i; - ext4_group_t first_group, group; - int first_block; - struct super_block *sb; - struct buffer_head *bhs; - struct buffer_head **bh; - struct inode *inode; - char *data; - char *bitmap; - struct ext4_group_info *grinfo; - - mb_debug(1, "init page %lu\n", page->index); - - inode = page->mapping->host; - sb = inode->i_sb; - ngroups = ext4_get_groups_count(sb); - blocksize = 1 << inode->i_blkbits; - blocks_per_page = PAGE_CACHE_SIZE / blocksize; - - groups_per_page = blocks_per_page >> 1; - if (groups_per_page == 0) - groups_per_page = 1; - - /* allocate buffer_heads to read bitmaps */ - if (groups_per_page > 1) { - i = sizeof(struct buffer_head *) * groups_per_page; - bh = kzalloc(i, GFP_NOFS); - if (bh == NULL) { - err = -ENOMEM; - goto out; - } - } else - bh = &bhs; - - first_group = page->index * blocks_per_page / 2; - - /* read all groups the page covers into the cache */ - for (i = 0, group = first_group; i < groups_per_page; i++, group++) { - if (group >= ngroups) - break; - - grinfo = ext4_get_group_info(sb, group); - /* - * If page is uptodate then we came here after online resize - * which added some new uninitialized group info structs, so - * we must skip all initialized uptodate buddies on the page, - * which may be currently in use by an allocating task. - */ - if (PageUptodate(page) && !EXT4_MB_GRP_NEED_INIT(grinfo)) { - bh[i] = NULL; - continue; - } - if (!(bh[i] = ext4_read_block_bitmap_nowait(sb, group))) { - err = -ENOMEM; - goto out; - } - mb_debug(1, "read bitmap for group %u\n", group); - } - - /* wait for I/O completion */ - for (i = 0, group = first_group; i < groups_per_page; i++, group++) { - if (bh[i] && ext4_wait_block_bitmap(sb, group, bh[i])) { - err = -EIO; - goto out; - } - } - - first_block = page->index * blocks_per_page; - for (i = 0; i < blocks_per_page; i++) { - int group; - - group = (first_block + i) >> 1; - if (group >= ngroups) - break; - - if (!bh[group - first_group]) - /* skip initialized uptodate buddy */ - continue; - - /* - * data carry information regarding this - * particular group in the format specified - * above - * - */ - data = page_address(page) + (i * blocksize); - bitmap = bh[group - first_group]->b_data; - - /* - * We place the buddy block and bitmap block - * close together - */ - if ((first_block + i) & 1) { - /* this is block of buddy */ - BUG_ON(incore == NULL); - mb_debug(1, "put buddy for group %u in page %lu/%x\n", - group, page->index, i * blocksize); - trace_ext4_mb_buddy_bitmap_load(sb, group); - grinfo = ext4_get_group_info(sb, group); - grinfo->bb_fragments = 0; - memset(grinfo->bb_counters, 0, - sizeof(*grinfo->bb_counters) * - (sb->s_blocksize_bits+2)); - /* - * incore got set to the group block bitmap below - */ - ext4_lock_group(sb, group); - /* init the buddy */ - memset(data, 0xff, blocksize); - ext4_mb_generate_buddy(sb, data, incore, group); - ext4_unlock_group(sb, group); - incore = NULL; - } else { - /* this is block of bitmap */ - BUG_ON(incore != NULL); - mb_debug(1, "put bitmap for group %u in page %lu/%x\n", - group, page->index, i * blocksize); - trace_ext4_mb_bitmap_load(sb, group); - - /* see comments in ext4_mb_put_pa() */ - ext4_lock_group(sb, group); - memcpy(data, bitmap, blocksize); - - /* mark all preallocated blks used in in-core bitmap */ - ext4_mb_generate_from_pa(sb, data, group); - ext4_mb_generate_from_freelist(sb, data, group); - ext4_unlock_group(sb, group); - - /* set incore so that the buddy information can be - * generated using this - */ - incore = data; - } - } - SetPageUptodate(page); - -out: - if (bh) { - for (i = 0; i < groups_per_page; i++) - brelse(bh[i]); - if (bh != &bhs) - kfree(bh); - } - return err; -} - -/* - * Lock the buddy and bitmap pages. This make sure other parallel init_group - * on the same buddy page doesn't happen whild holding the buddy page lock. - * Return locked buddy and bitmap pages on e4b struct. If buddy and bitmap - * are on the same page e4b->bd_buddy_page is NULL and return value is 0. - */ -static int ext4_mb_get_buddy_page_lock(struct super_block *sb, - ext4_group_t group, struct ext4_buddy *e4b) -{ - struct inode *inode = EXT4_SB(sb)->s_buddy_cache; - int block, pnum, poff; - int blocks_per_page; - struct page *page; - - e4b->bd_buddy_page = NULL; - e4b->bd_bitmap_page = NULL; - - blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize; - /* - * the buddy cache inode stores the block bitmap - * and buddy information in consecutive blocks. - * So for each group we need two blocks. - */ - block = group * 2; - pnum = block / blocks_per_page; - poff = block % blocks_per_page; - page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS); - if (!page) - return -EIO; - BUG_ON(page->mapping != inode->i_mapping); - e4b->bd_bitmap_page = page; - e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize); - - if (blocks_per_page >= 2) { - /* buddy and bitmap are on the same page */ - return 0; - } - - block++; - pnum = block / blocks_per_page; - poff = block % blocks_per_page; - page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS); - if (!page) - return -EIO; - BUG_ON(page->mapping != inode->i_mapping); - e4b->bd_buddy_page = page; - return 0; -} - -static void ext4_mb_put_buddy_page_lock(struct ext4_buddy *e4b) -{ - if (e4b->bd_bitmap_page) { - unlock_page(e4b->bd_bitmap_page); - page_cache_release(e4b->bd_bitmap_page); - } - if (e4b->bd_buddy_page) { - unlock_page(e4b->bd_buddy_page); - page_cache_release(e4b->bd_buddy_page); - } -} - -/* - * Locking note: This routine calls ext4_mb_init_cache(), which takes the - * block group lock of all groups for this page; do not hold the BG lock when - * calling this routine! - */ -static noinline_for_stack -int ext4_mb_init_group(struct super_block *sb, ext4_group_t group) -{ - - struct ext4_group_info *this_grp; - struct ext4_buddy e4b; - struct page *page; - int ret = 0; - - mb_debug(1, "init group %u\n", group); - this_grp = ext4_get_group_info(sb, group); - /* - * This ensures that we don't reinit the buddy cache - * page which map to the group from which we are already - * allocating. If we are looking at the buddy cache we would - * have taken a reference using ext4_mb_load_buddy and that - * would have pinned buddy page to page cache. - */ - ret = ext4_mb_get_buddy_page_lock(sb, group, &e4b); - if (ret || !EXT4_MB_GRP_NEED_INIT(this_grp)) { - /* - * somebody initialized the group - * return without doing anything - */ - goto err; - } - - page = e4b.bd_bitmap_page; - ret = ext4_mb_init_cache(page, NULL); - if (ret) - goto err; - if (!PageUptodate(page)) { - ret = -EIO; - goto err; - } - mark_page_accessed(page); - - if (e4b.bd_buddy_page == NULL) { - /* - * If both the bitmap and buddy are in - * the same page we don't need to force - * init the buddy - */ - ret = 0; - goto err; - } - /* init buddy cache */ - page = e4b.bd_buddy_page; - ret = ext4_mb_init_cache(page, e4b.bd_bitmap); - if (ret) - goto err; - if (!PageUptodate(page)) { - ret = -EIO; - goto err; - } - mark_page_accessed(page); -err: - ext4_mb_put_buddy_page_lock(&e4b); - return ret; -} - -/* - * Locking note: This routine calls ext4_mb_init_cache(), which takes the - * block group lock of all groups for this page; do not hold the BG lock when - * calling this routine! - */ -static noinline_for_stack int -ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group, - struct ext4_buddy *e4b) -{ - int blocks_per_page; - int block; - int pnum; - int poff; - struct page *page; - int ret; - struct ext4_group_info *grp; - struct ext4_sb_info *sbi = EXT4_SB(sb); - struct inode *inode = sbi->s_buddy_cache; - - mb_debug(1, "load group %u\n", group); - - blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize; - grp = ext4_get_group_info(sb, group); - - e4b->bd_blkbits = sb->s_blocksize_bits; - e4b->bd_info = grp; - e4b->bd_sb = sb; - e4b->bd_group = group; - e4b->bd_buddy_page = NULL; - e4b->bd_bitmap_page = NULL; - - if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) { - /* - * we need full data about the group - * to make a good selection - */ - ret = ext4_mb_init_group(sb, group); - if (ret) - return ret; - } - - /* - * the buddy cache inode stores the block bitmap - * and buddy information in consecutive blocks. - * So for each group we need two blocks. - */ - block = group * 2; - pnum = block / blocks_per_page; - poff = block % blocks_per_page; - - /* we could use find_or_create_page(), but it locks page - * what we'd like to avoid in fast path ... */ - page = find_get_page(inode->i_mapping, pnum); - if (page == NULL || !PageUptodate(page)) { - if (page) - /* - * drop the page reference and try - * to get the page with lock. If we - * are not uptodate that implies - * somebody just created the page but - * is yet to initialize the same. So - * wait for it to initialize. - */ - page_cache_release(page); - page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS); - if (page) { - BUG_ON(page->mapping != inode->i_mapping); - if (!PageUptodate(page)) { - ret = ext4_mb_init_cache(page, NULL); - if (ret) { - unlock_page(page); - goto err; - } - mb_cmp_bitmaps(e4b, page_address(page) + - (poff * sb->s_blocksize)); - } - unlock_page(page); - } - } - if (page == NULL || !PageUptodate(page)) { - ret = -EIO; - goto err; - } - e4b->bd_bitmap_page = page; - e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize); - mark_page_accessed(page); - - block++; - pnum = block / blocks_per_page; - poff = block % blocks_per_page; - - page = find_get_page(inode->i_mapping, pnum); - if (page == NULL || !PageUptodate(page)) { - if (page) - page_cache_release(page); - page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS); - if (page) { - BUG_ON(page->mapping != inode->i_mapping); - if (!PageUptodate(page)) { - ret = ext4_mb_init_cache(page, e4b->bd_bitmap); - if (ret) { - unlock_page(page); - goto err; - } - } - unlock_page(page); - } - } - if (page == NULL || !PageUptodate(page)) { - ret = -EIO; - goto err; - } - e4b->bd_buddy_page = page; - e4b->bd_buddy = page_address(page) + (poff * sb->s_blocksize); - mark_page_accessed(page); - - BUG_ON(e4b->bd_bitmap_page == NULL); - BUG_ON(e4b->bd_buddy_page == NULL); - - return 0; - -err: - if (page) - page_cache_release(page); - if (e4b->bd_bitmap_page) - page_cache_release(e4b->bd_bitmap_page); - if (e4b->bd_buddy_page) - page_cache_release(e4b->bd_buddy_page); - e4b->bd_buddy = NULL; - e4b->bd_bitmap = NULL; - return ret; -} - -static void ext4_mb_unload_buddy(struct ext4_buddy *e4b) -{ - if (e4b->bd_bitmap_page) - page_cache_release(e4b->bd_bitmap_page); - if (e4b->bd_buddy_page) - page_cache_release(e4b->bd_buddy_page); -} - - -static int mb_find_order_for_block(struct ext4_buddy *e4b, int block) -{ - int order = 1; - void *bb; - - BUG_ON(e4b->bd_bitmap == e4b->bd_buddy); - BUG_ON(block >= (1 << (e4b->bd_blkbits + 3))); - - bb = e4b->bd_buddy; - while (order <= e4b->bd_blkbits + 1) { - block = block >> 1; - if (!mb_test_bit(block, bb)) { - /* this block is part of buddy of order 'order' */ - return order; - } - bb += 1 << (e4b->bd_blkbits - order); - order++; - } - return 0; -} - -static void mb_clear_bits(void *bm, int cur, int len) -{ - __u32 *addr; - - len = cur + len; - while (cur < len) { - if ((cur & 31) == 0 && (len - cur) >= 32) { - /* fast path: clear whole word at once */ - addr = bm + (cur >> 3); - *addr = 0; - cur += 32; - continue; - } - mb_clear_bit(cur, bm); - cur++; - } -} - -void ext4_set_bits(void *bm, int cur, int len) -{ - __u32 *addr; - - len = cur + len; - while (cur < len) { - if ((cur & 31) == 0 && (len - cur) >= 32) { - /* fast path: set whole word at once */ - addr = bm + (cur >> 3); - *addr = 0xffffffff; - cur += 32; - continue; - } - mb_set_bit(cur, bm); - cur++; - } -} - -static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b, - int first, int count) -{ - int block = 0; - int max = 0; - int order; - void *buddy; - void *buddy2; - struct super_block *sb = e4b->bd_sb; - - BUG_ON(first + count > (sb->s_blocksize << 3)); - assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group)); - mb_check_buddy(e4b); - mb_free_blocks_double(inode, e4b, first, count); - - e4b->bd_info->bb_free += count; - if (first < e4b->bd_info->bb_first_free) - e4b->bd_info->bb_first_free = first; - - /* let's maintain fragments counter */ - if (first != 0) - block = !mb_test_bit(first - 1, e4b->bd_bitmap); - if (first + count < EXT4_SB(sb)->s_mb_maxs[0]) - max = !mb_test_bit(first + count, e4b->bd_bitmap); - if (block && max) - e4b->bd_info->bb_fragments--; - else if (!block && !max) - e4b->bd_info->bb_fragments++; - - /* let's maintain buddy itself */ - while (count-- > 0) { - block = first++; - order = 0; - - if (!mb_test_bit(block, e4b->bd_bitmap)) { - ext4_fsblk_t blocknr; - - blocknr = ext4_group_first_block_no(sb, e4b->bd_group); - blocknr += EXT4_C2B(EXT4_SB(sb), block); - ext4_grp_locked_error(sb, e4b->bd_group, - inode ? inode->i_ino : 0, - blocknr, - "freeing already freed block " - "(bit %u)", block); - } - mb_clear_bit(block, e4b->bd_bitmap); - e4b->bd_info->bb_counters[order]++; - - /* start of the buddy */ - buddy = mb_find_buddy(e4b, order, &max); - - do { - block &= ~1UL; - if (mb_test_bit(block, buddy) || - mb_test_bit(block + 1, buddy)) - break; - - /* both the buddies are free, try to coalesce them */ - buddy2 = mb_find_buddy(e4b, order + 1, &max); - - if (!buddy2) - break; - - if (order > 0) { - /* for special purposes, we don't set - * free bits in bitmap */ - mb_set_bit(block, buddy); - mb_set_bit(block + 1, buddy); - } - e4b->bd_info->bb_counters[order]--; - e4b->bd_info->bb_counters[order]--; - - block = block >> 1; - order++; - e4b->bd_info->bb_counters[order]++; - - mb_clear_bit(block, buddy2); - buddy = buddy2; - } while (1); - } - mb_set_largest_free_order(sb, e4b->bd_info); - mb_check_buddy(e4b); -} - -static int mb_find_extent(struct ext4_buddy *e4b, int order, int block, - int needed, struct ext4_free_extent *ex) -{ - int next = block; - int max; - void *buddy; - - assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group)); - BUG_ON(ex == NULL); - - buddy = mb_find_buddy(e4b, order, &max); - BUG_ON(buddy == NULL); - BUG_ON(block >= max); - if (mb_test_bit(block, buddy)) { - ex->fe_len = 0; - ex->fe_start = 0; - ex->fe_group = 0; - return 0; - } - - /* FIXME dorp order completely ? */ - if (likely(order == 0)) { - /* find actual order */ - order = mb_find_order_for_block(e4b, block); - block = block >> order; - } - - ex->fe_len = 1 << order; - ex->fe_start = block << order; - ex->fe_group = e4b->bd_group; - - /* calc difference from given start */ - next = next - ex->fe_start; - ex->fe_len -= next; - ex->fe_start += next; - - while (needed > ex->fe_len && - (buddy = mb_find_buddy(e4b, order, &max))) { - - if (block + 1 >= max) - break; - - next = (block + 1) * (1 << order); - if (mb_test_bit(next, e4b->bd_bitmap)) - break; - - order = mb_find_order_for_block(e4b, next); - - block = next >> order; - ex->fe_len += 1 << order; - } - - BUG_ON(ex->fe_start + ex->fe_len > (1 << (e4b->bd_blkbits + 3))); - return ex->fe_len; -} - -static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex) -{ - int ord; - int mlen = 0; - int max = 0; - int cur; - int start = ex->fe_start; - int len = ex->fe_len; - unsigned ret = 0; - int len0 = len; - void *buddy; - - BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3)); - BUG_ON(e4b->bd_group != ex->fe_group); - assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group)); - mb_check_buddy(e4b); - mb_mark_used_double(e4b, start, len); - - e4b->bd_info->bb_free -= len; - if (e4b->bd_info->bb_first_free == start) - e4b->bd_info->bb_first_free += len; - - /* let's maintain fragments counter */ - if (start != 0) - mlen = !mb_test_bit(start - 1, e4b->bd_bitmap); - if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0]) - max = !mb_test_bit(start + len, e4b->bd_bitmap); - if (mlen && max) - e4b->bd_info->bb_fragments++; - else if (!mlen && !max) - e4b->bd_info->bb_fragments--; - - /* let's maintain buddy itself */ - while (len) { - ord = mb_find_order_for_block(e4b, start); - - if (((start >> ord) << ord) == start && len >= (1 << ord)) { - /* the whole chunk may be allocated at once! */ - mlen = 1 << ord; - buddy = mb_find_buddy(e4b, ord, &max); - BUG_ON((start >> ord) >= max); - mb_set_bit(start >> ord, buddy); - e4b->bd_info->bb_counters[ord]--; - start += mlen; - len -= mlen; - BUG_ON(len < 0); - continue; - } - - /* store for history */ - if (ret == 0) - ret = len | (ord << 16); - - /* we have to split large buddy */ - BUG_ON(ord <= 0); - buddy = mb_find_buddy(e4b, ord, &max); - mb_set_bit(start >> ord, buddy); - e4b->bd_info->bb_counters[ord]--; - - ord--; - cur = (start >> ord) & ~1U; - buddy = mb_find_buddy(e4b, ord, &max); - mb_clear_bit(cur, buddy); - mb_clear_bit(cur + 1, buddy); - e4b->bd_info->bb_counters[ord]++; - e4b->bd_info->bb_counters[ord]++; - } - mb_set_largest_free_order(e4b->bd_sb, e4b->bd_info); - - ext4_set_bits(e4b->bd_bitmap, ex->fe_start, len0); - mb_check_buddy(e4b); - - return ret; -} - -/* - * Must be called under group lock! - */ -static void ext4_mb_use_best_found(struct ext4_allocation_context *ac, - struct ext4_buddy *e4b) -{ - struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); - int ret; - - BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group); - BUG_ON(ac->ac_status == AC_STATUS_FOUND); - - ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len); - ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical; - ret = mb_mark_used(e4b, &ac->ac_b_ex); - - /* preallocation can change ac_b_ex, thus we store actually - * allocated blocks for history */ - ac->ac_f_ex = ac->ac_b_ex; - - ac->ac_status = AC_STATUS_FOUND; - ac->ac_tail = ret & 0xffff; - ac->ac_buddy = ret >> 16; - - /* - * take the page reference. We want the page to be pinned - * so that we don't get a ext4_mb_init_cache_call for this - * group until we update the bitmap. That would mean we - * double allocate blocks. The reference is dropped - * in ext4_mb_release_context - */ - ac->ac_bitmap_page = e4b->bd_bitmap_page; - get_page(ac->ac_bitmap_page); - ac->ac_buddy_page = e4b->bd_buddy_page; - get_page(ac->ac_buddy_page); - /* store last allocated for subsequent stream allocation */ - if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) { - spin_lock(&sbi->s_md_lock); - sbi->s_mb_last_group = ac->ac_f_ex.fe_group; - sbi->s_mb_last_start = ac->ac_f_ex.fe_start; - spin_unlock(&sbi->s_md_lock); - } -} - -/* - * regular allocator, for general purposes allocation - */ - -static void ext4_mb_check_limits(struct ext4_allocation_context *ac, - struct ext4_buddy *e4b, - int finish_group) -{ - struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); - struct ext4_free_extent *bex = &ac->ac_b_ex; - struct ext4_free_extent *gex = &ac->ac_g_ex; - struct ext4_free_extent ex; - int max; - - if (ac->ac_status == AC_STATUS_FOUND) - return; - /* - * We don't want to scan for a whole year - */ - if (ac->ac_found > sbi->s_mb_max_to_scan && - !(ac->ac_flags & EXT4_MB_HINT_FIRST)) { - ac->ac_status = AC_STATUS_BREAK; - return; - } - - /* - * Haven't found good chunk so far, let's continue - */ - if (bex->fe_len < gex->fe_len) - return; - - if ((finish_group || ac->ac_found > sbi->s_mb_min_to_scan) - && bex->fe_group == e4b->bd_group) { - /* recheck chunk's availability - we don't know - * when it was found (within this lock-unlock - * period or not) */ - max = mb_find_extent(e4b, 0, bex->fe_start, gex->fe_len, &ex); - if (max >= gex->fe_len) { - ext4_mb_use_best_found(ac, e4b); - return; - } - } -} - -/* - * The routine checks whether found extent is good enough. If it is, - * then the extent gets marked used and flag is set to the context - * to stop scanning. Otherwise, the extent is compared with the - * previous found extent and if new one is better, then it's stored - * in the context. Later, the best found extent will be used, if - * mballoc can't find good enough extent. - * - * FIXME: real allocation policy is to be designed yet! - */ -static void ext4_mb_measure_extent(struct ext4_allocation_context *ac, - struct ext4_free_extent *ex, - struct ext4_buddy *e4b) -{ - struct ext4_free_extent *bex = &ac->ac_b_ex; - struct ext4_free_extent *gex = &ac->ac_g_ex; - - BUG_ON(ex->fe_len <= 0); - BUG_ON(ex->fe_len > EXT4_CLUSTERS_PER_GROUP(ac->ac_sb)); - BUG_ON(ex->fe_start >= EXT4_CLUSTERS_PER_GROUP(ac->ac_sb)); - BUG_ON(ac->ac_status != AC_STATUS_CONTINUE); - - ac->ac_found++; - - /* - * The special case - take what you catch first - */ - if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) { - *bex = *ex; - ext4_mb_use_best_found(ac, e4b); - return; - } - - /* - * Let's check whether the chuck is good enough - */ - if (ex->fe_len == gex->fe_len) { - *bex = *ex; - ext4_mb_use_best_found(ac, e4b); - return; - } - - /* - * If this is first found extent, just store it in the context - */ - if (bex->fe_len == 0) { - *bex = *ex; - return; - } - - /* - * If new found extent is better, store it in the context - */ - if (bex->fe_len < gex->fe_len) { - /* if the request isn't satisfied, any found extent - * larger than previous best one is better */ - if (ex->fe_len > bex->fe_len) - *bex = *ex; - } else if (ex->fe_len > gex->fe_len) { - /* if the request is satisfied, then we try to find - * an extent that still satisfy the request, but is - * smaller than previous one */ - if (ex->fe_len < bex->fe_len) - *bex = *ex; - } - - ext4_mb_check_limits(ac, e4b, 0); -} - -static noinline_for_stack -int ext4_mb_try_best_found(struct ext4_allocation_context *ac, - struct ext4_buddy *e4b) -{ - struct ext4_free_extent ex = ac->ac_b_ex; - ext4_group_t group = ex.fe_group; - int max; - int err; - - BUG_ON(ex.fe_len <= 0); - err = ext4_mb_load_buddy(ac->ac_sb, group, e4b); - if (err) - return err; - - ext4_lock_group(ac->ac_sb, group); - max = mb_find_extent(e4b, 0, ex.fe_start, ex.fe_len, &ex); - - if (max > 0) { - ac->ac_b_ex = ex; - ext4_mb_use_best_found(ac, e4b); - } - - ext4_unlock_group(ac->ac_sb, group); - ext4_mb_unload_buddy(e4b); - - return 0; -} - -static noinline_for_stack -int ext4_mb_find_by_goal(struct ext4_allocation_context *ac, - struct ext4_buddy *e4b) -{ - ext4_group_t group = ac->ac_g_ex.fe_group; - int max; - int err; - struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); - struct ext4_free_extent ex; - - if (!(ac->ac_flags & EXT4_MB_HINT_TRY_GOAL)) - return 0; - - err = ext4_mb_load_buddy(ac->ac_sb, group, e4b); - if (err) - return err; - - ext4_lock_group(ac->ac_sb, group); - max = mb_find_extent(e4b, 0, ac->ac_g_ex.fe_start, - ac->ac_g_ex.fe_len, &ex); - - if (max >= ac->ac_g_ex.fe_len && ac->ac_g_ex.fe_len == sbi->s_stripe) { - ext4_fsblk_t start; - - start = ext4_group_first_block_no(ac->ac_sb, e4b->bd_group) + - ex.fe_start; - /* use do_div to get remainder (would be 64-bit modulo) */ - if (do_div(start, sbi->s_stripe) == 0) { - ac->ac_found++; - ac->ac_b_ex = ex; - ext4_mb_use_best_found(ac, e4b); - } - } else if (max >= ac->ac_g_ex.fe_len) { - BUG_ON(ex.fe_len <= 0); - BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group); - BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start); - ac->ac_found++; - ac->ac_b_ex = ex; - ext4_mb_use_best_found(ac, e4b); - } else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) { - /* Sometimes, caller may want to merge even small - * number of blocks to an existing extent */ - BUG_ON(ex.fe_len <= 0); - BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group); - BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start); - ac->ac_found++; - ac->ac_b_ex = ex; - ext4_mb_use_best_found(ac, e4b); - } - ext4_unlock_group(ac->ac_sb, group); - ext4_mb_unload_buddy(e4b); - - return 0; -} - -/* - * The routine scans buddy structures (not bitmap!) from given order - * to max order and tries to find big enough chunk to satisfy the req - */ -static noinline_for_stack -void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac, - struct ext4_buddy *e4b) -{ - struct super_block *sb = ac->ac_sb; - struct ext4_group_info *grp = e4b->bd_info; - void *buddy; - int i; - int k; - int max; - - BUG_ON(ac->ac_2order <= 0); - for (i = ac->ac_2order; i <= sb->s_blocksize_bits + 1; i++) { - if (grp->bb_counters[i] == 0) - continue; - - buddy = mb_find_buddy(e4b, i, &max); - BUG_ON(buddy == NULL); - - k = mb_find_next_zero_bit(buddy, max, 0); - BUG_ON(k >= max); - - ac->ac_found++; - - ac->ac_b_ex.fe_len = 1 << i; - ac->ac_b_ex.fe_start = k << i; - ac->ac_b_ex.fe_group = e4b->bd_group; - - ext4_mb_use_best_found(ac, e4b); - - BUG_ON(ac->ac_b_ex.fe_len != ac->ac_g_ex.fe_len); - - if (EXT4_SB(sb)->s_mb_stats) - atomic_inc(&EXT4_SB(sb)->s_bal_2orders); - - break; - } -} - -/* - * The routine scans the group and measures all found extents. - * In order to optimize scanning, caller must pass number of - * free blocks in the group, so the routine can know upper limit. - */ -static noinline_for_stack -void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac, - struct ext4_buddy *e4b) -{ - struct super_block *sb = ac->ac_sb; - void *bitmap = e4b->bd_bitmap; - struct ext4_free_extent ex; - int i; - int free; - - free = e4b->bd_info->bb_free; - BUG_ON(free <= 0); - - i = e4b->bd_info->bb_first_free; - - while (free && ac->ac_status == AC_STATUS_CONTINUE) { - i = mb_find_next_zero_bit(bitmap, - EXT4_CLUSTERS_PER_GROUP(sb), i); - if (i >= EXT4_CLUSTERS_PER_GROUP(sb)) { - /* - * IF we have corrupt bitmap, we won't find any - * free blocks even though group info says we - * we have free blocks - */ - ext4_grp_locked_error(sb, e4b->bd_group, 0, 0, - "%d free clusters as per " - "group info. But bitmap says 0", - free); - break; - } - - mb_find_extent(e4b, 0, i, ac->ac_g_ex.fe_len, &ex); - BUG_ON(ex.fe_len <= 0); - if (free < ex.fe_len) { - ext4_grp_locked_error(sb, e4b->bd_group, 0, 0, - "%d free clusters as per " - "group info. But got %d blocks", - free, ex.fe_len); - /* - * The number of free blocks differs. This mostly - * indicate that the bitmap is corrupt. So exit - * without claiming the space. - */ - break; - } - - ext4_mb_measure_extent(ac, &ex, e4b); - - i += ex.fe_len; - free -= ex.fe_len; - } - - ext4_mb_check_limits(ac, e4b, 1); -} - -/* - * This is a special case for storages like raid5 - * we try to find stripe-aligned chunks for stripe-size-multiple requests - */ -static noinline_for_stack -void ext4_mb_scan_aligned(struct ext4_allocation_context *ac, - struct ext4_buddy *e4b) -{ - struct super_block *sb = ac->ac_sb; - struct ext4_sb_info *sbi = EXT4_SB(sb); - void *bitmap = e4b->bd_bitmap; - struct ext4_free_extent ex; - ext4_fsblk_t first_group_block; - ext4_fsblk_t a; - ext4_grpblk_t i; - int max; - - BUG_ON(sbi->s_stripe == 0); - - /* find first stripe-aligned block in group */ - first_group_block = ext4_group_first_block_no(sb, e4b->bd_group); - - a = first_group_block + sbi->s_stripe - 1; - do_div(a, sbi->s_stripe); - i = (a * sbi->s_stripe) - first_group_block; - - while (i < EXT4_CLUSTERS_PER_GROUP(sb)) { - if (!mb_test_bit(i, bitmap)) { - max = mb_find_extent(e4b, 0, i, sbi->s_stripe, &ex); - if (max >= sbi->s_stripe) { - ac->ac_found++; - ac->ac_b_ex = ex; - ext4_mb_use_best_found(ac, e4b); - break; - } - } - i += sbi->s_stripe; - } -} - -/* This is now called BEFORE we load the buddy bitmap. */ -static int ext4_mb_good_group(struct ext4_allocation_context *ac, - ext4_group_t group, int cr) -{ - unsigned free, fragments; - int flex_size = ext4_flex_bg_size(EXT4_SB(ac->ac_sb)); - struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group); - - BUG_ON(cr < 0 || cr >= 4); - - /* We only do this if the grp has never been initialized */ - if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) { - int ret = ext4_mb_init_group(ac->ac_sb, group); - if (ret) - return 0; - } - - free = grp->bb_free; - fragments = grp->bb_fragments; - if (free == 0) - return 0; - if (fragments == 0) - return 0; - - switch (cr) { - case 0: - BUG_ON(ac->ac_2order == 0); - - if (grp->bb_largest_free_order < ac->ac_2order) - return 0; - - /* Avoid using the first bg of a flexgroup for data files */ - if ((ac->ac_flags & EXT4_MB_HINT_DATA) && - (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) && - ((group % flex_size) == 0)) - return 0; - - return 1; - case 1: - if ((free / fragments) >= ac->ac_g_ex.fe_len) - return 1; - break; - case 2: - if (free >= ac->ac_g_ex.fe_len) - return 1; - break; - case 3: - return 1; - default: - BUG(); - } - - return 0; -} - -static noinline_for_stack int -ext4_mb_regular_allocator(struct ext4_allocation_context *ac) -{ - ext4_group_t ngroups, group, i; - int cr; - int err = 0; - struct ext4_sb_info *sbi; - struct super_block *sb; - struct ext4_buddy e4b; - - sb = ac->ac_sb; - sbi = EXT4_SB(sb); - ngroups = ext4_get_groups_count(sb); - /* non-extent files are limited to low blocks/groups */ - if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS))) - ngroups = sbi->s_blockfile_groups; - - BUG_ON(ac->ac_status == AC_STATUS_FOUND); - - /* first, try the goal */ - err = ext4_mb_find_by_goal(ac, &e4b); - if (err || ac->ac_status == AC_STATUS_FOUND) - goto out; - - if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) - goto out; - - /* - * ac->ac2_order is set only if the fe_len is a power of 2 - * if ac2_order is set we also set criteria to 0 so that we - * try exact allocation using buddy. - */ - i = fls(ac->ac_g_ex.fe_len); - ac->ac_2order = 0; - /* - * We search using buddy data only if the order of the request - * is greater than equal to the sbi_s_mb_order2_reqs - * You can tune it via /sys/fs/ext4/<partition>/mb_order2_req - */ - if (i >= sbi->s_mb_order2_reqs) { - /* - * This should tell if fe_len is exactly power of 2 - */ - if ((ac->ac_g_ex.fe_len & (~(1 << (i - 1)))) == 0) - ac->ac_2order = i - 1; - } - - /* if stream allocation is enabled, use global goal */ - if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) { - /* TBD: may be hot point */ - spin_lock(&sbi->s_md_lock); - ac->ac_g_ex.fe_group = sbi->s_mb_last_group; - ac->ac_g_ex.fe_start = sbi->s_mb_last_start; - spin_unlock(&sbi->s_md_lock); - } - - /* Let's just scan groups to find more-less suitable blocks */ - cr = ac->ac_2order ? 