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author | Kevin | 2014-11-15 09:58:27 +0800 |
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committer | Kevin | 2014-11-15 09:58:27 +0800 |
commit | 392e8802486cb573b916e746010e141a75f507e6 (patch) | |
tree | 50029aca02c81f087b90336e670b44e510782330 /ANDROID_3.4.5/fs/ext4/extents.c | |
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init android origin source code
Diffstat (limited to 'ANDROID_3.4.5/fs/ext4/extents.c')
-rw-r--r-- | ANDROID_3.4.5/fs/ext4/extents.c | 4866 |
1 files changed, 4866 insertions, 0 deletions
diff --git a/ANDROID_3.4.5/fs/ext4/extents.c b/ANDROID_3.4.5/fs/ext4/extents.c new file mode 100644 index 00000000..abcdeab6 --- /dev/null +++ b/ANDROID_3.4.5/fs/ext4/extents.c @@ -0,0 +1,4866 @@ +/* + * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com + * Written by Alex Tomas <alex@clusterfs.com> + * + * Architecture independence: + * Copyright (c) 2005, Bull S.A. + * Written by Pierre Peiffer <pierre.peiffer@bull.net> + * + * 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- + */ + +/* + * Extents support for EXT4 + * + * TODO: + * - ext4*_error() should be used in some situations + * - analyze all BUG()/BUG_ON(), use -EIO where appropriate + * - smart tree reduction + */ + +#include <linux/fs.h> +#include <linux/time.h> +#include <linux/jbd2.h> +#include <linux/highuid.h> +#include <linux/pagemap.h> +#include <linux/quotaops.h> +#include <linux/string.h> +#include <linux/slab.h> +#include <linux/falloc.h> +#include <asm/uaccess.h> +#include <linux/fiemap.h> +#include "ext4_jbd2.h" + +#include <trace/events/ext4.h> + +/* + * used by extent splitting. + */ +#define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \ + due to ENOSPC */ +#define EXT4_EXT_MARK_UNINIT1 0x2 /* mark first half uninitialized */ +#define EXT4_EXT_MARK_UNINIT2 0x4 /* mark second half uninitialized */ + +static int ext4_split_extent(handle_t *handle, + struct inode *inode, + struct ext4_ext_path *path, + struct ext4_map_blocks *map, + int split_flag, + int flags); + +static int ext4_split_extent_at(handle_t *handle, + struct inode *inode, + struct ext4_ext_path *path, + ext4_lblk_t split, + int split_flag, + int flags); + +static int ext4_ext_truncate_extend_restart(handle_t *handle, + struct inode *inode, + int needed) +{ + int err; + + if (!ext4_handle_valid(handle)) + return 0; + if (handle->h_buffer_credits > needed) + return 0; + err = ext4_journal_extend(handle, needed); + if (err <= 0) + return err; + err = ext4_truncate_restart_trans(handle, inode, needed); + if (err == 0) + err = -EAGAIN; + + return err; +} + +/* + * could return: + * - EROFS + * - ENOMEM + */ +static int ext4_ext_get_access(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path) +{ + if (path->p_bh) { + /* path points to block */ + return ext4_journal_get_write_access(handle, path->p_bh); + } + /* path points to leaf/index in inode body */ + /* we use in-core data, no need to protect them */ + return 0; +} + +/* + * could return: + * - EROFS + * - ENOMEM + * - EIO + */ +#define ext4_ext_dirty(handle, inode, path) \ + __ext4_ext_dirty(__func__, __LINE__, (handle), (inode), (path)) +static int __ext4_ext_dirty(const char *where, unsigned int line, + handle_t *handle, struct inode *inode, + struct ext4_ext_path *path) +{ + int err; + if (path->p_bh) { + /* path points to block */ + err = __ext4_handle_dirty_metadata(where, line, handle, + inode, path->p_bh); + } else { + /* path points to leaf/index in inode body */ + err = ext4_mark_inode_dirty(handle, inode); + } + return err; +} + +static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode, + struct ext4_ext_path *path, + ext4_lblk_t block) +{ + if (path) { + int depth = path->p_depth; + struct ext4_extent *ex; + + /* + * Try to predict block placement assuming that we are + * filling in a file which will eventually be + * non-sparse --- i.e., in the case of libbfd writing + * an ELF object sections out-of-order but in a way + * the eventually results in a contiguous object or + * executable file, or some database extending a table + * space file. However, this is actually somewhat + * non-ideal if we are writing a sparse file such as + * qemu or KVM writing a raw image file that is going + * to stay fairly sparse, since it will end up + * fragmenting the file system's free space. Maybe we + * should have some hueristics or some way to allow + * userspace to pass a hint to file system, + * especially if the latter case turns out to be + * common. + */ + ex = path[depth].p_ext; + if (ex) { + ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex); + ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block); + + if (block > ext_block) + return ext_pblk + (block - ext_block); + else + return ext_pblk - (ext_block - block); + } + + /* it looks like index is empty; + * try to find starting block from index itself */ + if (path[depth].p_bh) + return path[depth].p_bh->b_blocknr; + } + + /* OK. use inode's group */ + return ext4_inode_to_goal_block(inode); +} + +/* + * Allocation for a meta data block + */ +static ext4_fsblk_t +ext4_ext_new_meta_block(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path, + struct ext4_extent *ex, int *err, unsigned int flags) +{ + ext4_fsblk_t goal, newblock; + + goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block)); + newblock = ext4_new_meta_blocks(handle, inode, goal, flags, + NULL, err); + return newblock; +} + +static inline int ext4_ext_space_block(struct inode *inode, int check) +{ + int size; + + size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) + / sizeof(struct ext4_extent); +#ifdef AGGRESSIVE_TEST + if (!check && size > 6) + size = 6; +#endif + return size; +} + +static inline int ext4_ext_space_block_idx(struct inode *inode, int check) +{ + int size; + + size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) + / sizeof(struct ext4_extent_idx); +#ifdef AGGRESSIVE_TEST + if (!check && size > 5) + size = 5; +#endif + return size; +} + +static inline int ext4_ext_space_root(struct inode *inode, int check) +{ + int size; + + size = sizeof(EXT4_I(inode)->i_data); + size -= sizeof(struct ext4_extent_header); + size /= sizeof(struct ext4_extent); +#ifdef AGGRESSIVE_TEST + if (!check && size > 3) + size = 3; +#endif + return size; +} + +static inline int ext4_ext_space_root_idx(struct inode *inode, int check) +{ + int size; + + size = sizeof(EXT4_I(inode)->i_data); + size -= sizeof(struct ext4_extent_header); + size /= sizeof(struct ext4_extent_idx); +#ifdef AGGRESSIVE_TEST + if (!check && size > 4) + size = 4; +#endif + return size; +} + +/* + * Calculate the number of metadata blocks needed + * to allocate @blocks + * Worse case is one block per extent + */ +int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock) +{ + struct ext4_inode_info *ei = EXT4_I(inode); + int idxs; + + idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) + / sizeof(struct ext4_extent_idx)); + + /* + * If the new delayed allocation block is contiguous with the + * previous da block, it can share index blocks with the + * previous block, so we only need to allocate a new index + * block every idxs leaf blocks. At ldxs**2 blocks, we need + * an additional index block, and at ldxs**3 blocks, yet + * another index blocks. + */ + if (ei->i_da_metadata_calc_len && + ei->i_da_metadata_calc_last_lblock+1 == lblock) { + int num = 0; + + if ((ei->i_da_metadata_calc_len % idxs) == 0) + num++; + if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0) + num++; + if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) { + num++; + ei->i_da_metadata_calc_len = 0; + } else + ei->i_da_metadata_calc_len++; + ei->i_da_metadata_calc_last_lblock++; + return num; + } + + /* + * In the worst case we need a new set of index blocks at + * every level of the inode's extent tree. + */ + ei->i_da_metadata_calc_len = 1; + ei->i_da_metadata_calc_last_lblock = lblock; + return ext_depth(inode) + 1; +} + +static int +ext4_ext_max_entries(struct inode *inode, int depth) +{ + int max; + + if (depth == ext_depth(inode)) { + if (depth == 0) + max = ext4_ext_space_root(inode, 1); + else + max = ext4_ext_space_root_idx(inode, 1); + } else { + if (depth == 0) + max = ext4_ext_space_block(inode, 1); + else + max = ext4_ext_space_block_idx(inode, 1); + } + + return max; +} + +static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext) +{ + ext4_fsblk_t block = ext4_ext_pblock(ext); + int len = ext4_ext_get_actual_len(ext); + + if (len == 0) + return 0; + return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len); +} + +static int ext4_valid_extent_idx(struct inode *inode, + struct ext4_extent_idx *ext_idx) +{ + ext4_fsblk_t block = ext4_idx_pblock(ext_idx); + + return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1); +} + +static int ext4_valid_extent_entries(struct inode *inode, + struct ext4_extent_header *eh, + int depth) +{ + unsigned short entries; + if (eh->eh_entries == 0) + return 1; + + entries = le16_to_cpu(eh->eh_entries); + + if (depth == 0) { + /* leaf entries */ + struct ext4_extent *ext = EXT_FIRST_EXTENT(eh); + while (entries) { + if (!ext4_valid_extent(inode, ext)) + return 0; + ext++; + entries--; + } + } else { + struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh); + while (entries) { + if (!ext4_valid_extent_idx(inode, ext_idx)) + return 0; + ext_idx++; + entries--; + } + } + return 1; +} + +static int __ext4_ext_check(const char *function, unsigned int line, + struct inode *inode, struct ext4_extent_header *eh, + int depth) +{ + const char *error_msg; + int max = 0; + + if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) { + error_msg = "invalid magic"; + goto corrupted; + } + if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) { + error_msg = "unexpected eh_depth"; + goto corrupted; + } + if (unlikely(eh->eh_max == 0)) { + error_msg = "invalid eh_max"; + goto corrupted; + } + max = ext4_ext_max_entries(inode, depth); + if (unlikely(le16_to_cpu(eh->eh_max) > max)) { + error_msg = "too large eh_max"; + goto corrupted; + } + if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) { + error_msg = "invalid eh_entries"; + goto corrupted; + } + if (!ext4_valid_extent_entries(inode, eh, depth)) { + error_msg = "invalid extent entries"; + goto corrupted; + } + return 0; + +corrupted: + ext4_error_inode(inode, function, line, 0, + "bad header/extent: %s - magic %x, " + "entries %u, max %u(%u), depth %u(%u)", + error_msg, le16_to_cpu(eh->eh_magic), + le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max), + max, le16_to_cpu(eh->eh_depth), depth); + + return -EIO; +} + +#define ext4_ext_check(inode, eh, depth) \ + __ext4_ext_check(__func__, __LINE__, inode, eh, depth) + +int ext4_ext_check_inode(struct inode *inode) +{ + return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode)); +} + +#ifdef EXT_DEBUG +static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path) +{ + int k, l = path->p_depth; + + ext_debug("path:"); + for (k = 0; k <= l; k++, path++) { + if (path->p_idx) { + ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block), + ext4_idx_pblock(path->p_idx)); + } else if (path->p_ext) { + ext_debug(" %d:[%d]%d:%llu ", + le32_to_cpu(path->p_ext->ee_block), + ext4_ext_is_uninitialized(path->p_ext), + ext4_ext_get_actual_len(path->p_ext), + ext4_ext_pblock(path->p_ext)); + } else + ext_debug(" []"); + } + ext_debug("\n"); +} + +static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path) +{ + int depth = ext_depth(inode); + struct ext4_extent_header *eh; + struct ext4_extent *ex; + int i; + + if (!path) + return; + + eh = path[depth].p_hdr; + ex = EXT_FIRST_EXTENT(eh); + + ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino); + + for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) { + ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block), + ext4_ext_is_uninitialized(ex), + ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex)); + } + ext_debug("\n"); +} + +static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path, + ext4_fsblk_t newblock, int level) +{ + int depth = ext_depth(inode); + struct ext4_extent *ex; + + if (depth != level) { + struct ext4_extent_idx *idx; + idx = path[level].p_idx; + while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) { + ext_debug("%d: move %d:%llu in new index %llu\n", level, + le32_to_cpu(idx->ei_block), + ext4_idx_pblock(idx), + newblock); + idx++; + } + + return; + } + + ex = path[depth].p_ext; + while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) { + ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n", + le32_to_cpu(ex->ee_block), + ext4_ext_pblock(ex), + ext4_ext_is_uninitialized(ex), + ext4_ext_get_actual_len(ex), + newblock); + ex++; + } +} + +#else +#define ext4_ext_show_path(inode, path) +#define ext4_ext_show_leaf(inode, path) +#define ext4_ext_show_move(inode, path, newblock, level) +#endif + +void ext4_ext_drop_refs(struct ext4_ext_path *path) +{ + int depth = path->p_depth; + int i; + + for (i = 0; i <= depth; i++, path++) + if (path->p_bh) { + brelse(path->p_bh); + path->p_bh = NULL; + } +} + +/* + * ext4_ext_binsearch_idx: + * binary search for the closest index of the given block + * the header must be checked before calling this + */ +static void +ext4_ext_binsearch_idx(struct inode *inode, + struct ext4_ext_path *path, ext4_lblk_t block) +{ + struct ext4_extent_header *eh = path->p_hdr; + struct ext4_extent_idx *r, *l, *m; + + + ext_debug("binsearch for %u(idx): ", block); + + l = EXT_FIRST_INDEX(eh) + 1; + r = EXT_LAST_INDEX(eh); + while (l <= r) { + m = l + (r - l) / 2; + if (block < le32_to_cpu(m->ei_block)) + r = m - 1; + else + l = m + 1; + ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block), + m, le32_to_cpu(m->ei_block), + r, le32_to_cpu(r->ei_block)); + } + + path->p_idx = l - 1; + ext_debug(" -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block), + ext4_idx_pblock(path->p_idx)); + +#ifdef CHECK_BINSEARCH + { + struct ext4_extent_idx *chix, *ix; + int k; + + chix = ix = EXT_FIRST_INDEX(eh); + for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) { + if (k != 0 && + le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) { + printk(KERN_DEBUG "k=%d, ix=0x%p, " + "first=0x%p\n", k, + ix, EXT_FIRST_INDEX(eh)); + printk(KERN_DEBUG "%u <= %u\n", + le32_to_cpu(ix->ei_block), + le32_to_cpu(ix[-1].ei_block)); + } + BUG_ON(k && le32_to_cpu(ix->ei_block) + <= le32_to_cpu(ix[-1].ei_block)); + if (block < le32_to_cpu(ix->ei_block)) + break; + chix = ix; + } + BUG_ON(chix != path->p_idx); + } +#endif + +} + +/* + * ext4_ext_binsearch: + * binary search for closest extent of the given block + * the header must be checked before calling this + */ +static void +ext4_ext_binsearch(struct inode *inode, + struct ext4_ext_path *path, ext4_lblk_t block) +{ + struct ext4_extent_header *eh = path->p_hdr; + struct ext4_extent *r, *l, *m; + + if (eh->eh_entries == 0) { + /* + * this leaf is empty: + * we get such a leaf in split/add case + */ + return; + } + + ext_debug("binsearch for %u: ", block); + + l = EXT_FIRST_EXTENT(eh) + 1; + r = EXT_LAST_EXTENT(eh); + + while (l <= r) { + m = l + (r - l) / 2; + if (block < le32_to_cpu(m->ee_block)) + r = m - 1; + else + l = m + 1; + ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block), + m, le32_to_cpu(m->ee_block), + r, le32_to_cpu(r->ee_block)); + } + + path->p_ext = l - 1; + ext_debug(" -> %d:%llu:[%d]%d ", + le32_to_cpu(path->p_ext->ee_block), + ext4_ext_pblock(path->p_ext), + ext4_ext_is_uninitialized(path->p_ext), + ext4_ext_get_actual_len(path->p_ext)); + +#ifdef CHECK_BINSEARCH + { + struct ext4_extent *chex, *ex; + int k; + + chex = ex = EXT_FIRST_EXTENT(eh); + for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) { + BUG_ON(k && le32_to_cpu(ex->ee_block) + <= le32_to_cpu(ex[-1].ee_block)); + if (block < le32_to_cpu(ex->ee_block)) + break; + chex = ex; + } + BUG_ON(chex != path->p_ext); + } +#endif + +} + +int ext4_ext_tree_init(handle_t *handle, struct inode *inode) +{ + struct ext4_extent_header *eh; + + eh = ext_inode_hdr(inode); + eh->eh_depth = 0; + eh->eh_entries = 0; + eh->eh_magic = EXT4_EXT_MAGIC; + eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0)); + ext4_mark_inode_dirty(handle, inode); + ext4_ext_invalidate_cache(inode); + return 0; +} + +struct ext4_ext_path * +ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block, + struct ext4_ext_path *path) +{ + struct ext4_extent_header *eh; + struct buffer_head *bh; + short int depth, i, ppos = 0, alloc = 0; + + eh = ext_inode_hdr(inode); + depth = ext_depth(inode); + + /* account possible depth increase */ + if (!path) { + path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2), + GFP_NOFS); + if (!path) + return ERR_PTR(-ENOMEM); + alloc = 1; + } + path[0].p_hdr = eh; + path[0].p_bh = NULL; + + i = depth; + /* walk through the tree */ + while (i) { + int need_to_validate = 0; + + ext_debug("depth %d: num %d, max %d\n", + ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); + + ext4_ext_binsearch_idx(inode, path + ppos, block); + path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx); + path[ppos].p_depth = i; + path[ppos].p_ext = NULL; + + bh = sb_getblk(inode->i_sb, path[ppos].p_block); + if (unlikely(!bh)) + goto err; + if (!bh_uptodate_or_lock(bh)) { + trace_ext4_ext_load_extent(inode, block, + path[ppos].p_block); + if (bh_submit_read(bh) < 0) { + put_bh(bh); + goto err; + } + /* validate the extent entries */ + need_to_validate = 1; + } + eh = ext_block_hdr(bh); + ppos++; + if (unlikely(ppos > depth)) { + put_bh(bh); + EXT4_ERROR_INODE(inode, + "ppos %d > depth %d", ppos, depth); + goto err; + } + path[ppos].p_bh = bh; + path[ppos].p_hdr = eh; + i--; + + if (need_to_validate && ext4_ext_check(inode, eh, i)) + goto err; + } + + path[ppos].p_depth = i; + path[ppos].p_ext = NULL; + path[ppos].p_idx = NULL; + + /* find extent */ + ext4_ext_binsearch(inode, path + ppos, block); + /* if not an empty leaf */ + if (path[ppos].p_ext) + path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext); + + ext4_ext_show_path(inode, path); + + return path; + +err: + ext4_ext_drop_refs(path); + if (alloc) + kfree(path); + return ERR_PTR(-EIO); +} + +/* + * ext4_ext_insert_index: + * insert new index [@logical;@ptr] into the block at @curp; + * check where to insert: before @curp or after @curp + */ +static int ext4_ext_insert_index(handle_t *handle, struct inode *inode, + struct ext4_ext_path *curp, + int logical, ext4_fsblk_t ptr) +{ + struct ext4_extent_idx *ix; + int len, err; + + err = ext4_ext_get_access(handle, inode, curp); + if (err) + return err; + + if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) { + EXT4_ERROR_INODE(inode, + "logical %d == ei_block %d!", + logical, le32_to_cpu(curp->p_idx->ei_block)); + return -EIO; + } + + if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries) + >= le16_to_cpu(curp->p_hdr->eh_max))) { + EXT4_ERROR_INODE(inode, + "eh_entries %d >= eh_max %d!", + le16_to_cpu(curp->p_hdr->eh_entries), + le16_to_cpu(curp->p_hdr->eh_max)); + return -EIO; + } + + if (logical > le32_to_cpu(curp->p_idx->ei_block)) { + /* insert after */ + ext_debug("insert new index %d after: %llu\n", logical, ptr); + ix = curp->p_idx + 1; + } else { + /* insert before */ + ext_debug("insert new index %d before: %llu\n", logical, ptr); + ix = curp->p_idx; + } + + len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1; + BUG_ON(len < 0); + if (len > 0) { + ext_debug("insert new index %d: " + "move %d indices from 0x%p to 0x%p\n", + logical, len, ix, ix + 1); + memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx)); + } + + if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) { + EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!"); + return -EIO; + } + + ix->ei_block = cpu_to_le32(logical); + ext4_idx_store_pblock(ix, ptr); + le16_add_cpu(&curp->p_hdr->eh_entries, 1); + + if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) { + EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!"); + return -EIO; + } + + err = ext4_ext_dirty(handle, inode, curp); + ext4_std_error(inode->i_sb, err); + + return err; +} + +/* + * ext4_ext_split: + * inserts new subtree into the path, using free index entry + * at depth @at: + * - allocates all needed blocks (new leaf and all intermediate index blocks) + * - makes decision where to split + * - moves remaining extents and index entries (right to the split point) + * into the newly allocated blocks + * - initializes subtree + */ +static int ext4_ext_split(handle_t *handle, struct inode *inode, + unsigned int flags, + struct ext4_ext_path *path, + struct ext4_extent *newext, int at) +{ + struct buffer_head *bh = NULL; + int depth = ext_depth(inode); + struct ext4_extent_header *neh; + struct ext4_extent_idx *fidx; + int i = at, k, m, a; + ext4_fsblk_t newblock, oldblock; + __le32 border; + ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */ + int err = 0; + + /* make decision: where to split? */ + /* FIXME: now decision is simplest: at current extent */ + + /* if current leaf will be split, then we should use + * border from split point */ + if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) { + EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!"); + return -EIO; + } + if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) { + border = path[depth].p_ext[1].ee_block; + ext_debug("leaf will be split." + " next leaf starts at %d\n", + le32_to_cpu(border)); + } else { + border = newext->ee_block; + ext_debug("leaf will be added." + " next leaf starts at %d\n", + le32_to_cpu(border)); + } + + /* + * If error occurs, then we break processing + * and mark filesystem read-only. index won't + * be inserted and tree will be in consistent + * state. Next mount will repair buffers too. + */ + + /* + * Get array to track all allocated blocks. + * We need this to handle errors and free blocks + * upon them. + */ + ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS); + if (!ablocks) + return -ENOMEM; + + /* allocate all needed blocks */ + ext_debug("allocate %d blocks for indexes/leaf\n", depth - at); + for (a = 0; a < depth - at; a++) { + newblock = ext4_ext_new_meta_block(handle, inode, path, + newext, &err, flags); + if (newblock == 0) + goto cleanup; + ablocks[a] = newblock; + } + + /* initialize new leaf */ + newblock = ablocks[--a]; + if (unlikely(newblock == 0)) { + EXT4_ERROR_INODE(inode, "newblock == 0!"); + err = -EIO; + goto cleanup; + } + bh = sb_getblk(inode->i_sb, newblock); + if (!bh) { + err = -EIO; + goto cleanup; + } + lock_buffer(bh); + + err = ext4_journal_get_create_access(handle, bh); + if (err) + goto cleanup; + + neh = ext_block_hdr(bh); + neh->eh_entries = 0; + neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0)); + neh->eh_magic = EXT4_EXT_MAGIC; + neh->eh_depth = 0; + + /* move remainder of path[depth] to the new leaf */ + if (unlikely(path[depth].p_hdr->eh_entries != + path[depth].p_hdr->eh_max)) { + EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!", + path[depth].p_hdr->eh_entries, + path[depth].p_hdr->eh_max); + err = -EIO; + goto cleanup; + } + /* start copy from next extent */ + m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++; + ext4_ext_show_move(inode, path, newblock, depth); + if (m) { + struct ext4_extent *ex; + ex = EXT_FIRST_EXTENT(neh); + memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m); + le16_add_cpu(&neh->eh_entries, m); + } + + set_buffer_uptodate(bh); + unlock_buffer(bh); + + err = ext4_handle_dirty_metadata(handle, inode, bh); + if (err) + goto cleanup; + brelse(bh); + bh = NULL; + + /* correct old leaf */ + if (m) { + err = ext4_ext_get_access(handle, inode, path + depth); + if (err) + goto cleanup; + le16_add_cpu(&path[depth].p_hdr->eh_entries, -m); + err = ext4_ext_dirty(handle, inode, path + depth); + if (err) + goto cleanup; + + } + + /* create intermediate indexes */ + k = depth - at - 1; + if (unlikely(k < 0)) { + EXT4_ERROR_INODE(inode, "k %d < 0!", k); + err = -EIO; + goto cleanup; + } + if (k) + ext_debug("create %d intermediate indices\n", k); + /* insert new index into current index block */ + /* current depth stored in i var */ + i = depth - 1; + while (k--) { + oldblock = newblock; + newblock = ablocks[--a]; + bh = sb_getblk(inode->i_sb, newblock); + if (!bh) { + err = -EIO; + goto cleanup; + } + lock_buffer(bh); + + err = ext4_journal_get_create_access(handle, bh); + if (err) + goto cleanup; + + neh = ext_block_hdr(bh); + neh->eh_entries = cpu_to_le16(1); + neh->eh_magic = EXT4_EXT_MAGIC; + neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0)); + neh->eh_depth = cpu_to_le16(depth - i); + fidx = EXT_FIRST_INDEX(neh); + fidx->ei_block = border; + ext4_idx_store_pblock(fidx, oldblock); + + ext_debug("int.index at %d (block %llu): %u -> %llu\n", + i, newblock, le32_to_cpu(border), oldblock); + + /* move remainder of path[i] to the new index block */ + if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) != + EXT_LAST_INDEX(path[i].p_hdr))) { + EXT4_ERROR_INODE(inode, + "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!", + le32_to_cpu(path[i].p_ext->ee_block)); + err = -EIO; + goto cleanup; + } + /* start copy indexes */ + m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++; + ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx, + EXT_MAX_INDEX(path[i].p_hdr)); + ext4_ext_show_move(inode, path, newblock, i); + if (m) { + memmove(++fidx, path[i].p_idx, + sizeof(struct ext4_extent_idx) * m); + le16_add_cpu(&neh->eh_entries, m); + } + set_buffer_uptodate(bh); + unlock_buffer(bh); + + err = ext4_handle_dirty_metadata(handle, inode, bh); + if (err) + goto cleanup; + brelse(bh); + bh = NULL; + + /* correct old index */ + if (m) { + err = ext4_ext_get_access(handle, inode, path + i); + if (err) + goto cleanup; + le16_add_cpu(&path[i].p_hdr->eh_entries, -m); + err = ext4_ext_dirty(handle, inode, path + i); + if (err) + goto cleanup; + } + + i--; + } + + /* insert new index */ + err = ext4_ext_insert_index(handle, inode, path + at, + le32_to_cpu(border), newblock); + +cleanup: + if (bh) { + if (buffer_locked(bh)) + unlock_buffer(bh); + brelse(bh); + } + + if (err) { + /* free all allocated blocks in error case */ + for (i = 0; i < depth; i++) { + if (!ablocks[i]) + continue; + ext4_free_blocks(handle, inode, NULL, ablocks[i], 1, + EXT4_FREE_BLOCKS_METADATA); + } + } + kfree(ablocks); + + return err; +} + +/* + * ext4_ext_grow_indepth: + * implements tree growing procedure: + * - allocates new block + * - moves top-level data (index block or leaf) into the new block + * - initializes new top-level, creating index that points to the + * just created block + */ +static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, + unsigned int flags, + struct ext4_extent *newext) +{ + struct ext4_extent_header *neh; + struct buffer_head *bh; + ext4_fsblk_t newblock; + int err = 0; + + newblock = ext4_ext_new_meta_block(handle, inode, NULL, + newext, &err, flags); + if (newblock == 0) + return err; + + bh = sb_getblk(inode->i_sb, newblock); + if (!bh) { + err = -EIO; + ext4_std_error(inode->i_sb, err); + return err; + } + lock_buffer(bh); + + err = ext4_journal_get_create_access(handle, bh); + if (err) { + unlock_buffer(bh); + goto out; + } + + /* move top-level index/leaf into new block */ + memmove(bh->b_data, EXT4_I(inode)->i_data, + sizeof(EXT4_I(inode)->i_data)); + + /* set size of new block */ + neh = ext_block_hdr(bh); + /* old root could have indexes or leaves + * so calculate e_max right way */ + if (ext_depth(inode)) + neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0)); + else + neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0)); + neh->eh_magic = EXT4_EXT_MAGIC; + set_buffer_uptodate(bh); + unlock_buffer(bh); + + err = ext4_handle_dirty_metadata(handle, inode, bh); + if (err) + goto out; + + /* Update top-level index: num,max,pointer */ + neh = ext_inode_hdr(inode); + neh->eh_entries = cpu_to_le16(1); + ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock); + if (neh->eh_depth == 0) { + /* Root extent block becomes index block */ + neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0)); + EXT_FIRST_INDEX(neh)->ei_block = + EXT_FIRST_EXTENT(neh)->ee_block; + } + ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n", + le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max), + le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block), + ext4_idx_pblock(EXT_FIRST_INDEX(neh))); + + neh->eh_depth = cpu_to_le16(le16_to_cpu(neh->eh_depth) + 1); + ext4_mark_inode_dirty(handle, inode); +out: + brelse(bh); + + return err; +} + +/* + * ext4_ext_create_new_leaf: + * finds empty index and adds new leaf. + * if no free index is found, then it requests in-depth growing. + */ +static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode, + unsigned int flags, + struct ext4_ext_path *path, + struct ext4_extent *newext) +{ + struct ext4_ext_path *curp; + int depth, i, err = 0; + +repeat: + i = depth = ext_depth(inode); + + /* walk up to the tree and look for free index entry */ + curp = path + depth; + while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) { + i--; + curp--; + } + + /* we use already allocated block for index block, + * so subsequent data blocks should be contiguous */ + if (EXT_HAS_FREE_INDEX(curp)) { + /* if we found index with free entry, then use that + * entry: create all needed subtree and add new leaf */ + err = ext4_ext_split(handle, inode, flags, path, newext, i); + if (err) + goto out; + + /* refill path */ + ext4_ext_drop_refs(path); + path = ext4_ext_find_extent(inode, + (ext4_lblk_t)le32_to_cpu(newext->ee_block), + path); + if (IS_ERR(path)) + err = PTR_ERR(path); + } else { + /* tree is full, time to grow in depth */ + err = ext4_ext_grow_indepth(handle, inode, flags, newext); + if (err) + goto out; + + /* refill path */ + ext4_ext_drop_refs(path); + path = ext4_ext_find_extent(inode, + (ext4_lblk_t)le32_to_cpu(newext->ee_block), + path); + if (IS_ERR(path)) { + err = PTR_ERR(path); + goto out; + } + + /* + * only first (depth 0 -> 1) produces free space; + * in all other cases we have to split the grown tree + */ + depth = ext_depth(inode); + if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) { + /* now we need to split */ + goto repeat; + } + } + +out: + return err; +} + +/* + * search the closest allocated block to the left for *logical + * and returns it at @logical + it's physical address at @phys + * if *logical is the smallest allocated block, the function + * returns 0 at @phys + * return value contains 0 (success) or error code + */ +static int ext4_ext_search_left(struct inode *inode, + struct ext4_ext_path *path, + ext4_lblk_t *logical, ext4_fsblk_t *phys) +{ + struct ext4_extent_idx *ix; + struct ext4_extent *ex; + int depth, ee_len; + + if (unlikely(path == NULL)) { + EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical); + return -EIO; + } + depth = path->p_depth; + *phys = 0; + + if (depth == 0 && path->p_ext == NULL) + return 0; + + /* usually extent in the path covers blocks smaller + * then *logical, but it can be that extent is the + * first one in the file */ + + ex = path[depth].p_ext; + ee_len = ext4_ext_get_actual_len(ex); + if (*logical < le32_to_cpu(ex->ee_block)) { + if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) { + EXT4_ERROR_INODE(inode, + "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!", + *logical, le32_to_cpu(ex->ee_block)); + return -EIO; + } + while (--depth >= 0) { + ix = path[depth].p_idx; + if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) { + EXT4_ERROR_INODE(inode, + "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!", + ix != NULL ? le32_to_cpu(ix->ei_block) : 0, + EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ? + le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0, + depth); + return -EIO; + } + } + return 0; + } + + if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) { + EXT4_ERROR_INODE(inode, + "logical %d < ee_block %d + ee_len %d!", + *logical, le32_to_cpu(ex->ee_block), ee_len); + return -EIO; + } + + *logical = le32_to_cpu(ex->ee_block) + ee_len - 1; + *phys = ext4_ext_pblock(ex) + ee_len - 1; + return 0; +} + +/* + * search the closest allocated block to the right for *logical + * and returns it at @logical + it's physical address at @phys + * if *logical is the largest allocated block, the function + * returns 0 at @phys + * return value contains 0 (success) or error code + */ +static int ext4_ext_search_right(struct inode *inode, + struct ext4_ext_path *path, + ext4_lblk_t *logical, ext4_fsblk_t *phys, + struct ext4_extent **ret_ex) +{ + struct buffer_head *bh = NULL; + struct ext4_extent_header *eh; + struct ext4_extent_idx *ix; + struct ext4_extent *ex; + ext4_fsblk_t block; + int depth; /* Note, NOT eh_depth; depth from top of tree */ + int ee_len; + + if (unlikely(path == NULL)) { + EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical); + return -EIO; + } + depth = path->p_depth; + *phys = 0; + + if (depth == 0 && path->p_ext == NULL) + return 0; + + /* usually extent in the path covers blocks smaller + * then *logical, but it can be that extent is the + * first one in the file */ + + ex = path[depth].p_ext; + ee_len = ext4_ext_get_actual_len(ex); + if (*logical < le32_to_cpu(ex->ee_block)) { + if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) { + EXT4_ERROR_INODE(inode, + "first_extent(path[%d].p_hdr) != ex", + depth); + return -EIO; + } + while (--depth >= 0) { + ix = path[depth].p_idx; + if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) { + EXT4_ERROR_INODE(inode, + "ix != EXT_FIRST_INDEX *logical %d!", + *logical); + return -EIO; + } + } + goto found_extent; + } + + if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) { + EXT4_ERROR_INODE(inode, + "logical %d < ee_block %d + ee_len %d!", + *logical, le32_to_cpu(ex->ee_block), ee_len); + return -EIO; + } + + if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) { + /* next allocated block in this leaf */ + ex++; + goto found_extent; + } + + /* go up and search for index to the right */ + while (--depth >= 0) { + ix = path[depth].p_idx; + if (ix != EXT_LAST_INDEX(path[depth].p_hdr)) + goto got_index; + } + + /* we've gone up to the root and found no index to the right */ + return 0; + +got_index: + /* we've found index to the right, let's + * follow it and find the closest allocated + * block to the right */ + ix++; + block = ext4_idx_pblock(ix); + while (++depth < path->p_depth) { + bh = sb_bread(inode->i_sb, block); + if (bh == NULL) + return -EIO; + eh = ext_block_hdr(bh); + /* subtract from p_depth to get proper eh_depth */ + if (ext4_ext_check(inode, eh, path->p_depth - depth)) { + put_bh(bh); + return -EIO; + } + ix = EXT_FIRST_INDEX(eh); + block = ext4_idx_pblock(ix); + put_bh(bh); + } + + bh = sb_bread(inode->i_sb, block); + if (bh == NULL) + return -EIO; + eh = ext_block_hdr(bh); + if (ext4_ext_check(inode, eh, path->p_depth - depth)) { + put_bh(bh); + return -EIO; + } + ex = EXT_FIRST_EXTENT(eh); +found_extent: + *logical = le32_to_cpu(ex->ee_block); + *phys = ext4_ext_pblock(ex); + *ret_ex = ex; + if (bh) + put_bh(bh); + return 0; +} + +/* + * ext4_ext_next_allocated_block: + * returns allocated block in subsequent extent or EXT_MAX_BLOCKS. + * NOTE: it considers block number from index entry as + * allocated block. Thus, index entries have to be consistent + * with leaves. + */ +static ext4_lblk_t +ext4_ext_next_allocated_block(struct ext4_ext_path *path) +{ + int depth; + + BUG_ON(path == NULL); + depth = path->p_depth; + + if (depth == 0 && path->p_ext == NULL) + return EXT_MAX_BLOCKS; + + while (depth >= 0) { + if (depth == path->p_depth) { + /* leaf */ + if (path[depth].p_ext && + path[depth].p_ext != + EXT_LAST_EXTENT(path[depth].p_hdr)) + return le32_to_cpu(path[depth].p_ext[1].ee_block); + } else { + /* index */ + if (path[depth].p_idx != + EXT_LAST_INDEX(path[depth].p_hdr)) + return le32_to_cpu(path[depth].p_idx[1].ei_block); + } + depth--; + } + + return EXT_MAX_BLOCKS; +} + +/* + * ext4_ext_next_leaf_block: + * returns first allocated block from next leaf or EXT_MAX_BLOCKS + */ +static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path) +{ + int depth; + + BUG_ON(path == NULL); + depth = path->p_depth; + + /* zero-tree has no leaf blocks at all */ + if (depth == 0) + return EXT_MAX_BLOCKS; + + /* go to index block */ + depth--; + + while (depth >= 0) { + if (path[depth].p_idx != + EXT_LAST_INDEX(path[depth].p_hdr)) + return (ext4_lblk_t) + le32_to_cpu(path[depth].p_idx[1].ei_block); + depth--; + } + + return EXT_MAX_BLOCKS; +} + +/* + * ext4_ext_correct_indexes: + * if leaf gets modified and modified extent is first in the leaf, + * then we have to correct all indexes above. + * TODO: do we need to correct tree in all cases? + */ +static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path) +{ + struct ext4_extent_header *eh; + int depth = ext_depth(inode); + struct ext4_extent *ex; + __le32 border; + int k, err = 0; + + eh = path[depth].p_hdr; + ex = path[depth].p_ext; + + if (unlikely(ex == NULL || eh == NULL)) { + EXT4_ERROR_INODE(inode, + "ex %p == NULL or eh %p == NULL", ex, eh); + return -EIO; + } + + if (depth == 0) { + /* there is no tree at all */ + return 0; + } + + if (ex != EXT_FIRST_EXTENT(eh)) { + /* we correct tree if first leaf got modified only */ + return 0; + } + + /* + * TODO: we need correction if border is smaller than current one + */ + k = depth - 1; + border = path[depth].p_ext->ee_block; + err = ext4_ext_get_access(handle, inode, path + k); + if (err) + return err; + path[k].p_idx->ei_block = border; + err = ext4_ext_dirty(handle, inode, path + k); + if (err) + return err; + + while (k--) { + /* change all left-side indexes */ + if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr)) + break; + err = ext4_ext_get_access(handle, inode, path + k); + if (err) + break; + path[k].p_idx->ei_block = border; + err = ext4_ext_dirty(handle, inode, path + k); + if (err) + break; + } + + return err; +} + +int +ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1, + struct ext4_extent *ex2) +{ + unsigned short ext1_ee_len, ext2_ee_len, max_len; + + /* + * Make sure that either both extents are uninitialized, or + * both are _not_. + */ + if (ext4_ext_is_uninitialized(ex1) ^ ext4_ext_is_uninitialized(ex2)) + return 0; + + if (ext4_ext_is_uninitialized(ex1)) + max_len = EXT_UNINIT_MAX_LEN; + else + max_len = EXT_INIT_MAX_LEN; + + ext1_ee_len = ext4_ext_get_actual_len(ex1); + ext2_ee_len = ext4_ext_get_actual_len(ex2); + + if (le32_to_cpu(ex1->ee_block) + ext1_ee_len != + le32_to_cpu(ex2->ee_block)) + return 0; + + /* + * To allow future support for preallocated extents to be added + * as an RO_COMPAT feature, refuse to merge to extents if + * this can result in the top bit of ee_len being set. + */ + if (ext1_ee_len + ext2_ee_len > max_len) + return 0; +#ifdef AGGRESSIVE_TEST + if (ext1_ee_len >= 4) + return 0; +#endif + + if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2)) + return 1; + return 0; +} + +/* + * This function tries to merge the "ex" extent to the next extent in the tree. + * It always tries to merge towards right. If you want to merge towards + * left, pass "ex - 1" as argument instead of "ex". + * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns + * 1 if they got merged. + */ +static int ext4_ext_try_to_merge_right(struct inode *inode, + struct ext4_ext_path *path, + struct ext4_extent *ex) +{ + struct ext4_extent_header *eh; + unsigned int depth, len; + int merge_done = 0; + int uninitialized = 0; + + depth = ext_depth(inode); + BUG_ON(path[depth].p_hdr == NULL); + eh = path[depth].p_hdr; + + while (ex < EXT_LAST_EXTENT(eh)) { + if (!ext4_can_extents_be_merged(inode, ex, ex + 1)) + break; + /* merge with next extent! */ + if (ext4_ext_is_uninitialized(ex)) + uninitialized = 1; + ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) + + ext4_ext_get_actual_len(ex + 1)); + if (uninitialized) + ext4_ext_mark_uninitialized(ex); + + if (ex + 1 < EXT_LAST_EXTENT(eh)) { + len = (EXT_LAST_EXTENT(eh) - ex - 1) + * sizeof(struct ext4_extent); + memmove(ex + 1, ex + 2, len); + } + le16_add_cpu(&eh->eh_entries, -1); + merge_done = 1; + WARN_ON(eh->eh_entries == 0); + if (!eh->eh_entries) + EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!"); + } + + return merge_done; +} + +/* + * This function tries to merge the @ex extent to neighbours in the tree. + * return 1 if merge left else 0. + */ +static int ext4_ext_try_to_merge(struct inode *inode, + struct ext4_ext_path *path, + struct ext4_extent *ex) { + struct ext4_extent_header *eh; + unsigned int depth; + int merge_done = 0; + int ret = 0; + + depth = ext_depth(inode); + BUG_ON(path[depth].p_hdr == NULL); + eh = path[depth].p_hdr; + + if (ex > EXT_FIRST_EXTENT(eh)) + merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1); + + if (!merge_done) + ret = ext4_ext_try_to_merge_right(inode, path, ex); + + return ret; +} + +/* + * check if a portion of the "newext" extent overlaps with an + * existing extent. + * + * If there is an overlap discovered, it updates the length of the newext + * such that there will be no overlap, and then returns 1. + * If there is no overlap found, it returns 0. + */ +static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi, + struct inode *inode, + struct ext4_extent *newext, + struct ext4_ext_path *path) +{ + ext4_lblk_t b1, b2; + unsigned int depth, len1; + unsigned int ret = 0; + + b1 = le32_to_cpu(newext->ee_block); + len1 = ext4_ext_get_actual_len(newext); + depth = ext_depth(inode); + if (!path[depth].p_ext) + goto out; + b2 = le32_to_cpu(path[depth].p_ext->ee_block); + b2 &= ~(sbi->s_cluster_ratio - 1); + + /* + * get the next allocated block if the extent in the path + * is before the requested block(s) + */ + if (b2 < b1) { + b2 = ext4_ext_next_allocated_block(path); + if (b2 == EXT_MAX_BLOCKS) + goto out; + b2 &= ~(sbi->s_cluster_ratio - 1); + } + + /* check for wrap through zero on extent logical start block*/ + if (b1 + len1 < b1) { + len1 = EXT_MAX_BLOCKS - b1; + newext->ee_len = cpu_to_le16(len1); + ret = 1; + } + + /* check for overlap */ + if (b1 + len1 > b2) { + newext->ee_len = cpu_to_le16(b2 - b1); + ret = 1; + } +out: + return ret; +} + +/* + * ext4_ext_insert_extent: + * tries to merge requsted extent into the existing extent or + * inserts requested extent as new one into the tree, + * creating new leaf in the no-space case. + */ +int ext4_ext_insert_extent(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path, + struct ext4_extent *newext, int flag) +{ + struct ext4_extent_header *eh; + struct ext4_extent *ex, *fex; + struct ext4_extent *nearex; /* nearest extent */ + struct ext4_ext_path *npath = NULL; + int depth, len, err; + ext4_lblk_t next; + unsigned uninitialized = 0; + int flags = 0; + + if (unlikely(ext4_ext_get_actual_len(newext) == 0)) { + EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0"); + return -EIO; + } + depth = ext_depth(inode); + ex = path[depth].p_ext; + if (unlikely(path[depth].p_hdr == NULL)) { + EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); + return -EIO; + } + + /* try to insert block into found extent and return */ + if (ex && !(flag & EXT4_GET_BLOCKS_PRE_IO) + && ext4_can_extents_be_merged(inode, ex, newext)) { + ext_debug("append [%d]%d block to %u:[%d]%d (from %llu)\n", + ext4_ext_is_uninitialized(newext), + ext4_ext_get_actual_len(newext), + le32_to_cpu(ex->ee_block), + ext4_ext_is_uninitialized(ex), + ext4_ext_get_actual_len(ex), + ext4_ext_pblock(ex)); + err = ext4_ext_get_access(handle, inode, path + depth); + if (err) + return err; + + /* + * ext4_can_extents_be_merged should have checked that either + * both extents are uninitialized, or both aren't. Thus we + * need to check only one of them here. + */ + if (ext4_ext_is_uninitialized(ex)) + uninitialized = 1; + ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) + + ext4_ext_get_actual_len(newext)); + if (uninitialized) + ext4_ext_mark_uninitialized(ex); + eh = path[depth].p_hdr; + nearex = ex; + goto merge; + } + + depth = ext_depth(inode); + eh = path[depth].p_hdr; + if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) + goto has_space; + + /* probably next leaf has space for us? */ + fex = EXT_LAST_EXTENT(eh); + next = EXT_MAX_BLOCKS; + if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block)) + next = ext4_ext_next_leaf_block(path); + if (next != EXT_MAX_BLOCKS) { + ext_debug("next leaf block - %u\n", next); + BUG_ON(npath != NULL); + npath = ext4_ext_find_extent(inode, next, NULL); + if (IS_ERR(npath)) + return PTR_ERR(npath); + BUG_ON(npath->p_depth != path->p_depth); + eh = npath[depth].p_hdr; + if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) { + ext_debug("next leaf isn't full(%d)\n", + le16_to_cpu(eh->eh_entries)); + path = npath; + goto has_space; + } + ext_debug("next leaf has no free space(%d,%d)\n", + le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); + } + + /* + * There is no free space in the found leaf. + * We're gonna add a new leaf in the tree. + */ + if (flag & EXT4_GET_BLOCKS_PUNCH_OUT_EXT) + flags = EXT4_MB_USE_ROOT_BLOCKS; + err = ext4_ext_create_new_leaf(handle, inode, flags, path, newext); + if (err) + goto cleanup; + depth = ext_depth(inode); + eh = path[depth].p_hdr; + +has_space: + nearex = path[depth].p_ext; + + err = ext4_ext_get_access(handle, inode, path + depth); + if (err) + goto cleanup; + + if (!nearex) { + /* there is no extent in this leaf, create first one */ + ext_debug("first extent in the leaf: %u:%llu:[%d]%d\n", + le32_to_cpu(newext->ee_block), + ext4_ext_pblock(newext), + ext4_ext_is_uninitialized(newext), + ext4_ext_get_actual_len(newext)); + nearex = EXT_FIRST_EXTENT(eh); + } else { + if (le32_to_cpu(newext->ee_block) + > le32_to_cpu(nearex->ee_block)) { + /* Insert after */ + ext_debug("insert %u:%llu:[%d]%d before: " + "nearest %p\n", + le32_to_cpu(newext->ee_block), + ext4_ext_pblock(newext), + ext4_ext_is_uninitialized(newext), + ext4_ext_get_actual_len(newext), + nearex); + nearex++; + } else { + /* Insert before */ + BUG_ON(newext->ee_block == nearex->ee_block); + ext_debug("insert %u:%llu:[%d]%d after: " + "nearest %p\n", + le32_to_cpu(newext->ee_block), + ext4_ext_pblock(newext), + ext4_ext_is_uninitialized(newext), + ext4_ext_get_actual_len(newext), + nearex); + } + len = EXT_LAST_EXTENT(eh) - nearex + 1; + if (len > 0) { + ext_debug("insert %u:%llu:[%d]%d: " + "move %d extents from 0x%p to 0x%p\n", + le32_to_cpu(newext->ee_block), + ext4_ext_pblock(newext), + ext4_ext_is_uninitialized(newext), + ext4_ext_get_actual_len(newext), + len, nearex, nearex + 1); + memmove(nearex + 1, nearex, + len * sizeof(struct ext4_extent)); + } + } + + le16_add_cpu(&eh->eh_entries, 1); + path[depth].p_ext = nearex; + nearex->ee_block = newext->ee_block; + ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext)); + nearex->ee_len = newext->ee_len; + +merge: + /* try to merge extents to the right */ + if (!(flag & EXT4_GET_BLOCKS_PRE_IO)) + ext4_ext_try_to_merge(inode, path, nearex); + + /* try to merge extents to the left */ + + /* time to correct all indexes above */ + err = ext4_ext_correct_indexes(handle, inode, path); + if (err) + goto cleanup; + + err = ext4_ext_dirty(handle, inode, path + depth); + +cleanup: + if (npath) { + ext4_ext_drop_refs(npath); + kfree(npath); + } + ext4_ext_invalidate_cache(inode); + return err; +} + +static int ext4_ext_walk_space(struct inode *inode, ext4_lblk_t block, + ext4_lblk_t num, ext_prepare_callback func, + void *cbdata) +{ + struct ext4_ext_path *path = NULL; + struct ext4_ext_cache cbex; + struct ext4_extent *ex; + ext4_lblk_t next, start = 0, end = 0; + ext4_lblk_t last = block + num; + int depth, exists, err = 0; + + BUG_ON(func == NULL); + BUG_ON(inode == NULL); + + while (block < last && block != EXT_MAX_BLOCKS) { + num = last - block; + /* find extent for this block */ + down_read(&EXT4_I(inode)->i_data_sem); + path = ext4_ext_find_extent(inode, block, path); + up_read(&EXT4_I(inode)->i_data_sem); + if (IS_ERR(path)) { + err = PTR_ERR(path); + path = NULL; + break; + } + + depth = ext_depth(inode); + if (unlikely(path[depth].p_hdr == NULL)) { + EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); + err = -EIO; + break; + } + ex = path[depth].p_ext; + next = ext4_ext_next_allocated_block(path); + + exists = 0; + if (!ex) { + /* there is no extent yet, so try to allocate + * all requested space */ + start = block; + end = block + num; + } else if (le32_to_cpu(ex->ee_block) > block) { + /* need to allocate space before found extent */ + start = block; + end = le32_to_cpu(ex->ee_block); + if (block + num < end) + end = block + num; + } else if (block >= le32_to_cpu(ex->ee_block) + + ext4_ext_get_actual_len(ex)) { + /* need to allocate space after found extent */ + start = block; + end = block + num; + if (end >= next) + end = next; + } else if (block >= le32_to_cpu(ex->ee_block)) { + /* + * some part of requested space is covered + * by found extent + */ + start = block; + end = le32_to_cpu(ex->ee_block) + + ext4_ext_get_actual_len(ex); + if (block + num < end) + end = block + num; + exists = 1; + } else { + BUG(); + } + BUG_ON(end <= start); + + if (!exists) { + cbex.ec_block = start; + cbex.ec_len = end - start; + cbex.ec_start = 0; + } else { + cbex.ec_block = le32_to_cpu(ex->ee_block); + cbex.ec_len = ext4_ext_get_actual_len(ex); + cbex.ec_start = ext4_ext_pblock(ex); + } + + if (unlikely(cbex.ec_len == 0)) { + EXT4_ERROR_INODE(inode, "cbex.ec_len == 0"); + err = -EIO; + break; + } + err = func(inode, next, &cbex, ex, cbdata); + ext4_ext_drop_refs(path); + + if (err < 0) + break; + + if (err == EXT_REPEAT) + continue; + else if (err == EXT_BREAK) { + err = 0; + break; + } + + if (ext_depth(inode) != depth) { + /* depth was changed. we have to realloc path */ + kfree(path); + path = NULL; + } + + block = cbex.ec_block + cbex.ec_len; + } + + if (path) { + ext4_ext_drop_refs(path); + kfree(path); + } + + return err; +} + +static void +ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block, + __u32 len, ext4_fsblk_t start) +{ + struct ext4_ext_cache *cex; + BUG_ON(len == 0); + spin_lock(&EXT4_I(inode)->i_block_reservation_lock); + trace_ext4_ext_put_in_cache(inode, block, len, start); + cex = &EXT4_I(inode)->i_cached_extent; + cex->ec_block = block; + cex->ec_len = len; + cex->ec_start = start; + spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); +} + +/* + * ext4_ext_put_gap_in_cache: + * calculate boundaries of the gap that the requested block fits into + * and cache this gap + */ +static void +ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path, + ext4_lblk_t block) +{ + int depth = ext_depth(inode); + unsigned long len; + ext4_lblk_t lblock; + struct ext4_extent *ex; + + ex = path[depth].p_ext; + if (ex == NULL) { + /* there is no extent yet, so gap is [0;-] */ + lblock = 0; + len = EXT_MAX_BLOCKS; + ext_debug("cache gap(whole file):"); + } else if (block < le32_to_cpu(ex->ee_block)) { + lblock = block; + len = le32_to_cpu(ex->ee_block) - block; + ext_debug("cache gap(before): %u [%u:%u]", + block, + le32_to_cpu(ex->ee_block), + ext4_ext_get_actual_len(ex)); + } else if (block >= le32_to_cpu(ex->ee_block) + + ext4_ext_get_actual_len(ex)) { + ext4_lblk_t next; + lblock = le32_to_cpu(ex->ee_block) + + ext4_ext_get_actual_len(ex); + + next = ext4_ext_next_allocated_block(path); + ext_debug("cache gap(after): [%u:%u] %u", + le32_to_cpu(ex->ee_block), + ext4_ext_get_actual_len(ex), + block); + BUG_ON(next == lblock); + len = next - lblock; + } else { + lblock = len = 0; + BUG(); + } + + ext_debug(" -> %u:%lu\n", lblock, len); + ext4_ext_put_in_cache(inode, lblock, len, 0); +} + +/* + * ext4_ext_check_cache() + * Checks to see if the given block is in the cache. + * If it is, the cached extent is stored in the given + * cache extent pointer. If the cached extent is a hole, + * this routine should be used instead of + * ext4_ext_in_cache if the calling function needs to + * know the size of the hole. + * + * @inode: The files inode + * @block: The block to look for in the cache + * @ex: Pointer where the cached extent will be stored + * if it contains block + * + * Return 0 if cache is invalid; 1 if the cache is valid + */ +static int ext4_ext_check_cache(struct inode *inode, ext4_lblk_t block, + struct ext4_ext_cache *ex){ + struct ext4_ext_cache *cex; + struct ext4_sb_info *sbi; + int ret = 0; + + /* + * We borrow i_block_reservation_lock to protect i_cached_extent + */ + spin_lock(&EXT4_I(inode)->i_block_reservation_lock); + cex = &EXT4_I(inode)->i_cached_extent; + sbi = EXT4_SB(inode->i_sb); + + /* has cache valid data? */ + if (cex->ec_len == 0) + goto errout; + + if (in_range(block, cex->ec_block, cex->ec_len)) { + memcpy(ex, cex, sizeof(struct ext4_ext_cache)); + ext_debug("%u cached by %u:%u:%llu\n", + block, + cex->ec_block, cex->ec_len, cex->ec_start); + ret = 1; + } +errout: + trace_ext4_ext_in_cache(inode, block, ret); + spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); + return ret; +} + +/* + * ext4_ext_in_cache() + * Checks to see if the given block is in the cache. + * If it is, the cached extent is stored in the given + * extent pointer. + * + * @inode: The files inode + * @block: The block to look for in the cache + * @ex: Pointer where the cached extent will be stored + * if it contains block + * + * Return 0 if cache is invalid; 1 if the cache is valid + */ +static int +ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block, + struct ext4_extent *ex) +{ + struct ext4_ext_cache cex; + int ret = 0; + + if (ext4_ext_check_cache(inode, block, &cex)) { + ex->ee_block = cpu_to_le32(cex.ec_block); + ext4_ext_store_pblock(ex, cex.ec_start); + ex->ee_len = cpu_to_le16(cex.ec_len); + ret = 1; + } + + return ret; +} + + +/* + * ext4_ext_rm_idx: + * removes index from the index block. + */ +static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path) +{ + int err; + ext4_fsblk_t leaf; + + /* free index block */ + path--; + leaf = ext4_idx_pblock(path->p_idx); + if (unlikely(path->p_hdr->eh_entries == 0)) { + EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0"); + return -EIO; + } + err = ext4_ext_get_access(handle, inode, path); + if (err) + return err; + + if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) { + int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx; + len *= sizeof(struct ext4_extent_idx); + memmove(path->p_idx, path->p_idx + 1, len); + } + + le16_add_cpu(&path->p_hdr->eh_entries, -1); + err = ext4_ext_dirty(handle, inode, path); + if (err) + return err; + ext_debug("index is empty, remove it, free block %llu\n", leaf); + trace_ext4_ext_rm_idx(inode, leaf); + + ext4_free_blocks(handle, inode, NULL, leaf, 1, + EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET); + return err; +} + +/* + * ext4_ext_calc_credits_for_single_extent: + * This routine returns max. credits that needed to insert an extent + * to the extent tree. + * When pass the actual path, the caller should calculate credits + * under i_data_sem. + */ +int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks, + struct ext4_ext_path *path) +{ + if (path) { + int depth = ext_depth(inode); + int ret = 0; + + /* probably there is space in leaf? */ + if (le16_to_cpu(path[depth].p_hdr->eh_entries) + < le16_to_cpu(path[depth].p_hdr->eh_max)) { + + /* + * There are some space in the leaf tree, no + * need to account for leaf block credit + * + * bitmaps and block group descriptor blocks + * and other metadata blocks still need to be + * accounted. + */ + /* 1 bitmap, 1 block group descriptor */ + ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb); + return ret; + } + } + + return ext4_chunk_trans_blocks(inode, nrblocks); +} + +/* + * How many index/leaf blocks need to change/allocate to modify nrblocks? + * + * if nrblocks are fit in a single extent (chunk flag is 1), then + * in the worse case, each tree level index/leaf need to be changed + * if the tree split due to insert a new extent, then the old tree + * index/leaf need to be updated too + * + * If the nrblocks are discontiguous, they could cause + * the whole tree split more than once, but this is really rare. + */ +int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk) +{ + int index; + int depth = ext_depth(inode); + + if (chunk) + index = depth * 2; + else + index = depth * 3; + + return index; +} + +static int ext4_remove_blocks(handle_t *handle, struct inode *inode, + struct ext4_extent *ex, + ext4_fsblk_t *partial_cluster, + ext4_lblk_t from, ext4_lblk_t to) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + unsigned short ee_len = ext4_ext_get_actual_len(ex); + ext4_fsblk_t pblk; + int flags = EXT4_FREE_BLOCKS_FORGET; + + if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) + flags |= EXT4_FREE_BLOCKS_METADATA; + /* + * For bigalloc file systems, we never free a partial cluster + * at the beginning of the extent. Instead, we make a note + * that we tried freeing the cluster, and check to see if we + * need to free it on a subsequent call to ext4_remove_blocks, + * or at the end of the ext4_truncate() operation. + */ + flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER; + + trace_ext4_remove_blocks(inode, ex, from, to, *partial_cluster); + /* + * If we have a partial cluster, and it's different from the + * cluster of the last block, we need to explicitly free the + * partial cluster here. + */ + pblk = ext4_ext_pblock(ex) + ee_len - 1; + if (*partial_cluster && (EXT4_B2C(sbi, pblk) != *partial_cluster)) { + ext4_free_blocks(handle, inode, NULL, + EXT4_C2B(sbi, *partial_cluster), + sbi->s_cluster_ratio, flags); + *partial_cluster = 0; + } + +#ifdef EXTENTS_STATS + { + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + spin_lock(&sbi->s_ext_stats_lock); + sbi->s_ext_blocks += ee_len; + sbi->s_ext_extents++; + if (ee_len < sbi->s_ext_min) + sbi->s_ext_min = ee_len; + if (ee_len > sbi->s_ext_max) + sbi->s_ext_max = ee_len; + if (ext_depth(inode) > sbi->s_depth_max) + sbi->s_depth_max = ext_depth(inode); + spin_unlock(&sbi->s_ext_stats_lock); + } +#endif + if (from >= le32_to_cpu(ex->ee_block) + && to == le32_to_cpu(ex->ee_block) + ee_len - 1) { + /* tail removal */ + ext4_lblk_t num; + + num = le32_to_cpu(ex->ee_block) + ee_len - from; + pblk = ext4_ext_pblock(ex) + ee_len - num; + ext_debug("free last %u blocks starting %llu\n", num, pblk); + ext4_free_blocks(handle, inode, NULL, pblk, num, flags); + /* + * If the block range to be freed didn't start at the + * beginning of a cluster, and we removed the entire + * extent, save the partial cluster here, since we + * might need to delete if we determine that the + * truncate operation has removed all of the blocks in + * the cluster. + */ + if (pblk & (sbi->s_cluster_ratio - 1) && + (ee_len == num)) + *partial_cluster = EXT4_B2C(sbi, pblk); + else + *partial_cluster = 0; + } else if (from == le32_to_cpu(ex->ee_block) + && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) { + /* head removal */ + ext4_lblk_t num; + ext4_fsblk_t start; + + num = to - from; + start = ext4_ext_pblock(ex); + + ext_debug("free first %u blocks starting %llu\n", num, start); + ext4_free_blocks(handle, inode, NULL, start, num, flags); + + } else { + printk(KERN_INFO "strange request: removal(2) " + "%u-%u from %u:%u\n", + from, to, le32_to_cpu(ex->ee_block), ee_len); + } + return 0; +} + + +/* + * ext4_ext_rm_leaf() Removes the extents associated with the + * blocks appearing between "start" and "end", and splits the extents + * if "start" and "end" appear in the same extent + * + * @handle: The journal handle + * @inode: The files inode + * @path: The path to the leaf + * @start: The first block to remove + * @end: The last block to remove + */ +static int +ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path, ext4_fsblk_t *partial_cluster, + ext4_lblk_t start, ext4_lblk_t end) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + int err = 0, correct_index = 0; + int depth = ext_depth(inode), credits; + struct ext4_extent_header *eh; + ext4_lblk_t a, b; + unsigned num; + ext4_lblk_t ex_ee_block; + unsigned short ex_ee_len; + unsigned uninitialized = 0; + struct ext4_extent *ex; + + /* the header must be checked already in ext4_ext_remove_space() */ + ext_debug("truncate since %u in leaf to %u\n", start, end); + if (!path[depth].p_hdr) + path[depth].p_hdr = ext_block_hdr(path[depth].p_bh); + eh = path[depth].p_hdr; + if (unlikely(path[depth].p_hdr == NULL)) { + EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); + return -EIO; + } + /* find where to start removing */ + ex = EXT_LAST_EXTENT(eh); + + ex_ee_block = le32_to_cpu(ex->ee_block); + ex_ee_len = ext4_ext_get_actual_len(ex); + + trace_ext4_ext_rm_leaf(inode, start, ex, *partial_cluster); + + while (ex >= EXT_FIRST_EXTENT(eh) && + ex_ee_block + ex_ee_len > start) { + + if (ext4_ext_is_uninitialized(ex)) + uninitialized = 1; + else + uninitialized = 0; + + ext_debug("remove ext %u:[%d]%d\n", ex_ee_block, + uninitialized, ex_ee_len); + path[depth].p_ext = ex; + + a = ex_ee_block > start ? ex_ee_block : start; + b = ex_ee_block+ex_ee_len - 1 < end ? + ex_ee_block+ex_ee_len - 1 : end; + + ext_debug(" border %u:%u\n", a, b); + + /* If this extent is beyond the end of the hole, skip it */ + if (end < ex_ee_block) { + ex--; + ex_ee_block = le32_to_cpu(ex->ee_block); + ex_ee_len = ext4_ext_get_actual_len(ex); + continue; + } else if (b != ex_ee_block + ex_ee_len - 1) { + EXT4_ERROR_INODE(inode, + "can not handle truncate %u:%u " + "on extent %u:%u", + start, end, ex_ee_block, + ex_ee_block + ex_ee_len - 1); + err = -EIO; + goto out; + } else if (a != ex_ee_block) { + /* remove tail of the extent */ + num = a - ex_ee_block; + } else { + /* remove whole extent: excellent! */ + num = 0; + } + /* + * 3 for leaf, sb, and inode plus 2 (bmap and group + * descriptor) for each block group; assume two block + * groups plus ex_ee_len/blocks_per_block_group for + * the worst case + */ + credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb)); + if (ex == EXT_FIRST_EXTENT(eh)) { + correct_index = 1; + credits += (ext_depth(inode)) + 1; + } + credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb); + + err = ext4_ext_truncate_extend_restart(handle, inode, credits); + if (err) + goto out; + + err = ext4_ext_get_access(handle, inode, path + depth); + if (err) + goto out; + + err = ext4_remove_blocks(handle, inode, ex, partial_cluster, + a, b); + if (err) + goto out; + + if (num == 0) + /* this extent is removed; mark slot entirely unused */ + ext4_ext_store_pblock(ex, 0); + + ex->ee_len = cpu_to_le16(num); + /* + * Do not mark uninitialized if all the blocks in the + * extent have been removed. + */ + if (uninitialized && num) + ext4_ext_mark_uninitialized(ex); + /* + * If the extent was completely released, + * we need to remove it from the leaf + */ + if (num == 0) { + if (end != EXT_MAX_BLOCKS - 1) { + /* + * For hole punching, we need to scoot all the + * extents up when an extent is removed so that + * we dont have blank extents in the middle + */ + memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) * + sizeof(struct ext4_extent)); + + /* Now get rid of the one at the end */ + memset(EXT_LAST_EXTENT(eh), 0, + sizeof(struct ext4_extent)); + } + le16_add_cpu(&eh->eh_entries, -1); + } else + *partial_cluster = 0; + + err = ext4_ext_dirty(handle, inode, path + depth); + if (err) + goto out; + + ext_debug("new extent: %u:%u:%llu\n", ex_ee_block, num, + ext4_ext_pblock(ex)); + ex--; + ex_ee_block = le32_to_cpu(ex->ee_block); + ex_ee_len = ext4_ext_get_actual_len(ex); + } + + if (correct_index && eh->eh_entries) + err = ext4_ext_correct_indexes(handle, inode, path); + + /* + * If there is still a entry in the leaf node, check to see if + * it references the partial cluster. This is the only place + * where it could; if it doesn't, we can free the cluster. + */ + if (*partial_cluster && ex >= EXT_FIRST_EXTENT(eh) && + (EXT4_B2C(sbi, ext4_ext_pblock(ex) + ex_ee_len - 1) != + *partial_cluster)) { + int flags = EXT4_FREE_BLOCKS_FORGET; + + if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) + flags |= EXT4_FREE_BLOCKS_METADATA; + + ext4_free_blocks(handle, inode, NULL, + EXT4_C2B(sbi, *partial_cluster), + sbi->s_cluster_ratio, flags); + *partial_cluster = 0; + } + + /* if this leaf is free, then we should + * remove it from index block above */ + if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL) + err = ext4_ext_rm_idx(handle, inode, path + depth); + +out: + return err; +} + +/* + * ext4_ext_more_to_rm: + * returns 1 if current index has to be freed (even partial) + */ +static int +ext4_ext_more_to_rm(struct ext4_ext_path *path) +{ + BUG_ON(path->p_idx == NULL); + + if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr)) + return 0; + + /* + * if truncate on deeper level happened, it wasn't partial, + * so we have to consider current index for truncation + */ + if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block) + return 0; + return 1; +} + +static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start, + ext4_lblk_t end) +{ + struct super_block *sb = inode->i_sb; + int depth = ext_depth(inode); + struct ext4_ext_path *path; + ext4_fsblk_t partial_cluster = 0; + handle_t *handle; + int i, err; + + ext_debug("truncate since %u to %u\n", start, end); + + /* probably first extent we're gonna free will be last in block */ + handle = ext4_journal_start(inode, depth + 1); + if (IS_ERR(handle)) + return PTR_ERR(handle); + +again: + ext4_ext_invalidate_cache(inode); + + trace_ext4_ext_remove_space(inode, start, depth); + + /* + * Check if we are removing extents inside the extent tree. If that + * is the case, we are going to punch a hole inside the extent tree + * so we have to check whether we need to split the extent covering + * the last block to remove so we can easily remove the part of it + * in ext4_ext_rm_leaf(). + */ + if (end < EXT_MAX_BLOCKS - 1) { + struct ext4_extent *ex; + ext4_lblk_t ee_block; + + /* find extent for this block */ + path = ext4_ext_find_extent(inode, end, NULL); + if (IS_ERR(path)) { + ext4_journal_stop(handle); + return PTR_ERR(path); + } + depth = ext_depth(inode); + ex = path[depth].p_ext; + if (!ex) + goto cont; + + ee_block = le32_to_cpu(ex->ee_block); + + /* + * See if the last block is inside the extent, if so split + * the extent at 'end' block so we can easily remove the + * tail of the first part of the split extent in + * ext4_ext_rm_leaf(). + */ + if (end >= ee_block && + end < ee_block + ext4_ext_get_actual_len(ex) - 1) { + int split_flag = 0; + + if (ext4_ext_is_uninitialized(ex)) + split_flag = EXT4_EXT_MARK_UNINIT1 | + EXT4_EXT_MARK_UNINIT2; + + /* + * Split the extent in two so that 'end' is the last + * block in the first new extent + */ + err = ext4_split_extent_at(handle, inode, path, + end + 1, split_flag, + EXT4_GET_BLOCKS_PRE_IO | + EXT4_GET_BLOCKS_PUNCH_OUT_EXT); + + if (err < 0) + goto out; + } + ext4_ext_drop_refs(path); + kfree(path); + } +cont: + + /* + * We start scanning from right side, freeing all the blocks + * after i_size and walking into