// SPDX-License-Identifier: GPL-2.0 /* * 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 #include #include #include #include #include #include #include #include #include #include #include "ext4.h" #include "ext4_jbd2.h" #include "xattr.h" #include "acl.h" #include /* * 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) static struct buffer_head *ext4_append(handle_t *handle, struct inode *inode, ext4_lblk_t *block) { struct buffer_head *bh; int err; if (unlikely(EXT4_SB(inode->i_sb)->s_max_dir_size_kb && ((inode->i_size >> 10) >= EXT4_SB(inode->i_sb)->s_max_dir_size_kb))) return ERR_PTR(-ENOSPC); *block = inode->i_size >> inode->i_sb->s_blocksize_bits; bh = ext4_bread(handle, inode, *block, EXT4_GET_BLOCKS_CREATE); if (IS_ERR(bh)) return bh; inode->i_size += inode->i_sb->s_blocksize; EXT4_I(inode)->i_disksize = inode->i_size; BUFFER_TRACE(bh, "get_write_access"); err = ext4_journal_get_write_access(handle, bh); if (err) { brelse(bh); ext4_std_error(inode->i_sb, err); return ERR_PTR(err); } return bh; } static int ext4_dx_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent); /* * Hints to ext4_read_dirblock regarding whether we expect a directory * block being read to be an index block, or a block containing * directory entries (and if the latter, whether it was found via a * logical block in an htree index block). This is used to control * what sort of sanity checkinig ext4_read_dirblock() will do on the * directory block read from the storage device. EITHER will means * the caller doesn't know what kind of directory block will be read, * so no specific verification will be done. */ typedef enum { EITHER, INDEX, DIRENT, DIRENT_HTREE } dirblock_type_t; #define ext4_read_dirblock(inode, block, type) \ __ext4_read_dirblock((inode), (block), (type), __func__, __LINE__) static struct buffer_head *__ext4_read_dirblock(struct inode *inode, ext4_lblk_t block, dirblock_type_t type, const char *func, unsigned int line) { struct buffer_head *bh; struct ext4_dir_entry *dirent; int is_dx_block = 0; if (ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_EIO)) bh = ERR_PTR(-EIO); else bh = ext4_bread(NULL, inode, block, 0); if (IS_ERR(bh)) { __ext4_warning(inode->i_sb, func, line, "inode #%lu: lblock %lu: comm %s: " "error %ld reading directory block", inode->i_ino, (unsigned long)block, current->comm, PTR_ERR(bh)); return bh; } if (!bh && (type == INDEX || type == DIRENT_HTREE)) { ext4_error_inode(inode, func, line, block, "Directory hole found for htree %s block", (type == INDEX) ? "index" : "leaf"); return ERR_PTR(-EFSCORRUPTED); } if (!bh) return NULL; dirent = (struct ext4_dir_entry *) bh->b_data; /* Determine whether or not we have an index block */ if (is_dx(inode)) { if (block == 0) is_dx_block = 1; else if (ext4_rec_len_from_disk(dirent->rec_len, inode->i_sb->s_blocksize) == inode->i_sb->s_blocksize) is_dx_block = 1; } if (!is_dx_block && type == INDEX) { ext4_error_inode(inode, func, line, block, "directory leaf block found instead of index block"); brelse(bh); return ERR_PTR(-EFSCORRUPTED); } if (!ext4_has_metadata_csum(inode->i_sb) || buffer_verified(bh)) return bh; /* * An empty leaf block can get mistaken for a index block; for * this reason, we can only check the index checksum when the * caller is sure it should be an index block. */ if (is_dx_block && type == INDEX) { if (ext4_dx_csum_verify(inode, dirent) && !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC)) set_buffer_verified(bh); else { ext4_set_errno(inode->i_sb, EFSBADCRC); ext4_error_inode(inode, func, line, block, "Directory index failed checksum"); brelse(bh); return ERR_PTR(-EFSBADCRC); } } if (!is_dx_block) { if (ext4_dirblock_csum_verify(inode, bh) && !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC)) set_buffer_verified(bh); else { ext4_set_errno(inode->i_sb, EFSBADCRC); ext4_error_inode(inode, func, line, block, "Directory block failed checksum"); brelse(bh); return ERR_PTR(-EFSBADCRC); } } 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; }; /* * This goes at the end of each htree block. */ struct dx_tail { u32 dt_reserved; __le32 dt_checksum; /* crc32c(uuid+inum+dirblock) */ }; 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(struct ext4_filename *fname, struct inode *dir, struct dx_hash_info *hinfo, struct dx_frame *frame); static void dx_release(struct dx_frame *frames); static int dx_make_map(struct inode *dir, 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, struct ext4_filename *fname, struct ext4_dir_entry_2 **res_dir); static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname, struct inode *dir, struct inode *inode); /* checksumming functions */ void ext4_initialize_dirent_tail(struct buffer_head *bh, unsigned int blocksize) { struct ext4_dir_entry_tail *t = EXT4_DIRENT_TAIL(bh->b_data, blocksize); memset(t, 0, sizeof(struct ext4_dir_entry_tail)); t->det_rec_len = ext4_rec_len_to_disk( sizeof(struct ext4_dir_entry_tail), blocksize); t->det_reserved_ft = EXT4_FT_DIR_CSUM; } /* Walk through a dirent block to find a checksum "dirent" at the tail */ static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode, struct buffer_head *bh) { struct ext4_dir_entry_tail *t; #ifdef PARANOID struct ext4_dir_entry *d, *top; d = (struct ext4_dir_entry *)bh->b_data; top = (struct ext4_dir_entry *)(bh->b_data + (EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct ext4_dir_entry_tail))); while (d < top && d->rec_len) d = (struct ext4_dir_entry *)(((void *)d) + le16_to_cpu(d->rec_len)); if (d != top) return NULL; t = (struct ext4_dir_entry_tail *)d; #else t = EXT4_DIRENT_TAIL(bh->b_data, EXT4_BLOCK_SIZE(inode->i_sb)); #endif if (t->det_reserved_zero1 || le16_to_cpu(t->det_rec_len) != sizeof(struct ext4_dir_entry_tail) || t->det_reserved_zero2 || t->det_reserved_ft != EXT4_FT_DIR_CSUM) return NULL; return t; } static __le32 ext4_dirblock_csum(struct inode *inode, void *dirent, int size) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); struct ext4_inode_info *ei = EXT4_I(inode); __u32 csum; csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); return cpu_to_le32(csum); } #define warn_no_space_for_csum(inode) \ __warn_no_space_for_csum((inode), __func__, __LINE__) static void __warn_no_space_for_csum(struct inode *inode, const char *func, unsigned int line) { __ext4_warning_inode(inode, func, line, "No space for directory leaf checksum. Please run e2fsck -D."); } int ext4_dirblock_csum_verify(struct inode *inode, struct buffer_head *bh) { struct ext4_dir_entry_tail *t; if (!ext4_has_metadata_csum(inode->i_sb)) return 1; t = get_dirent_tail(inode, bh); if (!t) { warn_no_space_for_csum(inode); return 0; } if (t->det_checksum != ext4_dirblock_csum(inode, bh->b_data, (char *)t - bh->b_data)) return 0; return 1; } static void ext4_dirblock_csum_set(struct inode *inode, struct buffer_head *bh) { struct ext4_dir_entry_tail *t; if (!ext4_has_metadata_csum(inode->i_sb)) return; t = get_dirent_tail(inode, bh); if (!t) { warn_no_space_for_csum(inode); return; } t->det_checksum = ext4_dirblock_csum(inode, bh->b_data, (char *)t - bh->b_data); } int ext4_handle_dirty_dirblock(handle_t *handle, struct inode *inode, struct buffer_head *bh) { ext4_dirblock_csum_set(inode, bh); return ext4_handle_dirty_metadata(handle, inode, bh); } static struct dx_countlimit *get_dx_countlimit(struct inode *inode, struct ext4_dir_entry *dirent, int *offset) { struct ext4_dir_entry *dp; struct dx_root_info *root; int count_offset; if (le16_to_cpu(dirent->rec_len) == EXT4_BLOCK_SIZE(inode->i_sb)) count_offset = 8; else if (le16_to_cpu(dirent->rec_len) == 12) { dp = (struct ext4_dir_entry *)(((void *)dirent) + 12); if (le16_to_cpu(dp->rec_len) != EXT4_BLOCK_SIZE(inode->i_sb) - 12) return NULL; root = (struct dx_root_info *)(((void *)dp + 12)); if (root->reserved_zero || root->info_length != sizeof(struct dx_root_info)) return NULL; count_offset = 32; } else return NULL; if (offset) *offset = count_offset; return (struct dx_countlimit *)(((void *)dirent) + count_offset); } static __le32 ext4_dx_csum(struct inode *inode, struct ext4_dir_entry *dirent, int count_offset, int count, struct dx_tail *t) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); struct ext4_inode_info *ei = EXT4_I(inode); __u32 csum; int size; __u32 dummy_csum = 0; int offset = offsetof(struct dx_tail, dt_checksum); size = count_offset + (count * sizeof(struct dx_entry)); csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)dirent, size); csum = ext4_chksum(sbi, csum, (__u8 *)t, offset); csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum)); return cpu_to_le32(csum); } static int ext4_dx_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent) { struct dx_countlimit *c; struct dx_tail *t; int count_offset, limit, count; if (!ext4_has_metadata_csum(inode->i_sb)) return 1; c = get_dx_countlimit(inode, dirent, &count_offset); if (!c) { EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); return 0; } limit = le16_to_cpu(c->limit); count = le16_to_cpu(c->count); if (count_offset + (limit * sizeof(struct dx_entry)) > EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) { warn_no_space_for_csum(inode); return 