0 : 1; - /* - * cr == 0 try to get exact allocation, - * cr == 3 try to get anything - */ -repeat: - for (; cr < 4 && ac->ac_status == AC_STATUS_CONTINUE; cr++) { - ac->ac_criteria = cr; - /* - * searching for the right group start - * from the goal value specified - */ - group = ac->ac_g_ex.fe_group; - - for (i = 0; i < ngroups; group++, i++) { - if (group == ngroups) - group = 0; - - /* This now checks without needing the buddy page */ - if (!ext4_mb_good_group(ac, group, cr)) - continue; - - err = ext4_mb_load_buddy(sb, group, &e4b); - if (err) - goto out; - - ext4_lock_group(sb, group); - - /* - * We need to check again after locking the - * block group - */ - if (!ext4_mb_good_group(ac, group, cr)) { - ext4_unlock_group(sb, group); - ext4_mb_unload_buddy(&e4b); - continue; - } - - ac->ac_groups_scanned++; - if (cr == 0) - ext4_mb_simple_scan_group(ac, &e4b); - else if (cr == 1 && sbi->s_stripe && - !(ac->ac_g_ex.fe_len % sbi->s_stripe)) - ext4_mb_scan_aligned(ac, &e4b); - else - ext4_mb_complex_scan_group(ac, &e4b); - - ext4_unlock_group(sb, group); - ext4_mb_unload_buddy(&e4b); - - if (ac->ac_status != AC_STATUS_CONTINUE) - break; - } - } - - if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND && - !(ac->ac_flags & EXT4_MB_HINT_FIRST)) { - /* - * We've been searching too long. Let's try to allocate - * the best chunk we've found so far - */ - - ext4_mb_try_best_found(ac, &e4b); - if (ac->ac_status != AC_STATUS_FOUND) { - /* - * Someone more lucky has already allocated it. - * The only thing we can do is just take first - * found block(s) - printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n"); - */ - ac->ac_b_ex.fe_group = 0; - ac->ac_b_ex.fe_start = 0; - ac->ac_b_ex.fe_len = 0; - ac->ac_status = AC_STATUS_CONTINUE; - ac->ac_flags |= EXT4_MB_HINT_FIRST; - cr = 3; - atomic_inc(&sbi->s_mb_lost_chunks); - goto repeat; - } - } -out: - return err; -} - -static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos) -{ - struct super_block *sb = seq->private; - ext4_group_t group; - - if (*pos < 0 || *pos >= ext4_get_groups_count(sb)) - return NULL; - group = *pos + 1; - return (void *) ((unsigned long) group); -} - -static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos) -{ - struct super_block *sb = seq->private; - ext4_group_t group; - - ++*pos; - if (*pos < 0 || *pos >= ext4_get_groups_count(sb)) - return NULL; - group = *pos + 1; - return (void *) ((unsigned long) group); -} - -static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v) -{ - struct super_block *sb = seq->private; - ext4_group_t group = (ext4_group_t) ((unsigned long) v); - int i; - int err; - struct ext4_buddy e4b; - struct sg { - struct ext4_group_info info; - ext4_grpblk_t counters[16]; - } sg; - - group--; - if (group == 0) - seq_printf(seq, "#%-5s: %-5s %-5s %-5s " - "[ %-5s %-5s %-5s %-5s %-5s %-5s %-5s " - "%-5s %-5s %-5s %-5s %-5s %-5s %-5s ]\n", - "group", "free", "frags", "first", - "2^0", "2^1", "2^2", "2^3", "2^4", "2^5", "2^6", - "2^7", "2^8", "2^9", "2^10", "2^11", "2^12", "2^13"); - - i = (sb->s_blocksize_bits + 2) * sizeof(sg.info.bb_counters[0]) + - sizeof(struct ext4_group_info); - err = ext4_mb_load_buddy(sb, group, &e4b); - if (err) { - seq_printf(seq, "#%-5u: I/O error\n", group); - return 0; - } - ext4_lock_group(sb, group); - memcpy(&sg, ext4_get_group_info(sb, group), i); - ext4_unlock_group(sb, group); - ext4_mb_unload_buddy(&e4b); - - seq_printf(seq, "#%-5u: %-5u %-5u %-5u [", group, sg.info.bb_free, - sg.info.bb_fragments, sg.info.bb_first_free); - for (i = 0; i <= 13; i++) - seq_printf(seq, " %-5u", i <= sb->s_blocksize_bits + 1 ? - sg.info.bb_counters[i] : 0); - seq_printf(seq, " ]\n"); - - return 0; -} - -static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v) -{ -} - -static const struct seq_operations ext4_mb_seq_groups_ops = { - .start = ext4_mb_seq_groups_start, - .next = ext4_mb_seq_groups_next, - .stop = ext4_mb_seq_groups_stop, - .show = ext4_mb_seq_groups_show, -}; - -static int ext4_mb_seq_groups_open(struct inode *inode, struct file *file) -{ - struct super_block *sb = PDE(inode)->data; - int rc; - - rc = seq_open(file, &ext4_mb_seq_groups_ops); - if (rc == 0) { - struct seq_file *m = file->private_data; - m->private = sb; - } - return rc; - -} - -static const struct file_operations ext4_mb_seq_groups_fops = { - .owner = THIS_MODULE, - .open = ext4_mb_seq_groups_open, - .read = seq_read, - .llseek = seq_lseek, - .release = seq_release, -}; - -static struct kmem_cache *get_groupinfo_cache(int blocksize_bits) -{ - int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE; - struct kmem_cache *cachep = ext4_groupinfo_caches[cache_index]; - - BUG_ON(!cachep); - return cachep; -} - -/* Create and initialize ext4_group_info data for the given group. */ -int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group, - struct ext4_group_desc *desc) -{ - int i; - int metalen = 0; - struct ext4_sb_info *sbi = EXT4_SB(sb); - struct ext4_group_info **meta_group_info; - struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits); - - /* - * First check if this group is the first of a reserved block. - * If it's true, we have to allocate a new table of pointers - * to ext4_group_info structures - */ - if (group % EXT4_DESC_PER_BLOCK(sb) == 0) { - metalen = sizeof(*meta_group_info) << - EXT4_DESC_PER_BLOCK_BITS(sb); - meta_group_info = kmalloc(metalen, GFP_KERNEL); - if (meta_group_info == NULL) { - ext4_msg(sb, KERN_ERR, "can't allocate mem " - "for a buddy group"); - goto exit_meta_group_info; - } - sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)] = - meta_group_info; - } - - meta_group_info = - sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)]; - i = group & (EXT4_DESC_PER_BLOCK(sb) - 1); - - meta_group_info[i] = kmem_cache_alloc(cachep, GFP_KERNEL); - if (meta_group_info[i] == NULL) { - ext4_msg(sb, KERN_ERR, "can't allocate buddy mem"); - goto exit_group_info; - } - memset(meta_group_info[i], 0, kmem_cache_size(cachep)); - set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, - &(meta_group_info[i]->bb_state)); - - /* - * initialize bb_free to be able to skip - * empty groups without initialization - */ - if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { - meta_group_info[i]->bb_free = - ext4_free_clusters_after_init(sb, group, desc); - } else { - meta_group_info[i]->bb_free = - ext4_free_group_clusters(sb, desc); - } - - INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list); - init_rwsem(&meta_group_info[i]->alloc_sem); - meta_group_info[i]->bb_free_root = RB_ROOT; - meta_group_info[i]->bb_largest_free_order = -1; /* uninit */ - -#ifdef DOUBLE_CHECK - { - struct buffer_head *bh; - meta_group_info[i]->bb_bitmap = - kmalloc(sb->s_blocksize, GFP_KERNEL); - BUG_ON(meta_group_info[i]->bb_bitmap == NULL); - bh = ext4_read_block_bitmap(sb, group); - BUG_ON(bh == NULL); - memcpy(meta_group_info[i]->bb_bitmap, bh->b_data, - sb->s_blocksize); - put_bh(bh); - } -#endif - - return 0; - -exit_group_info: - /* If a meta_group_info table has been allocated, release it now */ - if (group % EXT4_DESC_PER_BLOCK(sb) == 0) { - kfree(sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)]); - sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)] = NULL; - } -exit_meta_group_info: - return -ENOMEM; -} /* ext4_mb_add_groupinfo */ - -static int ext4_mb_init_backend(struct super_block *sb) -{ - ext4_group_t ngroups = ext4_get_groups_count(sb); - ext4_group_t i; - struct ext4_sb_info *sbi = EXT4_SB(sb); - struct ext4_super_block *es = sbi->s_es; - int num_meta_group_infos; - int num_meta_group_infos_max; - int array_size; - struct ext4_group_desc *desc; - struct kmem_cache *cachep; - - /* This is the number of blocks used by GDT */ - num_meta_group_infos = (ngroups + EXT4_DESC_PER_BLOCK(sb) - - 1) >> EXT4_DESC_PER_BLOCK_BITS(sb); - - /* - * This is the total number of blocks used by GDT including - * the number of reserved blocks for GDT. - * The s_group_info array is allocated with this value - * to allow a clean online resize without a complex - * manipulation of pointer. - * The drawback is the unused memory when no resize - * occurs but it's very low in terms of pages - * (see comments below) - * Need to handle this properly when META_BG resizing is allowed - */ - num_meta_group_infos_max = num_meta_group_infos + - le16_to_cpu(es->s_reserved_gdt_blocks); - - /* - * array_size is the size of s_group_info array. We round it - * to the next power of two because this approximation is done - * internally by kmalloc so we can have some more memory - * for free here (e.g. may be used for META_BG resize). - */ - array_size = 1; - while (array_size < sizeof(*sbi->s_group_info) * - num_meta_group_infos_max) - array_size = array_size << 1; - /* An 8TB filesystem with 64-bit pointers requires a 4096 byte - * kmalloc. A 128kb malloc should suffice for a 256TB filesystem. - * So a two level scheme suffices for now. */ - sbi->s_group_info = ext4_kvzalloc(array_size, GFP_KERNEL); - if (sbi->s_group_info == NULL) { - ext4_msg(sb, KERN_ERR, "can't allocate buddy meta group"); - return -ENOMEM; - } - sbi->s_buddy_cache = new_inode(sb); - if (sbi->s_buddy_cache == NULL) { - ext4_msg(sb, KERN_ERR, "can't get new inode"); - goto err_freesgi; - } - /* To avoid potentially colliding with an valid on-disk inode number, - * use EXT4_BAD_INO for the buddy cache inode number. This inode is - * not in the inode hash, so it should never be found by iget(), but - * this will avoid confusion if it ever shows up during debugging. */ - sbi->s_buddy_cache->i_ino = EXT4_BAD_INO; - EXT4_I(sbi->s_buddy_cache)->i_disksize = 0; - for (i = 0; i < ngroups; i++) { - desc = ext4_get_group_desc(sb, i, NULL); - if (desc == NULL) { - ext4_msg(sb, KERN_ERR, "can't read descriptor %u", i); - goto err_freebuddy; - } - if (ext4_mb_add_groupinfo(sb, i, desc) != 0) - goto err_freebuddy; - } - - return 0; - -err_freebuddy: - cachep = get_groupinfo_cache(sb->s_blocksize_bits); - while (i-- > 0) - kmem_cache_free(cachep, ext4_get_group_info(sb, i)); - i = num_meta_group_infos; - while (i-- > 0) - kfree(sbi->s_group_info[i]); - iput(sbi->s_buddy_cache); -err_freesgi: - ext4_kvfree(sbi->s_group_info); - return -ENOMEM; -} - -static void ext4_groupinfo_destroy_slabs(void) -{ - int i; - - for (i = 0; i < NR_GRPINFO_CACHES; i++) { - if (ext4_groupinfo_caches[i]) - kmem_cache_destroy(ext4_groupinfo_caches[i]); - ext4_groupinfo_caches[i] = NULL; - } -} - -static int ext4_groupinfo_create_slab(size_t size) -{ - static DEFINE_MUTEX(ext4_grpinfo_slab_create_mutex); - int slab_size; - int blocksize_bits = order_base_2(size); - int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE; - struct kmem_cache *cachep; - - if (cache_index >= NR_GRPINFO_CACHES) - return -EINVAL; - - if (unlikely(cache_index < 0)) - cache_index = 0; - - mutex_lock(&ext4_grpinfo_slab_create_mutex); - if (ext4_groupinfo_caches[cache_index]) { - mutex_unlock(&ext4_grpinfo_slab_create_mutex); - return 0; /* Already created */ - } - - slab_size = offsetof(struct ext4_group_info, - bb_counters[blocksize_bits + 2]); - - cachep = kmem_cache_create(ext4_groupinfo_slab_names[cache_index], - slab_size, 0, SLAB_RECLAIM_ACCOUNT, - NULL); - - ext4_groupinfo_caches[cache_index] = cachep; - - mutex_unlock(&ext4_grpinfo_slab_create_mutex); - if (!cachep) { - printk(KERN_EMERG - "EXT4-fs: no memory for groupinfo slab cache\n"); - return -ENOMEM; - } - - return 0; -} - -int ext4_mb_init(struct super_block *sb, int needs_recovery) -{ - struct ext4_sb_info *sbi = EXT4_SB(sb); - unsigned i, j; - unsigned offset; - unsigned max; - int ret; - - i = (sb->s_blocksize_bits + 2) * sizeof(*sbi->s_mb_offsets); - - sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL); - if (sbi->s_mb_offsets == NULL) { - ret = -ENOMEM; - goto out; - } - - i = (sb->s_blocksize_bits + 2) * sizeof(*sbi->s_mb_maxs); - sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL); - if (sbi->s_mb_maxs == NULL) { - ret = -ENOMEM; - goto out; - } - - ret = ext4_groupinfo_create_slab(sb->s_blocksize); - if (ret < 0) - goto out; - - /* order 0 is regular bitmap */ - sbi->s_mb_maxs[0] = sb->s_blocksize << 3; - sbi->s_mb_offsets[0] = 0; - - i = 1; - offset = 0; - max = sb->s_blocksize << 2; - do { - sbi->s_mb_offsets[i] = offset; - sbi->s_mb_maxs[i] = max; - offset += 1 << (sb->s_blocksize_bits - i); - max = max >> 1; - i++; - } while (i <= sb->s_blocksize_bits + 1); - - spin_lock_init(&sbi->s_md_lock); - spin_lock_init(&sbi->s_bal_lock); - - sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN; - sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN; - sbi->s_mb_stats = MB_DEFAULT_STATS; - sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD; - sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS; - /* - * The default group preallocation is 512, which for 4k block - * sizes translates to 2 megabytes. However for bigalloc file - * systems, this is probably too big (i.e, if the cluster size - * is 1 megabyte, then group preallocation size becomes half a - * gigabyte!). As a default, we will keep a two megabyte - * group pralloc size for cluster sizes up to 64k, and after - * that, we will force a minimum group preallocation size of - * 32 clusters. This translates to 8 megs when the cluster - * size is 256k, and 32 megs when the cluster size is 1 meg, - * which seems reasonable as a default. - */ - sbi->s_mb_group_prealloc = max(MB_DEFAULT_GROUP_PREALLOC >> - sbi->s_cluster_bits, 32); - /* - * If there is a s_stripe > 1, then we set the s_mb_group_prealloc - * to the lowest multiple of s_stripe which is bigger than - * the s_mb_group_prealloc as determined above. We want - * the preallocation size to be an exact multiple of the - * RAID stripe size so that preallocations don't fragment - * the stripes. - */ - if (sbi->s_stripe > 1) { - sbi->s_mb_group_prealloc = roundup( - sbi->s_mb_group_prealloc, sbi->s_stripe); - } - - sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group); - if (sbi->s_locality_groups == NULL) { - ret = -ENOMEM; - goto