diff options
Diffstat (limited to 'fs/ext4/namei.c')
| -rw-r--r-- | fs/ext4/namei.c | 2607 |
1 files changed, 2607 insertions, 0 deletions
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c new file mode 100644 index 00000000..0a94cbbe --- /dev/null +++ b/fs/ext4/namei.c @@ -0,0 +1,2607 @@ +/* + * linux/fs/ext4/namei.c + * + * Copyright (C) 1992, 1993, 1994, 1995 + * Remy Card (card@masi.ibp.fr) + * Laboratoire MASI - Institut Blaise Pascal + * Universite Pierre et Marie Curie (Paris VI) + * + * from + * + * linux/fs/minix/namei.c + * + * Copyright (C) 1991, 1992 Linus Torvalds + * + * Big-endian to little-endian byte-swapping/bitmaps by + * David S. Miller (davem@caip.rutgers.edu), 1995 + * Directory entry file type support and forward compatibility hooks + * for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998 + * Hash Tree Directory indexing (c) + * Daniel Phillips, 2001 + * Hash Tree Directory indexing porting + * Christopher Li, 2002 + * Hash Tree Directory indexing cleanup + * Theodore Ts'o, 2002 + */ + +#include <linux/fs.h> +#include <linux/pagemap.h> +#include <linux/jbd2.h> +#include <linux/time.h> +#include <linux/fcntl.h> +#include <linux/stat.h> +#include <linux/string.h> +#include <linux/quotaops.h> +#include <linux/buffer_head.h> +#include <linux/bio.h> +#include "ext4.h" +#include "ext4_jbd2.h" + +#include "xattr.h" +#include "acl.h" + +#include <trace/events/ext4.h> +/* + * define how far ahead to read directories while searching them. + */ +#define NAMEI_RA_CHUNKS 2 +#define NAMEI_RA_BLOCKS 4 +#define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS) +#define NAMEI_RA_INDEX(c,b) (((c) * NAMEI_RA_BLOCKS) + (b)) + +static struct buffer_head *ext4_append(handle_t *handle, + struct inode *inode, + ext4_lblk_t *block, int *err) +{ + struct buffer_head *bh; + + *block = inode->i_size >> inode->i_sb->s_blocksize_bits; + + bh = ext4_bread(handle, inode, *block, 1, err); + if (bh) { + inode->i_size += inode->i_sb->s_blocksize; + EXT4_I(inode)->i_disksize = inode->i_size; + *err = ext4_journal_get_write_access(handle, bh); + if (*err) { + brelse(bh); + bh = NULL; + } + } + return bh; +} + +#ifndef assert +#define assert(test) J_ASSERT(test) +#endif + +#ifdef DX_DEBUG +#define dxtrace(command) command +#else +#define dxtrace(command) +#endif + +struct fake_dirent +{ + __le32 inode; + __le16 rec_len; + u8 name_len; + u8 file_type; +}; + +struct dx_countlimit +{ + __le16 limit; + __le16 count; +}; + +struct dx_entry +{ + __le32 hash; + __le32 block; +}; + +/* + * dx_root_info is laid out so that if it should somehow get overlaid by a + * dirent the two low bits of the hash version will be zero. Therefore, the + * hash version mod 4 should never be 0. Sincerely, the paranoia department. + */ + +struct dx_root +{ + struct fake_dirent dot; + char dot_name[4]; + struct fake_dirent dotdot; + char dotdot_name[4]; + struct dx_root_info + { + __le32 reserved_zero; + u8 hash_version; + u8 info_length; /* 8 */ + u8 indirect_levels; + u8 unused_flags; + } + info; + struct dx_entry entries[0]; +}; + +struct dx_node +{ + struct fake_dirent fake; + struct dx_entry entries[0]; +}; + + +struct dx_frame +{ + struct buffer_head *bh; + struct dx_entry *entries; + struct dx_entry *at; +}; + +struct dx_map_entry +{ + u32 hash; + u16 offs; + u16 size; +}; + +static inline ext4_lblk_t dx_get_block(struct dx_entry *entry); +static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value); +static inline unsigned dx_get_hash(struct dx_entry *entry); +static void dx_set_hash(struct dx_entry *entry, unsigned value); +static unsigned dx_get_count(struct dx_entry *entries); +static unsigned dx_get_limit(struct dx_entry *entries); +static void dx_set_count(struct dx_entry *entries, unsigned value); +static void dx_set_limit(struct dx_entry *entries, unsigned value); +static unsigned dx_root_limit(struct inode *dir, unsigned infosize); +static unsigned dx_node_limit(struct inode *dir); +static struct dx_frame *dx_probe(const struct qstr *d_name, + struct inode *dir, + struct dx_hash_info *hinfo, + struct dx_frame *frame, + int *err); +static void dx_release(struct dx_frame *frames); +static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize, + struct dx_hash_info *hinfo, struct dx_map_entry map[]); +static void dx_sort_map(struct dx_map_entry *map, unsigned count); +static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to, + struct dx_map_entry *offsets, int count, unsigned blocksize); +static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize); +static void dx_insert_block(struct dx_frame *frame, + u32 hash, ext4_lblk_t block); +static int ext4_htree_next_block(struct inode *dir, __u32 hash, + struct dx_frame *frame, + struct dx_frame *frames, + __u32 *start_hash); +static struct buffer_head * ext4_dx_find_entry(struct inode *dir, + const struct qstr *d_name, + struct ext4_dir_entry_2 **res_dir, + int *err); +static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry, + struct inode *inode); + +/* + * p is at least 6 bytes before the end of page + */ +static inline struct ext4_dir_entry_2 * +ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize) +{ + return (struct ext4_dir_entry_2 *)((char *)p + + ext4_rec_len_from_disk(p->rec_len, blocksize)); +} + +/* + * Future: use high four bits of block for coalesce-on-delete flags + * Mask them off for now. + */ + +static inline ext4_lblk_t dx_get_block(struct dx_entry *entry) +{ + return le32_to_cpu(entry->block) & 0x00ffffff; +} + +static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value) +{ + entry->block = cpu_to_le32(value); +} + +static inline unsigned dx_get_hash(struct dx_entry *entry) +{ + return le32_to_cpu(entry->hash); +} + +static inline void dx_set_hash(struct dx_entry *entry, unsigned value) +{ + entry->hash = cpu_to_le32(value); +} + +static inline unsigned dx_get_count(struct dx_entry *entries) +{ + return le16_to_cpu(((struct dx_countlimit *) entries)->count); +} + +static inline unsigned dx_get_limit(struct dx_entry *entries) +{ + return le16_to_cpu(((struct dx_countlimit *) entries)->limit); +} + +static inline void dx_set_count(struct dx_entry *entries, unsigned value) +{ + ((struct dx_countlimit *) entries)->count = cpu_to_le16(value); +} + +static inline void dx_set_limit(struct dx_entry *entries, unsigned value) +{ + ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value); +} + +static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize) +{ + unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) - + EXT4_DIR_REC_LEN(2) - infosize; + return entry_space / sizeof(struct dx_entry); +} + +static inline unsigned dx_node_limit(struct inode *dir) +{ + unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0); + return entry_space / sizeof(struct dx_entry); +} + +/* + * Debug + */ +#ifdef DX_DEBUG +static void dx_show_index(char * label, struct dx_entry *entries) +{ + int i, n = dx_get_count (entries); + printk(KERN_DEBUG "%s index ", label); + for (i = 0; i < n; i++) { + printk("%x->%lu ", i ? dx_get_hash(entries + i) : + 0, (unsigned long)dx_get_block(entries + i)); + } + printk("\n"); +} + +struct stats +{ + unsigned names; + unsigned space; + unsigned bcount; +}; + +static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de, + int size, int show_names) +{ + unsigned names = 0, space = 0; + char *base = (char *) de; + struct dx_hash_info h = *hinfo; + + printk("names: "); + while ((char *) de < base + size) + { + if (de->inode) + { + if (show_names) + { + int len = de->name_len; + char *name = de->name; + while (len--) printk("%c", *name++); + ext4fs_dirhash(de->name, de->name_len, &h); + printk(":%x.%u ", h.hash, + (unsigned) ((char *) de - base)); + } + space += EXT4_DIR_REC_LEN(de->name_len); + names++; + } + de = ext4_next_entry(de, size); + } + printk("(%i)\n", names); + return (struct stats) { names, space, 1 }; +} + +struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir, + struct dx_entry *entries, int levels) +{ + unsigned blocksize = dir->i_sb->s_blocksize; + unsigned count = dx_get_count(entries), names = 0, space = 0, i; + unsigned bcount = 0; + struct buffer_head *bh; + int err; + printk("%i indexed blocks...\n", count); + for (i = 0; i < count; i++, entries++) + { + ext4_lblk_t block = dx_get_block(entries); + ext4_lblk_t hash = i ? dx_get_hash(entries): 0; + u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash; + struct stats stats; + printk("%s%3u:%03u hash %8x/%8x ",levels?"":" ", i, block, hash, range); + if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue; + stats = levels? + dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1): + dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0); + names += stats.names; + space += stats.space; + bcount += stats.bcount; + brelse(bh); + } + if (bcount) + printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n", + levels ? "" : " ", names, space/bcount, + (space/bcount)*100/blocksize); + return (struct stats) { names, space, bcount}; +} +#endif /* DX_DEBUG */ + +/* + * Probe for a directory leaf block to search. + * + * dx_probe can return ERR_BAD_DX_DIR, which means there was a format + * error in the directory index, and the caller should fall back to + * searching the directory normally. The callers of dx_probe **MUST** + * check for this error code, and make sure it never gets reflected + * back to userspace. + */ +static struct dx_frame * +dx_probe(const struct qstr *d_name, struct inode *dir, + struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err) +{ + unsigned count, indirect; + struct dx_entry *at, *entries, *p, *q, *m; + struct dx_root *root; + struct buffer_head *bh; + struct dx_frame *frame = frame_in; + u32 hash; + + frame->bh = NULL; + if (!