0; } t = (struct dx_tail *)(((struct dx_entry *)c) + limit); if (t->dt_checksum != ext4_dx_csum(inode, dirent, count_offset, count, t)) return 0; return 1; } static void ext4_dx_csum_set(struct inode *inode, struct ext4_dir_entry *dirent) { struct dx_countlimit *c; struct dx_tail *t; int count_offset, limit, count; if (!ext4_has_metadata_csum(inode->i_sb)) return; c = get_dx_countlimit(inode, dirent, &count_offset); if (!c) { EXT4_ERROR_INODE(inode, "dir seems corrupt? Run e2fsck -D."); return; } limit = le16_to_cpu(c->limit); count = le16_to_cpu(c->count); if (count_offset + (limit * sizeof(struct dx_entry)) > EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) { warn_no_space_for_csum(inode); return; } t = (struct dx_tail *)(((struct dx_entry *)c) + limit); t->dt_checksum = ext4_dx_csum(inode, dirent, count_offset, count, t); } static inline int ext4_handle_dirty_dx_node(handle_t *handle, struct inode *inode, struct buffer_head *bh) { ext4_dx_csum_set(inode, (struct ext4_dir_entry *)bh->b_data); return ext4_handle_dirty_metadata(handle, inode, bh); } /* * 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) & 0x0fffffff; } 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; if (ext4_has_metadata_csum(dir->i_sb)) entry_space -= sizeof(struct dx_tail); 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); if (ext4_has_metadata_csum(dir->i_sb)) entry_space -= sizeof(struct dx_tail); 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(KERN_CONT " %x->%lu", i ? dx_get_hash(entries + i) : 0, (unsigned long)dx_get_block(entries + i)); } printk(KERN_CONT "\n"); } struct stats { unsigned names; unsigned space; unsigned bcount; }; static struct stats dx_show_leaf(struct inode *dir, 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) { #ifdef CONFIG_FS_ENCRYPTION int len; char *name; struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0); int res = 0; name = de->name; len = de->name_len; if (IS_ENCRYPTED(dir)) res = fscrypt_get_encryption_info(dir); if (res) { printk(KERN_WARNING "Error setting up" " fname crypto: %d\n", res); } if (!fscrypt_has_encryption_key(dir)) { /* Directory is not encrypted */ ext4fs_dirhash(dir, de->name, de->name_len, &h); printk("%*.s:(U)%x.%u ", len, name, h.hash, (unsigned) ((char *) de - base)); } else { struct fscrypt_str de_name = FSTR_INIT(name, len); /* Directory is encrypted */ res = fscrypt_fname_alloc_buffer( dir, len, &fname_crypto_str); if (res) printk(KERN_WARNING "Error " "allocating crypto " "buffer--skipping " "crypto\n"); res = fscrypt_fname_disk_to_usr(dir, 0, 0, &de_name, &fname_crypto_str); if (res) { printk(KERN_WARNING "Error " "converting filename " "from disk to usr" "\n"); name = "??"; len = 2; } else { name = fname_crypto_str.name; len = fname_crypto_str.len; } ext4fs_dirhash(dir, de->name, de->name_len, &h); printk("%*.s:(E)%x.%u ", len, name, h.hash, (unsigned) ((char *) de - base)); fscrypt_fname_free_buffer( &fname_crypto_str); } #else int len = de->name_len; char *name = de->name; ext4fs_dirhash(dir, de->name, de->name_len, &h); printk("%*.s:%x.%u ", len, name, h.hash, (unsigned) ((char *) de - base)); #endif } space += EXT4_DIR_REC_LEN(de->name_len); names++; } de = ext4_next_entry(de, size); } printk(KERN_CONT "(%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; 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); bh = ext4_bread(NULL,dir, block, 0); if (!bh || IS_ERR(bh)) continue; stats = levels? dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1): dx_show_leaf(dir, 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(struct ext4_filename *fname, struct inode *dir, struct dx_hash_info *hinfo, struct dx_frame *frame_in) { unsigned count, indirect; struct dx_entry *at, *entries, *p, *q, *m; struct dx_root *root; struct dx_frame *frame = frame_in; struct dx_frame *ret_err = ERR_PTR(ERR_BAD_DX_DIR); u32 hash; memset(frame_in, 0, EXT4_HTREE_LEVEL * sizeof(frame_in[0])); frame->bh = ext4_read_dirblock(dir, 0, INDEX); if (IS_ERR(frame->bh)) return (struct dx_frame *) frame->bh; root = (struct dx_root *) frame->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_inode(dir, "Unrecognised inode hash code %u", root->info.hash_version); goto fail; } if (fname) hinfo = &fname->hinfo; 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 (fname && fname_name(fname)) ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), hinfo); hash = hinfo->hash; if (root->info.unused_flags & 1) { ext4_warning_inode(dir, "Unimplemented hash flags: %#06x", root->info.unused_flags); goto fail; } indirect = root->info.indirect_levels; if (indirect >= ext4_dir_htree_level(dir->i_sb)) { ext4_warning(dir->i_sb, "Directory (ino: %lu) htree depth %#06x exceed" "supported value", dir->i_ino, ext4_dir_htree_level(dir->i_sb)); if (ext4_dir_htree_level(dir->i_sb) < EXT4_HTREE_LEVEL) { ext4_warning(dir->i_sb, "Enable large directory " "feature to access it"); } 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_inode(dir, "dx entry: limit %u != root limit %u", dx_get_limit(entries), dx_root_limit(dir, root->info.info_length)); goto fail; } dxtrace(printk("Look up %x", hash)); while (1) { count = dx_get_count(entries); if (!count || count > dx_get_limit(entries)) { ext4_warning_inode(dir, "dx entry: count %u beyond limit %u", count, dx_get_limit(entries)); goto fail; } p = entries + 1; q = entries + count - 1; while (p <= q) { m = p + (q - p) / 2; dxtrace(printk(KERN_CONT ".")); 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(KERN_CONT ",")); if (dx_get_hash(++at) > hash) { at--; break; } } assert (at == p - 1); } at = p - 1; dxtrace(printk(KERN_CONT " %x->%u\n", at == entries ? 0 : dx_get_hash(at), dx_get_block(at))); frame->entries = entries; frame->at = at; if (!indirect--) return frame; frame++; frame->bh = ext4_read_dirblock(dir, dx_get_block(at), INDEX); if (IS_ERR(frame->bh)) { ret_err = (struct dx_frame *) frame->bh; frame->bh = NULL; goto fail; } entries = ((struct dx_node *) frame->bh->b_data)->entries; if (dx_get_limit(entries) != dx_node_limit(dir)) { ext4_warning_inode(dir, "dx entry: limit %u != node limit %u", dx_get_limit(entries), dx_node_limit(dir)); goto fail; } } fail: while (frame >= frame_in) { brelse(frame->bh); frame--; } if (ret_err == ERR_PTR(ERR_BAD_DX_DIR)) ext4_warning_inode(dir, "Corrupt directory, running e2fsck is recommended"); return ret_err; } static void dx_release(struct dx_frame *frames) { struct dx_root_info *info; int i; unsigned int indirect_levels; if (frames[0].bh == NULL) return; info = &((struct dx_root *)frames[0].bh->b_data)->info; /* save local copy, "info" may be freed after brelse() */ indirect_levels = info->indirect_levels; for (i = 0; i <= indirect_levels; i++) { if (frames[i].bh == NULL) break; brelse(frames[i].bh); frames[i].bh = NULL; } } /* * 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 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--) { bh = ext4_read_dirblock(dir, dx_get_block(p->at), INDEX); if (IS_ERR(bh)) return PTR_ERR(bh); 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 = 0, count = 0; struct fscrypt_str fname_crypto_str = FSTR_INIT(NULL, 0), tmp_str; dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n", (unsigned long)block)); bh = ext4_read_dirblock(dir, block, DIRENT_HTREE); if (IS_ERR(bh)) return PTR_ERR(bh); 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)); #ifdef CONFIG_FS_ENCRYPTION /* Check if the directory is encrypted */ if (IS_ENCRYPTED(dir)) { err = fscrypt_get_encryption_info(dir); if (err < 0) { brelse(bh); return err; } err = fscrypt_fname_alloc_buffer(dir, EXT4_NAME_LEN, &fname_crypto_str); if (err < 0) { brelse(bh); return err; } } #endif for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) { if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data, bh->b_size, (block<i_sb)) + ((char *)de - bh->b_data))) { /* silently ignore the rest of the block */ break; } ext4fs_dirhash(dir, 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 (!IS_ENCRYPTED(dir)) { tmp_str.name = de->name; tmp_str.len = de->name_len; err = ext4_htree_store_dirent(dir_file, hinfo->hash, hinfo->minor_hash, de, &tmp_str); } else { int save_len = fname_crypto_str.len; struct fscrypt_str de_name = FSTR_INIT(de->name, de->name_len); /* Directory is encrypted */ err = fscrypt_fname_disk_to_usr(dir, hinfo->hash, hinfo->minor_hash, &de_name, &fname_crypto_str); if (err) { count = err; goto errout; } err = ext4_htree_store_dirent(dir_file, hinfo->hash, hinfo->minor_hash, de, &fname_crypto_str); fname_crypto_str.len = save_len; } if (err != 0) { count = err; goto errout; } count++; } errout: brelse(bh); #ifdef CONFIG_FS_ENCRYPTION fscrypt_fname_free_buffer(&fname_crypto_str); #endif 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[EXT4_HTREE_LEVEL], *frame; struct inode *dir; ext4_lblk_t block; int count = 0; int ret, err; __u32 hashval; struct fscrypt_str tmp_str; dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n", start_hash, start_minor_hash)); dir = file_inode(dir_file); 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; if (ext4_has_inline_data(dir)) { int has_inline_data = 1; count = ext4_inlinedir_to_tree(dir_file, dir, 0, &hinfo, start_hash, start_minor_hash, &has_inline_data); if (has_inline_data) { *next_hash = ~0; return count; } } 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); if (IS_ERR(frame)) return PTR_ERR(frame); /* Add '.' and '..' from the htree header */ if (!start_hash && !start_minor_hash) { de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data; tmp_str.name = de->name; tmp_str.len = de->name_len; err = ext4_htree_store_dirent(dir_file, 0, 0, de, &tmp_str); if (err != 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); tmp_str.name = de->name; tmp_str.len = de->name_len; err = ext4_htree_store_dirent(dir_file, 2, 0, de, &tmp_str); if (err != 0) goto errout; count++; } while (1) { if (fatal_signal_pending(current)) { err = -ERESTARTSYS; goto errout; } cond_resched(); 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); } static inline int search_dirblock(struct buffer_head *bh, struct inode *dir, struct ext4_filename *fname, unsigned int offset, struct ext4_dir_entry_2 **res_dir) { return ext4_search_dir(bh, bh->b_data, dir->i_sb->s_blocksize, dir, fname, offset, res_dir); } /* * 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 inode *dir, 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(dir, 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); } #ifdef CONFIG_UNICODE /* * Test whether a case-insensitive directory entry matches the filename * being searched for. If quick is set, assume the name being looked up * is already in the casefolded form. * * Returns: 0 if the directory entry matches, more than 0 if it * doesn't match or less than zero on error. */ int ext4_ci_compare(const struct inode *parent, const struct qstr *name, const struct qstr *entry, bool quick) { const struct ext4_sb_info *sbi = EXT4_SB(parent->i_sb); const struct unicode_map *um = sbi->s_encoding; int ret; if (quick) ret = utf8_strncasecmp_folded(um, name, entry); else ret = utf8_strncasecmp(um, name, entry); if (ret < 0) { /* Handle invalid character sequence as either an error * or as an opaque byte sequence. */ if (ext4_has_strict_mode(sbi)) return -EINVAL; if (name->len != entry->len) return 1; return !!memcmp(name->name, entry->name, name->len); } return ret; } void ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname, struct fscrypt_str *cf_name) { int len; if (!IS_CASEFOLDED(dir) || !EXT4_SB(dir->i_sb)->s_encoding) { cf_name->name = NULL; return; } cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS); if (!cf_name->name) return; len = utf8_casefold(EXT4_SB(dir->i_sb)->s_encoding, iname, cf_name->name, EXT4_NAME_LEN); if (len <= 0) { kfree(cf_name->name); cf_name->name = NULL; return; } cf_name->len = (unsigned) len; } #endif /* * Test whether a directory entry matches the filename being searched for. * * Return: %true if the directory entry matches, otherwise %false. */ static inline bool ext4_match(const struct inode *parent, const struct ext4_filename *fname, const struct ext4_dir_entry_2 *de) { struct fscrypt_name f; #ifdef CONFIG_UNICODE const struct qstr entry = {.name = de->name, .len = de->name_len}; #endif if (!de->inode) return false; f.usr_fname = fname->usr_fname; f.disk_name = fname->disk_name; #ifdef CONFIG_FS_ENCRYPTION f.crypto_buf = fname->crypto_buf; #endif #ifdef CONFIG_UNICODE if (EXT4_SB(parent->i_sb)->s_encoding && IS_CASEFOLDED(parent)) { if (fname->cf_name.name) { struct qstr cf = {.name = fname->cf_name.name, .len = fname->cf_name.len}; return !ext4_ci_compare(parent, &cf, &entry, true); } return !ext4_ci_compare(parent, fname->usr_fname, &entry, false); } #endif return fscrypt_match_name(&f, de->name, de->name_len); } /* * Returns 0 if not found, -1 on failure, and 1 on success */ int ext4_search_dir(struct buffer_head *bh, char *search_buf, int buf_size, struct inode *dir, struct ext4_filename *fname, unsigned int offset, struct ext4_dir_entry_2 **res_dir) { struct ext4_dir_entry_2 * de; char * dlimit; int de_len; de = (struct ext4_dir_entry_2 *)search_buf; dlimit = search_buf + buf_size; while ((char *) de < dlimit) { /* this code is executed quadratically often */ /* do minimal checking `by hand' */ if ((char *) de + de->name_len <= dlimit && ext4_match(dir, fname, de)) { /* found a match - just to be sure, do * a full check */ if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data, bh->b_size, 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; } static int is_dx_internal_node(struct inode *dir, ext4_lblk_t block, struct ext4_dir_entry *de) { struct super_block *sb = dir->i_sb; if (!is_dx(dir)) return 0; if (block == 0) return 1; if (de->inode == 0 && ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) == sb->s_blocksize) return 1; 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, struct ext4_filename *fname, struct ext4_dir_entry_2 **res_dir, int *inlined) { struct super_block *sb; struct buffer_head *bh_use[NAMEI_RA_SIZE]; struct buffer_head *bh, *ret = NULL; ext4_lblk_t start, block; const u8 *name = fname->usr_fname->name; size_t ra_max = 0; /* Number of bh's in the readahead buffer, bh_use[] */ size_t ra_ptr = 0; /* Current index into readahead buffer */ ext4_lblk_t nblocks; int i, namelen, retval; *res_dir = NULL; sb = dir->i_sb; namelen = fname->usr_fname->len; if (namelen > EXT4_NAME_LEN) return NULL; if (ext4_has_inline_data(dir)) { int has_inline_data = 1; ret = ext4_find_inline_entry(dir, fname, res_dir, &has_inline_data); if (has_inline_data) { if (inlined) *inlined = 1; goto cleanup_and_exit; } } 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)) { ret = ext4_dx_find_entry(dir, fname, res_dir); /* * On success, or if the error was file not found, * return. Otherwise, fall back to doing a search the * old fashioned way. */ if (!IS_ERR(ret) || PTR_ERR(ret) != ERR_BAD_DX_DIR) goto cleanup_and_exit; dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, " "falling back\n")); ret = NULL; } nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb); if (!nblocks) { ret = NULL; goto cleanup_and_exit; } 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; if (block < start) ra_max = start - block; else ra_max = nblocks - block; ra_max = min(ra_max, ARRAY_SIZE(bh_use)); retval = ext4_bread_batch(dir, block, ra_max, false /* wait */, bh_use); if (retval) { ret = ERR_PTR(retval); ra_max = 0; goto cleanup_and_exit; } } if ((bh = bh_use[ra_ptr++]) == NULL) goto next; wait_on_buffer(bh); if (!buffer_uptodate(bh)) { ext4_set_errno(sb, EIO); EXT4_ERROR_INODE(dir, "reading directory lblock %lu", (unsigned long) block); brelse(bh); ret = ERR_PTR(-EIO); goto cleanup_and_exit; } if (!buffer_verified(bh) && !is_dx_internal_node(dir, block, (struct ext4_dir_entry *)bh->b_data) && !ext4_dirblock_csum_verify(dir, bh)) { ext4_set_errno(sb, EFSBADCRC); EXT4_ERROR_INODE(dir, "checksumming directory " "block %lu", (unsigned long)block); brelse(bh); ret = ERR_PTR(-EFSBADCRC); goto cleanup_and_exit; } set_buffer_verified(bh); i = search_dirblock(bh, dir, fname, 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_find_entry(struct inode *dir, const struct qstr *d_name, struct ext4_dir_entry_2 **res_dir, int *inlined) { int err; struct ext4_filename fname; struct buffer_head *bh; err = ext4_fname_setup_filename(dir, d_name, 1, &fname); if (err == -ENOENT) return NULL; if (err) return ERR_PTR(err); bh = __ext4_find_entry(dir, &fname, res_dir, inlined); ext4_fname_free_filename(&fname); return bh; } static struct buffer_head *ext4_lookup_entry(struct inode *dir, struct dentry *dentry, struct ext4_dir_entry_2 **res_dir) { int err; struct ext4_filename fname; struct buffer_head *bh; err = ext4_fname_prepare_lookup(dir, dentry, &fname); if (err == -ENOENT) return NULL; if (err) return ERR_PTR(err); bh = __ext4_find_entry(dir, &fname, res_dir, NULL); ext4_fname_free_filename(&fname); return bh; } static struct buffer_head * ext4_dx_find_entry(struct inode *dir, struct ext4_filename *fname, struct ext4_dir_entry_2 **res_dir) { struct super_block * sb = dir->i_sb; struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; struct buffer_head *bh; ext4_lblk_t block; int retval; #ifdef CONFIG_FS_ENCRYPTION *res_dir = NULL; #endif frame = dx_probe(fname, dir, NULL, frames); if (IS_ERR(frame)) return (struct buffer_head *) frame; do { block = dx_get_block(frame->at); bh = ext4_read_dirblock(dir, block, DIRENT_HTREE); if (IS_ERR(bh)) goto errout; retval = search_dirblock(bh, dir, fname, block << EXT4_BLOCK_SIZE_BITS(sb), res_dir); if (retval == 1) goto success; brelse(bh); if (retval == -1) { bh = ERR_PTR(ERR_BAD_DX_DIR); goto errout; } /* Check to see if we should continue to search */ retval = ext4_htree_next_block(dir, fname->hinfo.hash, frame, frames, NULL); if (retval < 0) { ext4_warning_inode(dir, "error %d reading directory index block", retval); bh = ERR_PTR(retval); goto errout; } } while (retval == 1); bh = NULL; errout: dxtrace(printk(KERN_DEBUG "%s not found\n", fname->usr_fname->name)); success: dx_release(frames); return bh; } static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) { 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_lookup_entry(dir, dentry, &de); if (IS_ERR(bh)) return ERR_CAST(bh); 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(-EFSCORRUPTED); } if (unlikely(ino == dir->i_ino)) { EXT4_ERROR_INODE(dir, "'%pd' linked to parent dir", dentry); return ERR_PTR(-EFSCORRUPTED); } inode = ext4_iget(dir->i_sb, ino, EXT4_IGET_NORMAL); if (inode == ERR_PTR(-ESTALE)) { EXT4_ERROR_INODE(dir, "deleted inode referenced: %u", ino); return ERR_PTR(-EFSCORRUPTED); } if (!IS_ERR(inode) && IS_ENCRYPTED(dir) && (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) && !fscrypt_has_permitted_context(dir, inode)) { ext4_warning(inode->i_sb, "Inconsistent encryption contexts: %lu/%lu", dir->i_ino, inode->i_ino); iput(inode); return ERR_PTR(-EPERM); } } #ifdef CONFIG_UNICODE if (!inode && IS_CASEFOLDED(dir)) { /* Eventually we want to call d_add_ci(dentry, NULL) * for negative dentries in the encoding case as * well. For now, prevent the negative dentry * from being cached. */ return NULL; } #endif return d_splice_alias(inode, dentry); } struct dentry *ext4_get_parent(struct dentry *child) { __u32 ino; static const struct qstr dotdot = QSTR_INIT("..", 2); struct ext4_dir_entry_2 * de; struct buffer_head *bh; bh = ext4_find_entry(d_inode(child), &dotdot, &de, NULL); if (IS_ERR(bh)) return ERR_CAST(bh); if (!bh) return ERR_PTR(-ENOENT); ino = le32_to_cpu(de->inode); brelse(bh); if (!ext4_valid_inum(child->d_sb, ino)) { EXT4_ERROR_INODE(d_inode(child), "bad parent inode number: %u", ino); return ERR_PTR(-EFSCORRUPTED); } return d_obtain_alias(ext4_iget(child->d_sb, ino, EXT4_IGET_NORMAL)); } /* * 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) { 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 csum_size = 0; int err = 0, i; if (ext4_has_metadata_csum(dir->i_sb)) csum_size = sizeof(struct ext4_dir_entry_tail); bh2 = ext4_append(handle, dir, &newblock); if (IS_ERR(bh2)) { brelse(*bh); *bh = NULL; return (struct ext4_dir_entry_2 *) bh2; } 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(dir, (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 - csum_size) - (char *) de, blocksize); de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - (char *) de2, blocksize); if (csum_size) { ext4_initialize_dirent_tail(*bh, blocksize); ext4_initialize_dirent_tail(bh2, blocksize); } dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1)); dxtrace(dx_show_leaf(dir, 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_dirblock(handle, dir, bh2); if (err) goto journal_error; err = ext4_handle_dirty_dx_node(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); return ERR_PTR(err); } int ext4_find_dest_de(struct inode *dir, struct inode *inode, struct buffer_head *bh, void *buf, int buf_size, struct ext4_filename *fname, struct ext4_dir_entry_2 **dest_de) { struct ext4_dir_entry_2 *de; unsigned short reclen = EXT4_DIR_REC_LEN(fname_len(fname)); int nlen, rlen; unsigned int offset = 0; char *top; de = (struct ext4_dir_entry_2 *)buf; top = buf + buf_size - reclen; while ((char *) de <= top) { if (ext4_check_dir_entry(dir, NULL, de, bh, buf, buf_size, offset)) return -EFSCORRUPTED; if (ext4_match(dir, fname, de)) return -EEXIST; nlen = EXT4_DIR_REC_LEN(de->name_len); rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 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; *dest_de = de; return 0; } void ext4_insert_dentry(struct inode *inode, struct ext4_dir_entry_2 *de, int buf_size, struct ext4_filename *fname) { int nlen, rlen; nlen = EXT4_DIR_REC_LEN(de->name_len); rlen = ext4_rec_len_from_disk(de->rec_len, buf_size); 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, buf_size); de->rec_len = ext4_rec_len_to_disk(nlen, buf_size); de = de1; } de->file_type = EXT4_FT_UNKNOWN; de->inode = cpu_to_le32(inode->i_ino); ext4_set_de_type(inode->i_sb, de, inode->i_mode); de->name_len = fname_len(fname); memcpy(de->name, fname_name(fname), fname_len(fname)); } /* * 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 ext4_filename *fname, struct inode *dir, struct inode *inode, struct ext4_dir_entry_2 *de, struct buffer_head *bh) { unsigned int blocksize = dir->i_sb->s_blocksize; int csum_size = 0; int err; if (ext4_has_metadata_csum(inode->i_sb)) csum_size = sizeof(struct ext4_dir_entry_tail); if (!de) { err = ext4_find_dest_de(dir, inode, bh, bh->b_data, blocksize - csum_size, fname, &de); if (err) return err; } 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 */ ext4_insert_dentry(inode, de, blocksize, fname); /* * 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 = current_time(dir); ext4_update_dx_flag(dir); inode_inc_iversion(dir); ext4_mark_inode_dirty(handle, dir); BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); err = ext4_handle_dirty_dirblock(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 ext4_filename *fname, struct inode *dir, struct inode *inode, struct buffer_head *bh) { struct buffer_head *bh2; struct dx_root *root; struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; struct dx_entry *entries; struct ext4_dir_entry_2 *de, *de2; char *data2, *top; unsigned len; int retval; unsigned blocksize; ext4_lblk_t block; struct fake_dirent *fde; int csum_size = 0; if (ext4_has_metadata_csum(inode->i_sb)) csum_size = sizeof(struct ext4_dir_entry_tail); blocksize = dir->i_sb->s_blocksize; dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino)); BUFFER_TRACE(bh, "get_write_access"); 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 -EFSCORRUPTED; } len = ((char *) root) + (blocksize - csum_size) - (char *) de; /* Allocate new block for the 0th block's dirents */ bh2 = ext4_append(handle, dir, &block); if (IS_ERR(bh2)) { brelse(bh); return PTR_ERR(bh2); } ext4_set_inode_flag(dir, EXT4_INODE_INDEX); data2 = bh2->b_data; memcpy(data2, de, len); de = (struct ext4_dir_entry_2 *) data2; top = data2 + len; while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top) de = de2; de->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) - (char *) de, blocksize); if (csum_size) ext4_initialize_dirent_tail(bh2, 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 */ fname->hinfo.hash_version = root->info.hash_version; if (fname->hinfo.hash_version <= DX_HASH_TEA) fname->hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned; fname->hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed; ext4fs_dirhash(dir, fname_name(fname), fname_len(fname), &fname->hinfo); memset(frames, 0, sizeof(frames)); frame = frames; frame->entries = entries; frame->at = entries; frame->bh = bh; retval = ext4_handle_dirty_dx_node(handle, dir, frame->bh); if (retval) goto out_frames; retval = ext4_handle_dirty_dirblock(handle, dir, bh2); if (retval) goto out_frames; de = do_split(handle,dir, &bh2, frame, &fname->hinfo); if (IS_ERR(de)) { retval = PTR_ERR(de); goto out_frames; } retval = add_dirent_to_buf(handle, fname, dir, inode, de, bh2); out_frames: /* * 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. */ if (retval) ext4_mark_inode_dirty(handle, dir); dx_release(frames); brelse(bh2); 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 = d_inode(dentry->d_parent); struct buffer_head *bh = NULL; struct ext4_dir_entry_2 *de; struct super_block *sb; #ifdef CONFIG_UNICODE struct ext4_sb_info *sbi; #endif struct ext4_filename fname; int retval; int dx_fallback=0; unsigned blocksize; ext4_lblk_t block, blocks; int csum_size = 0; if (ext4_has_metadata_csum(inode->i_sb)) csum_size = sizeof(struct ext4_dir_entry_tail); sb = dir->i_sb; blocksize = sb->s_blocksize; if (!dentry->d_name.len) return -EINVAL; #ifdef CONFIG_UNICODE sbi = EXT4_SB(sb); if (ext4_has_strict_mode(sbi) && IS_CASEFOLDED(dir) && sbi->s_encoding && utf8_validate(sbi->s_encoding, &dentry->d_name)) return -EINVAL; #endif retval = ext4_fname_setup_filename(dir, &dentry->d_name, 0, &fname); if (retval) return retval; if (ext4_has_inline_data(dir)) { retval = ext4_try_add_inline_entry(handle, &fname, dir, inode); if (retval < 0) goto out; if (retval == 1) { retval = 0; goto out; } } if (is_dx(dir)) { retval = ext4_dx_add_entry(handle, &fname, dir, inode); if (!retval || (retval != ERR_BAD_DX_DIR)) goto out; 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_read_dirblock(dir, block, DIRENT); if (bh == NULL) { bh = ext4_bread(handle, dir, block, EXT4_GET_BLOCKS_CREATE); goto add_to_new_block; } if (IS_ERR(bh)) { retval = PTR_ERR(bh); bh = NULL; goto out; } retval = add_dirent_to_buf(handle, &fname, dir, inode, NULL, bh); if (retval != -ENOSPC) goto out; if (blocks == 1 && !dx_fallback && ext4_has_feature_dir_index(sb)) { retval = make_indexed_dir(handle, &fname, dir, inode, bh); bh = NULL; /* make_indexed_dir releases bh */ goto out; } brelse(bh); } bh = ext4_append(handle, dir, &block); add_to_new_block: if (IS_ERR(bh)) { retval = PTR_ERR(bh); bh = NULL; goto out; } de = (struct ext4_dir_entry_2 *) bh->b_data; de->inode = 0; de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize); if (csum_size) ext4_initialize_dirent_tail(bh, blocksize); retval = add_dirent_to_buf(handle, &fname, dir, inode, de, bh); out: ext4_fname_free_filename(&fname); 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 ext4_filename *fname, struct inode *dir, struct