out_free_groupinfo_slab; - } - for_each_possible_cpu(i) { - struct ext4_locality_group *lg; - lg = per_cpu_ptr(sbi->s_locality_groups, i); - mutex_init(&lg->lg_mutex); - for (j = 0; j < PREALLOC_TB_SIZE; j++) - INIT_LIST_HEAD(&lg->lg_prealloc_list[j]); - spin_lock_init(&lg->lg_prealloc_lock); - } - - /* init file for buddy data */ - ret = ext4_mb_init_backend(sb); - if (ret != 0) - goto out_free_locality_groups; - - if (sbi->s_proc) - proc_create_data("mb_groups", S_IRUGO, sbi->s_proc, - &ext4_mb_seq_groups_fops, sb); - - return 0; - -out_free_locality_groups: - free_percpu(sbi->s_locality_groups); - sbi->s_locality_groups = NULL; -out_free_groupinfo_slab: - ext4_groupinfo_destroy_slabs(); -out: - kfree(sbi->s_mb_offsets); - sbi->s_mb_offsets = NULL; - kfree(sbi->s_mb_maxs); - sbi->s_mb_maxs = NULL; - return ret; -} - -/* need to called with the ext4 group lock held */ -static void ext4_mb_cleanup_pa(struct ext4_group_info *grp) -{ - struct ext4_prealloc_space *pa; - struct list_head *cur, *tmp; - int count = 0; - - list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) { - pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list); - list_del(&pa->pa_group_list); - count++; - kmem_cache_free(ext4_pspace_cachep, pa); - } - if (count) - mb_debug(1, "mballoc: %u PAs left\n", count); - -} - -int ext4_mb_release(struct super_block *sb) -{ - ext4_group_t ngroups = ext4_get_groups_count(sb); - ext4_group_t i; - int num_meta_group_infos; - struct ext4_group_info *grinfo; - struct ext4_sb_info *sbi = EXT4_SB(sb); - struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits); - - if (sbi->s_proc) - remove_proc_entry("mb_groups", sbi->s_proc); - - if (sbi->s_group_info) { - for (i = 0; i < ngroups; i++) { - grinfo = ext4_get_group_info(sb, i); -#ifdef DOUBLE_CHECK - kfree(grinfo->bb_bitmap); -#endif - ext4_lock_group(sb, i); - ext4_mb_cleanup_pa(grinfo); - ext4_unlock_group(sb, i); - kmem_cache_free(cachep, grinfo); - } - num_meta_group_infos = (ngroups + - EXT4_DESC_PER_BLOCK(sb) - 1) >> - EXT4_DESC_PER_BLOCK_BITS(sb); - for (i = 0; i < num_meta_group_infos; i++) - kfree(sbi->s_group_info[i]); - ext4_kvfree(sbi->s_group_info); - } - kfree(sbi->s_mb_offsets); - kfree(sbi->s_mb_maxs); - if (sbi->s_buddy_cache) - iput(sbi->s_buddy_cache); - if (sbi->s_mb_stats) { - ext4_msg(sb, KERN_INFO, - "mballoc: %u blocks %u reqs (%u success)", - atomic_read(&sbi->s_bal_allocated), - atomic_read(&sbi->s_bal_reqs), - atomic_read(&sbi->s_bal_success)); - ext4_msg(sb, KERN_INFO, - "mballoc: %u extents scanned, %u goal hits, " - "%u 2^N hits, %u breaks, %u lost", - atomic_read(&sbi->s_bal_ex_scanned), - atomic_read(&sbi->s_bal_goals), - atomic_read(&sbi->s_bal_2orders), - atomic_read(&sbi->s_bal_breaks), - atomic_read(&sbi->s_mb_lost_chunks)); - ext4_msg(sb, KERN_INFO, - "mballoc: %lu generated and it took %Lu", - sbi->s_mb_buddies_generated, - sbi->s_mb_generation_time); - ext4_msg(sb, KERN_INFO, - "mballoc: %u preallocated, %u discarded", - atomic_read(&sbi->s_mb_preallocated), - atomic_read(&sbi->s_mb_discarded)); - } - - free_percpu(sbi->s_locality_groups); - - return 0; -} - -static inline int ext4_issue_discard(struct super_block *sb, - ext4_group_t block_group, ext4_grpblk_t cluster, int count) -{ - ext4_fsblk_t discard_block; - - discard_block = (EXT4_C2B(EXT4_SB(sb), cluster) + - ext4_group_first_block_no(sb, block_group)); - count = EXT4_C2B(EXT4_SB(sb), count); - trace_ext4_discard_blocks(sb, - (unsigned long long) discard_block, count); - return sb_issue_discard(sb, discard_block, count, GFP_NOFS, 0); -} - -/* - * This function is called by the jbd2 layer once the commit has finished, - * so we know we can free the blocks that were released with that commit. - */ -static void ext4_free_data_callback(struct super_block *sb, - struct ext4_journal_cb_entry *jce, - int rc) -{ - struct ext4_free_data *entry = (struct ext4_free_data *)jce; - struct ext4_buddy e4b; - struct ext4_group_info *db; - int err, count = 0, count2 = 0; - - mb_debug(1, "gonna free %u blocks in group %u (0x%p):", - entry->efd_count, entry->efd_group, entry); - - if (test_opt(sb, DISCARD)) - ext4_issue_discard(sb, entry->efd_group, - entry->efd_start_cluster, entry->efd_count); - - err = ext4_mb_load_buddy(sb, entry->efd_group, &e4b); - /* we expect to find existing buddy because it's pinned */ - BUG_ON(err != 0); - - - db = e4b.bd_info; - /* there are blocks to put in buddy to make them really free */ - count += entry->efd_count; - count2++; - ext4_lock_group(sb, entry->efd_group); - /* Take it out of per group rb tree */ - rb_erase(&entry->efd_node, &(db->bb_free_root)); - mb_free_blocks(NULL, &e4b, entry->efd_start_cluster, entry->efd_count); - - /* - * Clear the trimmed flag for the group so that the next - * ext4_trim_fs can trim it. - * If the volume is mounted with -o discard, online discard - * is supported and the free blocks will be trimmed online. - */ - if (!test_opt(sb, DISCARD)) - EXT4_MB_GRP_CLEAR_TRIMMED(db); - - if (!db->bb_free_root.rb_node) { - /* No more items in the per group rb tree - * balance refcounts from ext4_mb_free_metadata() - */ - page_cache_release(e4b.bd_buddy_page); - page_cache_release(e4b.bd_bitmap_page); - } - ext4_unlock_group(sb, entry->efd_group); - kmem_cache_free(ext4_free_data_cachep, entry); - ext4_mb_unload_buddy(&e4b); - - mb_debug(1, "freed %u blocks in %u structures\n", count, count2); -} - -#ifdef CONFIG_EXT4_DEBUG -u8 mb_enable_debug __read_mostly; - -static struct dentry *debugfs_dir; -static struct dentry *debugfs_debug; - -static void __init ext4_create_debugfs_entry(void) -{ - debugfs_dir = debugfs_create_dir("ext4", NULL); - if (debugfs_dir) - debugfs_debug = debugfs_create_u8("mballoc-debug", - S_IRUGO | S_IWUSR, - debugfs_dir, - &mb_enable_debug); -} - -static void ext4_remove_debugfs_entry(void) -{ - debugfs_remove(debugfs_debug); - debugfs_remove(debugfs_dir); -} - -#else - -static void __init ext4_create_debugfs_entry(void) -{ -} - -static void ext4_remove_debugfs_entry(void) -{ -} - -#endif - -int __init ext4_init_mballoc(void) -{ - ext4_pspace_cachep = KMEM_CACHE(ext4_prealloc_space, - SLAB_RECLAIM_ACCOUNT); - if (ext4_pspace_cachep == NULL) - return -ENOMEM; - - ext4_ac_cachep = KMEM_CACHE(ext4_allocation_context, - SLAB_RECLAIM_ACCOUNT); - if (ext4_ac_cachep == NULL) { - kmem_cache_destroy(ext4_pspace_cachep); - return -ENOMEM; - } - - ext4_free_data_cachep = KMEM_CACHE(ext4_free_data, - SLAB_RECLAIM_ACCOUNT); - if (ext4_free_data_cachep == NULL) { - kmem_cache_destroy(ext4_pspace_cachep); - kmem_cache_destroy(ext4_ac_cachep); - return -ENOMEM; - } - ext4_create_debugfs_entry(); - return 0; -} - -void ext4_exit_mballoc(void) -{ - /* - * Wait for completion of call_rcu()'s on ext4_pspace_cachep - * before destroying the slab cache. - */ - rcu_barrier(); - kmem_cache_destroy(ext4_pspace_cachep); - kmem_cache_destroy(ext4_ac_cachep); - kmem_cache_destroy(ext4_free_data_cachep); - ext4_groupinfo_destroy_slabs(); - ext4_remove_debugfs_entry(); -} - - -/* - * Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps - * Returns 0 if success or error code - */ -static noinline_for_stack int -ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac, - handle_t *handle, unsigned int reserv_clstrs) -{ - struct buffer_head *bitmap_bh = NULL; - struct ext4_group_desc *gdp; - struct buffer_head *gdp_bh; - struct ext4_sb_info *sbi; - struct super_block *sb; - ext4_fsblk_t block; - int err, len; - - BUG_ON(ac->ac_status != AC_STATUS_FOUND); - BUG_ON(ac->ac_b_ex.fe_len <= 0); - - sb = ac->ac_sb; - sbi = EXT4_SB(sb); - - err = -EIO; - bitmap_bh = ext4_read_block_bitmap(sb, ac->ac_b_ex.fe_group); - if (!bitmap_bh) - goto out_err; - - err = ext4_journal_get_write_access(handle, bitmap_bh); - if (err) - goto out_err; - - err = -EIO; - gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, &gdp_bh); - if (!gdp) - goto out_err; - - ext4_debug("using block group %u(%d)\n", ac->ac_b_ex.fe_group, - ext4_free_group_clusters(sb, gdp)); - - err = ext4_journal_get_write_access(handle, gdp_bh); - if (err) - goto out_err; - - block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); - - len = EXT4_C2B(sbi, ac->ac_b_ex.fe_len); - if (!ext4_data_block_valid(sbi, block, len)) { - ext4_error(sb, "Allocating blocks %llu-%llu which overlap " - "fs metadata", block, block+len); - /* File system mounted not to panic on error - * Fix the bitmap and repeat the block allocation - * We leak some of the blocks here. - */ - ext4_lock_group(sb, ac->ac_b_ex.fe_group); - ext4_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start, - ac->ac_b_ex.fe_len); - ext4_unlock_group(sb, ac->ac_b_ex.fe_group); - err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); - if (!err) - err = -EAGAIN; - goto out_err; - } - - ext4_lock_group(sb, ac->ac_b_ex.fe_group); -#ifdef AGGRESSIVE_CHECK - { - int i; - for (i = 0; i < ac->ac_b_ex.fe_len; i++) { - BUG_ON(mb_test_bit(ac->ac_b_ex.fe_start + i, - bitmap_bh->b_data)); - } - } -#endif - ext4_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start, - ac->ac_b_ex.fe_len); - if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { - gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT); - ext4_free_group_clusters_set(sb, gdp, - ext4_free_clusters_after_init(sb, - ac->ac_b_ex.fe_group, gdp)); - } - len = ext4_free_group_clusters(sb, gdp) - ac->ac_b_ex.fe_len; - ext4_free_group_clusters_set(sb, gdp, len); - gdp->bg_checksum = ext4_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp); - - ext4_unlock_group(sb, ac->ac_b_ex.fe_group); - percpu_counter_sub(&sbi->s_freeclusters_counter, ac->ac_b_ex.fe_len); - /* - * Now reduce the dirty block count also. Should not go negative - */ - if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED)) - /* release all the reserved blocks if non delalloc */ - percpu_counter_sub(&sbi->s_dirtyclusters_counter, - reserv_clstrs); - - if (sbi->s_log_groups_per_flex) { - ext4_group_t flex_group = ext4_flex_group(sbi, - ac->ac_b_ex.fe_group); - atomic_sub(ac->ac_b_ex.fe_len, - &sbi->s_flex_groups[flex_group].free_clusters); - } - - err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); - if (err) - goto out_err; - err = ext4_handle_dirty_metadata(handle, NULL, gdp_bh); - -out_err: - ext4_mark_super_dirty(sb); - brelse(bitmap_bh); - return err; -} - -/* - * here we normalize request for locality group - * Group request are normalized to s_mb_group_prealloc, which goes to - * s_strip if we set the same via mount option. - * s_mb_group_prealloc can be configured via - * /sys/fs/ext4/<partition>/mb_group_prealloc - * - * XXX: should we try to preallocate more than the group has now? - */ -static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac) -{ - struct super_block *sb = ac->ac_sb; - struct ext4_locality_group *lg = ac->ac_lg; - - BUG_ON(lg == NULL); - ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc; - mb_debug(1, "#%u: goal %u blocks for locality group\n", - current->pid, ac->ac_g_ex.fe_len); -} - -/* - * Normalization means making request better in terms of - * size and alignment - */ -static noinline_for_stack void -ext4_mb_normalize_request(struct ext4_allocation_context *ac, - struct ext4_allocation_request *ar) -{ - struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); - int bsbits, max; - ext4_lblk_t end; - loff_t size, start_off; - loff_t orig_size __maybe_unused; - ext4_lblk_t start; - struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); - struct ext4_prealloc_space *pa; - - /* do normalize only data requests, metadata requests - do not need preallocation */ - if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) - return; - - /* sometime caller may want exact blocks */ - if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) - return; - - /* caller may indicate that preallocation isn't - * required (it's a tail, for example) */ - if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC) - return; - - if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) { - ext4_mb_normalize_group_request(ac); - return ; - } - - bsbits = ac->ac_sb->s_blocksize_bits; - - /* first, let's learn actual file size - * given current request is allocated */ - size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len); - size = size << bsbits; - if (size < i_size_read(ac->ac_inode)) - size = i_size_read(ac->ac_inode); - orig_size = size; - - /* max size of free chunks */ - max = 2 << bsbits; - -#define NRL_CHECK_SIZE(req, size, max, chunk_size) \ - (req <= (size) || max <= (chunk_size)) - - /* first, try to predict filesize */ - /* XXX: should this table be tunable? */ - start_off = 0; - if (size <= 16 * 1024) { - size = 16 * 1024; - } else if (size <= 32 * 1024) { - size = 32 * 1024; - } else if (size <= 64 * 1024) { - size = 64 * 1024; - } else if (size <= 128 * 1024) { - size = 128 * 1024; - } else if (size <= 256 * 1024) { - size = 256 * 1024; - } else if (size <= 512 * 1024) { - size = 512 * 1024; - } else if (size <= 1024 * 1024) { - size = 1024 * 1024; - } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) { - start_off = ((loff_t)ac->ac_o_ex.fe_logical >> - (21 - bsbits)) << 21; - size = 2 * 1024 * 1024; - } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) { - start_off = ((loff_t)ac->ac_o_ex.fe_logical >> - (22 - bsbits)) << 22; - size = 4 * 1024 * 1024; - } else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len, - (8<<20)>>bsbits, max, 8 * 1024)) { - start_off = ((loff_t)ac->ac_o_ex.fe_logical >> - (23 - bsbits)) << 23; - size = 8 * 1024 * 1024; - } else { - start_off = (loff_t)ac->ac_o_ex.fe_logical << bsbits; - size = ac->ac_o_ex.fe_len << bsbits; - } - size = size >> bsbits; - start = start_off >> bsbits; - - /* don't cover already allocated blocks in selected range */ - if (ar->pleft && start <= ar->lleft) { - size -= ar->lleft + 1 - start; - start = ar->lleft + 1; - } - if (ar->pright && start + size - 1 >= ar->lright) - size -= start + size - ar->lright; - - end = start + size; - - /* check we don't cross already preallocated blocks */ - rcu_read_lock(); - list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) { - ext4_lblk_t pa_end; - - if (pa->pa_deleted) - continue; - spin_lock(&pa->pa_lock); - if (pa->pa_deleted) { - spin_unlock(&pa->pa_lock); - continue; - } - - pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb), - pa->pa_len); - - /* PA must not overlap original request */ - BUG_ON(!