(bh = ext4_bread (NULL,dir, 0, 0, err))) + goto fail; + root = (struct dx_root *) bh->b_data; + if (root->info.hash_version != DX_HASH_TEA && + root->info.hash_version != DX_HASH_HALF_MD4 && + root->info.hash_version != DX_HASH_LEGACY) { + ext4_warning(dir->i_sb, "Unrecognised inode hash code %d", + root->info.hash_version); + brelse(bh); + *err = ERR_BAD_DX_DIR; + goto fail; + } + hinfo->hash_version = root->info.hash_version; + if (hinfo->hash_version <= DX_HASH_TEA) + hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; + hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed; + if (d_name) + ext4fs_dirhash(d_name->name, d_name->len, hinfo); + hash = hinfo->hash; + + if (root->info.unused_flags & 1) { + ext4_warning(dir->i_sb, "Unimplemented inode hash flags: %#06x", + root->info.unused_flags); + brelse(bh); + *err = ERR_BAD_DX_DIR; + goto fail; + } + + if ((indirect = root->info.indirect_levels) > 1) { + ext4_warning(dir->i_sb, "Unimplemented inode hash depth: %#06x", + root->info.indirect_levels); + brelse(bh); + *err = ERR_BAD_DX_DIR; + goto fail; + } + + entries = (struct dx_entry *) (((char *)&root->info) + + root->info.info_length); + + if (dx_get_limit(entries) != dx_root_limit(dir, + root->info.info_length)) { + ext4_warning(dir->i_sb, "dx entry: limit != root limit"); + brelse(bh); + *err = ERR_BAD_DX_DIR; + goto fail; + } + + dxtrace(printk("Look up %x", hash)); + while (1) + { + count = dx_get_count(entries); + if (!count || count > dx_get_limit(entries)) { + ext4_warning(dir->i_sb, + "dx entry: no count or count > limit"); + brelse(bh); + *err = ERR_BAD_DX_DIR; + goto fail2; + } + + p = entries + 1; + q = entries + count - 1; + while (p <= q) + { + m = p + (q - p)/2; + dxtrace(printk(".")); + if (dx_get_hash(m) > hash) + q = m - 1; + else + p = m + 1; + } + + if (0) // linear search cross check + { + unsigned n = count - 1; + at = entries; + while (n--) + { + dxtrace(printk(",")); + if (dx_get_hash(++at) > hash) + { + at--; + break; + } + } + assert (at == p - 1); + } + + at = p - 1; + dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at))); + frame->bh = bh; + frame->entries = entries; + frame->at = at; + if (!indirect--) return frame; + if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err))) + goto fail2; + at = entries = ((struct dx_node *) bh->b_data)->entries; + if (dx_get_limit(entries) != dx_node_limit (dir)) { + ext4_warning(dir->i_sb, + "dx entry: limit != node limit"); + brelse(bh); + *err = ERR_BAD_DX_DIR; + goto fail2; + } + frame++; + frame->bh = NULL; + } +fail2: + while (frame >= frame_in) { + brelse(frame->bh); + frame--; + } +fail: + if (*err == ERR_BAD_DX_DIR) + ext4_warning(dir->i_sb, + "Corrupt dir inode %lu, running e2fsck is " + "recommended.", dir->i_ino); + return NULL; +} + +static void dx_release (struct dx_frame *frames) +{ + if (frames[0].bh == NULL) + return; + + if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels) + brelse(frames[1].bh); + brelse(frames[0].bh); +} + +/* + * This function increments the frame pointer to search the next leaf + * block, and reads in the necessary intervening nodes if the search + * should be necessary. Whether or not the search is necessary is + * controlled by the hash parameter. If the hash value is even, then + * the search is only continued if the next block starts with that + * hash value. This is used if we are searching for a specific file. + * + * If the hash value is HASH_NB_ALWAYS, then always go to the next block. + * + * This function returns 1 if the caller should continue to search, + * or 0 if it should not. If there is an error reading one of the + * index blocks, it will a negative error code. + * + * If start_hash is non-null, it will be filled in with the starting + * hash of the next page. + */ +static int ext4_htree_next_block(struct inode *dir, __u32 hash, + struct dx_frame *frame, + struct dx_frame *frames, + __u32 *start_hash) +{ + struct dx_frame *p; + struct buffer_head *bh; + int err, num_frames = 0; + __u32 bhash; + + p = frame; + /* + * Find the next leaf page by incrementing the frame pointer. + * If we run out of entries in the interior node, loop around and + * increment pointer in the parent node. When we break out of + * this loop, num_frames indicates the number of interior + * nodes need to be read. + */ + while (1) { + if (++(p->at) < p->entries + dx_get_count(p->entries)) + break; + if (p == frames) + return 0; + num_frames++; + p--; + } + + /* + * If the hash is 1, then continue only if the next page has a + * continuation hash of any value. This is used for readdir + * handling. Otherwise, check to see if the hash matches the + * desired contiuation hash. If it doesn't, return since + * there's no point to read in the successive index pages. + */ + bhash = dx_get_hash(p->at); + if (start_hash) + *start_hash = bhash; + if ((hash & 1) == 0) { + if ((bhash & ~1) != hash) + return 0; + } + /* + * If the hash is HASH_NB_ALWAYS, we always go to the next + * block so no check is necessary + */ + while (num_frames--) { + if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at), + 0, &err))) + return err; /* Failure */ + p++; + brelse(p->bh); + p->bh = bh; + p->at = p->entries = ((struct dx_node *) bh->b_data)->entries; + } + return 1; +} + + +/* + * This function fills a red-black tree with information from a + * directory block. It returns the number directory entries loaded + * into the tree. If there is an error it is returned in err. + */ +static int htree_dirblock_to_tree(struct file *dir_file, + struct inode *dir, ext4_lblk_t block, + struct dx_hash_info *hinfo, + __u32 start_hash, __u32 start_minor_hash) +{ + struct buffer_head *bh; + struct ext4_dir_entry_2 *de, *top; + int err, count = 0; + + dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n", + (unsigned long)block)); + if (!(bh = ext4_bread (NULL, dir, block, 0, &err))) + return err; + + de = (struct ext4_dir_entry_2 *) bh->b_data; + top = (struct ext4_dir_entry_2 *) ((char *) de + + dir->i_sb->s_blocksize - + EXT4_DIR_REC_LEN(0)); + for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) { + if (ext4_check_dir_entry(dir, NULL, de, bh, + (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb)) + + ((char *)de - bh->b_data))) { + /* On error, skip the f_pos to the next block. */ + dir_file->f_pos = (dir_file->f_pos | + (dir->i_sb->s_blocksize - 1)) + 1; + brelse(bh); + return count; + } + ext4fs_dirhash(de->name, de->name_len, hinfo); + if ((hinfo->hash < start_hash) || + ((hinfo->hash == start_hash) && + (hinfo->minor_hash < start_minor_hash))) + continue; + if (de->inode == 0) + continue; + if ((err = ext4_htree_store_dirent(dir_file, + hinfo->hash, hinfo->minor_hash, de)) != 0) { + brelse(bh); + return err; + } + count++; + } + brelse(bh); + return count; +} + + +/* + * This function fills a red-black tree with information from a + * directory. We start scanning the directory in hash order, starting + * at start_hash and start_minor_hash. + * + * This function returns the number of entries inserted into the tree, + * or a negative error code. + */ +int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash, + __u32 start_minor_hash, __u32 *next_hash) +{ + struct dx_hash_info hinfo; + struct ext4_dir_entry_2 *de; + struct dx_frame frames[2], *frame; + struct inode *dir; + ext4_lblk_t block; + int count = 0; + int ret, err; + __u32 hashval; + + dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n", + start_hash, start_minor_hash)); + dir = dir_file->f_path.dentry->d_inode; + if (!