the tree depth-wise. + */ + depth = ext_depth(inode); + path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_NOFS); + if (path == NULL) { + ext4_journal_stop(handle); + return -ENOMEM; + } + path[0].p_depth = depth; + path[0].p_hdr = ext_inode_hdr(inode); + + if (ext4_ext_check(inode, path[0].p_hdr, depth)) { + err = -EIO; + goto out; + } + i = err = 0; + + while (i >= 0 && err == 0) { + if (i == depth) { + /* this is leaf block */ + err = ext4_ext_rm_leaf(handle, inode, path, + &partial_cluster, start, + end); + /* root level has p_bh == NULL, brelse() eats this */ + brelse(path[i].p_bh); + path[i].p_bh = NULL; + i--; + continue; + } + + /* this is index block */ + if (!path[i].p_hdr) { + ext_debug("initialize header\n"); + path[i].p_hdr = ext_block_hdr(path[i].p_bh); + } + + if (!path[i].p_idx) { + /* this level hasn't been touched yet */ + path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr); + path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1; + ext_debug("init index ptr: hdr 0x%p, num %d\n", + path[i].p_hdr, + le16_to_cpu(path[i].p_hdr->eh_entries)); + } else { + /* we were already here, see at next index */ + path[i].p_idx--; + } + + ext_debug("level %d - index, first 0x%p, cur 0x%p\n", + i, EXT_FIRST_INDEX(path[i].p_hdr), + path[i].p_idx); + if (ext4_ext_more_to_rm(path + i)) { + struct buffer_head *bh; + /* go to the next level */ + ext_debug("move to level %d (block %llu)\n", + i + 1, ext4_idx_pblock(path[i].p_idx)); + memset(path + i + 1, 0, sizeof(*path)); + bh = sb_bread(sb, ext4_idx_pblock(path[i].p_idx)); + if (!bh) { + /* should we reset i_size? */ + err = -EIO; + break; + } + if (WARN_ON(i + 1 > depth)) { + err = -EIO; + break; + } + if (ext4_ext_check(inode, ext_block_hdr(bh), + depth - i - 1)) { + err = -EIO; + break; + } + path[i + 1].p_bh = bh; + + /* save actual number of indexes since this + * number is changed at the next iteration */ + path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries); + i++; + } else { + /* we finished processing this index, go up */ + if (path[i].p_hdr->eh_entries == 0 && i > 0) { + /* index is empty, remove it; + * handle must be already prepared by the + * truncatei_leaf() */ + err = ext4_ext_rm_idx(handle, inode, path + i); + } + /* root level has p_bh == NULL, brelse() eats this */ + brelse(path[i].p_bh); + path[i].p_bh = NULL; + i--; + ext_debug("return to level %d\n", i); + } + } + + trace_ext4_ext_remove_space_done(inode, start, depth, partial_cluster, + path->p_hdr->eh_entries); + + /* If we still have something in the partial cluster and we have removed + * even the first extent, then we should free the blocks in the partial + * cluster as well. */ + if (partial_cluster && path->p_hdr->eh_entries == 0) { + int flags = EXT4_FREE_BLOCKS_FORGET; + + if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) + flags |= EXT4_FREE_BLOCKS_METADATA; + + ext4_free_blocks(handle, inode, NULL, + EXT4_C2B(EXT4_SB(sb), partial_cluster), + EXT4_SB(sb)->s_cluster_ratio, flags); + partial_cluster = 0; + } + + /* TODO: flexible tree reduction should be here */ + if (path->p_hdr->eh_entries == 0) { + /* + * truncate to zero freed all the tree, + * so we need to correct eh_depth + */ + err = ext4_ext_get_access(handle, inode, path); + if (err == 0) { + ext_inode_hdr(inode)->eh_depth = 0; + ext_inode_hdr(inode)->eh_max = + cpu_to_le16(ext4_ext_space_root(inode, 0)); + err = ext4_ext_dirty(handle, inode, path); + } + } +out: + ext4_ext_drop_refs(path); + kfree(path); + if (err == -EAGAIN) + goto again; + ext4_journal_stop(handle); + + return err; +} + +/* + * called at mount time + */ +void ext4_ext_init(struct super_block *sb) +{ + /* + * possible initialization would be here + */ + + if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) { +#if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS) + printk(KERN_INFO "EXT4-fs: file extents enabled" +#ifdef AGGRESSIVE_TEST + ", aggressive tests" +#endif +#ifdef CHECK_BINSEARCH + ", check binsearch" +#endif +#ifdef EXTENTS_STATS + ", stats" +#endif + "\n"); +#endif +#ifdef EXTENTS_STATS + spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock); + EXT4_SB(sb)->s_ext_min = 1 << 30; + EXT4_SB(sb)->s_ext_max = 0; +#endif + } +} + +/* + * called at umount time + */ +void ext4_ext_release(struct super_block *sb) +{ + if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) + return; + +#ifdef EXTENTS_STATS + if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) { + struct ext4_sb_info *sbi = EXT4_SB(sb); + printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n", + sbi->s_ext_blocks, sbi->s_ext_extents, + sbi->s_ext_blocks / sbi->s_ext_extents); + printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n", + sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max); + } +#endif +} + +/* FIXME!! we need to try to merge to left or right after zero-out */ +static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex) +{ + ext4_fsblk_t ee_pblock; + unsigned int ee_len; + int ret; + + ee_len = ext4_ext_get_actual_len(ex); + ee_pblock = ext4_ext_pblock(ex); + + ret = sb_issue_zeroout(inode->i_sb, ee_pblock, ee_len, GFP_NOFS); + if (ret > 0) + ret = 0; + + return ret; +} + +/* + * ext4_split_extent_at() splits an extent at given block. + * + * @handle: the journal handle + * @inode: the file inode + * @path: the path to the extent + * @split: the logical block where the extent is splitted. + * @split_flags: indicates if the extent could be zeroout if split fails, and + * the states(init or uninit) of new extents. + * @flags: flags used to insert new extent to extent tree. + * + * + * Splits extent [a, b] into two extents [a, @split) and [@split, b], states + * of which are deterimined by split_flag. + * + * There are two cases: + * a> the extent are splitted into two extent. + * b> split is not needed, and just mark the extent. + * + * return 0 on success. + */ +static int ext4_split_extent_at(handle_t *handle, + struct inode *inode, + struct ext4_ext_path *path, + ext4_lblk_t split, + int split_flag, + int flags) +{ + ext4_fsblk_t newblock; + ext4_lblk_t ee_block; + struct ext4_extent *ex, newex, orig_ex; + struct ext4_extent *ex2 = NULL; + unsigned int ee_len, depth; + int err = 0; + + ext_debug("ext4_split_extents_at: inode %lu, logical" + "block %llu\n", inode->i_ino, (unsigned long long)split); + + ext4_ext_show_leaf(inode, path); + + depth = ext_depth(inode); + ex = path[depth].p_ext; + ee_block = le32_to_cpu(ex->ee_block); + ee_len = ext4_ext_get_actual_len(ex); + newblock = split - ee_block + ext4_ext_pblock(ex); + + BUG_ON(split < ee_block || split >= (ee_block + ee_len)); + + err = ext4_ext_get_access(handle, inode, path + depth); + if (err) + goto out; + + if (split == ee_block) { + /* + * case b: block @split is the block that the extent begins with + * then we just change the state of the extent, and splitting + * is not needed. + */ + if (split_flag & EXT4_EXT_MARK_UNINIT2) + ext4_ext_mark_uninitialized(ex); + else + ext4_ext_mark_initialized(ex); + + if (!(flags & EXT4_GET_BLOCKS_PRE_IO)) + ext4_ext_try_to_merge(inode, path, ex); + + err = ext4_ext_dirty(handle, inode, path + depth); + goto out; + } + + /* case a */ + memcpy(&orig_ex, ex, sizeof(orig_ex)); + ex->ee_len = cpu_to_le16(split - ee_block); + if (split_flag & EXT4_EXT_MARK_UNINIT1) + ext4_ext_mark_uninitialized(ex); + + /* + * path may lead to new leaf, not to original leaf any more + * after ext4_ext_insert_extent() returns, + */ + err = ext4_ext_dirty(handle, inode, path + depth); + if (err) + goto fix_extent_len; + + ex2 = &newex; + ex2->ee_block = cpu_to_le32(split); + ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block)); + ext4_ext_store_pblock(ex2, newblock); + if (split_flag & EXT4_EXT_MARK_UNINIT2) + ext4_ext_mark_uninitialized(ex2); + + err = ext4_ext_insert_extent(handle, inode, path, &newex, flags); + if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) { + err = ext4_ext_zeroout(inode, &orig_ex); + if (err) + goto fix_extent_len; + /* update the extent length and mark as initialized */ + ex->ee_len = cpu_to_le16(ee_len); + ext4_ext_try_to_merge(inode, path, ex); + err = ext4_ext_dirty(handle, inode, path + depth); + goto out; + } else if (err) + goto fix_extent_len; + +out: + ext4_ext_show_leaf(inode, path); + return err; + +fix_extent_len: + ex->ee_len = orig_ex.ee_len; + ext4_ext_dirty(handle, inode, path + depth); + return err; +} + +/* + * ext4_split_extents() splits an extent and mark extent which is covered + * by @map as split_flags indicates + * + * It may result in splitting the extent into multiple extents (upto three) + * There are three possibilities: + * a> There is no split required + * b> Splits in two extents: Split is happening at either end of the extent + * c> Splits in three extents: Somone is splitting in middle of the extent + * + */ +static int ext4_split_extent(handle_t *handle, + struct inode *inode, + struct ext4_ext_path *path, + struct ext4_map_blocks *map, + int split_flag, + int flags) +{ + ext4_lblk_t ee_block; + struct ext4_extent *ex; + unsigned int ee_len, depth; + int err = 0; + int uninitialized; + int split_flag1, flags1; + + depth = ext_depth(inode); + ex = path[depth].p_ext; + ee_block = le32_to_cpu(ex->ee_block); + ee_len = ext4_ext_get_actual_len(ex); + uninitialized = ext4_ext_is_uninitialized(ex); + + if (map->m_lblk + map->m_len < ee_block + ee_len) { + split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT ? + EXT4_EXT_MAY_ZEROOUT : 0; + flags1 = flags | EXT4_GET_BLOCKS_PRE_IO; + if (uninitialized) + split_flag1 |= EXT4_EXT_MARK_UNINIT1 | + EXT4_EXT_MARK_UNINIT2; + err = ext4_split_extent_at(handle, inode, path, + map->m_lblk + map->m_len, split_flag1, flags1); + if (err) + goto out; + } + + ext4_ext_drop_refs(path); + path = ext4_ext_find_extent(inode, map->m_lblk, path); + if (IS_ERR(path)) + return PTR_ERR(path); + + if (map->m_lblk >= ee_block) { + split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT ? + EXT4_EXT_MAY_ZEROOUT : 0; + if (uninitialized) + split_flag1 |= EXT4_EXT_MARK_UNINIT1; + if (split_flag & EXT4_EXT_MARK_UNINIT2) + split_flag1 |= EXT4_EXT_MARK_UNINIT2; + err = ext4_split_extent_at(handle, inode, path, + map->m_lblk, split_flag1, flags); + if (err) + goto out; + } + + ext4_ext_show_leaf(inode, path); +out: + return err ? err : map->m_len; +} + +#define EXT4_EXT_ZERO_LEN 7 +/* + * This function is called by ext4_ext_map_blocks() if someone tries to write + * to an uninitialized extent. It may result in splitting the uninitialized + * extent into multiple extents (up to three - one initialized and two + * uninitialized). + * There are three possibilities: + * a> There is no split required: Entire extent should be initialized + * b> Splits in two extents: Write is happening at either end of the extent + * c> Splits in three extents: Somone is writing in middle of the extent + * + * Pre-conditions: + * - The extent pointed to by 'path' is uninitialized. + * - The extent pointed to by 'path' contains a superset + * of the logical span [map->m_lblk, map->m_lblk + map->m_len). + * + * Post-conditions on success: + * - the returned value is the number of blocks beyond map->l_lblk + * that are allocated and initialized. + * It is guaranteed to be >= map->m_len. + */ +static int ext4_ext_convert_to_initialized(handle_t *handle, + struct inode *inode, + struct ext4_map_blocks *map, + struct ext4_ext_path *path) +{ + struct ext4_extent_header *eh; + struct ext4_map_blocks split_map; + struct ext4_extent zero_ex; + struct ext4_extent *ex; + ext4_lblk_t ee_block, eof_block; + unsigned int ee_len, depth; + int allocated; + int err = 0; + int split_flag = 0; + + ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical" + "block %llu, max_blocks %u\n", inode->i_ino, + (unsigned long long)map->m_lblk, map->m_len); + + eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >> + inode->i_sb->s_blocksize_bits; + if (eof_block < map->m_lblk + map->m_len) + eof_block = map->m_lblk + map->m_len; + + depth = ext_depth(inode); + eh = path[depth].p_hdr; + ex = path[depth].p_ext; + ee_block = le32_to_cpu(ex->ee_block); + ee_len = ext4_ext_get_actual_len(ex); + allocated = ee_len - (map->m_lblk - ee_block); + + trace_ext4_ext_convert_to_initialized_enter(inode, map, ex); + + /* Pre-conditions */ + BUG_ON(!ext4_ext_is_uninitialized(ex)); + BUG_ON(!in_range(map->m_lblk, ee_block, ee_len)); + + /* + * Attempt to transfer newly initialized blocks from the currently + * uninitialized extent to its left neighbor. This is much cheaper + * than an insertion followed by a merge as those involve costly + * memmove() calls. This is the common case in steady state for + * workloads doing fallocate(FALLOC_FL_KEEP_SIZE) followed by append + * writes. + * + * Limitations of the current logic: + * - L1: we only deal with writes at the start of the extent. + * The approach could be extended to writes at the end + * of the extent but this scenario was deemed less common. + * - L2: we do not deal with writes covering the whole extent. + * This would require removing the extent if the transfer + * is possible. + * - L3: we only attempt to merge with an extent stored in the + * same extent tree node. + */ + if ((map->m_lblk == ee_block) && /*L1*/ + (map->m_len < ee_len) && /*L2*/ + (ex > EXT_FIRST_EXTENT(eh))) { /*L3*/ + struct ext4_extent *prev_ex; + ext4_lblk_t prev_lblk; + ext4_fsblk_t prev_pblk, ee_pblk; + unsigned int prev_len, write_len; + + prev_ex = ex - 1; + prev_lblk = le32_to_cpu(prev_ex->ee_block); + prev_len = ext4_ext_get_actual_len(prev_ex); + prev_pblk = ext4_ext_pblock(prev_ex); + ee_pblk = ext4_ext_pblock(ex); + write_len = map->m_len; + + /* + * A transfer of blocks from 'ex' to 'prev_ex' is allowed + * upon those conditions: + * - C1: prev_ex is initialized, + * - C2: prev_ex is logically abutting ex, + * - C3: prev_ex is physically abutting ex, + * - C4: prev_ex can receive the additional blocks without + * overflowing the (initialized) length limit. + */ + if ((!ext4_ext_is_uninitialized(prev_ex)) && /*C1*/ + ((prev_lblk + prev_len) == ee_block) && /*C2*/ + ((prev_pblk + prev_len) == ee_pblk) && /*C3*/ + (prev_len < (EXT_INIT_MAX_LEN - write_len))) { /*C4*/ + err = ext4_ext_get_access(handle, inode, path + depth); + if (err) + goto out; + + trace_ext4_ext_convert_to_initialized_fastpath(inode, + map, ex, prev_ex); + + /* Shift the start of ex by 'write_len' blocks */ + ex->ee_block = cpu_to_le32(ee_block + write_len); + ext4_ext_store_pblock(ex, ee_pblk + write_len); + ex->ee_len = cpu_to_le16(ee_len - write_len); + ext4_ext_mark_uninitialized(ex); /* Restore the flag */ + + /* Extend prev_ex by 'write_len' blocks */ + prev_ex->ee_len = cpu_to_le16(prev_len + write_len); + + /* Mark the block containing both extents as dirty */ + ext4_ext_dirty(handle, inode, path + depth); + + /* Update path to point to the right extent */ + path[depth].p_ext = prev_ex; + + /* Result: number of initialized blocks past m_lblk */ + allocated = write_len; + goto out; + } + } + + WARN_ON(map->m_lblk < ee_block); + /* + * It is safe to convert extent to initialized via explicit + * zeroout only if extent is fully insde i_size or new_size. + */ + split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0; + + /* If extent has less than 2*EXT4_EXT_ZERO_LEN zerout directly */ + if (ee_len <= 2*EXT4_EXT_ZERO_LEN && + (EXT4_EXT_MAY_ZEROOUT & split_flag)) { + err = ext4_ext_zeroout(inode, ex); + if (err) + goto out; + + err = ext4_ext_get_access(handle, inode, path + depth); + if (err) + goto out; + ext4_ext_mark_initialized(ex); + ext4_ext_try_to_merge(inode, path, ex); + err = ext4_ext_dirty(handle, inode, path + depth); + goto out; + } + + /* + * four cases: + * 1. split the extent into three extents. + * 2. split the extent into two extents, zeroout the first half. + * 3. split the extent into two extents, zeroout the second half. + * 4. split the extent into two extents with out zeroout. + */ + split_map.m_lblk = map->m_lblk; + split_map.m_len = map->m_len; + + if (allocated > map->m_len) { + if (allocated <= EXT4_EXT_ZERO_LEN && + (EXT4_EXT_MAY_ZEROOUT & split_flag)) { + /* case 3 */ + zero_ex.ee_block = + cpu_to_le32(map->m_lblk); + zero_ex.ee_len = cpu_to_le16(allocated); + ext4_ext_store_pblock(&zero_ex, + ext4_ext_pblock(ex) + map->m_lblk - ee_block); + err = ext4_ext_zeroout(inode, &zero_ex); + if (err) + goto out; + split_map.m_lblk = map->m_lblk; + split_map.m_len = allocated; + } else if ((map->m_lblk - ee_block + map->m_len < + EXT4_EXT_ZERO_LEN) && + (EXT4_EXT_MAY_ZEROOUT & split_flag)) { + /* case 2 */ + if (map->m_lblk != ee_block) { + zero_ex.ee_block = ex->ee_block; + zero_ex.ee_len = cpu_to_le16(map->m_lblk - + ee_block); + ext4_ext_store_pblock(&zero_ex, + ext4_ext_pblock(ex)); + err = ext4_ext_zeroout(inode, &zero_ex); + if (err) + goto out; + } + + split_map.m_lblk = ee_block; + split_map.m_len = map->m_lblk - ee_block + map->m_len; + allocated = map->m_len; + } + } + + allocated = ext4_split_extent(handle, inode, path, + &split_map, split_flag, 0); + if (allocated < 0) + err = allocated; + +out: + return err ? err : allocated; +} + +/* + * This function is called by ext4_ext_map_blocks() from + * ext4_get_blocks_dio_write() when DIO to write + * to an uninitialized extent. + * + * Writing to an uninitialized extent may result in splitting the uninitialized + * extent into multiple /initialized uninitialized extents (up to three) + * There are three possibilities: + * a> There is no split required: Entire extent should be uninitialized + * b> Splits in two extents: Write is happening at either end of the extent + * c> Splits in three extents: Somone is writing in middle of the extent + * + * One of more index blocks maybe needed if the extent tree grow after + * the uninitialized extent split. To prevent ENOSPC occur at the IO + * complete, we need to split the uninitialized extent before DIO submit + * the IO. The uninitialized extent called at this time will be split + * into three uninitialized extent(at most). After IO complete, the part + * being filled will be convert to initialized by the end_io callback function + * via ext4_convert_unwritten_extents(). + * + * Returns the size of uninitialized extent to be written on success. + */ +static int ext4_split_unwritten_extents(handle_t *handle, + struct inode *inode, + struct ext4_map_blocks *map, + struct ext4_ext_path *path, + int flags) +{ + ext4_lblk_t eof_block; + ext4_lblk_t ee_block; + struct ext4_extent *ex; + unsigned int ee_len; + int split_flag = 0, depth; + + ext_debug("ext4_split_unwritten_extents: inode %lu, logical" + "block %llu, max_blocks %u\n", inode->i_ino, + (unsigned long long)map->m_lblk, map->m_len); + + eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >> + inode->i_sb->s_blocksize_bits; + if (eof_block < map->m_lblk + map->m_len) + eof_block = map->m_lblk + map->m_len; + /* + * It is safe to convert extent to initialized via explicit + * zeroout only if extent is fully insde i_size or new_size. + */ + depth = ext_depth(inode); + ex = path[depth].p_ext; + ee_block = le32_to_cpu(ex->ee_block); + ee_len = ext4_ext_get_actual_len(ex); + + split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0; + split_flag |= EXT4_EXT_MARK_UNINIT2; + + flags |= EXT4_GET_BLOCKS_PRE_IO; + return ext4_split_extent(handle, inode, path, map, split_flag, flags); +} + +static int ext4_convert_unwritten_extents_endio(handle_t *handle, + struct inode *inode, + struct ext4_ext_path *path) +{ + struct ext4_extent *ex; + int depth; + int err = 0; + + depth = ext_depth(inode); + ex = path[depth].p_ext; + + ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical" + "block %llu, max_blocks %u\n", inode->i_ino, + (unsigned long long)le32_to_cpu(ex->ee_block), + ext4_ext_get_actual_len(ex)); + + err = ext4_ext_get_access(handle, inode, path + depth); + if (err) + goto out; + /* first mark the extent as initialized */ + ext4_ext_mark_initialized(ex); + + /* note: ext4_ext_correct_indexes() isn't needed here because + * borders are not changed + */ + ext4_ext_try_to_merge(inode, path, ex); + + /* Mark modified extent as dirty */ + err = ext4_ext_dirty(handle, inode, path + depth); +out: + ext4_ext_show_leaf(inode, path); + return err; +} + +static void unmap_underlying_metadata_blocks(struct block_device *bdev, + sector_t block, int count) +{ + int i; + for (i = 0; i < count; i++) + unmap_underlying_metadata(bdev, block + i); +} + +/* + * Handle EOFBLOCKS_FL flag, clearing it if necessary + */ +static int check_eofblocks_fl(handle_t *handle, struct inode *inode, + ext4_lblk_t lblk, + struct ext4_ext_path *path, + unsigned int len) +{ + int i, depth; + struct ext4_extent_header *eh; + struct ext4_extent *last_ex; + + if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS)) + return 0; + + depth = ext_depth(inode); + eh = path[depth].p_hdr; + + /* + * We're going to remove EOFBLOCKS_FL entirely in future so we + * do not care for this case anymore. Simply remove the flag + * if there are no extents. + */ + if (unlikely(!eh->eh_entries)) + goto out; + last_ex = EXT_LAST_EXTENT(eh); + /* + * We should clear the EOFBLOCKS_FL flag if we are writing the + * last block in the last extent in the file. We test this by + * first checking to see if the caller to + * ext4_ext_get_blocks() was interested in the last block (or + * a block beyond the last block) in the current extent. If + * this turns out to be false, we can bail out from this + * function immediately. + */ + if (lblk + len < le32_to_cpu(last_ex->ee_block) + + ext4_ext_get_actual_len(last_ex)) + return 0; + /* + * If the caller does appear to be planning to write at or + * beyond the end of the current extent, we then test to see + * if the current extent is the last extent in the file, by + * checking to make sure it was reached via the rightmost node + * at each level of the tree. + */ + for (i = depth-1; i >= 0; i--) + if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr)) + return 0; +out: + ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS); + return ext4_mark_inode_dirty(handle, inode); +} + +/** + * ext4_find_delalloc_range: find delayed allocated block in the given range. + * + * Goes through the buffer heads in the range [lblk_start, lblk_end] and returns + * whether there are any buffers marked for delayed allocation. It returns '1' + * on the first delalloc'ed buffer head found. If no buffer head in the given + * range is marked for delalloc, it returns 0. + * lblk_start should always be <= lblk_end. + * search_hint_reverse is to indicate that searching in reverse from lblk_end to + * lblk_start might be more efficient (i.e., we will likely hit the delalloc'ed + * block sooner). This is useful when blocks are truncated sequentially from + * lblk_start towards lblk_end. + */ +static int ext4_find_delalloc_range(struct inode *inode, + ext4_lblk_t lblk_start, + ext4_lblk_t lblk_end, + int search_hint_reverse) +{ + struct address_space *mapping = inode->i_mapping; + struct buffer_head *head, *bh = NULL; + struct page *page; + ext4_lblk_t i, pg_lblk; + pgoff_t index; + + if (!test_opt(inode->i_sb, DELALLOC)) + return 0; + + /* reverse search wont work if fs block size is less than page size */ + if (inode->i_blkbits < PAGE_CACHE_SHIFT) + search_hint_reverse = 0; + + if (search_hint_reverse) + i = lblk_end; + else + i = lblk_start; + + index = i >> (PAGE_CACHE_SHIFT - inode->i_blkbits); + + while ((i >= lblk_start) && (i <= lblk_end)) { + page = find_get_page(mapping, index); + if (!page) + goto nextpage; + + if (!page_has_buffers(page)) + goto nextpage; + + head = page_buffers(page); + if (!head) + goto nextpage; + + bh = head; + pg_lblk = index << (PAGE_CACHE_SHIFT - + inode->i_blkbits); + do { + if (unlikely(pg_lblk < lblk_start)) { + /* + * This is possible when fs block size is less + * than page size and our cluster starts/ends in + * middle of the page. So we need to skip the + * initial few blocks till we reach the 'lblk' + */ + pg_lblk++; + continue; + } + + /* Check if the buffer is delayed allocated and that it + * is not yet mapped. (when da-buffers are mapped during + * their writeout, their da_mapped bit is set.) + */ + if (buffer_delay(bh) && !buffer_da_mapped(bh)) { + page_cache_release(page); + trace_ext4_find_delalloc_range(inode, + lblk_start, lblk_end, + search_hint_reverse, + 1, i); + return 1; + } + if (search_hint_reverse) + i--; + else + i++; + } while ((i >= lblk_start) && (i <= lblk_end) && + ((bh = bh->b_this_page) != head)); +nextpage: + if (page) + page_cache_release(page); + /* + * Move to next page. 'i' will be the first lblk in the next + * page. + */ + if (search_hint_reverse) + index--; + else + index++; + i = index << (PAGE_CACHE_SHIFT - inode->i_blkbits); + } + + trace_ext4_find_delalloc_range(inode, lblk_start, lblk_end, + search_hint_reverse, 0, 0); + return 0; +} + +int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk, + int search_hint_reverse) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + ext4_lblk_t lblk_start, lblk_end; + lblk_start = lblk & (~(sbi->s_cluster_ratio - 1)); + lblk_end = lblk_start + sbi->s_cluster_ratio - 1; + + return ext4_find_delalloc_range(inode, lblk_start, lblk_end, + search_hint_reverse); +} + +/** + * Determines how many complete clusters (out of those specified by the 'map') + * are under delalloc and were reserved quota for. + * This function is called when we are writing out the blocks that were + * originally written with their allocation delayed, but then the space was + * allocated using fallocate() before the delayed allocation could be resolved. + * The cases to look for are: + * ('=' indicated delayed allocated blocks + * '-' indicates non-delayed allocated blocks) + * (a) partial clusters towards beginning and/or end outside of allocated range + * are not delalloc'ed. + * Ex: + * |----c---=|====c====|====c====|===-c----| + * |++++++ allocated ++++++| + * ==> 4 complete clusters in above example + * + * (b) partial cluster (outside of allocated range) towards either end is + * marked for delayed allocation. In this case, we will exclude that + * cluster. + * Ex: + * |----====c========|========c========| + * |++++++ allocated ++++++| + * ==> 1 complete clusters in above example + * + * Ex: + * |================c================| + * |++++++ allocated ++++++| + * ==> 0 complete clusters in above example + * + * The ext4_da_update_reserve_space will be called only if we + * determine here that there were some "entire" clusters that span + * this 'allocated' range. + * In the non-bigalloc case, this function will just end up returning num_blks + * without ever calling ext4_find_delalloc_range. + */ +static unsigned int +get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start, + unsigned int num_blks) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + ext4_lblk_t alloc_cluster_start, alloc_cluster_end; + ext4_lblk_t lblk_from, lblk_to, c_offset; + unsigned int allocated_clusters = 0; + + alloc_cluster_start = EXT4_B2C(sbi, lblk_start); + alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1); + + /* max possible clusters for this allocation */ + allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1; + + trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks); + + /* Check towards left side */ + c_offset = lblk_start & (sbi->s_cluster_ratio - 1); + if (c_offset) { + lblk_from = lblk_start & (~(sbi->s_cluster_ratio - 1)); + lblk_to = lblk_from + c_offset - 1; + + if (ext4_find_delalloc_range(inode, lblk_from, lblk_to, 0)) + allocated_clusters--; + } + + /* Now check towards right. */ + c_offset = (lblk_start + num_blks) & (sbi->s_cluster_ratio - 1); + if (allocated_clusters && c_offset) { + lblk_from = lblk_start + num_blks; + lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1; + + if (ext4_find_delalloc_range(inode, lblk_from, lblk_to, 0)) + allocated_clusters--; + } + + return allocated_clusters; +} + +static int +ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode, + struct ext4_map_blocks *map, + struct ext4_ext_path *path, int flags, + unsigned int allocated, ext4_fsblk_t newblock) +{ + int ret = 0; + int err = 0; + ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio; + + ext_debug("ext4_ext_handle_uninitialized_extents: inode %lu, logical " + "block %llu, max_blocks %u, flags %x, allocated %u\n", + inode->i_ino, (unsigned long long)map->m_lblk, map->m_len, + flags, allocated); + ext4_ext_show_leaf(inode, path); + + trace_ext4_ext_handle_uninitialized_extents(inode, map, allocated, + newblock); + + /* get_block() before submit the IO, split the extent */ + if ((flags & EXT4_GET_BLOCKS_PRE_IO)) { + ret = ext4_split_unwritten_extents(handle, inode, map, + path, flags); + /* + * Flag the inode(non aio case) or end_io struct (aio case) + * that this IO needs to conversion to written when IO is + * completed + */ + if (io) + ext4_set_io_unwritten_flag(inode, io); + else + ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN); + if (ext4_should_dioread_nolock(inode)) + map->m_flags |= EXT4_MAP_UNINIT; + goto out; + } + /* IO end_io complete, convert the filled extent to written */ + if ((flags & EXT4_GET_BLOCKS_CONVERT)) { + ret = ext4_convert_unwritten_extents_endio(handle, inode, + path); + if (ret >= 0) { + ext4_update_inode_fsync_trans(handle, inode, 1); + err = check_eofblocks_fl(handle, inode, map->m_lblk, + path, map->m_len); + } else + err = ret; + goto out2; + } + /* buffered IO case */ + /* + * repeat fallocate creation request + * we already have an unwritten extent + */ + if (flags & EXT4_GET_BLOCKS_UNINIT_EXT) + goto map_out; + + /* buffered READ or buffered write_begin() lookup */ + if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { + /* + * We have blocks reserved already. We + * return allocated blocks so that delalloc + * won't do block reservation for us. But + * the buffer head will be unmapped so that + * a read from the block returns 0s. + */ + map->m_flags |= EXT4_MAP_UNWRITTEN; + goto out1; + } + + /* buffered write, writepage time, convert*/ + ret = ext4_ext_convert_to_initialized(handle, inode, map, path); + if (ret >= 0) + ext4_update_inode_fsync_trans(handle, inode, 1); +out: + if (ret <= 0) { + err = ret; + goto out2; + } else + allocated = ret; + map->m_flags |= EXT4_MAP_NEW; + /* + * if we allocated more blocks than requested + * we need to make sure we unmap the extra block + * allocated. The actual needed block will get + * unmapped later when we find the buffer_head marked + * new. + */ + if (allocated > map->m_len) { + unmap_underlying_metadata_blocks(inode->i_sb->s_bdev, + newblock + map->m_len, + allocated - map->m_len); + allocated = map->m_len; + } + + /* + * If we have done fallocate with the offset that is already + * delayed allocated, we would have block reservation + * and quota reservation done in the delayed write path. + * But fallocate would have already updated quota and block + * count for this offset. So cancel these reservation + */ + if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) { + unsigned int reserved_clusters; + reserved_clusters = get_reserved_cluster_alloc(inode, + map->m_lblk, map->m_len); + if (reserved_clusters) + ext4_da_update_reserve_space(inode, + reserved_clusters, + 0); + } + +map_out: + map->m_flags |= EXT4_MAP_MAPPED; + if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) { + err = check_eofblocks_fl(handle, inode, map->m_lblk, path, + map->m_len); + if (err < 0) + goto out2; + } +out1: + if (allocated > map->m_len) + allocated = map->m_len; + ext4_ext_show_leaf(inode, path); + map->m_pblk = newblock; + map->m_len = allocated; +out2: + if (path) { + ext4_ext_drop_refs(path); + kfree(path); + } + return err ? err : allocated; +} + +/* + * get_implied_cluster_alloc - check to see if the requested + * allocation (in the map structure) overlaps with a cluster already + * allocated in an extent. + * @sb The filesystem superblock structure + * @map The requested lblk->pblk mapping + * @ex The extent structure which might contain an implied + * cluster allocation + * + * This function is called by ext4_ext_map_blocks() after we failed to + * find blocks that were already in the inode's extent tree. Hence, + * we know that the beginning of the requested region cannot overlap + * the extent from the inode's extent tree. There are three cases we + * want to catch. The first is this case: + * + * |--- cluster # N--| + * |--- extent ---| |---- requested region ---| + * |==========| + * + * The second case that we need to test for is this one: + * + * |--------- cluster # N ----------------| + * |--- requested region --| |------- extent ----| + * |=======================| + * + * The third case is when the requested region lies between two extents + * within the same cluster: + * |------------- cluster # N-------------| + * |----- ex -----| |---- ex_right ----| + * |------ requested region ------| + * |================| + * + * In each of the above cases, we need to set the map->m_pblk and + * map->m_len so it corresponds to the return the extent labelled as + * "|====|" from cluster #N, since it is already in use for data in + * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to + * signal to ext4_ext_map_blocks() that map->m_pblk should be treated + * as a new "allocated" block region. Otherwise, we will return 0 and + * ext4_ext_map_blocks() will then allocate one or more new clusters + * by calling ext4_mb_new_blocks(). + */ +static int get_implied_cluster_alloc(struct super_block *sb, + struct ext4_map_blocks *map, + struct ext4_extent *ex, + struct ext4_ext_path *path) +{ + struct ext4_sb_info *sbi = EXT4_SB(sb); + ext4_lblk_t c_offset = map->m_lblk & (sbi->s_cluster_ratio-1); + ext4_lblk_t ex_cluster_start, ex_cluster_end; + ext4_lblk_t rr_cluster_start; + ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block); + ext4_fsblk_t ee_start = ext4_ext_pblock(ex); + unsigned short ee_len = ext4_ext_get_actual_len(ex); + + /* The extent passed in that we are trying to match */ + ex_cluster_start = EXT4_B2C(sbi, ee_block); + ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1); + + /* The requested region passed into ext4_map_blocks() */ + rr_cluster_start = EXT4_B2C(sbi, map->m_lblk); + + if ((rr_cluster_start == ex_cluster_end) || + (rr_cluster_start == ex_cluster_start)) { + if (rr_cluster_start == ex_cluster_end) + ee_start += ee_len - 1; + map->m_pblk = (ee_start & ~(sbi->s_cluster_ratio - 1)) + + c_offset; + map->m_len = min(map->m_len, + (unsigned) sbi->s_cluster_ratio - c_offset); + /* + * Check for and handle this case: + * + * |--------- cluster # N-------------| + * |------- extent ----| + * |--- requested region ---| + * |===========| + */ + + if (map->m_lblk < ee_block) + map->m_len = min(map->m_len, ee_block - map->m_lblk); + + /* + * Check for the case where there is already another allocated + * block to the right of 'ex' but before the end of the cluster. + * + * |------------- cluster # N-------------| + * |----- ex -----| |---- ex_right ----| + * |------ requested region ------| + * |================| + */ + if (map->m_lblk > ee_block) { + ext4_lblk_t next = ext4_ext_next_allocated_block(path); + map->m_len = min(map->m_len, next - map->m_lblk); + } + + trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1); + return 1; + } + + trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0); + return 0; +} + + +/* + * Block allocation/map/preallocation routine for extents based files + * + * + * Need to be called with + * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block + * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem) + * + * return > 0, number of of blocks already mapped/allocated + * if create == 0 and these are pre-allocated blocks + * buffer head is unmapped + * otherwise blocks are mapped + * + * return = 0, if plain look up failed (blocks have not been allocated) + * buffer head is unmapped + * + * return < 0, error case. + */ +int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, + struct ext4_map_blocks *map, int flags) +{ + struct ext4_ext_path *path = NULL; + struct ext4_extent newex, *ex, *ex2; + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + ext4_fsblk_t newblock = 0; + int free_on_err = 0, err = 0, depth, ret; + unsigned int allocated = 0, offset = 0; + unsigned int allocated_clusters = 0; + struct ext4_allocation_request ar; + ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio; + ext4_lblk_t cluster_offset; + + ext_debug("blocks %u/%u requested for inode %lu\n", + map->m_lblk, map->m_len, inode->i_ino); + trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags); + + /* check in cache */ + if (ext4_ext_in_cache(inode, map->m_lblk, &newex)) { + if (!newex.ee_start_lo && !newex.ee_start_hi) { + if ((sbi->s_cluster_ratio > 1) && + ext4_find_delalloc_cluster(inode, map->m_lblk, 0)) + map->m_flags |= EXT4_MAP_FROM_CLUSTER; + + if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { + /* + * block isn't allocated yet and + * user doesn't want to allocate it + */ + goto out2; + } + /* we should allocate requested block */ + } else { + /* block is already allocated */ + if (sbi->s_cluster_ratio > 1) + map->m_flags |= EXT4_MAP_FROM_CLUSTER; + newblock = map->m_lblk + - le32_to_cpu(newex.ee_block) + + ext4_ext_pblock(&newex); + /* number of remaining blocks in the extent */ + allocated = ext4_ext_get_actual_len(&newex) - + (map->m_lblk - le32_to_cpu(newex.ee_block)); + goto out; + } + } + + /* find extent for this block */ + path = ext4_ext_find_extent(inode, map->m_lblk, NULL); + if (IS_ERR(path)) { + err = PTR_ERR(path); + path = NULL; + goto out2; + } + + depth = ext_depth(inode); + + /* + * consistent leaf must not be empty; + * this situation is possible, though, _during_ tree modification; + * this is why assert can't be put in ext4_ext_find_extent() + */ + if (unlikely(path[depth].p_ext == NULL && depth != 0)) { + EXT4_ERROR_INODE(inode, "bad extent address " + "lblock: %lu, depth: %d pblock %lld", + (unsigned long) map->m_lblk, depth, + path[depth].p_block); + err = -EIO; + goto out2; + } + + ex = path[depth].p_ext; + if (ex) { + ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block); + ext4_fsblk_t ee_start = ext4_ext_pblock(ex); + unsigned short ee_len; + + /* + * Uninitialized extents are treated as holes, except that + * we split out initialized portions during a write. + */ + ee_len = ext4_ext_get_actual_len(ex); + + trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len); + + /* if found extent covers block, simply return it */ + if (in_range(map->m_lblk, ee_block, ee_len)) { + newblock = map->m_lblk - ee_block + ee_start; + /* number of remaining blocks in the extent */ + allocated = ee_len - (map->m_lblk - ee_block); + ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk, + ee_block, ee_len, newblock); + + /* + * Do not put uninitialized extent + * in the cache + */ + if (!ext4_ext_is_uninitialized(ex)) { + ext4_ext_put_in_cache(inode, ee_block, + ee_len, ee_start); + goto out; + } + ret = ext4_ext_handle_uninitialized_extents( + handle, inode, map, path, flags, + allocated, newblock); + return ret; + } + } + + if ((sbi->s_cluster_ratio > 1) && + ext4_find_delalloc_cluster(inode, map->m_lblk, 0)) + map->m_flags |= EXT4_MAP_FROM_CLUSTER; + + /* + * requested block isn't allocated yet; + * we couldn't try to create block if create flag is zero + */ + if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { + /* + * put just found gap into cache to speed up + * subsequent requests + */ + ext4_ext_put_gap_in_cache(inode, path, map->m_lblk); + goto out2; + } + + /* + * Okay, we need to do block allocation. + */ + map->m_flags &= ~EXT4_MAP_FROM_CLUSTER; + newex.ee_block = cpu_to_le32(map->m_lblk); + cluster_offset = map->m_lblk & (sbi->s_cluster_ratio-1); + + /* + * If we are doing bigalloc, check to see if the extent returned + * by ext4_ext_find_extent() implies a cluster we can use. + */ + if (cluster_offset && ex && + get_implied_cluster_alloc(inode->i_sb, map, ex, path)) { + ar.len = allocated = map->m_len; + newblock = map->m_pblk; + map->m_flags |= EXT4_MAP_FROM_CLUSTER; + goto got_allocated_blocks; + } + + /* find neighbour allocated blocks */ + ar.lleft = map->m_lblk; + err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft); + if (err) + goto out2; + ar.lright = map->m_lblk; + ex2 = NULL; + err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2); + if (err) + goto out2; + + /* Check if the extent after searching to the right implies a + * cluster we can use. */ + if ((sbi->s_cluster_ratio > 1) && ex2 && + get_implied_cluster_alloc(inode->i_sb, map, ex2, path)) { + ar.len = allocated = map->m_len; + newblock = map->m_pblk; + map->m_flags |= EXT4_MAP_FROM_CLUSTER; + goto got_allocated_blocks; + } + + /* + * See if request is beyond maximum number of blocks we can have in + * a single extent. For an initialized extent this limit is + * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is + * EXT_UNINIT_MAX_LEN. + */ + if (map->m_len > EXT_INIT_MAX_LEN && + !(flags & EXT4_GET_BLOCKS_UNINIT_EXT)) + map->m_len = EXT_INIT_MAX_LEN; + else if (map->m_len > EXT_UNINIT_MAX_LEN && + (flags & EXT4_GET_BLOCKS_UNINIT_EXT)) + map->m_len = EXT_UNINIT_MAX_LEN; + + /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */ + newex.ee_len = cpu_to_le16(map->m_len); + err = ext4_ext_check_overlap(sbi, inode, &newex, path); + if (err) + allocated = ext4_ext_get_actual_len(&newex); + else + allocated = map->m_len; + + /* allocate new block */ + ar.inode = inode; + ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk); + ar.logical = map->m_lblk; + /* + * We calculate the offset from the beginning of the cluster + * for the logical block number, since when we allocate a + * physical cluster, the physical block should start at the + * same offset from the beginning of the cluster. This is + * needed so that future calls to get_implied_cluster_alloc() + * work correctly. + */ + offset = map->m_lblk & (sbi->s_cluster_ratio - 1); + ar.len = EXT4_NUM_B2C(sbi, offset+allocated); + ar.goal -= offset; + ar.logical -= offset; + if (S_ISREG(inode->i_mode)) + ar.flags = EXT4_MB_HINT_DATA; + else + /* disable in-core preallocation for non-regular files */ + ar.flags = 0; + if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE) + ar.flags |= EXT4_MB_HINT_NOPREALLOC; + newblock = ext4_mb_new_blocks(handle, &ar, &err); + if (!newblock) + goto out2; + ext_debug("allocate new block: goal %llu, found %llu/%u\n", + ar.goal, newblock, allocated); + free_on_err = 1; + allocated_clusters = ar.len; + ar.len = EXT4_C2B(sbi, ar.len) - offset; + if (ar.len > allocated) + ar.len = allocated; + +got_allocated_blocks: + /* try to insert new extent into found leaf and return */ + ext4_ext_store_pblock(&newex, newblock + offset); + newex.ee_len = cpu_to_le16(ar.len); + /* Mark uninitialized */ + if (flags & EXT4_GET_BLOCKS_UNINIT_EXT){ + ext4_ext_mark_uninitialized(&newex); + /* + * io_end structure was created for every IO write to an + * uninitialized extent. To avoid unnecessary conversion, + * here we flag the IO that really needs the conversion. + * For non asycn direct IO case, flag the inode state + * that we need to perform conversion when IO is done. + */ + if ((flags & EXT4_GET_BLOCKS_PRE_IO)) { + if (io) + ext4_set_io_unwritten_flag(inode, io); + else + ext4_set_inode_state(inode, + EXT4_STATE_DIO_UNWRITTEN); + } + if (ext4_should_dioread_nolock(inode)) + map->m_flags |= EXT4_MAP_UNINIT; + } + + err = 0; + if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) + err = check_eofblocks_fl(handle, inode, map->m_lblk, + path, ar.len); + if (!err) + err = ext4_ext_insert_extent(handle, inode, path, + &newex, flags); + if (err && free_on_err) { + int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ? + EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0; + /* free data blocks we just allocated */ + /* not a good idea to call discard here directly, + * but otherwise we'd need to call it every free() */ + ext4_discard_preallocations(inode); + ext4_free_blocks(handle, inode, NULL, ext4_ext_pblock(&newex), + ext4_ext_get_actual_len(&newex), fb_flags); + goto out2; + } + + /* previous routine could use block we allocated */ + newblock = ext4_ext_pblock(&newex); + allocated = ext4_ext_get_actual_len(&newex); + if (allocated > map->m_len) + allocated = map->m_len; + map->m_flags |= EXT4_MAP_NEW; + + /* + * Update reserved blocks/metadata blocks after successful + * block allocation which had been deferred till now. + */ + if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) { + unsigned int reserved_clusters; + /* + * Check how many clusters we had reserved this allocated range + */ + reserved_clusters = get_reserved_cluster_alloc(inode, + map->m_lblk, allocated); + if (map->m_flags & EXT4_MAP_FROM_CLUSTER) { + if (reserved_clusters) { + /* + * We have clusters reserved for this range. + * But since we are not doing actual allocation + * and are simply using blocks from previously + * allocated cluster, we should release the + * reservation and not claim quota. + */ + ext4_da_update_reserve_space(inode, + reserved_clusters, 0); + } + } else { + BUG_ON(allocated_clusters < reserved_clusters); + /* We will claim quota for all newly allocated blocks.*/ + ext4_da_update_reserve_space(inode, allocated_clusters, + 1); + if (reserved_clusters < allocated_clusters) { + struct ext4_inode_info *ei = EXT4_I(inode); + int reservation = allocated_clusters - + reserved_clusters; + /* + * It seems we claimed few clusters outside of + * the range of this allocation. We should give + * it back to the reservation pool. This can + * happen in the following case: + * + * * Suppose s_cluster_ratio is 4 (i.e., each + * cluster has 4 blocks. Thus, the clusters + * are [0-3],[4-7],[8-11]... + * * First comes delayed allocation write for + * logical blocks 10 & 11. Since there were no + * previous delayed allocated blocks in the + * range [8-11], we would reserve 1 cluster + * for this write. + * * Next comes write for logical blocks 3 to 8. + * In this case, we will reserve 2 clusters + * (for [0-3] and [4-7]; and not for [8-11] as + * that range has a delayed allocated blocks. + * Thus total reserved clusters now becomes 3. + * * Now, during the delayed allocation writeout + * time, we will first write blocks [3-8] and + * allocate 3 clusters for writing these + * blocks. Also, we would claim all these + * three clusters above. + * * Now when we come here to writeout the + * blocks [10-11], we would expect to claim + * the reservation of 1 cluster we had made + * (and we would claim it since there are no + * more delayed allocated blocks in the range + * [8-11]. But our reserved cluster count had + * already gone to 0. + * + * Thus, at the step 4 above when we determine + * that there are still some unwritten delayed + * allocated blocks outside of our current + * block range, we should increment the + * reserved clusters count so that when the + * remaining blocks finally gets written, we + * could claim them. + */ + dquot_reserve_block(inode, + EXT4_C2B(sbi, reservation)); + spin_lock(&ei->i_block_reservation_lock); + ei->i_reserved_data_blocks += reservation; + spin_unlock(&ei->i_block_reservation_lock); + } + } + } + + /* + * Cache the extent and update transaction to commit on fdatasync only + * when it is _not_ an uninitialized extent. + */ + if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0) { + ext4_ext_put_in_cache(inode, map->m_lblk, allocated, newblock); + ext4_update_inode_fsync_trans(handle, inode, 1); + } else + ext4_update_inode_fsync_trans(handle, inode, 0); +out: + if (allocated > map->m_len) + allocated = map->m_len; + ext4_ext_show_leaf(inode, path); + map->m_flags |= EXT4_MAP_MAPPED; + map->m_pblk = newblock; + map->m_len = allocated; +out2: + if (path) { + ext4_ext_drop_refs(path); + kfree(path); + } + + trace_ext4_ext_map_blocks_exit(inode, map->m_lblk, + newblock, map->m_len, err ? err : allocated); + + return err ? err : allocated; +} + +void ext4_ext_truncate(struct inode *inode) +{ + struct address_space *mapping = inode->i_mapping; + struct super_block *sb = inode->i_sb; + ext4_lblk_t last_block; + handle_t *handle; + loff_t page_len; + int err = 0; + + /* + * finish any pending end_io work so we won't run the risk of + * converting any truncated blocks to initialized later + */ + ext4_flush_completed_IO(inode); + + /* + * probably first extent we're gonna free will be last in block + */ + err = ext4_writepage_trans_blocks(inode); + handle = ext4_journal_start(inode, err); + if (IS_ERR(handle)) + return; + + if (inode->i_size % PAGE_CACHE_SIZE != 0) { + page_len = PAGE_CACHE_SIZE - + (inode->i_size & (PAGE_CACHE_SIZE - 1)); + + err = ext4_discard_partial_page_buffers(handle, + mapping, inode->i_size, page_len, 0); + + if (err) + goto out_stop; + } + + if (ext4_orphan_add(handle, inode)) + goto out_stop; + + down_write(&EXT4_I(inode)->i_data_sem); + ext4_ext_invalidate_cache(inode); + + ext4_discard_preallocations(inode); + + /* + * TODO: optimization is possible here. + * Probably we need not scan at all, + * because page truncation is enough. + */ + + /* we have to know where to truncate from in crash case */ + EXT4_I(inode)->i_disksize = inode->i_size; + ext4_mark_inode_dirty(handle, inode); + + last_block = (inode->i_size + sb->s_blocksize - 1) + >> EXT4_BLOCK_SIZE_BITS(sb); + err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1); + + /* In a multi-transaction truncate, we only make the final + * transaction synchronous. + */ + if (IS_SYNC(inode)) + ext4_handle_sync(handle); + + up_write(&EXT4_I(inode)->i_data_sem); + +out_stop: + /* + * If this was a simple ftruncate() and the file will remain alive, + * then we need to clear up the orphan record which we created above. + * However, if this was a real unlink then we were called by + * ext4_delete_inode(), and we allow that function to clean up the + * orphan info for us. + */ + if (inode->i_nlink) + ext4_orphan_del(handle, inode); + + inode->i_mtime = inode->i_ctime = ext4_current_time(inode); + ext4_mark_inode_dirty(handle, inode); + ext4_journal_stop(handle); +} + +static void ext4_falloc_update_inode(struct inode *inode, + int mode, loff_t new_size, int update_ctime) +{ + struct timespec now; + + if (update_ctime) { + now = current_fs_time(inode->i_sb); + if (!timespec_equal(&inode->i_ctime, &now)) + inode->i_ctime = now; + } + /* + * Update only when preallocation was requested beyond + * the file size. + */ + if (!