(ac->ac_o_ex.fe_logical >= pa_end || - ac->ac_o_ex.fe_logical < pa->pa_lstart)); - - /* skip PAs this normalized request doesn't overlap with */ - if (pa->pa_lstart >= end || pa_end <= start) { - spin_unlock(&pa->pa_lock); - continue; - } - BUG_ON(pa->pa_lstart <= start && pa_end >= end); - - /* adjust start or end to be adjacent to this pa */ - if (pa_end <= ac->ac_o_ex.fe_logical) { - BUG_ON(pa_end < start); - start = pa_end; - } else if (pa->pa_lstart > ac->ac_o_ex.fe_logical) { - BUG_ON(pa->pa_lstart > end); - end = pa->pa_lstart; - } - spin_unlock(&pa->pa_lock); - } - rcu_read_unlock(); - size = end - start; - - /* XXX: extra loop to check we really don't overlap preallocations */ - rcu_read_lock(); - list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) { - ext4_lblk_t pa_end; - - spin_lock(&pa->pa_lock); - if (pa->pa_deleted == 0) { - pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb), - pa->pa_len); - BUG_ON(!(start >= pa_end || end <= pa->pa_lstart)); - } - spin_unlock(&pa->pa_lock); - } - rcu_read_unlock(); - - if (start + size <= ac->ac_o_ex.fe_logical && - start > ac->ac_o_ex.fe_logical) { - ext4_msg(ac->ac_sb, KERN_ERR, - "start %lu, size %lu, fe_logical %lu", - (unsigned long) start, (unsigned long) size, - (unsigned long) ac->ac_o_ex.fe_logical); - } - BUG_ON(start + size <= ac->ac_o_ex.fe_logical && - start > ac->ac_o_ex.fe_logical); - BUG_ON(size <= 0 || size > EXT4_CLUSTERS_PER_GROUP(ac->ac_sb)); - - /* now prepare goal request */ - - /* XXX: is it better to align blocks WRT to logical - * placement or satisfy big request as is */ - ac->ac_g_ex.fe_logical = start; - ac->ac_g_ex.fe_len = EXT4_NUM_B2C(sbi, size); - - /* define goal start in order to merge */ - if (ar->pright && (ar->lright == (start + size))) { - /* merge to the right */ - ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size, - &ac->ac_f_ex.fe_group, - &ac->ac_f_ex.fe_start); - ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL; - } - if (ar->pleft && (ar->lleft + 1 == start)) { - /* merge to the left */ - ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1, - &ac->ac_f_ex.fe_group, - &ac->ac_f_ex.fe_start); - ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL; - } - - mb_debug(1, "goal: %u(was %u) blocks at %u\n", (unsigned) size, - (unsigned) orig_size, (unsigned) start); -} - -static void ext4_mb_collect_stats(struct ext4_allocation_context *ac) -{ - struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); - - if (sbi->s_mb_stats && ac->ac_g_ex.fe_len > 1) { - atomic_inc(&sbi->s_bal_reqs); - atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated); - if (ac->ac_b_ex.fe_len >= ac->ac_o_ex.fe_len) - atomic_inc(&sbi->s_bal_success); - atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned); - if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start && - ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group) - atomic_inc(&sbi->s_bal_goals); - if (ac->ac_found > sbi->s_mb_max_to_scan) - atomic_inc(&sbi->s_bal_breaks); - } - - if (ac->ac_op == EXT4_MB_HISTORY_ALLOC) - trace_ext4_mballoc_alloc(ac); - else - trace_ext4_mballoc_prealloc(ac); -} - -/* - * Called on failure; free up any blocks from the inode PA for this - * context. We don't need this for MB_GROUP_PA because we only change - * pa_free in ext4_mb_release_context(), but on failure, we've already - * zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed. - */ -static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac) -{ - struct ext4_prealloc_space *pa = ac->ac_pa; - int len; - - if (pa && pa->pa_type == MB_INODE_PA) { - len = ac->ac_b_ex.fe_len; - pa->pa_free += len; - } - -} - -/* - * use blocks preallocated to inode - */ -static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac, - struct ext4_prealloc_space *pa) -{ - struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); - ext4_fsblk_t start; - ext4_fsblk_t end; - int len; - - /* found preallocated blocks, use them */ - start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart); - end = min(pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len), - start + EXT4_C2B(sbi, ac->ac_o_ex.fe_len)); - len = EXT4_NUM_B2C(sbi, end - start); - ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group, - &ac->ac_b_ex.fe_start); - ac->ac_b_ex.fe_len = len; - ac->ac_status = AC_STATUS_FOUND; - ac->ac_pa = pa; - - BUG_ON(start < pa->pa_pstart); - BUG_ON(end > pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len)); - BUG_ON(pa->pa_free < len); - pa->pa_free -= len; - - mb_debug(1, "use %llu/%u from inode pa %p\n", start, len, pa); -} - -/* - * use blocks preallocated to locality group - */ -static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac, - struct ext4_prealloc_space *pa) -{ - unsigned int len = ac->ac_o_ex.fe_len; - - ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart, - &ac->ac_b_ex.fe_group, - &ac->ac_b_ex.fe_start); - ac->ac_b_ex.fe_len = len; - ac->ac_status = AC_STATUS_FOUND; - ac->ac_pa = pa; - - /* we don't correct pa_pstart or pa_plen here to avoid - * possible race when the group is being loaded concurrently - * instead we correct pa later, after blocks are marked - * in on-disk bitmap -- see ext4_mb_release_context() - * Other CPUs are prevented from allocating from this pa by lg_mutex - */ - mb_debug(1, "use %u/%u from group pa %p\n", pa->pa_lstart-len, len, pa); -} - -/* - * Return the prealloc space that have minimal distance - * from the goal block. @cpa is the prealloc - * space that is having currently known minimal distance - * from the goal block. - */ -static struct ext4_prealloc_space * -ext4_mb_check_group_pa(ext4_fsblk_t goal_block, - struct ext4_prealloc_space *pa, - struct ext4_prealloc_space *cpa) -{ - ext4_fsblk_t cur_distance, new_distance; - - if (cpa == NULL) { - atomic_inc(&pa->pa_count); - return pa; - } - cur_distance = abs(goal_block - cpa->pa_pstart); - new_distance = abs(goal_block - pa->pa_pstart); - - if (cur_distance <= new_distance) - return cpa; - - /* drop the previous reference */ - atomic_dec(&cpa->pa_count); - atomic_inc(&pa->pa_count); - return pa; -} - -/* - * search goal blocks in preallocated space - */ -static noinline_for_stack int -ext4_mb_use_preallocated(struct ext4_allocation_context *ac) -{ - struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); - int order, i; - struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); - struct ext4_locality_group *lg; - struct ext4_prealloc_space *pa, *cpa = NULL; - ext4_fsblk_t goal_block; - - /* only data can be preallocated */ - if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) - return 0; - - /* first, try per-file preallocation */ - rcu_read_lock(); - list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) { - - /* all fields in this condition don't change, - * so we can skip locking for them */ - if (ac->ac_o_ex.fe_logical < pa->pa_lstart || - ac->ac_o_ex.fe_logical >= (pa->pa_lstart + - EXT4_C2B(sbi, pa->pa_len))) - continue; - - /* non-extent files can't have physical blocks past 2^32 */ - if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)) && - (pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len) > - EXT4_MAX_BLOCK_FILE_PHYS)) - continue; - - /* found preallocated blocks, use them */ - spin_lock(&pa->pa_lock); - if (pa->pa_deleted == 0 && pa->pa_free) { - atomic_inc(&pa->pa_count); - ext4_mb_use_inode_pa(ac, pa); - spin_unlock(&pa->pa_lock); - ac->ac_criteria = 10; - rcu_read_unlock(); - return 1; - } - spin_unlock(&pa->pa_lock); - } - rcu_read_unlock(); - - /* can we use group allocation? */ - if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)) - return 0; - - /* inode may have no locality group for some reason */ - lg = ac->ac_lg; - if (lg == NULL) - return 0; - order = fls(ac->ac_o_ex.fe_len) - 1; - if (order > PREALLOC_TB_SIZE - 1) - /* The max size of hash table is PREALLOC_TB_SIZE */ - order = PREALLOC_TB_SIZE - 1; - - goal_block = ext4_grp_offs_to_block(ac->ac_sb, &ac->ac_g_ex); - /* - * search for the prealloc space that is having - * minimal distance from the goal block. - */ - for (i = order; i < PREALLOC_TB_SIZE; i++) { - rcu_read_lock(); - list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[i], - pa_inode_list) { - spin_lock(&pa->pa_lock); - if (pa->pa_deleted == 0 && - pa->pa_free >= ac->ac_o_ex.fe_len) { - - cpa = ext4_mb_check_group_pa(goal_block, - pa, cpa); - } - spin_unlock(&pa->pa_lock); - } - rcu_read_unlock(); - } - if (cpa) { - ext4_mb_use_group_pa(ac, cpa); - ac->ac_criteria = 20; - return 1; - } - return 0; -} - -/* - * the function goes through all block freed in the group - * but not yet committed and marks them used in in-core bitmap. - * buddy must be generated from this bitmap - * Need to be called with the ext4 group lock held - */ -static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap, - ext4_group_t group) -{ - struct rb_node *n; - struct ext4_group_info *grp; - struct ext4_free_data *entry; - - grp = ext4_get_group_info(sb, group); - n = rb_first(&(grp->bb_free_root)); - - while (n) { - entry = rb_entry(n, struct ext4_free_data, efd_node); - ext4_set_bits(bitmap, entry->efd_start_cluster, entry->efd_count); - n = rb_next(n); - } - return; -} - -/* - * the function goes through all preallocation in this group and marks them - * used in in-core bitmap. buddy must be generated from this bitmap - * Need to be called with ext4 group lock held - */ -static noinline_for_stack -void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap, - ext4_group_t group) -{ - struct ext4_group_info *grp = ext4_get_group_info(sb, group); - struct ext4_prealloc_space *pa; - struct list_head *cur; - ext4_group_t groupnr; - ext4_grpblk_t start; - int preallocated = 0; - int len; - - /* all form of preallocation discards first load group, - * so the only competing code is preallocation use. - * we don't need any locking here - * notice we do NOT ignore preallocations with pa_deleted - * otherwise we could leave used blocks available for - * allocation in buddy when concurrent ext4_mb_put_pa() - * is dropping preallocation - */ - list_for_each(cur, &grp->bb_prealloc_list) { - pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list); - spin_lock(&pa->pa_lock); - ext4_get_group_no_and_offset(sb, pa->pa_pstart, - &groupnr, &start); - len = pa->pa_len; - spin_unlock(&pa->pa_lock); - if (unlikely(len == 0)) - continue; - BUG_ON(groupnr != group); - ext4_set_bits(bitmap, start, len); - preallocated += len; - } - mb_debug(1, "prellocated %u for group %u\n", preallocated, group); -} - -static void ext4_mb_pa_callback(struct rcu_head *head) -{ - struct ext4_prealloc_space *pa; - pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu); - kmem_cache_free(ext4_pspace_cachep, pa); -} - -/* - * drops a reference to preallocated space descriptor - * if this was the last reference and the space is consumed - */ -static void ext4_mb_put_pa(struct ext4_allocation_context *ac, - struct super_block *sb, struct ext4_prealloc_space *pa) -{ - ext4_group_t grp; - ext4_fsblk_t grp_blk; - - if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0) - return; - - /* in this short window concurrent discard can set pa_deleted */ - spin_lock(&pa->pa_lock); - if (pa->pa_deleted == 1) { - spin_unlock(&pa->pa_lock); - return; - } - - pa->pa_deleted = 1; - spin_unlock(&pa->pa_lock); - - grp_blk = pa->pa_pstart; - /* - * If doing group-based preallocation, pa_pstart may be in the - * next group when pa is used up - */ - if (pa->pa_type == MB_GROUP_PA) - grp_blk--; - - ext4_get_group_no_and_offset(sb, grp_blk, &grp, NULL); - - /* - * possible race: - * - * P1 (buddy init) P2 (regular allocation) - * find block B in PA - * copy on-disk bitmap to buddy - * mark B in on-disk bitmap - * drop PA from group - * mark all PAs in buddy - * - * thus, P1 initializes buddy with B available. to prevent this - * we make "copy" and "mark all PAs" atomic and serialize "drop PA" - * against that pair - */ - ext4_lock_group(sb, grp); - list_del(&pa->pa_group_list); - ext4_unlock_group(sb, grp); - - spin_lock(pa->pa_obj_lock); - list_del_rcu(&pa->pa_inode_list); - spin_unlock(pa->pa_obj_lock); - - call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); -} - -/* - * creates new preallocated space for given inode - */ -static noinline_for_stack int -ext4_mb_new_inode_pa(struct ext4_allocation_context *ac) -{ - struct super_block *sb = ac->ac_sb; - struct ext4_sb_info *sbi = EXT4_SB(sb); - struct ext4_prealloc_space *pa; - struct ext4_group_info *grp; - struct ext4_inode_info *ei; - - /* preallocate only when found space is larger then requested */ - BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len); - BUG_ON(ac->ac_status != AC_STATUS_FOUND); - BUG_ON(!S_ISREG(ac->ac_inode->i_mode)); - - pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS); - if (pa == NULL) - return -ENOMEM; - - if (ac->ac_b_ex.fe_len < ac->ac_g_ex.fe_len) { - int winl; - int wins; - int win; - int offs; - - /* we can't allocate as much as normalizer wants. - * so, found space must get proper lstart - * to cover original request */ - BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical); - BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len); - - /* we're limited by original request in that - * logical block must be covered any way - * winl is window we can move our chunk within */ - winl = ac->ac_o_ex.fe_logical - ac->ac_g_ex.fe_logical; - - /* also, we should cover whole original request */ - wins = EXT4_C2B(sbi, ac->ac_b_ex.fe_len - ac->ac_o_ex.fe_len); - - /* the smallest one defines real window */ - win = min(winl, wins); - - offs = ac->ac_o_ex.fe_logical % - EXT4_C2B(sbi, ac->ac_b_ex.fe_len); - if (offs && offs < win) - win = offs; - - ac->ac_b_ex.fe_logical = ac->ac_o_ex.fe_logical - - EXT4_B2C(sbi, win); - BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical); - BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len); - } - - /* preallocation can change ac_b_ex, thus we store actually - * allocated blocks for history */ - ac->ac_f_ex = ac->ac_b_ex; - - pa->pa_lstart = ac->ac_b_ex.fe_logical; - pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); - pa->pa_len = ac->ac_b_ex.fe_len; - pa->pa_free = pa->pa_len; - atomic_set(&pa->pa_count, 1); - spin_lock_init(&pa->pa_lock); - INIT_LIST_HEAD(&pa->pa_inode_list); - INIT_LIST_HEAD(&pa->pa_group_list); - pa->pa_deleted = 0; - pa->pa_type = MB_INODE_PA; - - mb_debug(1, "new inode pa %p: %llu/%u for %u\n", pa, - pa->pa_pstart, pa->pa_len, pa->pa_lstart); - trace_ext4_mb_new_inode_pa(ac, pa); - - ext4_mb_use_inode_pa(ac, pa); - atomic_add(pa->pa_free, &sbi->s_mb_preallocated); - - ei = EXT4_I(ac->ac_inode); - grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group); - - pa->pa_obj_lock = &ei->i_prealloc_lock; - pa->pa_inode = ac->ac_inode; - - ext4_lock_group(sb, ac->ac_b_ex.fe_group); - list_add(&pa->pa_group_list, &grp->bb_prealloc_list); - ext4_unlock_group(sb, ac->ac_b_ex.fe_group); - - spin_lock(pa->pa_obj_lock); - list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list); - spin_unlock(pa->pa_obj_lock); - - return 0; -} - -/* - * creates