(ext4_test_inode_flag(dir, EXT4_INODE_INDEX))) { + hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; + if (hinfo.hash_version <= DX_HASH_TEA) + hinfo.hash_version += + EXT4_SB(dir->i_sb)->s_hash_unsigned; + hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; + count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo, + start_hash, start_minor_hash); + *next_hash = ~0; + return count; + } + hinfo.hash = start_hash; + hinfo.minor_hash = 0; + frame = dx_probe(NULL, dir, &hinfo, frames, &err); + if (!frame) + return err; + + /* Add '.' and '..' from the htree header */ + if (!start_hash && !start_minor_hash) { + de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; + if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0) + goto errout; + count++; + } + if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) { + de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; + de = ext4_next_entry(de, dir->i_sb->s_blocksize); + if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0) + goto errout; + count++; + } + + while (1) { + block = dx_get_block(frame->at); + ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo, + start_hash, start_minor_hash); + if (ret < 0) { + err = ret; + goto errout; + } + count += ret; + hashval = ~0; + ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS, + frame, frames, &hashval); + *next_hash = hashval; + if (ret < 0) { + err = ret; + goto errout; + } + /* + * Stop if: (a) there are no more entries, or + * (b) we have inserted at least one entry and the + * next hash value is not a continuation + */ + if ((ret == 0) || + (count && ((hashval & 1) == 0))) + break; + } + dx_release(frames); + dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, " + "next hash: %x\n", count, *next_hash)); + return count; +errout: + dx_release(frames); + return (err); +} + + +/* + * Directory block splitting, compacting + */ + +/* + * Create map of hash values, offsets, and sizes, stored at end of block. + * Returns number of entries mapped. + */ +static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize, + struct dx_hash_info *hinfo, + struct dx_map_entry *map_tail) +{ + int count = 0; + char *base = (char *) de; + struct dx_hash_info h = *hinfo; + + while ((char *) de < base + blocksize) { + if (de->name_len && de->inode) { + ext4fs_dirhash(de->name, de->name_len, &h); + map_tail--; + map_tail->hash = h.hash; + map_tail->offs = ((char *) de - base)>>2; + map_tail->size = le16_to_cpu(de->rec_len); + count++; + cond_resched(); + } + /* XXX: do we need to check rec_len == 0 case? -Chris */ + de = ext4_next_entry(de, blocksize); + } + return count; +} + +/* Sort map by hash value */ +static void dx_sort_map (struct dx_map_entry *map, unsigned count) +{ + struct dx_map_entry *p, *q, *top = map + count - 1; + int more; + /* Combsort until bubble sort doesn't suck */ + while (count > 2) { + count = count*10/13; + if (count - 9 < 2) /* 9, 10 -> 11 */ + count = 11; + for (p = top, q = p - count; q >= map; p--, q--) + if (p->hash < q->hash) + swap(*p, *q); + } + /* Garden variety bubble sort */ + do { + more = 0; + q = top; + while (q-- > map) { + if (q[1].hash >= q[0].hash) + continue; + swap(*(q+1), *q); + more = 1; + } + } while(more); +} + +static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block) +{ + struct dx_entry *entries = frame->entries; + struct dx_entry *old = frame->at, *new = old + 1; + int count = dx_get_count(entries); + + assert(count < dx_get_limit(entries)); + assert(old < entries + count); + memmove(new + 1, new, (char *)(entries + count) - (char *)(new)); + dx_set_hash(new, hash); + dx_set_block(new, block); + dx_set_count(entries, count + 1); +} + +static void ext4_update_dx_flag(struct inode *inode) +{ + if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb, + EXT4_FEATURE_COMPAT_DIR_INDEX)) + ext4_clear_inode_flag(inode, EXT4_INODE_INDEX); +} + +/* + * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure. + * + * `len <= EXT4_NAME_LEN' is guaranteed by caller. + * `de != NULL' is guaranteed by caller. + */ +static inline int ext4_match (int len, const char * const name, + struct ext4_dir_entry_2 * de) +{ + if (len != de->name_len) + return 0; + if (!de->inode) + return 0; + return !memcmp(name, de->name, len); +} + +/* + * Returns 0 if not found, -1 on failure, and 1 on success + */ +static inline int search_dirblock(struct buffer_head *bh, + struct inode *dir, + const struct qstr *d_name, + unsigned int offset, + struct ext4_dir_entry_2 ** res_dir) +{ + struct ext4_dir_entry_2 * de; + char * dlimit; + int de_len; + const char *name = d_name->name; + int namelen = d_name->len; + + de = (struct ext4_dir_entry_2 *) bh->b_data; + dlimit = bh->b_data + dir->i_sb->s_blocksize; + while ((char *) de < dlimit) { + /* this code is executed quadratically often */ + /* do minimal checking `by hand' */ + + if ((char *) de + namelen <= dlimit && + ext4_match (namelen, name, de)) { + /* found a match - just to be sure, do a full check */ + if (ext4_check_dir_entry(dir, NULL, de, bh, offset)) + return -1; + *res_dir = de; + return 1; + } + /* prevent looping on a bad block */ + de_len = ext4_rec_len_from_disk(de->rec_len, + dir->i_sb->s_blocksize); + if (de_len <= 0) + return -1; + offset += de_len; + de = (struct ext4_dir_entry_2 *) ((char *) de + de_len); + } + return 0; +} + + +/* + * ext4_find_entry() + * + * finds an entry in the specified directory with the wanted name. It + * returns the cache buffer in which the entry was found, and the entry + * itself (as a parameter - res_dir). It does NOT read the inode of the + * entry - you'll have to do that yourself if you want to. + * + * The returned buffer_head has ->b_count elevated. The caller is expected + * to brelse() it when appropriate. + */ +static struct buffer_head * ext4_find_entry (struct inode *dir, + const struct qstr *d_name, + struct ext4_dir_entry_2 ** res_dir) +{ + struct super_block *sb; + struct buffer_head *bh_use[NAMEI_RA_SIZE]; + struct buffer_head *bh, *ret = NULL; + ext4_lblk_t start, block, b; + const u8 *name = d_name->name; + int ra_max = 0; /* Number of bh's in the readahead + buffer, bh_use[] */ + int ra_ptr = 0; /* Current index into readahead + buffer */ + int num = 0; + ext4_lblk_t nblocks; + int i, err; + int namelen; + + *res_dir = NULL; + sb = dir->i_sb; + namelen = d_name->len; + if (namelen > EXT4_NAME_LEN) + return NULL; + if ((namelen <= 2) && (name[0] == '.') && + (name[1] == '.' || name[1] == '\0')) { + /* + * "." or ".." will only be in the first block + * NFS may look up ".."; "." should be handled by the VFS + */ + block = start = 0; + nblocks = 1; + goto restart; + } + if (is_dx(dir)) { + bh = ext4_dx_find_entry(dir, d_name, res_dir, &err); + /* + * On success, or if the error was file not found, + * return. Otherwise, fall back to doing a search the + * old fashioned way. + */ + if (bh || (err != ERR_BAD_DX_DIR)) + return bh; + dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, " + "falling back\n")); + } + nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); + start = EXT4_I(dir)->i_dir_start_lookup; + if (start >= nblocks) + start = 0; + block = start; +restart: + do { + /* + * We deal with the read-ahead logic here. + */ + if (ra_ptr >= ra_max) { + /* Refill the readahead buffer */ + ra_ptr = 0; + b = block; + for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) { + /* + * Terminate if we reach the end of the + * directory and must wrap, or if our + * search has finished at this block. + */ + if (b >= nblocks || (num && block == start)) { + bh_use[ra_max] = NULL; + break; + } + num++; + bh = ext4_getblk(NULL, dir, b++, 0, &err); + bh_use[ra_max] = bh; + if (bh) + ll_rw_block(READ | REQ_META | REQ_PRIO, + 1, &bh); + } + } + if ((bh = bh_use[ra_ptr++]) == NULL) + goto next; + wait_on_buffer(bh); + if (!buffer_uptodate(bh)) { + /* read error, skip block & hope for the best */ + EXT4_ERROR_INODE(dir, "reading directory lblock %lu", + (unsigned long) block); + brelse(bh); + goto next; + } + i = search_dirblock(bh, dir, d_name, + block << EXT4_BLOCK_SIZE_BITS(sb), res_dir); + if (i == 1) { + EXT4_I(dir)->i_dir_start_lookup = block; + ret = bh; + goto cleanup_and_exit; + } else { + brelse(bh); + if (i < 0) + goto cleanup_and_exit; + } + next: + if (++block >= nblocks) + block = 0; + } while (block != start); + + /* + * If the directory has grown while we were searching, then + * search the last part of the directory before giving up. + */ + block = nblocks; + nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); + if (block < nblocks) { + start = 0; + goto restart; + } + +cleanup_and_exit: + /* Clean up the read-ahead blocks */ + for (; ra_ptr < ra_max; ra_ptr++) + brelse(bh_use[ra_ptr]); + return ret; +} + +static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name, + struct ext4_dir_entry_2 **res_dir, int *err) +{ + struct super_block * sb = dir->i_sb; + struct dx_hash_info hinfo; + struct dx_frame frames[2], *frame; + struct buffer_head *bh; + ext4_lblk_t block; + int retval; + + if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err))) + return NULL; + do { + block = dx_get_block(frame->at); + if (!(bh = ext4_bread(NULL, dir, block, 0, err))) + goto errout; + + retval = search_dirblock(bh, dir, d_name, + block << EXT4_BLOCK_SIZE_BITS(sb), + res_dir); + if (retval == 1) { /* Success! */ + dx_release(frames); + return bh; + } + brelse(bh); + if (retval == -1) { + *err = ERR_BAD_DX_DIR; + goto errout; + } + + /* Check to see if we should continue to search */ + retval = ext4_htree_next_block(dir, hinfo.hash, frame, + frames, NULL); + if (retval < 0) { + ext4_warning(sb, + "error reading index page in directory #%lu", + dir->i_ino); + *err = retval; + goto errout; + } + } while (retval == 1); + + *err = -ENOENT; +errout: + dxtrace(printk(KERN_DEBUG "%s not found\n", d_name->name)); + dx_release (frames); + return NULL; +} + +static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) +{ + struct inode *inode; + struct ext4_dir_entry_2 *de; + struct buffer_head *bh; + + if (dentry->d_name.len > EXT4_NAME_LEN) + return ERR_PTR(-ENAMETOOLONG); + + bh = ext4_find_entry(dir, &dentry->d_name, &de); + inode = NULL; + if (bh) { + __u32 ino = le32_to_cpu(de->inode); + brelse(bh); + if (!ext4_valid_inum(dir->i_sb, ino)) { + EXT4_ERROR_INODE(dir, "bad inode number: %u", ino); + return ERR_PTR(-EIO); + } + if (unlikely(ino == dir->i_ino)) { + EXT4_ERROR_INODE(dir, "'%.