/* * linux/fs/ext4/ialloc.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) * * BSD ufs-inspired inode and directory allocation by * Stephen Tweedie (sct@redhat.com), 1993 * Big-endian to little-endian byte-swapping/bitmaps by * David S. Miller (davem@caip.rutgers.edu), 1995 */ #include #include #include #include #include #include #include #include #include #include #include "ext4.h" #include "ext4_jbd2.h" #include "xattr.h" #include "acl.h" #include /* * ialloc.c contains the inodes allocation and deallocation routines */ /* * The free inodes are managed by bitmaps. A file system contains several * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap * block for inodes, N blocks for the inode table and data blocks. * * The file system contains group descriptors which are located after the * super block. Each descriptor contains the number of the bitmap block and * the free blocks count in the block. */ /* * To avoid calling the atomic setbit hundreds or thousands of times, we only * need to use it within a single byte (to ensure we get endianness right). * We can use memset for the rest of the bitmap as there are no other users. */ void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap) { int i; if (start_bit >= end_bit) return; ext4_debug("mark end bits +%d through +%d used\n", start_bit, end_bit); for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++) ext4_set_bit(i, bitmap); if (i < end_bit) memset(bitmap + (i >> 3), 0xff, (end_bit - i) >> 3); } void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate) { if (uptodate) { set_buffer_uptodate(bh); set_bitmap_uptodate(bh); } unlock_buffer(bh); put_bh(bh); } static int ext4_validate_inode_bitmap(struct super_block *sb, struct ext4_group_desc *desc, ext4_group_t block_group, struct buffer_head *bh) { ext4_fsblk_t blk; struct ext4_group_info *grp = ext4_get_group_info(sb, block_group); struct ext4_sb_info *sbi = EXT4_SB(sb); if (buffer_verified(bh)) return 0; if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) return -EFSCORRUPTED; ext4_lock_group(sb, block_group); if (buffer_verified(bh)) goto verified; blk = ext4_inode_bitmap(sb, desc); if (!ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh, EXT4_INODES_PER_GROUP(sb) / 8)) { ext4_unlock_group(sb, block_group); ext4_error(sb, "Corrupt inode bitmap - block_group = %u, " "inode_bitmap = %llu", block_group, blk); grp = ext4_get_group_info(sb, block_group); if (!EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) { int count; count = ext4_free_inodes_count(sb, desc); percpu_counter_sub(&sbi->s_freeinodes_counter, count); } set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state); return -EFSBADCRC; } set_buffer_verified(bh); verified: ext4_unlock_group(sb, block_group); return 0; } /* * Read the inode allocation bitmap for a given block_group, reading * into the specified slot in the superblock's bitmap cache. * * Return buffer_head of bitmap on success or NULL. */ static struct buffer_head * ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group) { struct ext4_group_desc *desc; struct ext4_sb_info *sbi = EXT4_SB(sb); struct buffer_head *bh = NULL; ext4_fsblk_t bitmap_blk; int err; desc = ext4_get_group_desc(sb, block_group, NULL); if (!desc) return ERR_PTR(-EFSCORRUPTED); bitmap_blk = ext4_inode_bitmap(sb, desc); if ((bitmap_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) || (bitmap_blk >= ext4_blocks_count(sbi->s_es))) { ext4_error(sb, "Invalid inode bitmap blk %llu in " "block_group %u", bitmap_blk, block_group); return ERR_PTR(-EFSCORRUPTED); } bh = sb_getblk(sb, bitmap_blk); if (unlikely(!bh)) { ext4_error(sb, "Cannot read inode bitmap - " "block_group = %u, inode_bitmap = %llu", block_group, bitmap_blk); return ERR_PTR(-EIO); } if (bitmap_uptodate(bh)) goto verify; lock_buffer(bh); if (bitmap_uptodate(bh)) { unlock_buffer(bh); goto verify; } ext4_lock_group(sb, block_group); if (ext4_has_group_desc_csum(sb) && (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) { if (block_group == 0) { ext4_unlock_group(sb, block_group); unlock_buffer(bh); ext4_error(sb, "Inode bitmap for bg 0 marked " "uninitialized"); err = -EFSCORRUPTED; goto out; } memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8); ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8, bh->b_data); set_bitmap_uptodate(bh); set_buffer_uptodate(bh); set_buffer_verified(bh); ext4_unlock_group(sb, block_group); unlock_buffer(bh); return bh; } ext4_unlock_group(sb, block_group); if (buffer_uptodate(bh)) { /* * if not uninit if bh is uptodate, * bitmap is also uptodate */ set_bitmap_uptodate(bh); unlock_buffer(bh); goto verify; } /* * submit the buffer_head for reading */ trace_ext4_load_inode_bitmap(sb, block_group); bh->b_end_io = ext4_end_bitmap_read; get_bh(bh); submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh); wait_on_buffer(bh); if (!buffer_uptodate(bh)) { put_bh(bh); ext4_error(sb, "Cannot read inode bitmap - " "block_group = %u, inode_bitmap = %llu", block_group, bitmap_blk); return ERR_PTR(-EIO); } verify: err = ext4_validate_inode_bitmap(sb, desc, block_group, bh); if (err) goto out; return bh; out: put_bh(bh); return ERR_PTR(err); } /* * NOTE! When we get the inode, we're the only people * that have access to it, and as such there are no * race conditions we have to worry about. The inode * is not on the hash-lists, and it cannot be reached * through the filesystem because the directory entry * has been deleted earlier. * * HOWEVER: we must make sure that we get no aliases, * which means that we have to call "clear_inode()" * _before_ we mark the inode not in use in the inode * bitmaps. Otherwise a newly created file might use * the same inode number (not actually the same pointer * though), and then we'd have two inodes sharing the * same inode number and space on the harddisk. */ void ext4_free_inode(handle_t *handle, struct inode *inode) { struct super_block *sb = inode->i_sb; int is_directory; unsigned long ino; struct buffer_head *bitmap_bh = NULL; struct buffer_head *bh2; ext4_group_t block_group; unsigned long bit; struct ext4_group_desc *gdp; struct ext4_super_block *es; struct ext4_sb_info *sbi; int fatal = 0, err, count, cleared; struct ext4_group_info *grp; if (!sb) { printk(KERN_ERR "EXT4-fs: %s:%d: inode on " "nonexistent device\n", __func__, __LINE__); return; } if (atomic_read(&inode->i_count) > 1) { ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: count=%d", __func__, __LINE__, inode->i_ino, atomic_read(&inode->i_count)); return; } if (inode->i_nlink) { ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: nlink=%d\n", __func__, __LINE__, inode->i_ino, inode->i_nlink); return; } sbi = EXT4_SB(sb); ino = inode->i_ino; ext4_debug("freeing inode %lu\n", ino); trace_ext4_free_inode(inode); /* * Note: we must free any quota before locking the superblock, * as writing the quota to disk may need the lock as well. */ dquot_initialize(inode); ext4_xattr_delete_inode(handle, inode); dquot_free_inode(inode); dquot_drop(inode); is_directory = S_ISDIR(inode->i_mode); /* Do this BEFORE marking the inode not in use or returning an error */ ext4_clear_inode(inode); es = EXT4_SB(sb)->s_es; if (ino < EXT4_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) { ext4_error(sb, "reserved or nonexistent inode %lu", ino); goto error_return; } block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb); bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb); bitmap_bh = ext4_read_inode_bitmap(sb, block_group); /* Don't bother if the inode bitmap is corrupt. */ grp = ext4_get_group_info(sb, block_group); if (IS_ERR(bitmap_bh)) { fatal = PTR_ERR(bitmap_bh); bitmap_bh = NULL; goto error_return; } if (unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp))) { fatal = -EFSCORRUPTED; goto error_return; } BUFFER_TRACE(bitmap_bh, "get_write_access"); fatal = ext4_journal_get_write_access(handle, bitmap_bh); if (fatal) goto error_return; fatal = -ESRCH; gdp = ext4_get_group_desc(sb, block_group, &bh2); if (gdp) { BUFFER_TRACE(bh2, "get_write_access"); fatal = ext4_journal_get_write_access(handle, bh2); } ext4_lock_group(sb, block_group); cleared = ext4_test_and_clear_bit(bit, bitmap_bh->b_data); if (fatal || !cleared) { ext4_unlock_group(sb, block_group); goto out; } count = ext4_free_inodes_count(sb, gdp) + 1; ext4_free_inodes_set(sb, gdp, count); if (is_directory) { count = ext4_used_dirs_count(sb, gdp) - 1; ext4_used_dirs_set(sb, gdp, count); percpu_counter_dec(&sbi->s_dirs_counter); } ext4_inode_bitmap_csum_set(sb, block_group, gdp, bitmap_bh, EXT4_INODES_PER_GROUP(sb) / 