new preallocated space for locality group inodes belongs to - */ -static noinline_for_stack int -ext4_mb_new_group_pa(struct ext4_allocation_context *ac) -{ - struct super_block *sb = ac->ac_sb; - struct ext4_locality_group *lg; - struct ext4_prealloc_space *pa; - struct ext4_group_info *grp; - - /* preallocate only when found space is larger then requested */ - BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len); - BUG_ON(ac->ac_status != AC_STATUS_FOUND); - BUG_ON(!S_ISREG(ac->ac_inode->i_mode)); - - BUG_ON(ext4_pspace_cachep == NULL); - pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS); - if (pa == NULL) - return -ENOMEM; - - /* preallocation can change ac_b_ex, thus we store actually - * allocated blocks for history */ - ac->ac_f_ex = ac->ac_b_ex; - - pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); - pa->pa_lstart = pa->pa_pstart; - pa->pa_len = ac->ac_b_ex.fe_len; - pa->pa_free = pa->pa_len; - atomic_set(&pa->pa_count, 1); - spin_lock_init(&pa->pa_lock); - INIT_LIST_HEAD(&pa->pa_inode_list); - INIT_LIST_HEAD(&pa->pa_group_list); - pa->pa_deleted = 0; - pa->pa_type = MB_GROUP_PA; - - mb_debug(1, "new group pa %p: %llu/%u for %u\n", pa, - pa->pa_pstart, pa->pa_len, pa->pa_lstart); - trace_ext4_mb_new_group_pa(ac, pa); - - ext4_mb_use_group_pa(ac, pa); - atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated); - - grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group); - lg = ac->ac_lg; - BUG_ON(lg == NULL); - - pa->pa_obj_lock = &lg->lg_prealloc_lock; - pa->pa_inode = NULL; - - ext4_lock_group(sb, ac->ac_b_ex.fe_group); - list_add(&pa->pa_group_list, &grp->bb_prealloc_list); - ext4_unlock_group(sb, ac->ac_b_ex.fe_group); - - /* - * We will later add the new pa to the right bucket - * after updating the pa_free in ext4_mb_release_context - */ - return 0; -} - -static int ext4_mb_new_preallocation(struct ext4_allocation_context *ac) -{ - int err; - - if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) - err = ext4_mb_new_group_pa(ac); - else - err = ext4_mb_new_inode_pa(ac); - return err; -} - -/* - * finds all unused blocks in on-disk bitmap, frees them in - * in-core bitmap and buddy. - * @pa must be unlinked from inode and group lists, so that - * nobody else can find/use it. - * the caller MUST hold group/inode locks. - * TODO: optimize the case when there are no in-core structures yet - */ -static noinline_for_stack int -ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh, - struct ext4_prealloc_space *pa) -{ - struct super_block *sb = e4b->bd_sb; - struct ext4_sb_info *sbi = EXT4_SB(sb); - unsigned int end; - unsigned int next; - ext4_group_t group; - ext4_grpblk_t bit; - unsigned long long grp_blk_start; - int err = 0; - int free = 0; - - BUG_ON(pa->pa_deleted == 0); - ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit); - grp_blk_start = pa->pa_pstart - EXT4_C2B(sbi, bit); - BUG_ON(group != e4b->bd_group && pa->pa_len != 0); - end = bit + pa->pa_len; - - while (bit < end) { - bit = mb_find_next_zero_bit(bitmap_bh->b_data, end, bit); - if (bit >= end) - break; - next = mb_find_next_bit(bitmap_bh->b_data, end, bit); - mb_debug(1, " free preallocated %u/%u in group %u\n", - (unsigned) ext4_group_first_block_no(sb, group) + bit, - (unsigned) next - bit, (unsigned) group); - free += next - bit; - - trace_ext4_mballoc_discard(sb, NULL, group, bit, next - bit); - trace_ext4_mb_release_inode_pa(pa, (grp_blk_start + - EXT4_C2B(sbi, bit)), - next - bit); - mb_free_blocks(pa->pa_inode, e4b, bit, next - bit); - bit = next + 1; - } - if (free != pa->pa_free) { - ext4_msg(e4b->bd_sb, KERN_CRIT, - "pa %p: logic %lu, phys. %lu, len %lu", - pa, (unsigned long) pa->pa_lstart, - (unsigned long) pa->pa_pstart, - (unsigned long) pa->pa_len); - ext4_grp_locked_error(sb, group, 0, 0, "free %u, pa_free %u", - free, pa->pa_free); - /* - * pa is already deleted so we use the value obtained - * from the bitmap and continue. - */ - } - atomic_add(free, &sbi->s_mb_discarded); - - return err; -} - -static noinline_for_stack int -ext4_mb_release_group_pa(struct ext4_buddy *e4b, - struct ext4_prealloc_space *pa) -{ - struct super_block *sb = e4b->bd_sb; - ext4_group_t group; - ext4_grpblk_t bit; - - trace_ext4_mb_release_group_pa(sb, pa); - BUG_ON(pa->pa_deleted == 0); - ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit); - BUG_ON(group != e4b->bd_group && pa->pa_len != 0); - mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len); - atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded); - trace_ext4_mballoc_discard(sb, NULL, group, bit, pa->pa_len); - - return 0; -} - -/* - * releases all preallocations in given group - * - * first, we need to decide discard policy: - * - when do we discard - * 1) ENOSPC - * - how many do we discard - * 1) how many requested - */ -static noinline_for_stack int -ext4_mb_discard_group_preallocations(struct super_block *sb, - ext4_group_t group, int needed) -{ - struct ext4_group_info *grp = ext4_get_group_info(sb, group); - struct buffer_head *bitmap_bh = NULL; - struct ext4_prealloc_space *pa, *tmp; - struct list_head list; - struct ext4_buddy e4b; - int err; - int busy = 0; - int free = 0; - - mb_debug(1, "discard preallocation for group %u\n", group); - - if (list_empty(&grp->bb_prealloc_list)) - return 0; - - bitmap_bh = ext4_read_block_bitmap(sb, group); - if (bitmap_bh == NULL) { - ext4_error(sb, "Error reading block bitmap for %u", group); - return 0; - } - - err = ext4_mb_load_buddy(sb, group, &e4b); - if (err) { - ext4_error(sb, "Error loading buddy information for %u", group); - put_bh(bitmap_bh); - return 0; - } - - if (needed == 0) - needed = EXT4_CLUSTERS_PER_GROUP(sb) + 1; - - INIT_LIST_HEAD(&list); -repeat: - ext4_lock_group(sb, group); - list_for_each_entry_safe(pa, tmp, - &grp->bb_prealloc_list, pa_group_list) { - spin_lock(&pa->pa_lock); - if (atomic_read(&pa->pa_count)) { - spin_unlock(&pa->pa_lock); - busy = 1; - continue; - } - if (pa->pa_deleted) { - spin_unlock(&pa->pa_lock); - continue; - } - - /* seems this one can be freed ... */ - pa->pa_deleted = 1; - - /* we can trust pa_free ... */ - free += pa->pa_free; - - spin_unlock(&pa->pa_lock); - - list_del(&pa->pa_group_list); - list_add(&pa->u.pa_tmp_list, &list); - } - - /* if we still need more blocks and some PAs were used, try again */ - if (free < needed && busy) { - busy = 0; - ext4_unlock_group(sb, group); - /* - * Yield the CPU here so that we don't get soft lockup - * in non preempt case. - */ - yield(); - goto repeat; - } - - /* found anything to free? */ - if (list_empty(&list)) { - BUG_ON(free != 0); - goto out; - } - - /* now free all selected PAs */ - list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) { - - /* remove from object (inode or locality group) */ - spin_lock(pa->pa_obj_lock); - list_del_rcu(&pa->pa_inode_list); - spin_unlock(pa->pa_obj_lock); - - if (pa->pa_type == MB_GROUP_PA) - ext4_mb_release_group_pa(&e4b, pa); - else - ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa); - - list_del(&pa->u.pa_tmp_list); - call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); - } - -out: - ext4_unlock_group(sb, group); - ext4_mb_unload_buddy(&e4b); - put_bh(bitmap_bh); - return free; -} - -/* - * releases all non-used preallocated blocks for given inode - * - * It's important to discard preallocations under i_data_sem - * We don't want another block to be served from the prealloc - * space when we are discarding the inode prealloc space. - * - * FIXME!! Make sure it is valid at all the call sites - */ -void ext4_discard_preallocations(struct inode *inode) -{ - struct ext4_inode_info *ei = EXT4_I(inode); - struct super_block *sb = inode->i_sb; - struct buffer_head *bitmap_bh = NULL; - struct ext4_prealloc_space *pa, *tmp; - ext4_group_t group = 0; - struct list_head list; - struct ext4_buddy e4b; - int err; - - if (!S_ISREG(inode->i_mode)) { - /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/ - return; - } - - mb_debug(1, "discard preallocation for inode %lu\n", inode->i_ino); - trace_ext4_discard_preallocations(inode); - - INIT_LIST_HEAD(&list); - -repeat: - /* first, collect all pa's in the inode */ - spin_lock(&ei->i_prealloc_lock); - while (!list_empty(&ei->i_prealloc_list)) { - pa = list_entry(ei->i_prealloc_list.next, - struct ext4_prealloc_space, pa_inode_list); - BUG_ON(pa->pa_obj_lock != &ei->i_prealloc_lock); - spin_lock(&pa->pa_lock); - if (atomic_read(&pa->pa_count)) { - /* this shouldn't happen often - nobody should - * use preallocation while we're discarding it */ - spin_unlock(&pa->pa_lock); - spin_unlock(&ei->i_prealloc_lock); - ext4_msg(sb, KERN_ERR, - "uh-oh! used pa while discarding"); - WARN_ON(1); - schedule_timeout_uninterruptible(HZ); - goto repeat; - - } - if (pa->pa_deleted == 0) { - pa->pa_deleted = 1; - spin_unlock(&pa->pa_lock); - list_del_rcu(&pa->pa_inode_list); - list_add(&pa->u.pa_tmp_list, &list); - continue; - } - - /* someone is deleting pa right now */ - spin_unlock(&pa->pa_lock); - spin_unlock(&ei->i_prealloc_lock); - - /* we have to wait here because pa_deleted - * doesn't mean pa is already unlinked from - * the list. as we might be called from - * ->clear_inode() the inode will get freed - * and concurrent thread which is unlinking - * pa from inode's list may access already - * freed memory, bad-bad-bad */ - - /* XXX: if this happens too often, we can - * add a flag to force wait only in case - * of ->clear_inode(), but not in case of - * regular truncate */ - schedule_timeout_uninterruptible(HZ); - goto repeat; - } - spin_unlock(&ei->i_prealloc_lock); - - list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) { - BUG_ON(pa->pa_type != MB_INODE_PA); - ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL); - - err = ext4_mb_load_buddy(sb, group, &e4b); - if (err) { - ext4_error(sb, "Error loading buddy information for %u", - group); - continue; - } - - bitmap_bh = ext4_read_block_bitmap(sb, group); - if (bitmap_bh == NULL) { - ext4_error(sb, "Error reading block bitmap for %u", - group); - ext4_mb_unload_buddy(&e4b); - continue; - } - - ext4_lock_group(sb, group); - list_del(&pa->pa_group_list); - ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa); - ext4_unlock_group(sb, group); - - ext4_mb_unload_buddy(&e4b); - put_bh(bitmap_bh); - - list_del(&pa->u.pa_tmp_list); - call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); - } -} - -#ifdef CONFIG_EXT4_DEBUG -static void ext4_mb_show_ac(struct ext4_allocation_context *ac) -{ - struct super_block *sb = ac->ac_sb; - ext4_group_t ngroups, i; - - if (!mb_enable_debug || - (EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)) - return; - - ext4_msg(ac->ac_sb, KERN_ERR, "Can't allocate:" - " Allocation context details:"); - ext4_msg(ac->ac_sb, KERN_ERR, "status %d flags %d", - ac->ac_status, ac->ac_flags); - ext4_msg(ac->ac_sb, KERN_ERR, "orig %lu/%lu/%lu@%lu, " - "goal %lu/%lu/%lu@%lu, " - "best %lu/%lu/%lu@%lu cr %d", - (unsigned long)ac->ac_o_ex.fe_group, - (unsigned long)ac->ac_o_ex.fe_start, - (unsigned long)ac->ac_o_ex.fe_len, - (unsigned long)ac->ac_o_ex.fe_logical, - (unsigned long)ac->ac_g_ex.fe_group, - (unsigned long)ac->ac_g_ex.fe_start, - (unsigned long)ac->ac_g_ex.fe_len, - (unsigned long)ac->ac_g_ex.fe_logical, - (unsigned long)ac->ac_b_ex.fe_group, - (unsigned long)ac->ac_b_ex.fe_start, - (unsigned long)ac->ac_b_ex.fe_len, - (unsigned long)ac->ac_b_ex.fe_logical, - (int)ac->ac_criteria); - ext4_msg(ac->ac_sb, KERN_ERR, "%lu scanned, %d found", - ac->ac_ex_scanned, ac->ac_found); - ext4_msg(ac->ac_sb, KERN_ERR, "groups: "); - ngroups = ext4_get_groups_count(sb); - for (i = 0; i < ngroups; i++) { - struct ext4_group_info *grp = ext4_get_group_info(sb, i); - struct ext4_prealloc_space *pa; - ext4_grpblk_t start; - struct list_head *cur; - ext4_lock_group(sb, i); - list_for_each(cur, &grp->bb_prealloc_list) { - pa = list_entry(cur, struct ext4_prealloc_space, - pa_group_list); - spin_lock(&pa->pa_lock); - ext4_get_group_no_and_offset(sb, pa->pa_pstart, - NULL, &start); - spin_unlock(&pa->pa_lock); - printk(KERN_ERR "PA:%u:%d:%u \n", i, - start, pa->pa_len); - } - ext4_unlock_group(sb, i); - - if (grp->bb_free == 0) - continue; - printk(KERN_ERR "%u: %d/%d \n", - i, grp->bb_free, grp->bb_fragments); - } - printk(KERN_ERR "\n"); -} -#else -static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac) -{ - return; -} -#endif - -/* - * We use locality group preallocation for small size file. The size of the - * file is determined by the current size or the resulting size after - * allocation which ever is larger - * - * One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req - */ -static void ext4_mb_group_or_file(struct ext4_allocation_context *ac) -{ - struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); - int bsbits = ac->ac_sb->s_blocksize_bits; - loff_t size, isize; - - if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) - return; - - if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) - return; - - size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len); - isize = (i_size_read(ac->ac_inode) + ac->ac_sb->s_blocksize - 1) - >> bsbits; - - if ((size == isize) && - !ext4_fs_is_busy(sbi) && - (atomic_read(&ac->ac_inode->i_writecount) == 0)) { - ac->ac_flags |= EXT4_MB_HINT_NOPREALLOC; - return; - } - - if (sbi->s_mb_group_prealloc <= 0) { - ac->ac_flags |= EXT4_MB_STREAM_ALLOC; - return; - } - - /* don't use group allocation for large files */ - size = max(size, isize); - if (size > sbi->s_mb_stream_request) { - ac->ac_flags |= EXT4_MB_STREAM_ALLOC; - return; - } - - BUG_ON(ac->ac_lg != NULL); - /* - * locality group prealloc space are per cpu. The reason for having - * per cpu locality group is to reduce the contention between block - * request from multiple CPUs. - */ - ac->ac_lg = __this_cpu_ptr(sbi->s_locality_groups); - - /* we're going to use group allocation */ - ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC; - - /* serialize all allocations in the group */ - mutex_lock(&ac->ac_lg->lg_mutex); -} - -static noinline_for_stack int -ext4_mb_initialize_context(struct ext4_allocation_context *ac, - struct ext4_allocation_request *ar) -{ - struct super_block *sb = ar->inode->i_sb; - struct ext4_sb_info *sbi = EXT4_SB(sb); - struct ext4_super_block *es = sbi->s_es; - ext4_group_t group; - unsigned int len; - ext4_fsblk_t goal; - ext4_grpblk_t block; - - /* we can't allocate > group size */ - len = ar->len; - - /* just a dirty hack to filter too big requests */ - if (len >= EXT4_CLUSTERS_PER_GROUP(sb) - 10) - len = EXT4_CLUSTERS_PER_GROUP(sb) - 10; - - /* start searching from the goal */ - goal = ar->goal; - if (goal < le32_to_cpu(es->s_first_data_block) || - goal >= ext4_blocks_count(es)) - goal = le32_to_cpu(es->s_first_data_block); - ext4_get_group_no_and_offset(sb, goal, &group, &block); - - /* set up allocation goals */ - memset(ac, 0, sizeof(struct ext4_allocation_context)); - ac->ac_b_ex.fe_logical = ar->logical & ~(sbi->s_cluster_ratio - 1); - ac->ac_status = AC_STATUS_CONTINUE; - ac->ac_sb = sb; - ac->ac_inode = ar->inode; - ac->ac_o_ex.fe_logical = ac->ac_b_ex.fe_logical; - ac->ac_o_ex.fe_group = group; - ac->ac_o_ex.fe_start = block; - ac->ac_o_ex.fe_len = len; - ac->ac_g_ex = ac->ac_o_ex; - ac->ac_flags = ar->flags; - - /* we have to define context: we'll we work with a file or - * locality group. this is a policy, actually */ - ext4_mb_group_or_file(ac); - - mb_debug(1, "init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, " - "left: %u/%u, right %u/%u to %swritable\n", - (unsigned) ar->len, (unsigned) ar->logical, - (unsigned) ar->goal, ac->ac_flags, ac->ac_2order, - (unsigned) ar->lleft, (unsigned) ar->pleft, - (unsigned) ar->lright, (unsigned) ar->pright, - atomic_read(&ar->inode->i_writecount) ? "" : "non-"); - return 0; - -} - -static noinline_for_stack void -ext4_mb_discard_lg_preallocations(struct super_block *sb, - struct ext4_locality_group *lg, - int order, int total_entries) -{ - ext4_group_t group = 0; - struct ext4_buddy e4b; - struct list_head discard_list; - struct ext4_prealloc_space *pa, *tmp; - - mb_debug(1, "discard locality group preallocation\n"); - - INIT_LIST_HEAD(&discard_list); - - spin_lock(&lg->lg_prealloc_lock); - list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[order], - pa_inode_list) { - spin_lock(&pa->pa_lock); - if (atomic_read(&pa->pa_count)) { - /* - * This is the pa that we just used - * for block allocation. So don't - * free that - */ - spin_unlock(&pa->pa_lock); - continue; - } - if (pa->pa_deleted) { - spin_unlock(&pa->pa_lock); - continue; - } - /* only lg prealloc space */ - BUG_ON(pa->pa_type != MB_GROUP_PA); - - /* seems this one can be freed ... */ - pa->pa_deleted = 1; - spin_unlock(&pa->pa_lock); - - list_del_rcu(&pa->pa_inode_list); - list_add(&pa->u.pa_tmp_list, &discard_list); - - total_entries--; - if (total_entries <= 5) { - /* - * we want to keep only 5 entries - * allowing it to grow to 8. This - * mak sure we don't call discard - * soon for this list. - */ - break; - } - } - spin_unlock(&lg->lg_prealloc_lock); - - list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) { - - ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL); - if (ext4_mb_load_buddy(sb, group, &e4b)) { - ext4_error(sb, "Error loading buddy information for %u", - group); - continue; - } - ext4_lock_group(sb, group); - list_del(&pa->pa_group_list); - ext4_mb_release_group_pa(&e4b, pa); - ext4_unlock_group(sb, group); - - ext4_mb_unload_buddy(&e4b); - list_del(&pa->u.pa_tmp_list); - call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); - } -} - -/* - * We have incremented pa_count. So it cannot be freed at this - * point. Also we hold lg_mutex. So no parallel allocation is - * possible from this lg. That means pa_free cannot be updated. - * - * A parallel ext4_mb_discard_group_preallocations is possible. - * which can cause the lg_prealloc_list to be updated. - */ - -static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac) -{ - int order, added = 0, lg_prealloc_count = 1; - struct super_block *sb = ac->ac_sb; - struct ext4_locality_group *lg = ac->ac_lg; - struct ext4_prealloc_space *tmp_pa, *pa = ac->ac_pa; - - order = fls(pa->pa_free) - 1; - if (order > PREALLOC_TB_SIZE - 1) - /* The max size of hash table is PREALLOC_TB_SIZE */ - order = PREALLOC_TB_SIZE - 1; - /* Add the prealloc space to lg */ - rcu_read_lock(); - list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order], - pa_inode_list) { - spin_lock(&tmp_pa->pa_lock); - if (tmp_pa->pa_deleted) { - spin_unlock(&tmp_pa->pa_lock); - continue; - } - if (!added && pa->pa_free < tmp_pa->pa_free) { - /* Add to the tail of the previous entry */ - list_add_tail_rcu(&pa->pa_inode_list, - &tmp_pa->pa_inode_list); - added = 1; - /* - * we want to count the total - * number of entries in the list - */ - } - spin_unlock(&tmp_pa->pa_lock); - lg_prealloc_count++; - } - if (!added) - list_add_tail_rcu(&pa->pa_inode_list, - &lg->lg_prealloc_list[order]); - rcu_read_unlock(); - - /* Now trim the list to be not more than 8 elements */ - if (lg_prealloc_count > 8) { - ext4_mb_discard_lg_preallocations(sb, lg, - order, lg_prealloc_count); - return; - } - return ; -} - -/* - * release all resource we used in allocation - */ -static int ext4_mb_release_context(struct ext4_allocation_context *ac) -{ - struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); - struct ext4_prealloc_space *pa = ac->ac_pa; - if (pa) { - if (pa->pa_type == MB_GROUP_PA) { - /* see comment in ext4_mb_use_group_pa() */ - spin_lock(&pa->pa_lock); - pa->pa_pstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len); - pa->pa_lstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len); - pa->pa_free -= ac->ac_b_ex.fe_len; - pa->pa_len -= ac->ac_b_ex.fe_len; - spin_unlock(&pa->pa_lock); - } - } - if (pa) { - /* - * We want to add the pa to the right bucket. - * Remove it from the list and while adding - * make sure the list to which we are adding - * doesn't grow big. - */ - if ((pa->pa_type == MB_GROUP_PA) && likely(pa->pa_free)) { - spin_lock(pa->pa_obj_lock); - list_del_rcu(&pa->pa_inode_list); - spin_unlock(pa->pa_obj_lock); - ext4_mb_add_n_trim(ac); - } - ext4_mb_put_pa(ac, ac->ac_sb, pa); - } - if (ac->ac_bitmap_page) - page_cache_release(ac->ac_bitmap_page); - if (ac->ac_buddy_page) - page_cache_release(ac->ac_buddy_page); - if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) - mutex_unlock(&ac->ac_lg->lg_mutex); - ext4_mb_collect_stats(ac); - return 0; -} - -static int ext4_mb_discard_preallocations(struct super_block *sb, int needed) -{ - ext4_group_t i, ngroups = ext4_get_groups_count(sb); - int ret; - int freed = 0; - - trace_ext4_mb_discard_preallocations(sb, needed); - for (i = 0; i < ngroups && needed > 0; i++) { - ret = ext4_mb_discard_group_preallocations(sb, i, needed); - freed += ret; - needed -= ret; - } - - return freed; -} - -/* - * Main entry point into mballoc to allocate blocks - * it tries to use preallocation first, then falls back - * to usual allocation - */ -ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle, - struct ext4_allocation_request *ar, int *errp) -{ - int freed; - struct ext4_allocation_context *ac = NULL; - struct ext4_sb_info *sbi; - struct super_block *sb; - ext4_fsblk_t block = 0; - unsigned int inquota = 0; - unsigned int reserv_clstrs = 0; - - sb = ar->inode->i_sb; - sbi = EXT4_SB(sb); - - trace_ext4_request_blocks(ar); - - /* Allow to use superuser reservation for quota file */ - if (IS_NOQUOTA(ar->inode)) - ar->flags |= EXT4_MB_USE_ROOT_BLOCKS; - - /* - * For delayed allocation, we could skip the ENOSPC and - * EDQUOT check, as blocks and quotas have been already - * reserved when data being copied into pagecache. - */ - if (ext4_test_inode_state(ar->inode, EXT4_STATE_DELALLOC_RESERVED)) - ar->flags |= EXT4_MB_DELALLOC_RESERVED; - else { - /* Without delayed allocation we need to verify - * there is enough free blocks to do block allocation - * and verify allocation doesn't exceed the quota limits. - */ - while (ar->len && - ext4_claim_free_clusters(sbi, ar->len, ar->flags)) { - - /* let others to free the space */ - yield(); - ar->len = ar->len >> 1; - } - if (!ar->len) { - *errp = -ENOSPC; - return 0; - } - reserv_clstrs = ar->len; - if (ar->flags & EXT4_MB_USE_ROOT_BLOCKS) { - dquot_alloc_block_nofail(ar->inode, - EXT4_C2B(sbi, ar->len)); - } else { - while (ar->len && - dquot_alloc_block(ar->inode, - EXT4_C2B(sbi, ar->len))) { - - ar->flags |= EXT4_MB_HINT_NOPREALLOC; - ar->len--; - } - } - inquota = ar->len; - if (ar->len == 0) { - *errp = -EDQUOT; - goto out; - } - } - - ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS); - if (!ac) { - ar->len = 0; - *errp = -ENOMEM; - goto out; - } - - *errp = ext4_mb_initialize_context(ac, ar); - if (*errp) { - ar->len = 0; - goto out; - } - - ac->ac_op = EXT4_MB_HISTORY_PREALLOC; - if (!ext4_mb_use_preallocated(ac)) { - ac->ac_op = EXT4_MB_HISTORY_ALLOC; - ext4_mb_normalize_request(ac, ar); -repeat: - /* allocate space in core */ - *errp = ext4_mb_regular_allocator(ac); - if (*errp) - goto errout; - - /* as we've just preallocated more space than - * user requested orinally, we store allocated - * space in a special descriptor */ - if (ac->ac_status == AC_STATUS_FOUND && - ac->ac_o_ex.fe_len < ac->ac_b_ex.fe_len) - ext4_mb_new_preallocation(ac); - } - if (likely(ac->ac_status == AC_STATUS_FOUND)) { - *errp = ext4_mb_mark_diskspace_used(ac, handle, reserv_clstrs); - if (*errp == -EAGAIN) { - /* - * drop the reference that we took - * in ext4_mb_use_best_found - */ - ext4_mb_release_context(ac); - ac->ac_b_ex.fe_group = 0; - ac->ac_b_ex.fe_start = 0; - ac->ac_b_ex.fe_len = 0; - ac->ac_status = AC_STATUS_CONTINUE; - goto repeat; - } else if (*errp) - errout: - ext4_discard_allocated_blocks(ac); - else { - block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); - ar->len = ac->ac_b_ex.fe_len; - } - } else { - freed = ext4_mb_discard_preallocations(sb, ac->ac_o_ex.fe_len); - if (freed) - goto repeat; - *errp = -ENOSPC; - } - - if (*errp) { - ac->ac_b_ex.fe_len = 0; - ar->len = 0; - ext4_mb_show_ac(ac); - } - ext4_mb_release_context(ac); -out: - if (ac) - kmem_cache_free(ext4_ac_cachep, ac); - if (inquota && ar->len < inquota) - dquot_free_block(ar->inode, EXT4_C2B(sbi, inquota - ar->len)); - if (!ar->len) { - if (!ext4_test_inode_state(ar->inode, - EXT4_STATE_DELALLOC_RESERVED)) - /* release all the reserved blocks if non delalloc */ - percpu_counter_sub(&sbi->s_dirtyclusters_counter, - reserv_clstrs); - } - - trace_ext4_allocate_blocks(ar, (unsigned long long)block); - - return block; -} - -/* - * We can merge two free data extents only if the physical blocks - * are contiguous, AND the extents were freed by the same transaction, - * AND the blocks are associated with the same group. - */ -static int can_merge(struct ext4_free_data *entry1, - struct ext4_free_data *entry2) -{ - if ((entry1->efd_tid == entry2->efd_tid) && - (entry1->efd_group == entry2->efd_group) && - ((entry1->efd_start_cluster + entry1->efd_count) == entry2->efd_start_cluster)) - return 1; - return 0; -} - -static noinline_for_stack int -ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b, - struct ext4_free_data *new_entry) -{ - ext4_group_t group = e4b->bd_group; - ext4_grpblk_t cluster; - struct ext4_free_data *entry; - struct ext4_group_info *db = e4b->bd_info; - struct super_block *sb = e4b->bd_sb; - struct ext4_sb_info *sbi = EXT4_SB(sb); - struct rb_node **n = &db->bb_free_root.rb_node, *node; - struct rb_node *parent = NULL, *new_node; - - BUG_ON(!ext4_handle_valid(handle)); - BUG_ON(e4b->bd_bitmap_page == NULL); - BUG_ON(e4b->bd_buddy_page == NULL); - - new_node = &new_entry->efd_node; - cluster = new_entry->efd_start_cluster; - - if (!*n) { - /* first free block exent. We need to - protect buddy cache from being freed, - * otherwise we'll refresh it from - * on-disk bitmap and lose not-yet-available - * blocks */ - page_cache_get(e4b->bd_buddy_page); - page_cache_get(e4b->bd_bitmap_page); - } - while (*n) { - parent = *n; - entry = rb_entry(parent, struct ext4_free_data, efd_node); - if (cluster < entry->efd_start_cluster) - n = &(*n)->rb_left; - else if (cluster >= (entry->efd_start_cluster + entry->efd_count)) - n = &(*n)->rb_right; - else { - ext4_grp_locked_error(sb, group, 0, - ext4_group_first_block_no(sb, group) + - EXT4_C2B(sbi, cluster), - "Block already on to-be-freed list"); - return 0; - } - } - - rb_link_node(new_node, parent, n); - rb_insert_color(new_node, &db->bb_free_root); - - /* Now try to see the extent can be merged to left and right */ - node = rb_prev(new_node); - if (node) { - entry = rb_entry(node, struct ext4_free_data, efd_node); - if (can_merge(entry, new_entry)) { - new_entry->efd_start_cluster = entry->efd_start_cluster; - new_entry->efd_count += entry->efd_count; - rb_erase(node, &(db->bb_free_root)); - ext4_journal_callback_del(handle, &entry->efd_jce); - kmem_cache_free(ext4_free_data_cachep, entry); - } - } - - node = rb_next(new_node); - if (node) { - entry = rb_entry(node, struct ext4_free_data, efd_node); - if (can_merge(new_entry, entry)) { - new_entry->efd_count += entry->efd_count; - rb_erase(node, &(db->bb_free_root)); - ext4_journal_callback_del(handle, &entry->efd_jce); - kmem_cache_free(ext4_free_data_cachep, entry); - } - } - /* Add the extent to transaction's private list */ - ext4_journal_callback_add(handle, ext4_free_data_callback, - &new_entry->efd_jce); - return 0; -} - -/** - * ext4_free_blocks() -- Free given blocks and update quota - * @handle: handle for this transaction - * @inode: inode - * @block: start physical block to free - * @count: number of blocks to count - * @flags: flags used by ext4_free_blocks - */ -void ext4_free_blocks(handle_t *handle, struct inode *inode, - struct buffer_head *bh, ext4_fsblk_t block, - unsigned long count, int flags) -{ - struct buffer_head *bitmap_bh = NULL; - struct super_block *sb = inode->i_sb; - struct ext4_group_desc *gdp; - unsigned long freed = 0; - unsigned int overflow; - ext4_grpblk_t bit; - struct buffer_head *gd_bh; - ext4_group_t block_group; - struct ext4_sb_info *sbi; - struct ext4_buddy e4b; - unsigned int count_clusters; - int err = 0; - int ret; - - if (bh) { - if (block) - BUG_ON(block != bh->b_blocknr); - else - block = bh->b_blocknr; - } - - sbi = EXT4_SB(sb); - if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) && - !ext4_data_block_valid(sbi, block, count)) { - ext4_error(sb, "Freeing blocks not in datazone - " - "block = %llu, count = %lu", block, count); - goto error_return; - } - - ext4_debug("freeing block %llu\n", block); - trace_ext4_free_blocks(inode, block, count, flags); - - if (flags & EXT4_FREE_BLOCKS_FORGET) { - struct buffer_head *tbh = bh; - int i; - - BUG_ON(bh && (count > 1)); - - for (i = 0; i < count; i++) { - if (!bh) - tbh = sb_find_get_block(inode->i_sb, - block + i); - if (unlikely(!tbh)) - continue; - ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA, - inode, tbh, block + i); - } - } - - /* - * We need to make sure we don't reuse the freed block until - * after the transaction is committed, which we can do by - * treating the block as metadata, below. We make an - * exception if the inode is to be written in writeback mode - * since writeback mode has weak data consistency guarantees. - */ - if (!ext4_should_writeback_data(inode)) - flags |= EXT4_FREE_BLOCKS_METADATA; - - /* - * If the extent to be freed does not begin