*s' linked to parent dir", + dentry->d_name.len, + dentry->d_name.name); + return ERR_PTR(-EIO); + } + inode = ext4_iget(dir->i_sb, ino); + if (inode == ERR_PTR(-ESTALE)) { + EXT4_ERROR_INODE(dir, + "deleted inode referenced: %u", + ino); + return ERR_PTR(-EIO); + } + } + return d_splice_alias(inode, dentry); +} + + +struct dentry *ext4_get_parent(struct dentry *child) +{ + __u32 ino; + static const struct qstr dotdot = { + .name = "..", + .len = 2, + }; + struct ext4_dir_entry_2 * de; + struct buffer_head *bh; + + bh = ext4_find_entry(child->d_inode, &dotdot, &de); + if (!bh) + return ERR_PTR(-ENOENT); + ino = le32_to_cpu(de->inode); + brelse(bh); + + if (!ext4_valid_inum(child->d_inode->i_sb, ino)) { + EXT4_ERROR_INODE(child->d_inode, + "bad parent inode number: %u", ino); + return ERR_PTR(-EIO); + } + + return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino)); +} + +#define S_SHIFT 12 +static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = { + [S_IFREG >> S_SHIFT] = EXT4_FT_REG_FILE, + [S_IFDIR >> S_SHIFT] = EXT4_FT_DIR, + [S_IFCHR >> S_SHIFT] = EXT4_FT_CHRDEV, + [S_IFBLK >> S_SHIFT] = EXT4_FT_BLKDEV, + [S_IFIFO >> S_SHIFT] = EXT4_FT_FIFO, + [S_IFSOCK >> S_SHIFT] = EXT4_FT_SOCK, + [S_IFLNK >> S_SHIFT] = EXT4_FT_SYMLINK, +}; + +static inline void ext4_set_de_type(struct super_block *sb, + struct ext4_dir_entry_2 *de, + umode_t mode) { + if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE)) + de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT]; +} + +/* + * Move count entries from end of map between two memory locations. + * Returns pointer to last entry moved. + */ +static struct ext4_dir_entry_2 * +dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count, + unsigned blocksize) +{ + unsigned rec_len = 0; + + while (count--) { + struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) + (from + (map->offs<<2)); + rec_len = EXT4_DIR_REC_LEN(de->name_len); + memcpy (to, de, rec_len); + ((struct ext4_dir_entry_2 *) to)->rec_len = + ext4_rec_len_to_disk(rec_len, blocksize); + de->inode = 0; + map++; + to += rec_len; + } + return (struct ext4_dir_entry_2 *) (to - rec_len); +} + +/* + * Compact each dir entry in the range to the minimal rec_len. + * Returns pointer to last entry in range. + */ +static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize) +{ + struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base; + unsigned rec_len = 0; + + prev = to = de; + while ((char*)de < base + blocksize) { + next = ext4_next_entry(de, blocksize); + if (de->inode && de->name_len) { + rec_len = EXT4_DIR_REC_LEN(de->name_len); + if (de > to) + memmove(to, de, rec_len); + to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize); + prev = to; + to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len); + } + de = next; + } + return prev; +} + +/* + * Split a full leaf block to make room for a new dir entry. + * Allocate a new block, and move entries so that they are approx. equally full. + * Returns pointer to de in block into which the new entry will be inserted. + */ +static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir, + struct buffer_head **bh,struct dx_frame *frame, + struct dx_hash_info *hinfo, int *error) +{ + unsigned blocksize = dir->i_sb->s_blocksize; + unsigned count, continued; + struct buffer_head *bh2; + ext4_lblk_t newblock; + u32 hash2; + struct dx_map_entry *map; + char *data1 = (*bh)->b_data, *data2; + unsigned split, move, size; + struct ext4_dir_entry_2 *de = NULL, *de2; + int err = 0, i; + + bh2 = ext4_append (handle, dir, &newblock, &err); + if (!(bh2)) { + brelse(*bh); + *bh = NULL; + goto errout; + } + + BUFFER_TRACE(*bh, "get_write_access"); + err = ext4_journal_get_write_access(handle, *bh); + if (err) + goto journal_error; + + BUFFER_TRACE(frame->bh, "get_write_access"); + err = ext4_journal_get_write_access(handle, frame->bh); + if (err) + goto journal_error; + + data2 = bh2->b_data; + + /* create map in the end of data2 block */ + map = (struct dx_map_entry *) (data2 + blocksize); + count = dx_make_map((struct ext4_dir_entry_2 *) data1, + blocksize, hinfo, map); + map -= count; + dx_sort_map(map, count); + /* Split the existing block in the middle, size-wise */ + size = 0; + move = 0; + for (i = count-1; i >= 0; i--) { + /* is more than half of this entry in 2nd half of the block? */ + if (size + map[i].size/2 > blocksize/2) + break; + size += map[i].size; + move++; + } + /* map index at which we will split */ + split = count - move; + hash2 = map[split].hash; + continued = hash2 == map[split - 1].hash; + dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n", + (unsigned long)dx_get_block(frame->at), + hash2, split, count-split)); + + /* Fancy dance to stay within two buffers */ + de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize); + de = dx_pack_dirents(data1, blocksize); + de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de, + blocksize); + de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2, + blocksize); + dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1)); + dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1)); + + /* Which block gets the new entry? */ + if (hinfo->hash >= hash2) + { + swap(*bh, bh2); + de = de2; + } + dx_insert_block(frame, hash2 + continued, newblock); + err = ext4_handle_dirty_metadata(handle, dir, bh2); + if (err) + goto journal_error; + err = ext4_handle_dirty_metadata(handle, dir, frame->bh); + if (err) + goto journal_error; + brelse(bh2); + dxtrace(dx_show_index("frame", frame->entries)); + return de; + +journal_error: + brelse(*bh); + brelse(bh2); + *bh = NULL; + ext4_std_error(dir->i_sb, err); +errout: + *error = err; + return NULL; +} + +/* + * Add a new entry into a directory (leaf) block. If de is non-NULL, + * it points to a directory entry which is guaranteed to be large + * enough for new directory entry. If de is NULL, then + * add_dirent_to_buf will attempt search the directory block for + * space. It will return -ENOSPC if no space is available, and -EIO + * and -EEXIST if directory entry already exists. + */ +static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry, + struct inode *inode, struct ext4_dir_entry_2 *de, + struct buffer_head *bh) +{ + struct inode *dir = dentry->d_parent->d_inode; + const char *name = dentry->d_name.name; + int namelen = dentry->d_name.len; + unsigned int offset = 0; + unsigned int blocksize = dir->i_sb->s_blocksize; + unsigned short reclen; + int nlen, rlen, err; + char *top; + + reclen = EXT4_DIR_REC_LEN(namelen); + if (!de) { + de = (struct ext4_dir_entry_2 *)bh->b_data; + top = bh->b_data + blocksize - reclen; + while ((char *) de <= top) { + if (ext4_check_dir_entry(dir, NULL, de, bh, offset)) + return -EIO; + if (ext4_match(namelen, name, de)) + return -EEXIST; + nlen = EXT4_DIR_REC_LEN(de->name_len); + rlen = ext4_rec_len_from_disk(de->rec_len, blocksize); + if ((de->inode? rlen - nlen: rlen) >= reclen) + break; + de = (struct ext4_dir_entry_2 *)((char *)de + rlen); + offset += rlen; + } + if ((char *) de > top) + return -ENOSPC; + } + BUFFER_TRACE(bh, "get_write_access"); + err = ext4_journal_get_write_access(handle, bh); + if (err) { + ext4_std_error(dir->i_sb, err); + return err; + } + + /* By now the buffer is marked for journaling */ + nlen = EXT4_DIR_REC_LEN(de->name_len); + rlen = ext4_rec_len_from_disk(de->rec_len, blocksize); + if (de->inode) { + struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen); + de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, blocksize); + de->rec_len = ext4_rec_len_to_disk(nlen, blocksize); + de = de1; + } + de->file_type = EXT4_FT_UNKNOWN; + if (inode) { + de->inode = cpu_to_le32(inode->i_ino); + ext4_set_de_type(dir->i_sb, de, inode->i_mode); + } else + de->inode = 0; + de->name_len = namelen; + memcpy(de->name, name, namelen); + /* + * XXX shouldn't update any times until successful + * completion of syscall, but too many callers depend + * on this. + * + * XXX similarly, too many callers depend on + * ext4_new_inode() setting the times, but error + * recovery deletes the inode, so the worst that can + * happen is that the times are slightly out of date + * and/or different from the directory change time. + */ + dir->i_mtime = dir->i_ctime = ext4_current_time(dir); + ext4_update_dx_flag(dir); + dir->i_version++; + ext4_mark_inode_dirty(handle, dir); + BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); + err = ext4_handle_dirty_metadata(handle, dir, bh); + if (err) + ext4_std_error(dir->i_sb, err); + return 0; +} + +/* + * This converts a one block unindexed directory to a 3 block indexed + * directory, and adds the dentry to the indexed directory. + */ +static int make_indexed_dir(handle_t *handle, struct dentry *dentry, + struct inode *inode, struct buffer_head *bh) +{ + struct inode *dir = dentry->d_parent->d_inode; + const char *name = dentry->d_name.name; + int namelen = dentry->d_name.len; + struct buffer_head *bh2; + struct dx_root *root; + struct dx_frame frames[2], *frame; + struct dx_entry *entries; + struct ext4_dir_entry_2 *de, *de2; + char *data1, *top; + unsigned len; + int retval; + unsigned blocksize; + struct dx_hash_info hinfo; + ext4_lblk_t block; + struct fake_dirent *fde; + + blocksize = dir->i_sb->s_blocksize; + dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino)); + retval = ext4_journal_get_write_access(handle, bh); + if (retval) { + ext4_std_error(dir->i_sb, retval); + brelse(bh); + return retval; + } + root = (struct dx_root *) bh->b_data; + + /* The 0th block becomes the root, move the dirents out */ + fde = &root->dotdot; + de = (struct ext4_dir_entry_2 *)((char *)fde + + ext4_rec_len_from_disk(fde->rec_len, blocksize)); + if ((char *) de >= (((char *) root) + blocksize)) { + EXT4_ERROR_INODE(dir, "invalid rec_len for '..'"); + brelse(bh); + return -EIO; + } + len = ((char *) root) + blocksize - (char *) de; + + /* Allocate new block for the 0th block's dirents */ + bh2 = ext4_append(handle, dir, &block, &retval); + if (!(bh2)) { + brelse(bh); + return retval; + } + ext4_set_inode_flag(dir, EXT4_INODE_INDEX); + data1 = bh2->b_data; + + memcpy (data1, de, len); + de = (struct ext4_dir_entry_2 *) data1; + top = data1 + len; + while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) + de = de2; + de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de, + blocksize); + /* Initialize the root; the dot dirents already exist */ + de = (struct ext4_dir_entry_2 *) (&root->dotdot); + de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2), + blocksize); + memset (&root->info, 0, sizeof(root->info)); + root->info.info_length = sizeof(root->info); + root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version; + entries = root->entries; + dx_set_block(entries, 1); + dx_set_count(entries, 1); + dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info))); + + /* Initialize as for dx_probe */ + hinfo.hash_version = root->info.hash_version; + if (hinfo.hash_version <= DX_HASH_TEA) + hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; + hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; + ext4fs_dirhash(name, namelen, &hinfo); + frame = frames; + frame->entries = entries; + frame->at = entries; + frame->bh = bh; + bh = bh2; + + ext4_handle_dirty_metadata(handle, dir, frame->bh); + ext4_handle_dirty_metadata(handle, dir, bh); + + de = do_split(handle,dir, &bh, frame, &hinfo, &retval); + if (!de) { + /* + * Even if the block split failed, we have to properly write + * out all the changes we did so far. Otherwise we can end up + * with corrupted filesystem. + */ + ext4_mark_inode_dirty(handle, dir); + dx_release(frames); + return retval; + } + dx_release(frames); + + retval = add_dirent_to_buf(handle, dentry, inode, de, bh); + brelse(bh); + return retval; +} + +/* + * ext4_add_entry() + * + * adds a file entry to the specified directory, using the same + * semantics as ext4_find_entry(). It returns NULL if it failed. + * + * NOTE!! The inode part of 'de' is left at 0 - which means you + * may not sleep between calling this and putting something into + * the entry, as someone else might have used it while you slept. + */ +static int ext4_add_entry(handle_t *handle, struct dentry *dentry, + struct inode *inode) +{ + struct inode *dir = dentry->d_parent->d_inode; + struct buffer_head *bh; + struct ext4_dir_entry_2 *de; + struct super_block *sb; + int retval; + int dx_fallback=0; + unsigned blocksize; + ext4_lblk_t block, blocks; + + sb = dir->i_sb; + blocksize = sb->s_blocksize; + if (!dentry->d_name.len) + return -EINVAL; + if (is_dx(dir)) { + retval = ext4_dx_add_entry(handle, dentry, inode); + if (!retval || (retval != ERR_BAD_DX_DIR)) + return retval; + ext4_clear_inode_flag(dir, EXT4_INODE_INDEX); + dx_fallback++; + ext4_mark_inode_dirty(handle, dir); + } + blocks = dir->i_size >> sb->s_blocksize_bits; + for (block = 0; block < blocks; block++) { + bh = ext4_bread(handle, dir, block, 0, &retval); + if(!bh) + return retval; + retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh); + if (retval != -ENOSPC) { + brelse(bh); + return retval; + } + + if (blocks == 1 && !dx_fallback && + EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) + return make_indexed_dir(handle, dentry, inode, bh); + brelse(bh); + } + bh = ext4_append(handle, dir, &block, &retval); + if (!bh) + return retval; + de = (struct ext4_dir_entry_2 *) bh->b_data; + de->inode = 0; + de->rec_len = ext4_rec_len_to_disk(blocksize, blocksize); + retval = add_dirent_to_buf(handle, dentry, inode, de, bh); + brelse(bh); + if (retval == 0) + ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY); + return retval; +} + +/* + * Returns 0 for success, or a negative error value + */ +static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry, + struct inode *inode) +{ + struct dx_frame frames[2], *frame; + struct dx_entry *entries, *at; + struct dx_hash_info hinfo; + struct buffer_head *bh; + struct inode *dir = dentry->d_parent->d_inode; + struct super_block *sb = dir->i_sb; + struct ext4_dir_entry_2 *de; + int err; + + frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err); + if (!frame) + return err; + entries = frame->entries; + at = frame->at; + + if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err))) + goto cleanup; + + BUFFER_TRACE(bh, "get_write_access"); + err = ext4_journal_get_write_access(handle, bh); + if (err) + goto journal_error; + + err = add_dirent_to_buf(handle, dentry, inode, NULL, bh); + if (err != -ENOSPC) + goto cleanup; + + /* Block full, should compress but for now just split */ + dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n", + dx_get_count(entries), dx_get_limit(entries))); + /* Need to split index? */ + if (dx_get_count(entries) == dx_get_limit(entries)) { + ext4_lblk_t newblock; + unsigned icount = dx_get_count(entries); + int levels = frame - frames; + struct dx_entry *entries2; + struct dx_node *node2; + struct buffer_head *bh2; + + if (levels && (dx_get_count(frames->entries) == + dx_get_limit(frames->entries))) { + ext4_warning(sb, "Directory index full!"); + err = -ENOSPC; + goto cleanup; + } + bh2 = ext4_append (handle, dir, &newblock, &err); + if (!(bh2)) + goto cleanup; + node2 = (struct dx_node *)(bh2->b_data); + entries2 = node2->entries; + memset(&node2->fake, 0, sizeof(struct fake_dirent)); + node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize, + sb->s_blocksize); + BUFFER_TRACE(frame->bh, "get_write_access"); + err = ext4_journal_get_write_access(handle, frame->bh); + if (err) + goto journal_error; + if (levels) { + unsigned icount1 = icount/2, icount2 = icount - icount1; + unsigned hash2 = dx_get_hash(entries + icount1); + dxtrace(printk(KERN_DEBUG "Split index %i/%i\n", + icount1, icount2)); + + BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */ + err = ext4_journal_get_write_access(handle, + frames[0].bh); + if (err) + goto journal_error; + + memcpy((char *) entries2, (char *) (entries + icount1), + icount2 * sizeof(struct dx_entry)); + dx_set_count(entries, icount1); + dx_set_count(entries2, icount2); + dx_set_limit(entries2, dx_node_limit(dir)); + + /* Which index block gets the new entry? */ + if (at - entries >= icount1) { + frame->at = at = at - entries - icount1 + entries2; + frame->entries = entries = entries2; + swap(frame->bh, bh2); + } + dx_insert_block(frames + 0, hash2, newblock); + dxtrace(dx_show_index("node", frames[1].entries)); + dxtrace(dx_show_index("node", + ((struct dx_node *) bh2->b_data)->entries)); + err = ext4_handle_dirty_metadata(handle, dir, bh2); + if (err) + goto journal_error; + brelse (bh2); + } else { + dxtrace(printk(KERN_DEBUG + "Creating second level index...