inode *inode) { struct dx_frame frames[EXT4_HTREE_LEVEL], *frame; struct dx_entry *entries, *at; struct buffer_head *bh; struct super_block *sb = dir->i_sb; struct ext4_dir_entry_2 *de; int restart; int err; again: restart = 0; frame = dx_probe(fname, dir, NULL, frames); if (IS_ERR(frame)) return PTR_ERR(frame); entries = frame->entries; at = frame->at; bh = ext4_read_dirblock(dir, dx_get_block(frame->at), DIRENT_HTREE); if (IS_ERR(bh)) { err = PTR_ERR(bh); bh = NULL; 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, fname, dir, inode, NULL, bh); if (err != -ENOSPC) goto cleanup; err = 0; /* 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; int levels = frame - frames + 1; unsigned int icount; int add_level = 1; struct dx_entry *entries2; struct dx_node *node2; struct buffer_head *bh2; while (frame > frames) { if (dx_get_count((frame - 1)->entries) < dx_get_limit((frame - 1)->entries)) { add_level = 0; break; } frame--; /* split higher index block */ at = frame->at; entries = frame->entries; restart = 1; } if (add_level && levels == ext4_dir_htree_level(sb)) { ext4_warning(sb, "Directory (ino: %lu) index full, " "reach max htree level :%d", dir->i_ino, levels); if (ext4_dir_htree_level(sb) < EXT4_HTREE_LEVEL) { ext4_warning(sb, "Large directory feature is " "not enabled on this " "filesystem"); } err = -ENOSPC; goto cleanup; } icount = dx_get_count(entries); bh2 = ext4_append(handle, dir, &newblock); if (IS_ERR(bh2)) { err = PTR_ERR(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 (!add_level) { 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, (frame - 1)->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((frame - 1), hash2, newblock); dxtrace(dx_show_index("node", frame->entries)); dxtrace(dx_show_index("node", ((struct dx_node *) bh2->b_data)->entries)); err = ext4_handle_dirty_dx_node(handle, dir, bh2); if (err) goto journal_error; brelse (bh2); err = ext4_handle_dirty_dx_node(handle, dir, (frame - 1)->bh); if (err) goto journal_error; if (restart) { err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); goto journal_error; } } else { struct dx_root *dxroot; 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); dxroot = (struct dx_root *)frames[0].bh->b_data; dxroot->info.indirect_levels += 1; dxtrace(printk(KERN_DEBUG "Creating %d level index...\n", dxroot->info.indirect_levels)); err = ext4_handle_dirty_dx_node(handle, dir, frame->bh); if (err) goto journal_error; err = ext4_handle_dirty_dx_node(handle, dir, bh2); brelse(bh2); restart = 1; goto journal_error; } } de = do_split(handle, dir, &bh, frame, &fname->hinfo); if (IS_ERR(de)) { err = PTR_ERR(de); goto cleanup; } err = add_dirent_to_buf(handle, fname, dir, inode, de, bh); goto cleanup; journal_error: ext4_std_error(dir->i_sb, err); /* this is a no-op if err == 0 */ cleanup: brelse(bh); dx_release(frames); /* @restart is true means htree-path has been changed, we need to * repeat dx_probe() to find out valid htree-path */ if (restart && err == 0) goto again; return err; } /* * ext4_generic_delete_entry deletes a directory entry by merging it * with the previous entry */ int ext4_generic_delete_entry(handle_t *handle, struct inode *dir, struct ext4_dir_entry_2 *de_del, struct buffer_head *bh, void *entry_buf, int buf_size, int csum_size) { struct ext4_dir_entry_2 *de, *pde; unsigned int blocksize = dir->i_sb->s_blocksize; int i; i = 0; pde = NULL; de = (struct ext4_dir_entry_2 *)entry_buf; while (i < buf_size - csum_size) { if (ext4_check_dir_entry(dir, NULL, de, bh, bh->b_data, bh->b_size, i)) return -EFSCORRUPTED; if (de == de_del) { 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; inode_inc_iversion(dir); return 0; } i += ext4_rec_len_from_disk(de->rec_len, blocksize); pde = de; de = ext4_next_entry(de, blocksize); } return -ENOENT; } static int ext4_delete_entry(handle_t *handle, struct inode *dir, struct ext4_dir_entry_2 *de_del, struct buffer_head *bh) { int err, csum_size = 0; if (ext4_has_inline_data(dir)) { int has_inline_data = 1; err = ext4_delete_inline_entry(handle, dir, de_del, bh, &has_inline_data); if (has_inline_data) return err; } if (ext4_has_metadata_csum(dir->i_sb)) csum_size = sizeof(struct ext4_dir_entry_tail); BUFFER_TRACE(bh, "get_write_access"); err = ext4_journal_get_write_access(handle, bh); if (unlikely(err)) goto out; err = ext4_generic_delete_entry(handle, dir, de_del, bh, bh->b_data, dir->i_sb->s_blocksize, csum_size); if (err) goto out; BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); err = ext4_handle_dirty_dirblock(handle, dir, bh); if (unlikely(err)) goto out; return 0; out: if (err != -ENOENT) ext4_std_error(dir->i_sb, err); return err; } /* * Set directory link count to 1 if nlinks > EXT4_LINK_MAX, or if nlinks == 2 * since this indicates that nlinks count was previously 1 to avoid overflowing * the 16-bit i_links_count field on disk. Directories with i_nlink == 1 mean * that subdirectory link counts are not being maintained accurately. * * The caller has already checked for i_nlink overflow in case the DIR_LINK * feature is not enabled and returned -EMLINK. The is_dx() check is a proxy * for checking S_ISDIR(inode) (since the INODE_INDEX feature will not be set * on regular files) and to avoid creating huge/slow non-HTREE directories. */ static void ext4_inc_count(handle_t *handle, struct inode *inode) { inc_nlink(inode); if (is_dx(inode) && (inode->i_nlink > EXT4_LINK_MAX || inode->i_nlink == 2)) set_nlink(inode, 1); } /* * 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); } /* * Add non-directory inode to a directory. On success, the inode reference is * consumed by dentry is instantiation. This is also indicated by clearing of * *inodep pointer. On failure, the caller is responsible for dropping the * inode reference in the safe context. */ static int ext4_add_nondir(handle_t *handle, struct dentry *dentry, struct inode **inodep) { struct inode *dir = d_inode(dentry->d_parent); struct inode *inode = *inodep; int err = ext4_add_entry(handle, dentry, inode); if (!err) { ext4_mark_inode_dirty(handle, inode); if (IS_DIRSYNC(dir)) ext4_handle_sync(handle); d_instantiate_new(dentry, inode); *inodep = NULL; return 0; } drop_nlink(inode); ext4_orphan_add(handle, inode); unlock_new_inode(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, bool excl) { handle_t *handle; struct inode *inode; int err, credits, retries = 0; err = dquot_initialize(dir); if (err) return err; credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); retry: inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0, NULL, EXT4_HT_DIR, credits); handle = ext4_journal_current_handle(); 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); } if (handle) ext4_journal_stop(handle); if (!IS_ERR_OR_NULL(inode)) iput(inode); 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, credits, retries = 0; err = dquot_initialize(dir); if (err) return err; credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); retry: inode = ext4_new_inode_start_handle(dir, mode, &dentry->d_name, 0, NULL, EXT4_HT_DIR, credits); handle = ext4_journal_current_handle(); err = PTR_ERR(inode); if (!IS_ERR(inode)) { init_special_inode(inode, inode->i_mode, rdev); inode->i_op = &ext4_special_inode_operations; err = ext4_add_nondir(handle, dentry, &inode); } if (handle) ext4_journal_stop(handle); if (!IS_ERR_OR_NULL(inode)) iput(inode); if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) goto retry; return err; } static int ext4_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) { handle_t *handle; struct inode *inode; int err, retries = 0; err = dquot_initialize(dir); if (err) return err; retry: inode = ext4_new_inode_start_handle(dir, mode, NULL, 0, NULL, EXT4_HT_DIR, EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) + 4 + EXT4_XATTR_TRANS_BLOCKS); handle = ext4_journal_current_handle(); 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); d_tmpfile(dentry, inode); err = ext4_orphan_add(handle, inode); if (err) goto err_unlock_inode; mark_inode_dirty(inode); unlock_new_inode(inode); } if (handle) ext4_journal_stop(handle); if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries)) goto retry; return err; err_unlock_inode: ext4_journal_stop(handle); unlock_new_inode(inode); return err; } struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode, struct ext4_dir_entry_2 *de, int blocksize, int csum_size, unsigned int parent_ino, int dotdot_real_len) { 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(inode->i_sb, de, S_IFDIR); de = ext4_next_entry(de, blocksize); de->inode = cpu_to_le32(parent_ino); de->name_len = 2; if (!dotdot_real_len) de->rec_len = ext4_rec_len_to_disk(blocksize - (csum_size + EXT4_DIR_REC_LEN(1)), blocksize); else de->rec_len = ext4_rec_len_to_disk( EXT4_DIR_REC_LEN(de->name_len), blocksize); strcpy(de->name, ".."); ext4_set_de_type(inode->i_sb, de, S_IFDIR); return ext4_next_entry(de, blocksize); } static int ext4_init_new_dir(handle_t *handle, struct inode *dir, struct inode *inode) { struct buffer_head *dir_block = NULL; struct ext4_dir_entry_2 *de; ext4_lblk_t block = 0; unsigned int blocksize = dir->i_sb->s_blocksize; int