on a cluster - * boundary, we need to deal with partial clusters at the - * beginning and end of the extent. Normally we will free - * blocks at the beginning or the end unless we are explicitly - * requested to avoid doing so. - */ - overflow = block & (sbi->s_cluster_ratio - 1); - if (overflow) { - if (flags & EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER) { - overflow = sbi->s_cluster_ratio - overflow; - block += overflow; - if (count > overflow) - count -= overflow; - else - return; - } else { - block -= overflow; - count += overflow; - } - } - overflow = count & (sbi->s_cluster_ratio - 1); - if (overflow) { - if (flags & EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER) { - if (count > overflow) - count -= overflow; - else - return; - } else - count += sbi->s_cluster_ratio - overflow; - } - -do_more: - overflow = 0; - ext4_get_group_no_and_offset(sb, block, &block_group, &bit); - - /* - * Check to see if we are freeing blocks across a group - * boundary. - */ - if (EXT4_C2B(sbi, bit) + count > EXT4_BLOCKS_PER_GROUP(sb)) { - overflow = EXT4_C2B(sbi, bit) + count - - EXT4_BLOCKS_PER_GROUP(sb); - count -= overflow; - } - count_clusters = EXT4_B2C(sbi, count); - bitmap_bh = ext4_read_block_bitmap(sb, block_group); - if (!bitmap_bh) { - err = -EIO; - goto error_return; - } - gdp = ext4_get_group_desc(sb, block_group, &gd_bh); - if (!gdp) { - err = -EIO; - goto error_return; - } - - if (in_range(ext4_block_bitmap(sb, gdp), block, count) || - in_range(ext4_inode_bitmap(sb, gdp), block, count) || - in_range(block, ext4_inode_table(sb, gdp), - EXT4_SB(sb)->s_itb_per_group) || - in_range(block + count - 1, ext4_inode_table(sb, gdp), - EXT4_SB(sb)->s_itb_per_group)) { - - ext4_error(sb, "Freeing blocks in system zone - " - "Block = %llu, count = %lu", block, count); - /* err = 0. ext4_std_error should be a no op */ - goto error_return; - } - - BUFFER_TRACE(bitmap_bh, "getting write access"); - err = ext4_journal_get_write_access(handle, bitmap_bh); - if (err) - goto error_return; - - /* - * We are about to modify some metadata. Call the journal APIs - * to unshare ->b_data if a currently-committing transaction is - * using it - */ - BUFFER_TRACE(gd_bh, "get_write_access"); - err = ext4_journal_get_write_access(handle, gd_bh); - if (err) - goto error_return; -#ifdef AGGRESSIVE_CHECK - { - int i; - for (i = 0; i < count_clusters; i++) - BUG_ON(!mb_test_bit(bit + i, bitmap_bh->b_data)); - } -#endif - trace_ext4_mballoc_free(sb, inode, block_group, bit, count_clusters); - - err = ext4_mb_load_buddy(sb, block_group, &e4b); - if (err) - goto error_return; - - if ((flags & EXT4_FREE_BLOCKS_METADATA) && ext4_handle_valid(handle)) { - struct ext4_free_data *new_entry; - /* - * blocks being freed are metadata. these blocks shouldn't - * be used until this transaction is committed - */ - new_entry = kmem_cache_alloc(ext4_free_data_cachep, GFP_NOFS); - if (!new_entry) { - ext4_mb_unload_buddy(&e4b); - err = -ENOMEM; - goto error_return; - } - new_entry->efd_start_cluster = bit; - new_entry->efd_group = block_group; - new_entry->efd_count = count_clusters; - new_entry->efd_tid = handle->h_transaction->t_tid; - - ext4_lock_group(sb, block_group); - mb_clear_bits(bitmap_bh->b_data, bit, count_clusters); - ext4_mb_free_metadata(handle, &e4b, new_entry); - } else { - /* need to update group_info->bb_free and bitmap - * with group lock held. generate_buddy look at - * them with group lock_held - */ - ext4_lock_group(sb, block_group); - mb_clear_bits(bitmap_bh->b_data, bit, count_clusters); - mb_free_blocks(inode, &e4b, bit, count_clusters); - } - - ret = ext4_free_group_clusters(sb, gdp) + count_clusters; - ext4_free_group_clusters_set(sb, gdp, ret); - gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp); - ext4_unlock_group(sb, block_group); - percpu_counter_add(&sbi->s_freeclusters_counter, count_clusters); - - if (sbi->s_log_groups_per_flex) { - ext4_group_t flex_group = ext4_flex_group(sbi, block_group); - atomic_add(count_clusters, - &sbi->s_flex_groups[flex_group].free_clusters); - } - - ext4_mb_unload_buddy(&e4b); - - freed += count; - - if (!(flags & EXT4_FREE_BLOCKS_NO_QUOT_UPDATE)) - dquot_free_block(inode, EXT4_C2B(sbi, count_clusters)); - - /* We dirtied the bitmap block */ - BUFFER_TRACE(bitmap_bh, "dirtied bitmap block"); - err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); - - /* And the group descriptor block */ - BUFFER_TRACE(gd_bh, "dirtied group descriptor block"); - ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh); - if (!err) - err = ret; - - if (overflow && !err) { - block += count; - count = overflow; - put_bh(bitmap_bh); - goto do_more; - } - ext4_mark_super_dirty(sb); -error_return: - brelse(bitmap_bh); - ext4_std_error(sb, err); - return; -} - -/** - * ext4_group_add_blocks() -- Add given blocks to an existing group - * @handle: handle to this transaction - * @sb: super block - * @block: start physcial block to add to the block group - * @count: number of blocks to free - * - * This marks the blocks as free in the bitmap and buddy. - */ -int ext4_group_add_blocks(handle_t *handle, struct super_block *sb, - ext4_fsblk_t block, unsigned long count) -{ - struct buffer_head *bitmap_bh = NULL; - struct buffer_head *gd_bh; - ext4_group_t block_group; - ext4_grpblk_t bit; - unsigned int i; - struct ext4_group_desc *desc; - struct ext4_sb_info *sbi = EXT4_SB(sb); - struct ext4_buddy e4b; - int err = 0, ret, blk_free_count; - ext4_grpblk_t blocks_freed; - - ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1); - - if (count == 0) - return 0; - - ext4_get_group_no_and_offset(sb, block, &block_group, &bit); - /* - * Check to see if we are freeing blocks across a group - * boundary. - */ - if (bit + count > EXT4_BLOCKS_PER_GROUP(sb)) { - ext4_warning(sb, "too much blocks added to group %u\n", - block_group); - err = -EINVAL; - goto error_return; - } - - bitmap_bh = ext4_read_block_bitmap(sb, block_group); - if (!bitmap_bh) { - err = -EIO; - goto error_return; - } - - desc = ext4_get_group_desc(sb, block_group, &gd_bh); - if (!desc) { - err = -EIO; - goto error_return; - } - - if (in_range(ext4_block_bitmap(sb, desc), block, count) || - in_range(ext4_inode_bitmap(sb, desc), block, count) || - in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) || - in_range(block + count - 1, ext4_inode_table(sb, desc), - sbi->s_itb_per_group)) { - ext4_error(sb, "Adding blocks in system zones - " - "Block = %llu, count = %lu", - block, count); - err = -EINVAL; - goto error_return; - } - - BUFFER_TRACE(bitmap_bh, "getting write access"); - err = ext4_journal_get_write_access(handle, bitmap_bh); - if (err) - goto error_return; - - /* - * We are about to modify some metadata. Call the journal APIs - * to unshare ->b_data if a currently-committing transaction is - * using it - */ - BUFFER_TRACE(gd_bh, "get_write_access"); - err = ext4_journal_get_write_access(handle, gd_bh); - if (err) - goto error_return; - - for (i = 0, blocks_freed = 0; i < count; i++) { - BUFFER_TRACE(bitmap_bh, "clear bit"); - if (!mb_test_bit(bit + i, bitmap_bh->b_data)) { - ext4_error(sb, "bit already cleared for block %llu", - (ext4_fsblk_t)(block + i)); - BUFFER_TRACE(bitmap_bh, "bit already cleared"); - } else { - blocks_freed++; - } - } - - err = ext4_mb_load_buddy(sb, block_group, &e4b); - if (err) - goto error_return; - - /* - * need to update group_info->bb_free and bitmap - * with group lock held. generate_buddy look at - * them with group lock_held - */ - ext4_lock_group(sb, block_group); - mb_clear_bits(bitmap_bh->b_data, bit, count); - mb_free_blocks(NULL, &e4b, bit, count); - blk_free_count = blocks_freed + ext4_free_group_clusters(sb, desc); - ext4_free_group_clusters_set(sb, desc, blk_free_count); - desc->bg_checksum = ext4_group_desc_csum(sbi, block_group, desc); - ext4_unlock_group(sb, block_group); - percpu_counter_add(&sbi->s_freeclusters_counter, - EXT4_B2C(sbi, blocks_freed)); - - if (sbi->s_log_groups_per_flex) { - ext4_group_t flex_group = ext4_flex_group(sbi, block_group); - atomic_add(EXT4_B2C(sbi, blocks_freed), - &sbi->s_flex_groups[flex_group].free_clusters); - } - - ext4_mb_unload_buddy(&e4b); - - /* We dirtied the bitmap block */ - BUFFER_TRACE(bitmap_bh, "dirtied bitmap block"); - err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); - - /* And the group descriptor block */ - BUFFER_TRACE(gd_bh, "dirtied group descriptor block"); - ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh); - if (!err) - err = ret; - -error_return: - brelse(bitmap_bh); - ext4_std_error(sb, err); - return err; -} - -/** - * ext4_trim_extent -- function to TRIM one single free extent in the group - * @sb: super block for the file system - * @start: starting block of the free extent in the alloc. group - * @count: number of blocks to TRIM - * @group: alloc. group we are working with - * @e4b: ext4 buddy for the group - * - * Trim "count" blocks starting at "start" in the "group". To assure that no - * one will allocate those blocks, mark it as used in buddy bitmap. This must - * be called with under the group lock. - */ -static void ext4_trim_extent(struct super_block *sb, int start, int count, - ext4_group_t group, struct ext4_buddy *e4b) -{ - struct ext4_free_extent ex; - - trace_ext4_trim_extent(sb, group, start, count); - - assert_spin_locked(ext4_group_lock_ptr(sb, group)); - - ex.fe_start = start; - ex.fe_group = group; - ex.fe_len = count; - - /* - * Mark blocks used, so no one can reuse them while - * being trimmed. - */ - mb_mark_used(e4b, &ex); - ext4_unlock_group(sb, group); - ext4_issue_discard(sb, group, start, count); - ext4_lock_group(sb, group); - mb_free_blocks(NULL, e4b, start, ex.fe_len); -} - -/** - * ext4_trim_all_free -- function to trim all free space in alloc. group - * @sb: super block for file system - * @group: group to be trimmed - * @start: first group block to examine - * @max: last group block to examine - * @minblocks: minimum extent block count - * - * ext4_trim_all_free walks through group's buddy bitmap searching for free - * extents. When the free block is found, ext4_trim_extent is called to TRIM - * the extent. - * - * - * ext4_trim_all_free walks through group's block bitmap searching for free - * extents. When the free extent is found, mark it as used in group buddy - * bitmap. Then issue a TRIM command on this extent and free the extent in - * the group buddy bitmap. This is done until whole group is scanned. - */ -static ext4_grpblk_t -ext4_trim_all_free(struct super_block *sb, ext4_group_t group, - ext4_grpblk_t start, ext4_grpblk_t max, - ext4_grpblk_t minblocks) -{ - void *bitmap; - ext4_grpblk_t next, count = 0, free_count = 0; - struct ext4_buddy e4b; - int ret; - - trace_ext4_trim_all_free(sb, group, start, max); - - ret = ext4_mb_load_buddy(sb, group, &e4b); - if (ret) { - ext4_error(sb, "Error in loading buddy " - "information for %u", group); - return ret; - } - bitmap = e4b.bd_bitmap; - - ext4_lock_group(sb, group); - if (EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) && - minblocks >= atomic_read(&EXT4_SB(sb)->s_last_trim_minblks)) - goto out; - - start = (e4b.bd_info->bb_first_free > start) ? - e4b.bd_info->bb_first_free : start; - - while (start <= max) { - start = mb_find_next_zero_bit(bitmap, max + 1, start); - if (start > max) - break; - next = mb_find_next_bit(bitmap, max + 1, start); - - if ((next - start) >= minblocks) { - ext4_trim_extent(sb, start, - next - start, group, &e4b); - count += next - start; - } - free_count += next - start; - start = next + 1; - - if (fatal_signal_pending(current)) { - count = -ERESTARTSYS; - break; - } - - if (need_resched()) { - ext4_unlock_group(sb, group); - cond_resched(); - ext4_lock_group(sb, group); - } - - if ((e4b.bd_info->bb_free - free_count) < minblocks) - break; - } - - if (!ret) - EXT4_MB_GRP_SET_TRIMMED(e4b.bd_info); -out: - ext4_unlock_group(sb, group); - ext4_mb_unload_buddy(&e4b); - - ext4_debug("trimmed %d blocks in the group %d\n", - count, group); - - return count; -} - -/** - * ext4_trim_fs() -- trim ioctl handle function - * @sb: superblock for filesystem - * @range: fstrim_range structure - * - * start: First Byte to trim - * len: number of Bytes to trim from start - * minlen: minimum extent length in Bytes - * ext4_trim_fs goes through all allocation groups containing Bytes from - * start to start+len. For each such a group ext4_trim_all_free function - * is invoked to trim all free space. - */ -int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range) -{ - struct ext4_group_info *grp; - ext4_group_t group, first_group, last_group; - ext4_grpblk_t cnt = 0, first_cluster, last_cluster; - uint64_t start, end, minlen, trimmed = 0; - ext4_fsblk_t first_data_blk = - le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block); - ext4_fsblk_t max_blks = ext4_blocks_count(EXT4_SB(sb)->s_es); - int ret = 0; - - start = range->start >> sb->s_blocksize_bits; - end = start + (range->len >> sb->s_blocksize_bits) - 1; - minlen = range->minlen >> sb->s_blocksize_bits; - - if (unlikely(minlen > EXT4_CLUSTERS_PER_GROUP(sb)) || - unlikely(start >= max_blks)) - return -EINVAL; - if (end >= max_blks) - end = max_blks - 1; - if (end <= first_data_blk) - goto out; - if (start < first_data_blk) - start = first_data_blk; - - /* Determine first and last group to examine based on start and end */ - ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) start, - &first_group, &first_cluster); - ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) end, - &last_group, &last_cluster); - - /* end now represents the last cluster to discard in this group */ - end = EXT4_CLUSTERS_PER_GROUP(sb) - 1; - - for (group = first_group; group <= last_group; group++) { - grp = ext4_get_group_info(sb, group); - /* We only do this if the grp has never been initialized */ - if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) { - ret = ext4_mb_init_group(sb, group); - if (ret) - break; - } - - /* - * For all the groups except the last one, last cluster will - * always be EXT4_CLUSTERS_PER_GROUP(sb)-1, so we only need to - * change it for the last group, note that last_cluster is - * already computed earlier by ext4_get_group_no_and_offset() - */ - if (group == last_group) - end = last_cluster; - - if (grp->bb_free >= minlen) { - cnt = ext4_trim_all_free(sb, group, first_cluster, - end, minlen); - if (cnt < 0) { - ret = cnt; - break; - } - trimmed += cnt; - } - - /* - * For every group except the first one, we are sure - * that the first cluster to discard will be cluster #0. - */ - first_cluster = 0; - } - - if (!ret) - atomic_set(&EXT4_SB(sb)->s_last_trim_minblks, minlen); - -out: - range->len = trimmed * sb->s_blocksize; - return ret; -} |