\n")); + memcpy((char *) entries2, (char *) entries, + icount * sizeof(struct dx_entry)); + dx_set_limit(entries2, dx_node_limit(dir)); + + /* Set up root */ + dx_set_count(entries, 1); + dx_set_block(entries + 0, newblock); + ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1; + + /* Add new access path frame */ + frame = frames + 1; + frame->at = at = at - entries + entries2; + frame->entries = entries = entries2; + frame->bh = bh2; + err = ext4_journal_get_write_access(handle, + frame->bh); + if (err) + goto journal_error; + } + err = ext4_handle_dirty_metadata(handle, dir, frames[0].bh); + if (err) { + ext4_std_error(inode->i_sb, err); + goto cleanup; + } + } + de = do_split(handle, dir, &bh, frame, &hinfo, &err); + if (!de) + goto cleanup; + err = add_dirent_to_buf(handle, dentry, inode, de, bh); + goto cleanup; + +journal_error: + ext4_std_error(dir->i_sb, err); +cleanup: + if (bh) + brelse(bh); + dx_release(frames); + return err; +} + +/* + * ext4_delete_entry deletes a directory entry by merging it with the + * previous entry + */ +static int ext4_delete_entry(handle_t *handle, + struct inode *dir, + struct ext4_dir_entry_2 *de_del, + struct buffer_head *bh) +{ + struct ext4_dir_entry_2 *de, *pde; + unsigned int blocksize = dir->i_sb->s_blocksize; + int i, err; + + i = 0; + pde = NULL; + de = (struct ext4_dir_entry_2 *) bh->b_data; + while (i < bh->b_size) { + if (ext4_check_dir_entry(dir, NULL, de, bh, i)) + return -EIO; + if (de == de_del) { + BUFFER_TRACE(bh, "get_write_access"); + err = ext4_journal_get_write_access(handle, bh); + if (unlikely(err)) { + ext4_std_error(dir->i_sb, err); + return err; + } + if (pde) + pde->rec_len = ext4_rec_len_to_disk( + ext4_rec_len_from_disk(pde->rec_len, + blocksize) + + ext4_rec_len_from_disk(de->rec_len, + blocksize), + blocksize); + else + de->inode = 0; + dir->i_version++; + BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); + err = ext4_handle_dirty_metadata(handle, dir, bh); + if (unlikely(err)) { + ext4_std_error(dir->i_sb, err); + return err; + } + return 0; + } + i += ext4_rec_len_from_disk(de->rec_len, blocksize); + pde = de; + de = ext4_next_entry(de, blocksize); + } + return -ENOENT; +} + +/* + * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2, + * since this indicates that nlinks count was previously 1. + */ +static void ext4_inc_count(handle_t *handle, struct inode *inode) +{ + inc_nlink(inode); + if (is_dx(inode) && inode->i_nlink > 1) { + /* limit is 16-bit i_links_count */ + if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) { + set_nlink(inode, 1); + EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb, + EXT4_FEATURE_RO_COMPAT_DIR_NLINK); + } + } +} + +/* + * If a directory had nlink == 1, then we should let it be 1. This indicates + * directory has >EXT4_LINK_MAX subdirs. + */ +static void ext4_dec_count(handle_t *handle, struct inode *inode) +{ + if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) + drop_nlink(inode); +} + + +static int ext4_add_nondir(handle_t *handle, + struct dentry *dentry, struct inode *inode) +{ + int err = ext4_add_entry(handle, dentry, inode); + if (!err) { + ext4_mark_inode_dirty(handle, inode); + d_instantiate(dentry, inode); + unlock_new_inode(inode); + return 0; + } + drop_nlink(inode); + unlock_new_inode(inode); + iput(inode); + return err; +} + +/* + * By the time this is called, we already have created + * the directory cache entry for the new file, but it + * is so far negative - it has no inode. + * + * If the create succeeds, we fill in the inode information + * with d_instantiate(). + */ +static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode, + struct nameidata *nd) +{ + handle_t *handle; + struct inode *inode; + int err, retries = 0; + + dquot_initialize(dir); + +retry: + handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 + + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb)); + if (IS_ERR(handle)) + return PTR_ERR(handle); + + if (IS_DIRSYNC(dir)) + ext4_handle_sync(handle); + + inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0, NULL); + err = PTR_ERR(inode); + if (!IS_ERR(inode)) { + inode->i_op = &ext4_file_inode_operations; + inode->i_fop = &ext4_file_operations; + ext4_set_aops(inode); + err = ext4_add_nondir(handle, dentry, inode); + } + ext4_journal_stop(handle); + if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) + goto retry; + return err; +} + +static int ext4_mknod(struct inode *dir, struct dentry *dentry, + umode_t mode, dev_t rdev) +{ + handle_t *handle; + struct inode *inode; + int err, retries = 0; + + if (!new_valid_dev(rdev)) + return -EINVAL; + + dquot_initialize(dir); + +retry: + handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 + + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb)); + if (IS_ERR(handle)) + return PTR_ERR(handle); + + if (IS_DIRSYNC(dir)) + ext4_handle_sync(handle); + + inode = ext4_new_inode(handle, dir, mode, &dentry->d_name, 0, NULL); + err = PTR_ERR(inode); + if (!IS_ERR(inode)) { + init_special_inode(inode, inode->i_mode, rdev); +#ifdef CONFIG_EXT4_FS_XATTR + inode->i_op = &ext4_special_inode_operations; +#endif + err = ext4_add_nondir(handle, dentry, inode); + } + ext4_journal_stop(handle); + if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) + goto retry; + return err; +} + +static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) +{ + handle_t *handle; + struct inode *inode; + struct buffer_head *dir_block = NULL; + struct ext4_dir_entry_2 *de; + unsigned int blocksize = dir->i_sb->s_blocksize; + int err, retries = 0; + + if (EXT4_DIR_LINK_MAX(dir)) + return -EMLINK; + + dquot_initialize(dir); + +retry: + handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 + + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb)); + if (IS_ERR(handle)) + return PTR_ERR(handle); + + if (IS_DIRSYNC(dir)) + ext4_handle_sync(handle); + + inode = ext4_new_inode(handle, dir, S_IFDIR | mode, + &dentry->d_name, 0, NULL); + err = PTR_ERR(inode); + if (IS_ERR(inode)) + goto out_stop; + + inode->i_op = &ext4_dir_inode_operations; + inode->i_fop = &ext4_dir_operations; + inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize; + dir_block = ext4_bread(handle, inode, 0, 1, &err); + if (!dir_block) + goto out_clear_inode; + BUFFER_TRACE(dir_block, "get_write_access"); + err = ext4_journal_get_write_access(handle, dir_block); + if (err) + goto out_clear_inode; + de = (struct ext4_dir_entry_2 *) dir_block->b_data; + de->inode = cpu_to_le32(inode->i_ino); + de->name_len = 1; + de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len), + blocksize); + strcpy(de->name, "."); + ext4_set_de_type(dir->i_sb, de, S_IFDIR); + de = ext4_next_entry(de, blocksize); + de->inode = cpu_to_le32(dir->i_ino); + de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(1), + blocksize); + de->name_len = 2; + strcpy(de->name, ".."); + ext4_set_de_type(dir->i_sb, de, S_IFDIR); + set_nlink(inode, 2); + BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata"); + err = ext4_handle_dirty_metadata(handle, inode, dir_block); + if (err) + goto out_clear_inode; + err = ext4_mark_inode_dirty(handle, inode); + if (!err) + err = ext4_add_entry(handle, dentry, inode); + if (err) { +out_clear_inode: + clear_nlink(inode); + unlock_new_inode(inode); + ext4_mark_inode_dirty(handle, inode); + iput(inode); + goto out_stop; + } + ext4_inc_count(handle, dir); + ext4_update_dx_flag(dir); + err = ext4_mark_inode_dirty(handle, dir); + if (err) + goto out_clear_inode; + d_instantiate(dentry, inode); + unlock_new_inode(inode); +out_stop: + brelse(dir_block); + ext4_journal_stop(handle); + if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) + goto retry; + return err; +} + +/* + * routine to check that the specified directory is empty (for rmdir) + */ +static int empty_dir(struct inode *inode) +{ + unsigned int offset; + struct buffer_head *bh; + struct ext4_dir_entry_2 *de, *de1; + struct super_block *sb; + int err = 0; + + sb = inode->i_sb; + if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) || + !(bh = ext4_bread(NULL, inode, 0, 0, &err))) { + if (err) + EXT4_ERROR_INODE(inode, + "error %d reading directory lblock 0", err); + else + ext4_warning(inode->i_sb, + "bad directory (dir #%lu) - no data block", + inode->i_ino); + return 1; + } + de = (struct ext4_dir_entry_2 *) bh->b_data; + de1 = ext4_next_entry(de, sb->s_blocksize); + if (le32_to_cpu(de->inode) != inode->i_ino || + !le32_to_cpu(de1->inode) || + strcmp(".", de->name) || + strcmp("..", de1->name)) { + ext4_warning(inode->i_sb, + "bad directory (dir #%lu) - no `.' or `..'", + inode->i_ino); + brelse(bh); + return 1; + } + offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) + + ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize); + de = ext4_next_entry(de1, sb->s_blocksize); + while (offset < inode->i_size) { + if (!bh || + (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) { + unsigned int lblock; + err = 0; + brelse(bh); + lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb); + bh = ext4_bread(NULL, inode, lblock, 0, &err); + if (!bh) { + if (err) + EXT4_ERROR_INODE(inode, + "error %d reading directory " + "lblock %u", err, lblock); + offset += sb->s_blocksize; + continue; + } + de = (struct ext4_dir_entry_2 *) bh->b_data; + } + if (ext4_check_dir_entry(inode, NULL, de, bh, offset)) { + de = (struct ext4_dir_entry_2 *)(bh->b_data + + sb->s_blocksize); + offset = (offset | (sb->s_blocksize - 1)) + 1; + continue; + } + if (le32_to_cpu(de->inode)) { + brelse(bh); + return 0; + } + offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); + de = ext4_next_entry(de, sb->s_blocksize); + } + brelse(bh); + return 1; +} + +/* ext4_orphan_add() links an unlinked or truncated inode into a list of + * such inodes, starting