csum_size = 0; int err; if (ext4_has_metadata_csum(dir->i_sb)) csum_size = sizeof(struct ext4_dir_entry_tail); if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { err = ext4_try_create_inline_dir(handle, dir, inode); if (err < 0 && err != -ENOSPC) goto out; if (!err) goto out; } inode->i_size = 0; dir_block = ext4_append(handle, inode, &block); if (IS_ERR(dir_block)) return PTR_ERR(dir_block); de = (struct ext4_dir_entry_2 *)dir_block->b_data; ext4_init_dot_dotdot(inode, de, blocksize, csum_size, dir->i_ino, 0); set_nlink(inode, 2); if (csum_size) ext4_initialize_dirent_tail(dir_block, blocksize); BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata"); err = ext4_handle_dirty_dirblock(handle, inode, dir_block); if (err) goto out; set_buffer_verified(dir_block); out: brelse(dir_block); return err; } static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) { handle_t *handle; struct inode *inode; int err, credits, retries = 0; if (EXT4_DIR_LINK_MAX(dir)) return -EMLINK; err = dquot_initialize(dir); if (err) return err; credits = (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3); retry: inode = ext4_new_inode_start_handle(dir, S_IFDIR | mode, &dentry->d_name, 0, NULL, EXT4_HT_DIR, credits); handle = ext4_journal_current_handle(); err = PTR_ERR(inode); if (IS_ERR(inode)) goto out_stop; inode->i_op = &ext4_dir_inode_operations; inode->i_fop = &ext4_dir_operations; err = ext4_init_new_dir(handle, dir, inode); 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); ext4_orphan_add(handle, inode); unlock_new_inode(inode); ext4_mark_inode_dirty(handle, inode); ext4_journal_stop(handle); iput(inode); goto out_retry; } 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_new(dentry, inode); if (IS_DIRSYNC(dir)) ext4_handle_sync(handle); out_stop: if (handle) ext4_journal_stop(handle); out_retry: 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) */ bool ext4_empty_dir(struct inode *inode) { unsigned int offset; struct buffer_head *bh; struct ext4_dir_entry_2 *de; struct super_block *sb; if (ext4_has_inline_data(inode)) { int has_inline_data = 1; int ret; ret = empty_inline_dir(inode, &has_inline_data); if (has_inline_data) return ret; } sb = inode->i_sb; if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)) { EXT4_ERROR_INODE(inode, "invalid size"); return true; } /* The first directory block must not be a hole, * so treat it as DIRENT_HTREE */ bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE); if (IS_ERR(bh)) return true; de = (struct ext4_dir_entry_2 *) bh->b_data; if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size, 0) || le32_to_cpu(de->inode) != inode->i_ino || strcmp(".", de->name)) { ext4_warning_inode(inode, "directory missing '.'"); brelse(bh); return true; } offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); de = ext4_next_entry(de, sb->s_blocksize); if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size, offset) || le32_to_cpu(de->inode) == 0 || strcmp("..", de->name)) { ext4_warning_inode(inode, "directory missing '..'"); brelse(bh); return true; } offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); while (offset < inode->i_size) { if (!(offset & (sb->s_blocksize - 1))) { unsigned int lblock; brelse(bh); lblock = offset >> EXT4_BLOCK_SIZE_BITS(sb); bh = ext4_read_dirblock(inode, lblock, EITHER); if (bh == NULL) { offset += sb->s_blocksize; continue; } if (IS_ERR(bh)) return true; } de = (struct ext4_dir_entry_2 *) (bh->b_data + (offset & (sb->s_blocksize - 1))); if (ext4_check_dir_entry(inode, NULL, de, bh, bh->b_data, bh->b_size, offset)) { offset = (offset | (sb->s_blocksize - 1)) + 1; continue; } if (le32_to_cpu(de->inode)) { brelse(bh); return false; } offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize); } brelse(bh); return true; } /* * 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(). * * Orphan list manipulation functions must be called under i_mutex unless * we are just creating the inode or deleting it. */ int ext4_orphan_add(handle_t *handle, struct inode *inode) { struct super_block *sb = inode->i_sb; struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_iloc iloc; int err = 0, rc; bool dirty = false; if (!sbi->s_journal || is_bad_inode(inode)) return 0; WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) && !inode_is_locked(inode)); /* * Exit early if inode already is on orphan list. This is a big speedup * since we don't have to contend on the global s_orphan_lock. */ if (!list_empty(&EXT4_I(inode)->i_orphan)) return 0; /* * 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(sbi->s_sbh, "get_write_access"); err = ext4_journal_get_write_access(handle, sbi->s_sbh); if (err) goto out; err = ext4_reserve_inode_write(handle, inode, &iloc); if (err) goto out; mutex_lock(&sbi->s_orphan_lock); /* * 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(sbi->s_es->s_inodes_count))) { /* Insert this inode at the head of the on-disk orphan list */ NEXT_ORPHAN(inode) = le32_to_cpu(sbi->s_es->s_last_orphan); sbi->s_es->s_last_orphan = cpu_to_le32(inode->i_ino); dirty = true; } list_add(&EXT4_I(inode)->i_orphan, &sbi->s_orphan); mutex_unlock(&sbi->s_orphan_lock); if (dirty) { err = ext4_handle_dirty_super(handle, sb); rc = ext4_mark_iloc_dirty(handle, inode, &iloc); if (!err) err = rc; if (err) { /* * We have to remove inode from in-memory list if * addition to on disk orphan list failed. Stray orphan * list entries can cause panics at unmount time. */ mutex_lock(&sbi->s_orphan_lock); list_del_init(&EXT4_I(inode)->i_orphan); mutex_unlock(&sbi->s_orphan_lock); } } else brelse(iloc.bh); 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: ext4_std_error(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 = EXT4_SB(inode->i_sb); __u32 ino_next; struct ext4_iloc iloc; int err = 0; if (!sbi->s_journal && !(sbi->s_mount_state & EXT4_ORPHAN_FS)) return 0; WARN_ON_ONCE(!(inode->i_state & (I_NEW | I_FREEING)) && !inode_is_locked(inode)); /* Do this quick check before taking global s_orphan_lock. */ if (list_empty(&ei->i_orphan)) return 0; if (handle) { /* Grab inode buffer early before taking global s_orphan_lock */ err = ext4_reserve_inode_write(handle, inode, &iloc); } mutex_lock(&sbi->s_orphan_lock); jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino); prev = ei->i_orphan.prev; 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 (!handle || err) { mutex_unlock(&sbi->s_orphan_lock); goto out_err; } ino_next = NEXT_ORPHAN(inode); 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) { mutex_unlock(&sbi->s_orphan_lock); goto out_brelse; } sbi->s_es->s_last_orphan = cpu_to_le32(ino_next); mutex_unlock(&sbi->s_orphan_lock); err = ext4_handle_dirty_super(handle, inode->i_sb); } 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) { mutex_unlock(&sbi->s_orphan_lock); goto out_brelse; } NEXT_ORPHAN(i_prev) = ino_next; err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2); mutex_unlock(&sbi->s_orphan_lock); } 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); 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 = NULL; if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) return -EIO; /* Initialize quotas before so that eventual writes go in * separate transaction */ retval = dquot_initialize(dir); if (retval) return retval; retval = dquot_initialize(d_inode(dentry)); if (retval) return retval; retval = -ENOENT; bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); if (IS_ERR(bh)) return PTR_ERR(bh); if (!bh) goto end_rmdir; inode = d_inode(dentry); retval = -EFSCORRUPTED; if (le32_to_cpu(de->inode) != inode->i_ino) goto end_rmdir; retval = -ENOTEMPTY; if (!ext4_empty_dir(inode)) goto end_rmdir; handle = ext4_journal_start(dir, EXT4_HT_DIR, EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); if (IS_ERR(handle)) { retval = PTR_ERR(handle); handle = NULL; goto end_rmdir; } if (IS_DIRSYNC(dir)) ext4_handle_sync(handle); retval = ext4_delete_entry(handle, dir, de, bh); if (retval) goto end_rmdir; if (!EXT4_DIR_LINK_EMPTY(inode)) ext4_warning_inode(inode, "empty directory '%.*s' has too many links (%u)", dentry->d_name.len, dentry->d_name.name, inode->i_nlink); inode_inc_iversion(inode); 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 = 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); #ifdef CONFIG_UNICODE /* VFS negative dentries are incompatible with Encoding and * Case-insensitiveness. Eventually we'll want avoid * invalidating the dentries here, alongside with returning the * negative dentries at ext4_lookup(), when it is better * supported by the VFS for the CI case. */ if (IS_CASEFOLDED(dir)) d_invalidate(dentry); #endif end_rmdir: brelse(bh); if (handle) ext4_journal_stop(handle); 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 = NULL; if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) return -EIO; trace_ext4_unlink_enter(dir, dentry); /* Initialize quotas before so that eventual writes go * in separate transaction */ retval = dquot_initialize(dir); if (retval) return retval; retval = dquot_initialize(d_inode(dentry)); if (retval) return retval; retval = -ENOENT; bh = ext4_find_entry(dir, &dentry->d_name, &de, NULL); if (IS_ERR(bh)) return PTR_ERR(bh); if (!bh) goto end_unlink; inode = d_inode(dentry); retval = -EFSCORRUPTED; if (le32_to_cpu(de->inode) != inode->i_ino) goto end_unlink; handle = ext4_journal_start(dir, EXT4_HT_DIR, EXT4_DATA_TRANS_BLOCKS(dir->i_sb)); if (IS_ERR(handle)) { retval = PTR_ERR(handle); handle = NULL; goto end_unlink; } if (IS_DIRSYNC(dir)) ext4_handle_sync(handle); retval = ext4_delete_entry(handle, dir, de, bh); if (retval) goto end_unlink; dir->i_ctime = dir->i_mtime = current_time(dir); ext4_update_dx_flag(dir); ext4_mark_inode_dirty(handle, dir); if (inode->i_nlink == 0) ext4_warning_inode(inode, "Deleting file '%.