(mode & FALLOC_FL_KEEP_SIZE)) { + if (new_size > i_size_read(inode)) + i_size_write(inode, new_size); + if (new_size > EXT4_I(inode)->i_disksize) + ext4_update_i_disksize(inode, new_size); + } else { + /* + * Mark that we allocate beyond EOF so the subsequent truncate + * can proceed even if the new size is the same as i_size. + */ + if (new_size > i_size_read(inode)) + ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS); + } + +} + +/* + * preallocate space for a file. This implements ext4's fallocate file + * operation, which gets called from sys_fallocate system call. + * For block-mapped files, posix_fallocate should fall back to the method + * of writing zeroes to the required new blocks (the same behavior which is + * expected for file systems which do not support fallocate() system call). + */ +long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) +{ + struct inode *inode = file->f_path.dentry->d_inode; + handle_t *handle; + loff_t new_size; + unsigned int max_blocks; + int ret = 0; + int ret2 = 0; + int retries = 0; + int flags; + struct ext4_map_blocks map; + unsigned int credits, blkbits = inode->i_blkbits; + + /* + * currently supporting (pre)allocate mode for extent-based + * files _only_ + */ + if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) + return -EOPNOTSUPP; + + /* Return error if mode is not supported */ + if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) + return -EOPNOTSUPP; + + if (mode & FALLOC_FL_PUNCH_HOLE) + return ext4_punch_hole(file, offset, len); + + trace_ext4_fallocate_enter(inode, offset, len, mode); + map.m_lblk = offset >> blkbits; + /* + * We can't just convert len to max_blocks because + * If blocksize = 4096 offset = 3072 and len = 2048 + */ + max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) + - map.m_lblk; + /* + * credits to insert 1 extent into extent tree + */ + credits = ext4_chunk_trans_blocks(inode, max_blocks); + mutex_lock(&inode->i_mutex); + ret = inode_newsize_ok(inode, (len + offset)); + if (ret) { + mutex_unlock(&inode->i_mutex); + trace_ext4_fallocate_exit(inode, offset, max_blocks, ret); + return ret; + } + flags = EXT4_GET_BLOCKS_CREATE_UNINIT_EXT; + if (mode & FALLOC_FL_KEEP_SIZE) + flags |= EXT4_GET_BLOCKS_KEEP_SIZE; + /* + * Don't normalize the request if it can fit in one extent so + * that it doesn't get unnecessarily split into multiple + * extents. + */ + if (len <= EXT_UNINIT_MAX_LEN << blkbits) + flags |= EXT4_GET_BLOCKS_NO_NORMALIZE; +retry: + while (ret >= 0 && ret < max_blocks) { + map.m_lblk = map.m_lblk + ret; + map.m_len = max_blocks = max_blocks - ret; + handle = ext4_journal_start(inode, credits); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + break; + } + ret = ext4_map_blocks(handle, inode, &map, flags); + if (ret <= 0) { +#ifdef EXT4FS_DEBUG + WARN_ON(ret <= 0); + printk(KERN_ERR "%s: ext4_ext_map_blocks " + "returned error inode#%lu, block=%u, " + "max_blocks=%u", __func__, + inode->i_ino, map.m_lblk, max_blocks); +#endif + ext4_mark_inode_dirty(handle, inode); + ret2 = ext4_journal_stop(handle); + break; + } + if ((map.m_lblk + ret) >= (EXT4_BLOCK_ALIGN(offset + len, + blkbits) >> blkbits)) + new_size = offset + len; + else + new_size = ((loff_t) map.m_lblk + ret) << blkbits; + + ext4_falloc_update_inode(inode, mode, new_size, + (map.m_flags & EXT4_MAP_NEW)); + ext4_mark_inode_dirty(handle, inode); + ret2 = ext4_journal_stop(handle); + if (ret2) + break; + } + if (ret == -ENOSPC && + ext4_should_retry_alloc(inode->i_sb, &retries)) { + ret = 0; + goto retry; + } + mutex_unlock(&inode->i_mutex); + trace_ext4_fallocate_exit(inode, offset, max_blocks, + ret > 0 ? ret2 : ret); + return ret > 0 ? ret2 : ret; +} + +/* + * This function convert a range of blocks to written extents + * The caller of this function will pass the start offset and the size. + * all unwritten extents within this range will be converted to + * written extents. + * + * This function is called from the direct IO end io call back + * function, to convert the fallocated extents after IO is completed. + * Returns 0 on success. + */ +int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset, + ssize_t len) +{ + handle_t *handle; + unsigned int max_blocks; + int ret = 0; + int ret2 = 0; + struct ext4_map_blocks map; + unsigned int credits, blkbits = inode->i_blkbits; + + map.m_lblk = offset >> blkbits; + /* + * We can't just convert len to max_blocks because + * If blocksize = 4096 offset = 3072 and len = 2048 + */ + max_blocks = ((EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) - + map.m_lblk); + /* + * credits to insert 1 extent into extent tree + */ + credits = ext4_chunk_trans_blocks(inode, max_blocks); + while (ret >= 0 && ret < max_blocks) { + map.m_lblk += ret; + map.m_len = (max_blocks -= ret); + handle = ext4_journal_start(inode, credits); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + break; + } + ret = ext4_map_blocks(handle, inode, &map, + EXT4_GET_BLOCKS_IO_CONVERT_EXT); + if (ret <= 0) { + WARN_ON(ret <= 0); + ext4_msg(inode->i_sb, KERN_ERR, + "%s:%d: inode #%lu: block %u: len %u: " + "ext4_ext_map_blocks returned %d", + __func__, __LINE__, inode->i_ino, map.m_lblk, + map.m_len, ret); + } + ext4_mark_inode_dirty(handle, inode); + ret2 = ext4_journal_stop(handle); + if (ret <= 0 || ret2 ) + break; + } + return ret > 0 ? ret2 : ret; +} + +/* + * Callback function called for each extent to gather FIEMAP information. + */ +static int ext4_ext_fiemap_cb(struct inode *inode, ext4_lblk_t next, + struct ext4_ext_cache *newex, struct ext4_extent *ex, + void *data) +{ + __u64 logical; + __u64 physical; + __u64 length; + __u32 flags = 0; + int ret = 0; + struct fiemap_extent_info *fieinfo = data; + unsigned char blksize_bits; + + blksize_bits = inode->i_sb->s_blocksize_bits; + logical = (__u64)newex->ec_block << blksize_bits; + + if (newex->ec_start == 0) { + /* + * No extent in extent-tree contains block @newex->ec_start, + * then the block may stay in 1)a hole or 2)delayed-extent. + * + * Holes or delayed-extents are processed as follows. + * 1. lookup dirty pages with specified range in pagecache. + * If no page is got, then there is no delayed-extent and + * return with EXT_CONTINUE. + * 2. find the 1st mapped buffer, + * 3. check if the mapped buffer is both in the request range + * and a delayed buffer. If not, there is no delayed-extent, + * then return. + * 4. a delayed-extent is found, the extent will be collected. + */ + ext4_lblk_t end = 0; + pgoff_t last_offset; + pgoff_t offset; + pgoff_t index; + pgoff_t start_index = 0; + struct page **pages = NULL; + struct buffer_head *bh = NULL; + struct buffer_head *head = NULL; + unsigned int nr_pages = PAGE_SIZE / sizeof(struct page *); + + pages = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (pages == NULL) + return -ENOMEM; + + offset = logical >> PAGE_SHIFT; +repeat: + last_offset = offset; + head = NULL; + ret = find_get_pages_tag(inode->i_mapping, &offset, + PAGECACHE_TAG_DIRTY, nr_pages, pages); + + if (!(flags & FIEMAP_EXTENT_DELALLOC)) { + /* First time, try to find a mapped buffer. */ + if (ret == 0) { +out: + for (index = 0; index < ret; index++) + page_cache_release(pages[index]); + /* just a hole. */ + kfree(pages); + return EXT_CONTINUE; + } + index = 0; + +next_page: + /* Try to find the 1st mapped buffer. */ + end = ((__u64)pages[index]->index << PAGE_SHIFT) >> + blksize_bits; + if (!page_has_buffers(pages[index])) + goto out; + head = page_buffers(pages[index]); + if (!head) + goto out; + + index++; + bh = head; + do { + if (end >= newex->ec_block + + newex->ec_len) + /* The buffer is out of + * the request range. + */ + goto out; + + if (buffer_mapped(bh) && + end >= newex->ec_block) { + start_index = index - 1; + /* get the 1st mapped buffer. */ + goto found_mapped_buffer; + } + + bh = bh->b_this_page; + end++; + } while (bh != head); + + /* No mapped buffer in the range found in this page, + * We need to look up next page. + */ + if (index >= ret) { + /* There is no page left, but we need to limit + * newex->ec_len. + */ + newex->ec_len = end - newex->ec_block; + goto out; + } + goto next_page; + } else { + /*Find contiguous delayed buffers. */ + if (ret > 0 && pages[0]->index == last_offset) + head = page_buffers(pages[0]); + bh = head; + index = 1; + start_index = 0; + } + +found_mapped_buffer: + if (bh != NULL && buffer_delay(bh)) { + /* 1st or contiguous delayed buffer found. */ + if (!(flags & FIEMAP_EXTENT_DELALLOC)) { + /* + * 1st delayed buffer found, record + * the start of extent. + */ + flags |= FIEMAP_EXTENT_DELALLOC; + newex->ec_block = end; + logical = (__u64)end << blksize_bits; + } + /* Find contiguous delayed buffers. */ + do { + if (!buffer_delay(bh)) + goto found_delayed_extent; + bh = bh->b_this_page; + end++; + } while (bh != head); + + for (; index < ret; index++) { + if (!page_has_buffers(pages[index])) { + bh = NULL; + break; + } + head = page_buffers(pages[index]); + if (!head) { + bh = NULL; + break; + } + + if (pages[index]->index != + pages[start_index]->index + index + - start_index) { + /* Blocks are not contiguous. */ + bh = NULL; + break; + } + bh = head; + do { + if (!buffer_delay(bh)) + /* Delayed-extent ends. */ + goto found_delayed_extent; + bh = bh->b_this_page; + end++; + } while (bh != head); + } + } else if (!(flags & FIEMAP_EXTENT_DELALLOC)) + /* a hole found. */ + goto out; + +found_delayed_extent: + newex->ec_len = min(end - newex->ec_block, + (ext4_lblk_t)EXT_INIT_MAX_LEN); + if (ret == nr_pages && bh != NULL && + newex->ec_len < EXT_INIT_MAX_LEN && + buffer_delay(bh)) { + /* Have not collected an extent and continue. */ + for (index = 0; index < ret; index++) + page_cache_release(pages[index]); + goto repeat; + } + + for (index = 0; index < ret; index++) + page_cache_release(pages[index]); + kfree(pages); + } + + physical = (__u64)newex->ec_start << blksize_bits; + length = (__u64)newex->ec_len << blksize_bits; + + if (ex && ext4_ext_is_uninitialized(ex)) + flags |= FIEMAP_EXTENT_UNWRITTEN; + + if (next == EXT_MAX_BLOCKS) + flags |= FIEMAP_EXTENT_LAST; + + ret = fiemap_fill_next_extent(fieinfo, logical, physical, + length, flags); + if (ret < 0) + return ret; + if (ret == 1) + return EXT_BREAK; + return EXT_CONTINUE; +} +/* fiemap flags we can handle specified here */ +#define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR) + +static int ext4_xattr_fiemap(struct inode *inode, + struct fiemap_extent_info *fieinfo) +{ + __u64 physical = 0; + __u64 length; + __u32 flags = FIEMAP_EXTENT_LAST; + int blockbits = inode->i_sb->s_blocksize_bits; + int error = 0; + + /* in-inode? */ + if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { + struct ext4_iloc iloc; + int offset; /* offset of xattr in inode */ + + error = ext4_get_inode_loc(inode, &iloc); + if (error) + return error; + physical = iloc.bh->b_blocknr << blockbits; + offset = EXT4_GOOD_OLD_INODE_SIZE + + EXT4_I(inode)->i_extra_isize; + physical += offset; + length = EXT4_SB(inode->i_sb)->s_inode_size - offset; + flags |= FIEMAP_EXTENT_DATA_INLINE; + brelse(iloc.bh); + } else { /* external block */ + physical = EXT4_I(inode)->i_file_acl << blockbits; + length = inode->i_sb->s_blocksize; + } + + if (physical) + error = fiemap_fill_next_extent(fieinfo, 0, physical, + length, flags); + return (error < 0 ? error : 0); +} + +/* + * ext4_ext_punch_hole + * + * Punches a hole of "length" bytes in a file starting + * at byte "offset" + * + * @inode: The inode of the file to punch a hole in + * @offset: The starting byte offset of the hole + * @length: The length of the hole + * + * Returns the number of blocks removed or negative on err + */ +int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length) +{ + struct inode *inode = file->f_path.dentry->d_inode; + struct super_block *sb = inode->i_sb; + ext4_lblk_t first_block, stop_block; + struct address_space *mapping = inode->i_mapping; + handle_t *handle; + loff_t first_page, last_page, page_len; + loff_t first_page_offset, last_page_offset; + int credits, err = 0; + + /* No need to punch hole beyond i_size */ + if (offset >= inode->i_size) + return 0; + + /* + * If the hole extends beyond i_size, set the hole + * to end after the page that contains i_size + */ + if (offset + length > inode->i_size) { + length = inode->i_size + + PAGE_CACHE_SIZE - (inode->i_size & (PAGE_CACHE_SIZE - 1)) - + offset; + } + + first_page = (offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; + last_page = (offset + length) >> PAGE_CACHE_SHIFT; + + first_page_offset = first_page << PAGE_CACHE_SHIFT; + last_page_offset = last_page << PAGE_CACHE_SHIFT; + + /* + * Write out all dirty pages to avoid race conditions + * Then release them. + */ + if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) { + err = filemap_write_and_wait_range(mapping, + offset, offset + length - 1); + + if (err) + return err; + } + + /* Now release the pages */ + if (last_page_offset > first_page_offset) { + truncate_inode_pages_range(mapping, first_page_offset, + last_page_offset-1); + } + + /* finish any pending end_io work */ + ext4_flush_completed_IO(inode); + + credits = ext4_writepage_trans_blocks(inode); + handle = ext4_journal_start(inode, credits); + if (IS_ERR(handle)) + return PTR_ERR(handle); + + err = ext4_orphan_add(handle, inode); + if (err) + goto out; + + /* + * Now we need to zero out the non-page-aligned data in the + * pages at the start and tail of the hole, and unmap the buffer + * heads for the block aligned regions of the page that were + * completely zeroed. + */ + if (first_page > last_page) { + /* + * If the file space being truncated is contained within a page + * just zero out and unmap the middle of that page + */ + err = ext4_discard_partial_page_buffers(handle, + mapping, offset, length, 0); + + if (err) + goto out; + } else { + /* + * zero out and unmap the partial page that contains + * the start of the hole + */ + page_len = first_page_offset - offset; + if (page_len > 0) { + err = ext4_discard_partial_page_buffers(handle, mapping, + offset, page_len, 0); + if (err) + goto out; + } + + /* + * zero out and unmap the partial page that contains + * the end of the hole + */ + page_len = offset + length - last_page_offset; + if (page_len > 0) { + err = ext4_discard_partial_page_buffers(handle, mapping, + last_page_offset, page_len, 0); + if (err) + goto out; + } + } + + /* + * If i_size is contained in the last page, we need to + * unmap and zero the partial page after i_size + */ + if (inode->i_size >> PAGE_CACHE_SHIFT == last_page && + inode->i_size % PAGE_CACHE_SIZE != 0) { + + page_len = PAGE_CACHE_SIZE - + (inode->i_size & (PAGE_CACHE_SIZE - 1)); + + if (page_len > 0) { + err = ext4_discard_partial_page_buffers(handle, + mapping, inode->i_size, page_len, 0); + + if (err) + goto out; + } + } + + first_block = (offset + sb->s_blocksize - 1) >> + EXT4_BLOCK_SIZE_BITS(sb); + stop_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb); + + /* If there are no blocks to remove, return now */ + if (first_block >= stop_block) + goto out; + + down_write(&EXT4_I(inode)->i_data_sem); + ext4_ext_invalidate_cache(inode); + ext4_discard_preallocations(inode); + + err = ext4_ext_remove_space(inode, first_block, stop_block - 1); + + ext4_ext_invalidate_cache(inode); + ext4_discard_preallocations(inode); + + if (IS_SYNC(inode)) + ext4_handle_sync(handle); + + up_write(&EXT4_I(inode)->i_data_sem); + +out: + ext4_orphan_del(handle, inode); + inode->i_mtime = inode->i_ctime = ext4_current_time(inode); + ext4_mark_inode_dirty(handle, inode); + ext4_journal_stop(handle); + return err; +} +int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, + __u64 start, __u64 len) +{ + ext4_lblk_t start_blk; + int error = 0; + + /* fallback to generic here if not in extents fmt */ + if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) + return generic_block_fiemap(inode, fieinfo, start, len, + ext4_get_block); + + if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS)) + return -EBADR; + + if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) { + error = ext4_xattr_fiemap(inode, fieinfo); + } else { + ext4_lblk_t len_blks; + __u64 last_blk; + + start_blk = start >> inode->i_sb->s_blocksize_bits; + last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits; + if (last_blk >= EXT_MAX_BLOCKS) + last_blk = EXT_MAX_BLOCKS-1; + len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1; + + /* + * Walk the extent tree gathering extent information. + * ext4_ext_fiemap_cb will push extents back to user. + */ + error = ext4_ext_walk_space(inode, start_blk, len_blks, + ext4_ext_fiemap_cb, fieinfo); + } + + return error; +} |