at the superblock, in case we crash before the + * file is closed/deleted, or in case the inode truncate spans multiple + * transactions and the last transaction is not recovered after a crash. + * + * At filesystem recovery time, we walk this list deleting unlinked + * inodes and truncating linked inodes in ext4_orphan_cleanup(). + */ +int ext4_orphan_add(handle_t *handle, struct inode *inode) +{ + struct super_block *sb = inode->i_sb; + struct ext4_iloc iloc; + int err = 0, rc; + + if (!ext4_handle_valid(handle)) + return 0; + + mutex_lock(&EXT4_SB(sb)->s_orphan_lock); + if (!list_empty(&EXT4_I(inode)->i_orphan)) + goto out_unlock; + + /* + * Orphan handling is only valid for files with data blocks + * being truncated, or files being unlinked. Note that we either + * hold i_mutex, or the inode can not be referenced from outside, + * so i_nlink should not be bumped due to race + */ + J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || + S_ISLNK(inode->i_mode)) || inode->i_nlink == 0); + + BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); + err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); + if (err) + goto out_unlock; + + err = ext4_reserve_inode_write(handle, inode, &iloc); + if (err) + goto out_unlock; + /* + * Due to previous errors inode may be already a part of on-disk + * orphan list. If so skip on-disk list modification. + */ + if (NEXT_ORPHAN(inode) && NEXT_ORPHAN(inode) <= + (le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))) + goto mem_insert; + + /* Insert this inode at the head of the on-disk orphan list... */ + NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan); + EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino); + err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh); + rc = ext4_mark_iloc_dirty(handle, inode, &iloc); + if (!err) + err = rc; + + /* Only add to the head of the in-memory list if all the + * previous operations succeeded. If the orphan_add is going to + * fail (possibly taking the journal offline), we can't risk + * leaving the inode on the orphan list: stray orphan-list + * entries can cause panics at unmount time. + * + * This is safe: on error we're going to ignore the orphan list + * anyway on the next recovery. */ +mem_insert: + if (!err) + list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan); + + jbd_debug(4, "superblock will point to %lu\n", inode->i_ino); + jbd_debug(4, "orphan inode %lu will point to %d\n", + inode->i_ino, NEXT_ORPHAN(inode)); +out_unlock: + mutex_unlock(&EXT4_SB(sb)->s_orphan_lock); + ext4_std_error(inode->i_sb, err); + return err; +} + +/* + * ext4_orphan_del() removes an unlinked or truncated inode from the list + * of such inodes stored on disk, because it is finally being cleaned up. + */ +int ext4_orphan_del(handle_t *handle, struct inode *inode) +{ + struct list_head *prev; + struct ext4_inode_info *ei = EXT4_I(inode); + struct ext4_sb_info *sbi; + __u32 ino_next; + struct ext4_iloc iloc; + int err = 0; + + /* ext4_handle_valid() assumes a valid handle_t pointer */ + if (handle && !ext4_handle_valid(handle)) + return 0; + + mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock); + if (list_empty(&ei->i_orphan)) + goto out; + + ino_next = NEXT_ORPHAN(inode); + prev = ei->i_orphan.prev; + sbi = EXT4_SB(inode->i_sb); + + jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino); + + list_del_init(&ei->i_orphan); + + /* If we're on an error path, we may not have a valid + * transaction handle with which to update the orphan list on + * disk, but we still need to remove the inode from the linked + * list in memory. */ + if (sbi->s_journal && !handle) + goto out; + + err = ext4_reserve_inode_write(handle, inode, &iloc); + if (err) + goto out_err; + + if (prev == &sbi->s_orphan) { + jbd_debug(4, "superblock will point to %u\n", ino_next); + BUFFER_TRACE(sbi->s_sbh, "get_write_access"); + err = ext4_journal_get_write_access(handle, sbi->s_sbh); + if (err) + goto out_brelse; + sbi->s_es->s_last_orphan = cpu_to_le32(ino_next); + err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh); + } else { + struct ext4_iloc iloc2; + struct inode *i_prev = + &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode; + + jbd_debug(4, "orphan inode %lu will point to %u\n", + i_prev->i_ino, ino_next); + err = ext4_reserve_inode_write(handle, i_prev, &iloc2); + if (err) + goto out_brelse; + NEXT_ORPHAN(i_prev) = ino_next; + err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2); + } + if (err) + goto out_brelse; + NEXT_ORPHAN(inode) = 0; + err = ext4_mark_iloc_dirty(handle, inode, &iloc); + +out_err: + ext4_std_error(inode->i_sb, err); +out: + mutex_unlock(&EXT4_SB(inode->i_sb)->s_orphan_lock); + return err; + +out_brelse: + brelse(iloc.bh); + goto out_err; +} + +static int ext4_rmdir(struct inode *dir, struct dentry *dentry) +{ + int retval; + struct inode *inode; + struct buffer_head *bh; + struct ext4_dir_entry_2 *de; + handle_t *handle; + + /* Initialize quotas before so that eventual writes go in + * separate transaction */ + dquot_initialize(dir); + dquot_initialize(dentry->d_inode); + + handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb)); + if (IS_ERR(handle)) + return PTR_ERR(handle); + + retval = -ENOENT; + bh = ext4_find_entry(dir, &dentry->d_name, &de); + if (!bh) + goto end_rmdir; + + if (IS_DIRSYNC(dir)) + ext4_handle_sync(handle); + + inode = dentry->d_inode; + + retval = -EIO; + if (le32_to_cpu(de->inode) != inode->i_ino) + goto end_rmdir; + + retval = -ENOTEMPTY; + if (!empty_dir(inode)) + goto end_rmdir; + + retval = ext4_delete_entry(handle, dir, de, bh); + if (retval) + goto end_rmdir; + if (!EXT4_DIR_LINK_EMPTY(inode)) + ext4_warning(inode->i_sb, + "empty directory has too many links (%d)", + inode->i_nlink); + inode->i_version++; + clear_nlink(inode); + /* There's no need to set i_disksize: the fact that i_nlink is + * zero will ensure that the right thing happens during any + * recovery. */ + inode->i_size = 0; + ext4_orphan_add(handle, inode); + inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode); + ext4_mark_inode_dirty(handle, inode); + ext4_dec_count(handle, dir); + ext4_update_dx_flag(dir); + ext4_mark_inode_dirty(handle, dir); + +end_rmdir: + ext4_journal_stop(handle); + brelse(bh); + return retval; +} + +static int ext4_unlink(struct inode *dir, struct dentry *dentry) +{ + int retval; + struct inode *inode; + struct buffer_head *bh; + struct ext4_dir_entry_2 *de; + handle_t *handle; + + trace_ext4_unlink_enter(dir, dentry); + /* Initialize quotas before so that eventual writes go + * in separate transaction */ + dquot_initialize(dir); + dquot_initialize(dentry->d_inode); + + handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb)); + if (IS_ERR(handle)) + return PTR_ERR(handle); + + if (IS_DIRSYNC(dir)) + ext4_handle_sync(handle); + + retval = -ENOENT; + bh = ext4_find_entry(dir, &dentry->d_name, &de); + if (!bh) + goto end_unlink; + + inode = dentry->d_inode; + + retval = -EIO; + if (le32_to_cpu(de->inode) != inode->i_ino) + goto end_unlink; + + if (!inode->i_nlink) { + ext4_warning(inode->i_sb, + "Deleting nonexistent file (%lu), %d", + inode->i_ino, inode->i_nlink); + set_nlink(inode, 1); + } + retval = ext4_delete_entry(handle, dir, de, bh); + if (retval) + goto end_unlink; + dir->i_ctime = dir->i_mtime = ext4_current_time(dir); + ext4_update_dx_flag(dir); + ext4_mark_inode_dirty(handle, dir); + drop_nlink(inode); + if (!inode->i_nlink) + ext4_orphan_add(handle, inode); + inode->i_ctime = ext4_current_time(inode); + ext4_mark_inode_dirty(handle, inode); + retval = 0; + +end_unlink: + ext4_journal_stop(handle); + brelse(bh); + trace_ext4_unlink_exit(dentry, retval); + return retval; +} + +static int ext4_symlink(struct inode *dir, + struct dentry *dentry, const char *symname) +{ + handle_t *handle; + struct inode *inode; + int l, err, retries = 0; + int credits; + + l = strlen(symname)+1; + if (l > dir->i_sb->s_blocksize) + return -ENAMETOOLONG; + + dquot_initialize(dir); + + if (l > EXT4_N_BLOCKS * 4) { + /* + * For non-fast symlinks, we just allocate inode and put it on + * orphan list in the first transaction => we need bitmap, + * group descriptor, sb, inode block, quota blocks, and + * possibly selinux xattr blocks. + */ + credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) + + EXT4_XATTR_TRANS_BLOCKS; + } else { + /* + * Fast symlink. We have to add entry to directory + * (EXT4_DATA_TRANS_BLOCKS + EXT4_INDEX_EXTRA_TRANS_BLOCKS), + * allocate new inode (bitmap, group descriptor, inode block, + * quota blocks, sb is already counted in previous macros). + */ + credits = EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 + + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb); + } +retry: + handle = ext4_journal_start(dir, credits); + if (IS_ERR(handle)) + return PTR_ERR(handle); + + if (IS_DIRSYNC(dir)) + ext4_handle_sync(handle); + + inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO, + &dentry->d_name, 0, NULL); + err = PTR_ERR(inode); + if (IS_ERR(inode)) + goto