*s' with no links", dentry->d_name.len, dentry->d_name.name); else drop_nlink(inode); if (!inode->i_nlink) ext4_orphan_add(handle, inode); inode->i_ctime = current_time(inode); ext4_mark_inode_dirty(handle, inode); #ifdef CONFIG_UNICODE /* VFS negative dentries are incompatible with Encoding and * Case-insensitiveness. Eventually we'll want avoid * invalidating the dentries here, alongside with returning the * negative dentries at ext4_lookup(), when it is better * supported by the VFS for the CI case. */ if (IS_CASEFOLDED(dir)) d_invalidate(dentry); #endif end_unlink: brelse(bh); if (handle) ext4_journal_stop(handle); 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 err, len = strlen(symname); int credits; struct fscrypt_str disk_link; if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb)))) return -EIO; err = fscrypt_prepare_symlink(dir, symname, len, dir->i_sb->s_blocksize, &disk_link); if (err) return err; err = dquot_initialize(dir); if (err) return err; if ((disk_link.len > 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; } inode = ext4_new_inode_start_handle(dir, S_IFLNK|S_IRWXUGO, &dentry->d_name, 0, NULL, EXT4_HT_DIR, credits); handle = ext4_journal_current_handle(); if (IS_ERR(inode)) { if (handle) ext4_journal_stop(handle); return PTR_ERR(inode); } if (IS_ENCRYPTED(inode)) { err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link); if (err) goto err_drop_inode; inode->i_op = &ext4_encrypted_symlink_inode_operations; } if ((disk_link.len > EXT4_N_BLOCKS * 4)) { if (!IS_ENCRYPTED(inode)) inode->i_op = &ext4_symlink_inode_operations; inode_nohighmem(inode); 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); handle = NULL; if (err) goto err_drop_inode; err = __page_symlink(inode, disk_link.name, disk_link.len, 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_HT_DIR, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 1); if (IS_ERR(handle)) { err = PTR_ERR(handle); handle = NULL; goto err_drop_inode; } set_nlink(inode, 1); err = ext4_orphan_del(handle, inode); if (err) goto err_drop_inode; } else { /* clear the extent format for fast symlink */ ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS); if (!IS_ENCRYPTED(inode)) { inode->i_op = &ext4_fast_symlink_inode_operations; inode->i_link = (char *)&EXT4_I(inode)->i_data; } memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name, disk_link.len); inode->i_size = disk_link.len - 1; } EXT4_I(inode)->i_disksize = inode->i_size; err = ext4_add_nondir(handle, dentry, &inode); if (handle) ext4_journal_stop(handle); if (inode) iput(inode); goto out_free_encrypted_link; err_drop_inode: if (handle) ext4_journal_stop(handle); clear_nlink(inode); unlock_new_inode(inode); iput(inode); out_free_encrypted_link: if (disk_link.name != (unsigned char *)symname) kfree(disk_link.name); return err; } static int ext4_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) { handle_t *handle; struct inode *inode = d_inode(old_dentry); int err, retries = 0; if (inode->i_nlink >= EXT4_LINK_MAX) return -EMLINK; err = fscrypt_prepare_link(old_dentry, dir, dentry); if (err) return err; if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) && (!projid_eq(EXT4_I(dir)->i_projid, EXT4_I(old_dentry->d_inode)->i_projid))) return -EXDEV; err = dquot_initialize(dir); if (err) return err; retry: handle = ext4_journal_start(dir, EXT4_HT_DIR, (EXT4_DATA_TRANS_BLOCKS(dir->i_sb) + EXT4_INDEX_EXTRA_TRANS_BLOCKS) + 1); if (IS_ERR(handle)) return PTR_ERR(handle); if (IS_DIRSYNC(dir)) ext4_handle_sync(handle); inode->i_ctime = 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); /* this can happen only for tmpfile being * linked the first time */ if (inode->i_nlink == 1) ext4_orphan_del(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; } /* * Try to find buffer head where contains the parent block. * It should be the inode block if it is inlined or the 1st block * if it is a normal dir. */ static struct buffer_head *ext4_get_first_dir_block(handle_t *handle, struct inode *inode, int *retval, struct ext4_dir_entry_2 **parent_de, int *inlined) { struct buffer_head *bh; if (!ext4_has_inline_data(inode)) { /* The first directory block must not be a hole, so * treat it as DIRENT_HTREE */ bh = ext4_read_dirblock(inode, 0, DIRENT_HTREE); if (IS_ERR(bh)) { *retval = PTR_ERR(bh); return NULL; } *parent_de = ext4_next_entry( (struct ext4_dir_entry_2 *)bh->b_data, inode->i_sb->s_blocksize); return bh; } *inlined = 1; return ext4_get_first_inline_block(inode, parent_de, retval); } struct ext4_renament { struct inode *dir; struct dentry *dentry; struct inode *inode; bool is_dir; int dir_nlink_delta; /* entry for "dentry" */ struct buffer_head *bh; struct ext4_dir_entry_2 *de; int inlined; /* entry for ".." in inode if it's a directory */ struct buffer_head *dir_bh; struct ext4_dir_entry_2 *parent_de; int dir_inlined; }; static int ext4_rename_dir_prepare(handle_t *handle, struct ext4_renament *ent) { int retval; ent->dir_bh = ext4_get_first_dir_block(handle, ent->inode, &retval, &ent->parent_de, &ent->dir_inlined); if (!ent->dir_bh) return retval; if (le32_to_cpu(ent->parent_de->inode) != ent->dir->i_ino) return -EFSCORRUPTED; BUFFER_TRACE(ent->dir_bh, "get_write_access"); return ext4_journal_get_write_access(handle, ent->dir_bh); } static int ext4_rename_dir_finish(handle_t *handle, struct ext4_renament *ent, unsigned dir_ino) { int retval; ent->parent_de->inode = cpu_to_le32(dir_ino); BUFFER_TRACE(ent->dir_bh, "call ext4_handle_dirty_metadata"); if (!ent->dir_inlined) { if (is_dx(ent->inode)) { retval = ext4_handle_dirty_dx_node(handle, ent->inode, ent->dir_bh); } else { retval = ext4_handle_dirty_dirblock(handle, ent->inode, ent->dir_bh); } } else { retval = ext4_mark_inode_dirty(handle, ent->inode); } if (retval) { ext4_std_error(ent->dir->i_sb, retval); return retval; } return 0; } static int ext4_setent(handle_t *handle, struct ext4_renament *ent, unsigned ino, unsigned file_type) { int retval; BUFFER_TRACE(ent->bh, "get write access"); retval = ext4_journal_get_write_access(handle, ent->bh); if (retval) return retval; ent->de->inode = cpu_to_le32(ino); if (ext4_has_feature_filetype(ent->dir->i_sb)) ent->de->file_type = file_type; inode_inc_iversion(ent->dir); ent->dir->i_ctime = ent->dir->i_mtime = current_time(ent->dir); ext4_mark_inode_dirty(handle, ent->dir); BUFFER_TRACE(ent->bh, "call ext4_handle_dirty_metadata"); if (!ent->inlined) { retval = ext4_handle_dirty_dirblock(handle, ent->dir, ent->bh); if (unlikely(retval)) { ext4_std_error(ent->dir->i_sb, retval); return retval; } } brelse(ent->bh); ent->bh = NULL; return 0; } static int ext4_find_delete_entry(handle_t *handle, struct inode *dir, const struct qstr *d_name) { int retval = -ENOENT; struct buffer_head *bh; struct ext4_dir_entry_2 *de; bh = ext4_find_entry(dir, d_name, &de, NULL); if (IS_ERR(bh)) return PTR_ERR(bh); if (bh) { retval = ext4_delete_entry(handle, dir, de, bh); brelse(bh); } return retval; } static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent, int force_reread) { int retval; /* * ent->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 ent->bh so just checking inum * and the name isn't enough. */ if (le32_to_cpu(ent->de->inode) != ent->inode->i_ino || ent->de->name_len != ent->dentry->d_name.len || strncmp(ent->de->name, ent->dentry->d_name.name, ent->de->name_len) || force_reread) { retval = ext4_find_delete_entry(handle, ent->dir, &ent->dentry->d_name); } else { retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh); if (retval == -ENOENT) { retval = ext4_find_delete_entry(handle, ent->dir, &ent->dentry->d_name); } } if (retval) { ext4_warning_inode(ent->dir, "Deleting old file: nlink %d, error=%d", ent->dir->i_nlink, retval); } } static void ext4_update_dir_count(handle_t *handle, struct ext4_renament *ent) { if (ent->dir_nlink_delta) { if (ent->dir_nlink_delta == -1) ext4_dec_count(handle, ent->dir); else ext4_inc_count(handle, ent->dir); ext4_mark_inode_dirty(handle, ent->dir); } } static struct inode *ext4_whiteout_for_rename(struct ext4_renament *ent, int credits, handle_t **h) { struct inode *wh; handle_t *handle; int retries = 0; /* * for inode block, sb block, group summaries, * and inode bitmap */ credits += (EXT4_MAXQUOTAS_TRANS_BLOCKS(ent->dir->i_sb) + EXT4_XATTR_TRANS_BLOCKS + 4); retry: wh = ext4_new_inode_start_handle(ent->dir, S_IFCHR | WHITEOUT_MODE, &ent->dentry->d_name, 0, NULL, EXT4_HT_DIR, credits); handle = ext4_journal_current_handle(); if (IS_ERR(wh)) { if (handle) ext4_journal_stop(handle); if (PTR_ERR(wh) == -ENOSPC && ext4_should_retry_alloc(ent->dir->i_sb, &retries)) goto retry; } else { *h = handle; init_special_inode(wh, wh->i_mode, WHITEOUT_DEV); wh->i_op = &ext4_special_inode_operations; } return wh; } /* * Anybody can rename anything with this: the permission checks are left to the * higher-level routines. * * n.b. old_{dentry,inode) refers to the source dentry/inode * while new_{dentry,inode) refers to the destination dentry/inode * This comes from rename(const char *oldpath, const char *newpath) */ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags) { handle_t *handle = NULL; struct ext4_renament old = { .dir = old_dir, .dentry = old_dentry, .inode = d_inode(old_dentry), }; struct ext4_renament new = { .dir = new_dir, .dentry = new_dentry, .inode = d_inode(new_dentry), }; int force_reread; int retval; struct inode *whiteout = NULL; int credits; u8 old_file_type; if (new.inode && new.inode->i_nlink == 0) { EXT4_ERROR_INODE(new.inode, "target of rename is already freed"); return -EFSCORRUPTED; } if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) && (!projid_eq(EXT4_I(new_dir)->i_projid, EXT4_I(old_dentry->d_inode)->i_projid))) return -EXDEV; retval = dquot_initialize(old.dir); if (retval) return retval; retval = dquot_initialize(new.dir); if (retval) return retval; /* Initialize quotas before so that eventual writes go * in separate transaction */ if (new.inode) { retval = dquot_initialize(new.inode); if (retval) return retval; } old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL); if (IS_ERR(old.bh)) return PTR_ERR(old.bh); /* * 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 ;-< */ retval = -ENOENT; if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) goto end_rename; new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, &new.de, &new.inlined); if (IS_ERR(new.bh)) { retval = PTR_ERR(new.bh); new.bh = NULL; goto end_rename; } if (new.bh) { if (!new.inode) { brelse(new.bh); new.bh = NULL; } } if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC)) ext4_alloc_da_blocks(old.inode); credits = (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2); if (!(flags & RENAME_WHITEOUT)) { handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits); if (IS_ERR(handle)) { retval = PTR_ERR(handle); handle = NULL; goto end_rename; } } else { whiteout = ext4_whiteout_for_rename(&old, credits, &handle); if (IS_ERR(whiteout)) { retval = PTR_ERR(whiteout); whiteout = NULL; goto end_rename; } } if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) ext4_handle_sync(handle); if (S_ISDIR(old.inode->i_mode)) { if (new.inode) { retval = -ENOTEMPTY; if (!ext4_empty_dir(new.inode)) goto end_rename; } else { retval = -EMLINK; if (new.dir != old.dir && EXT4_DIR_LINK_MAX(new.dir)) goto end_rename; } retval = ext4_rename_dir_prepare(handle, &old); if (retval) goto end_rename; } /* * If we're renaming a file within an inline_data dir and adding or * setting the new dirent causes a conversion from inline_data to * extents/blockmap, we need to force the dirent delete code to * re-read the directory, or else we end up trying to delete a dirent * from what is now the extent tree root (or a block map). */ force_reread = (new.dir->i_ino == old.dir->i_ino && ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA)); old_file_type = old.de->file_type; if (whiteout) { /* * Do this before adding a new entry, so the old entry is sure * to be still pointing to the valid old entry. */ retval = ext4_setent(handle, &old, whiteout->i_ino, EXT4_FT_CHRDEV); if (retval) goto end_rename; ext4_mark_inode_dirty(handle, whiteout); } if (!new.bh) { retval = ext4_add_entry(handle, new.dentry, old.inode); if (retval) goto end_rename; } else { retval = ext4_setent(handle, &new, old.inode->i_ino, old_file_type); if (retval) goto end_rename; } if (force_reread) force_reread = !ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA); /* * Like most other Unix systems, set the ctime for inodes on a * rename. */ old.inode->i_ctime = current_time(old.inode); ext4_mark_inode_dirty(handle, old.inode); if (!whiteout) { /* * ok, that's it */ ext4_rename_delete(handle, &old, force_reread); } if (new.inode) { ext4_dec_count(handle, new.inode); new.inode->i_ctime = current_time(new.inode); } old.dir->i_ctime = old.dir->i_mtime = current_time(old.dir); ext4_update_dx_flag(old.dir); if (old.dir_bh) { retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); if (retval) goto end_rename; ext4_dec_count(handle, old.dir); if (new.inode) { /* checked ext4_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); } retval = 0; end_rename: brelse(old.dir_bh); brelse(old.bh); brelse(new.bh); if (whiteout) { if (retval) drop_nlink(whiteout); unlock_new_inode(whiteout); iput(whiteout); } if (handle) ext4_journal_stop(handle); return retval; } static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) { handle_t *handle = NULL; struct ext4_renament old = { .dir = old_dir, .dentry = old_dentry, .inode = d_inode(old_dentry), }; struct ext4_renament new = { .dir = new_dir, .dentry = new_dentry, .inode = d_inode(new_dentry), }; u8 new_file_type; int retval; struct timespec64 ctime; if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) && !projid_eq(EXT4_I(new_dir)->i_projid, EXT4_I(old_dentry->d_inode)->i_projid)) || (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) && !projid_eq(EXT4_I(old_dir)->i_projid, EXT4_I(new_dentry->d_inode)->i_projid))) return -EXDEV; retval = dquot_initialize(old.dir); if (retval) return retval; retval = dquot_initialize(new.dir); if (retval) return retval; old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, &old.inlined); if (IS_ERR(old.bh)) return PTR_ERR(old.bh); /* * 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 ;-< */ retval = -ENOENT; if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino) goto end_rename; new.bh = ext4_find_entry(new.dir, &new.dentry->d_name, &new.de, &new.inlined); if (IS_ERR(new.bh)) { retval = PTR_ERR(new.bh); new.bh = NULL; goto end_rename; } /* RENAME_EXCHANGE case: old *and* new must both exist */ if (!new.bh || le32_to_cpu(new.de->inode) != new.inode->i_ino) goto end_rename; handle = ext4_journal_start(old.dir, EXT4_HT_DIR, (2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) + 2 * EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2)); if (IS_ERR(handle)) { retval = PTR_ERR(handle); handle = NULL; goto end_rename; } if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) ext4_handle_sync(handle); if (S_ISDIR(old.inode->i_mode)) { old.is_dir = true; retval = ext4_rename_dir_prepare(handle, &old); if (retval) goto end_rename; } if (S_ISDIR(new.inode->i_mode)) { new.is_dir = true; retval = ext4_rename_dir_prepare(handle, &new); if (retval) goto end_rename; } /* * Other than the special case of overwriting a directory, parents' * nlink only needs to be modified if this is a cross directory rename. */ if (old.dir != new.dir && old.is_dir != new.is_dir) { old.dir_nlink_delta = old.is_dir ? -1 : 1; new.dir_nlink_delta = -old.dir_nlink_delta; retval = -EMLINK; if ((old.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(old.dir)) || (new.dir_nlink_delta > 0 && EXT4_DIR_LINK_MAX(new.dir))) goto end_rename; } new_file_type = new.de->file_type; retval = ext4_setent(handle, &new, old.inode->i_ino, old.de->file_type); if (retval) goto end_rename; retval = ext4_setent(handle, &old, new.inode->i_ino, new_file_type); if (retval) goto end_rename; /* * Like most other Unix systems, set the ctime for inodes on a * rename. */ ctime = current_time(old.inode); old.inode->i_ctime = ctime; new.inode->i_ctime = ctime; ext4_mark_inode_dirty(handle, old.inode); ext4_mark_inode_dirty(handle, new.inode); if (old.dir_bh) { retval = ext4_rename_dir_finish(handle, &old, new.dir->i_ino); if (retval) goto end_rename; } if (new.dir_bh) { retval = ext4_rename_dir_finish(handle, &new, old.dir->i_ino); if (retval) goto end_rename; } ext4_update_dir_count(handle, &old); ext4_update_dir_count(handle, &new); retval = 0; end_rename: brelse(old.dir_bh); brelse(new.dir_bh); brelse(old.bh); brelse(new.bh); if (handle) ext4_journal_stop(handle); return retval; } static int ext4_rename2(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags) { int err; if (unlikely(ext4_forced_shutdown(EXT4_SB(old_dir->i_sb)))) return -EIO; if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) return -EINVAL; err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry, flags); if (err) return err; if (flags & RENAME_EXCHANGE) { return ext4_cross_rename(old_dir, old_dentry, new_dir, new_dentry); } return ext4_rename(old_dir, old_dentry, new_dir, new_dentry, flags); } /* * 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, .tmpfile = ext4_tmpfile, .rename = ext4_rename2, .setattr = ext4_setattr, .getattr = ext4_getattr, .listxattr = ext4_listxattr, .get_acl = ext4_get_acl, .set_acl = ext4_set_acl, .fiemap = ext4_fiemap, }; const struct inode_operations ext4_special_inode_operations = { .setattr = ext4_setattr, .getattr = ext4_getattr, .listxattr = ext4_listxattr, .get_acl = ext4_get_acl, .set_acl = ext4_set_acl, };