out_stop; + + if (l > EXT4_N_BLOCKS * 4) { + inode->i_op = &ext4_symlink_inode_operations; + ext4_set_aops(inode); + /* + * We cannot call page_symlink() with transaction started + * because it calls into ext4_write_begin() which can wait + * for transaction commit if we are running out of space + * and thus we deadlock. So we have to stop transaction now + * and restart it when symlink contents is written. + * + * To keep fs consistent in case of crash, we have to put inode + * to orphan list in the mean time. + */ + drop_nlink(inode); + err = ext4_orphan_add(handle, inode); + ext4_journal_stop(handle); + if (err) + goto err_drop_inode; + err = __page_symlink(inode, symname, l, 1); + if (err) + goto err_drop_inode; + /* + * Now inode is being linked into dir (EXT4_DATA_TRANS_BLOCKS + * + EXT4_INDEX_EXTRA_TRANS_BLOCKS), inode is also modified + */ + handle = ext4_journal_start(dir, + EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1); + if (IS_ERR(handle)) { + err = PTR_ERR(handle); + goto err_drop_inode; + } + set_nlink(inode, 1); + err = ext4_orphan_del(handle, inode); + if (err) { + ext4_journal_stop(handle); + clear_nlink(inode); + goto err_drop_inode; + } + } else { + /* clear the extent format for fast symlink */ + ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); + inode->i_op = &ext4_fast_symlink_inode_operations; + memcpy((char *)&EXT4_I(inode)->i_data, symname, l); + inode->i_size = l-1; + } + EXT4_I(inode)->i_disksize = inode->i_size; + err = ext4_add_nondir(handle, dentry, inode); +out_stop: + ext4_journal_stop(handle); + if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) + goto retry; + return err; +err_drop_inode: + unlock_new_inode(inode); + iput(inode); + return err; +} + +static int ext4_link(struct dentry *old_dentry, + struct inode *dir, struct dentry *dentry) +{ + handle_t *handle; + struct inode *inode = old_dentry->d_inode; + int err, retries = 0; + + if (inode->i_nlink >= EXT4_LINK_MAX) + return -EMLINK; + + dquot_initialize(dir); + +retry: + handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + + EXT4_INDEX_EXTRA_TRANS_BLOCKS); + if (IS_ERR(handle)) + return PTR_ERR(handle); + + if (IS_DIRSYNC(dir)) + ext4_handle_sync(handle); + + inode->i_ctime = ext4_current_time(inode); + ext4_inc_count(handle, inode); + ihold(inode); + + err = ext4_add_entry(handle, dentry, inode); + if (!err) { + ext4_mark_inode_dirty(handle, inode); + d_instantiate(dentry, inode); + } else { + drop_nlink(inode); + iput(inode); + } + ext4_journal_stop(handle); + if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) + goto retry; + return err; +} + +#define PARENT_INO(buffer, size) \ + (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer), size)->inode) + +/* + * Anybody can rename anything with this: the permission checks are left to the + * higher-level routines. + */ +static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry) +{ + handle_t *handle; + struct inode *old_inode, *new_inode; + struct buffer_head *old_bh, *new_bh, *dir_bh; + struct ext4_dir_entry_2 *old_de, *new_de; + int retval, force_da_alloc = 0; + + dquot_initialize(old_dir); + dquot_initialize(new_dir); + + old_bh = new_bh = dir_bh = NULL; + + /* Initialize quotas before so that eventual writes go + * in separate transaction */ + if (new_dentry->d_inode) + dquot_initialize(new_dentry->d_inode); + handle = ext4_journal_start(old_dir, 2 * + EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) + + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2); + if (IS_ERR(handle)) + return PTR_ERR(handle); + + if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir)) + ext4_handle_sync(handle); + + old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de); + /* + * Check for inode number is _not_ due to possible IO errors. + * We might rmdir the source, keep it as pwd of some process + * and merrily kill the link to whatever was created under the + * same name. Goodbye sticky bit ;-< + */ + old_inode = old_dentry->d_inode; + retval = -ENOENT; + if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino) + goto end_rename; + + new_inode = new_dentry->d_inode; + new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, &new_de); + if (new_bh) { + if (!new_inode) { + brelse(new_bh); + new_bh = NULL; + } + } + if (S_ISDIR(old_inode->i_mode)) { + if (new_inode) { + retval = -ENOTEMPTY; + if (!empty_dir(new_inode)) + goto end_rename; + } + retval = -EIO; + dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval); + if (!dir_bh) + goto end_rename; + if (le32_to_cpu(PARENT_INO(dir_bh->b_data, + old_dir->i_sb->s_blocksize)) != old_dir->i_ino) + goto end_rename; + retval = -EMLINK; + if (!new_inode && new_dir != old_dir && + EXT4_DIR_LINK_MAX(new_dir)) + goto end_rename; + BUFFER_TRACE(dir_bh, "get_write_access"); + retval = ext4_journal_get_write_access(handle, dir_bh); + if (retval) + goto end_rename; + } + if (!new_bh) { + retval = ext4_add_entry(handle, new_dentry, old_inode); + if (retval) + goto end_rename; + } else { + BUFFER_TRACE(new_bh, "get write access"); + retval = ext4_journal_get_write_access(handle, new_bh); + if (retval) + goto end_rename; + new_de->inode = cpu_to_le32(old_inode->i_ino); + if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb, + EXT4_FEATURE_INCOMPAT_FILETYPE)) + new_de->file_type = old_de->file_type; + new_dir->i_version++; + new_dir->i_ctime = new_dir->i_mtime = + ext4_current_time(new_dir); + ext4_mark_inode_dirty(handle, new_dir); + BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata"); + retval = ext4_handle_dirty_metadata(handle, new_dir, new_bh); + if (unlikely(retval)) { + ext4_std_error(new_dir->i_sb, retval); + goto end_rename; + } + brelse(new_bh); + new_bh = NULL; + } + + /* + * Like most other Unix systems, set the ctime for inodes on a + * rename. + */ + old_inode->i_ctime = ext4_current_time(old_inode); + ext4_mark_inode_dirty(handle, old_inode); + + /* + * ok, that's it + */ + if (le32_to_cpu(old_de->inode) != old_inode->i_ino || + old_de->name_len != old_dentry->d_name.len || + strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) || + (retval = ext4_delete_entry(handle, old_dir, + old_de, old_bh)) == -ENOENT) { + /* old_de could have moved from under us during htree split, so + * make sure that we are deleting the right entry. We might + * also be pointing to a stale entry in the unused part of + * old_bh so just checking inum and the name isn't enough. */ + struct buffer_head *old_bh2; + struct ext4_dir_entry_2 *old_de2; + + old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de2); + if (old_bh2) { + retval = ext4_delete_entry(handle, old_dir, + old_de2, old_bh2); + brelse(old_bh2); + } + } + if (retval) { + ext4_warning(old_dir->i_sb, + "Deleting old file (%lu), %d, error=%d", + old_dir->i_ino, old_dir->i_nlink, retval); + } + + if (new_inode) { + ext4_dec_count(handle, new_inode); + new_inode->i_ctime = ext4_current_time(new_inode); + } + old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir); + ext4_update_dx_flag(old_dir); + if (dir_bh) { + PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) = + cpu_to_le32(new_dir->i_ino); + BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata"); + retval = ext4_handle_dirty_metadata(handle, old_inode, dir_bh); + if (retval) { + ext4_std_error(old_dir->i_sb, retval); + goto end_rename; + } + ext4_dec_count(handle, old_dir); + if (new_inode) { + /* checked empty_dir above, can't have another parent, + * ext4_dec_count() won't work for many-linked dirs */ + clear_nlink(new_inode); + } else { + ext4_inc_count(handle, new_dir); + ext4_update_dx_flag(new_dir); + ext4_mark_inode_dirty(handle, new_dir); + } + } + ext4_mark_inode_dirty(handle, old_dir); + if (new_inode) { + ext4_mark_inode_dirty(handle, new_inode); + if (!new_inode->i_nlink) + ext4_orphan_add(handle, new_inode); + if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC)) + force_da_alloc = 1; + } + retval = 0; + +end_rename: + brelse(dir_bh); + brelse(old_bh); + brelse(new_bh); + ext4_journal_stop(handle); + if (retval == 0 && force_da_alloc) + ext4_alloc_da_blocks(old_inode); + return retval; +} + +/* + * directories can handle most operations... + */ +const struct inode_operations ext4_dir_inode_operations = { + .create = ext4_create, + .lookup = ext4_lookup, + .link = ext4_link, + .unlink = ext4_unlink, + .symlink = ext4_symlink, + .mkdir = ext4_mkdir, + .rmdir = ext4_rmdir, + .mknod = ext4_mknod, + .rename = ext4_rename, + .setattr = ext4_setattr, +#ifdef CONFIG_EXT4_FS_XATTR + .setxattr = generic_setxattr, + .getxattr = generic_getxattr, + .listxattr = ext4_listxattr, + .removexattr = generic_removexattr, +#endif + .get_acl = ext4_get_acl, + .fiemap = ext4_fiemap, +}; + +const struct inode_operations ext4_special_inode_operations = { + .setattr = ext4_setattr, +#ifdef CONFIG_EXT4_FS_XATTR + .setxattr = generic_setxattr, + .getxattr = generic_getxattr, + .listxattr = ext4_listxattr, + .removexattr = generic_removexattr, +#endif + .get_acl = ext4_get_acl, +}; |