8); ext4_group_desc_csum_set(sb, block_group, gdp); ext4_unlock_group(sb, block_group); percpu_counter_inc(&sbi->s_freeinodes_counter); if (sbi->s_log_groups_per_flex) { struct flex_groups *fg; fg = sbi_array_rcu_deref(sbi, s_flex_groups, ext4_flex_group(sbi, block_group)); atomic_inc(&fg->free_inodes); if (is_directory) atomic_dec(&fg->used_dirs); } BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata"); fatal = ext4_handle_dirty_metadata(handle, NULL, bh2); out: if (cleared) { BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata"); err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); if (!fatal) fatal = err; } else { ext4_error(sb, "bit already cleared for inode %lu", ino); if (gdp && !EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) { int count; count = ext4_free_inodes_count(sb, gdp); percpu_counter_sub(&sbi->s_freeinodes_counter, count); } set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state); } error_return: brelse(bitmap_bh); ext4_std_error(sb, fatal); } struct orlov_stats { __u64 free_clusters; __u32 free_inodes; __u32 used_dirs; }; /* * Helper function for Orlov's allocator; returns critical information * for a particular block group or flex_bg. If flex_size is 1, then g * is a block group number; otherwise it is flex_bg number. */ static void get_orlov_stats(struct super_block *sb, ext4_group_t g, int flex_size, struct orlov_stats *stats) { struct ext4_group_desc *desc; if (flex_size > 1) { struct flex_groups *fg = sbi_array_rcu_deref(EXT4_SB(sb), s_flex_groups, g); stats->free_inodes = atomic_read(&fg->free_inodes); stats->free_clusters = atomic64_read(&fg->free_clusters); stats->used_dirs = atomic_read(&fg->used_dirs); return; } desc = ext4_get_group_desc(sb, g, NULL); if (desc) { stats->free_inodes = ext4_free_inodes_count(sb, desc); stats->free_clusters = ext4_free_group_clusters(sb, desc); stats->used_dirs = ext4_used_dirs_count(sb, desc); } else { stats->free_inodes = 0; stats->free_clusters = 0; stats->used_dirs = 0; } } /* * Orlov's allocator for directories. * * We always try to spread first-level directories. * * If there are blockgroups with both free inodes and free blocks counts * not worse than average we return one with smallest directory count. * Otherwise we simply return a random group. * * For the rest rules look so: * * It's OK to put directory into a group unless * it has too many directories already (max_dirs) or * it has too few free inodes left (min_inodes) or * it has too few free blocks left (min_blocks) or * Parent's group is preferred, if it doesn't satisfy these * conditions we search cyclically through the rest. If none * of the groups look good we just look for a group with more * free inodes than average (starting at parent's group). */ static int find_group_orlov(struct super_block *sb, struct inode *parent, ext4_group_t *group, umode_t mode, const struct qstr *qstr) { ext4_group_t parent_group = EXT4_I(parent)->i_block_group; struct ext4_sb_info *sbi = EXT4_SB(sb); ext4_group_t real_ngroups = ext4_get_groups_count(sb); int inodes_per_group = EXT4_INODES_PER_GROUP(sb); unsigned int freei, avefreei, grp_free; ext4_fsblk_t freeb, avefreec; unsigned int ndirs; int max_dirs, min_inodes; ext4_grpblk_t min_clusters; ext4_group_t i, grp, g, ngroups; struct ext4_group_desc *desc; struct orlov_stats stats; int flex_size = ext4_flex_bg_size(sbi); struct dx_hash_info hinfo; ngroups = real_ngroups; if (flex_size > 1) { ngroups = (real_ngroups + flex_size - 1) >> sbi->s_log_groups_per_flex; parent_group >>= sbi->s_log_groups_per_flex; } freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter); avefreei = freei / ngroups; freeb = EXT4_C2B(sbi, percpu_counter_read_positive(&sbi->s_freeclusters_counter)); avefreec = freeb; do_div(avefreec, ngroups); ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter); if (S_ISDIR(mode) && ((parent == d_inode(sb->s_root)) || (ext4_test_inode_flag(parent, EXT4_INODE_TOPDIR)))) { int best_ndir = inodes_per_group; int ret = -1; if (qstr) { hinfo.hash_version = DX_HASH_HALF_MD4; hinfo.seed = sbi->s_hash_seed; ext4fs_dirhash(qstr->name, qstr->len, &hinfo); grp = hinfo.hash; } else grp = prandom_u32(); parent_group = (unsigned)grp % ngroups; for (i = 0; i < ngroups; i++) { g = (parent_group + i) % ngroups; get_orlov_stats(sb, g, flex_size, &stats); if (!stats.free_inodes) continue; if (stats.used_dirs >= best_ndir) continue; if (stats.free_inodes < avefreei) continue; if (stats.free_clusters < avefreec) continue; grp = g; ret = 0; best_ndir = stats.used_dirs; } if (ret) goto fallback; found_flex_bg: if (flex_size == 1) { *group = grp; return 0; } /* * We pack inodes at the beginning of the flexgroup's * inode tables. Block allocation decisions will do * something similar, although regular files will * start at 2nd block group of the flexgroup. See * ext4_ext_find_goal() and ext4_find_near(). */ grp *= flex_size; for (i = 0; i < flex_size; i++) { if (grp+i >= real_ngroups) break; desc = ext4_get_group_desc(sb, grp+i, NULL); if (desc && ext4_free_inodes_count(sb, desc)) { *group = grp+i; return 0; } } goto fallback; } max_dirs = ndirs / ngroups + inodes_per_group / 16; min_inodes = avefreei - inodes_per_group*flex_size / 4; if (min_inodes < 1) min_inodes = 1; min_clusters = avefreec - EXT4_CLUSTERS_PER_GROUP(sb)*flex_size / 4; /* * Start looking in the flex group where we last allocated an * inode for this parent directory */ if (EXT4_I(parent)->i_last_alloc_group != ~0) { parent_group = EXT4_I(parent)->i_last_alloc_group; if (flex_size > 1) parent_group >>= sbi->s_log_groups_per_flex; } for (i = 0; i < ngroups; i++) { grp = (parent_group + i) % ngroups; get_orlov_stats(sb, grp, flex_size, &stats); if (stats.used_dirs >= max_dirs) continue; if (stats.free_inodes < min_inodes) continue; if (stats.free_clusters < min_clusters) continue; goto found_flex_bg; } fallback: ngroups = real_ngroups; avefreei = freei / ngroups; fallback_retry: parent_group = EXT4_I(parent)->i_block_group; for (i = 0; i < ngroups; i++) { grp = (parent_group + i) % ngroups; desc = ext4_get_group_desc(sb, grp, NULL); if (desc) { grp_free = ext4_free_inodes_count(sb, desc); if (grp_free && grp_free >= avefreei) { *group = grp; return 0; } } } if (avefreei) { /* * The free-inodes counter is approximate, and for really small * filesystems the above test can fail to find any blockgroups */ avefreei = 0; goto fallback_retry; } return -1; } static int find_group_other(struct super_block *sb, struct inode *parent, ext4_group_t *group, umode_t mode) { ext4_group_t parent_group = EXT4_I(parent)->i_block_group; ext4_group_t i, last, ngroups = ext4_get_groups_count(sb); struct ext4_group_desc *desc; int flex_size = ext4_flex_bg_size(EXT4_SB(sb)); /* * Try to place the inode is the same flex group as its * parent. If we can't find space, use the Orlov algorithm to * find another flex group, and store that information in the * parent directory's inode information so that use that flex * group for future allocations. */ if (flex_size > 1) { int retry = 0; try_again: parent_group &= ~(flex_size-1); last = parent_group + flex_size; if (last > ngroups) last = ngroups; for (i = parent_group; i < last; i++) { desc = ext4_get_group_desc(sb, i, NULL); if (desc && ext4_free_inodes_count(sb, desc)) { *group = i; return 0; } } if (!retry && EXT4_I(parent)->i_last_alloc_group != ~0) { retry = 1; parent_group = EXT4_I(parent)->i_last_alloc_group; goto try_again; } /* * If this didn't work, use the Orlov search algorithm * to find a new flex group; we pass in the mode to * avoid the topdir algorithms. */ *group = parent_group + flex_size; if (*group > ngroups) *group = 0; return find_group_orlov(sb, parent, group, mode, NULL); } /* * Try to place the inode in its parent directory */ *group = parent_group; desc = ext4_get_group_desc(sb, *group, NULL); if (desc && ext4_free_inodes_count(sb, desc) && ext4_free_group_clusters(sb, desc)) return 0; /* * We're going to place this inode in a different blockgroup from its * parent. We want to cause files in a common directory to all land in * the same blockgroup. But we want files which are in a different * directory which shares a blockgroup with our parent to land in a * different blockgroup. * * So add our directory's i_ino into the starting point for the hash. */ *group = (*group + parent->i_ino) % ngroups; /* * Use a quadratic hash to find a group with a free inode and some free * blocks. */ for (i = 1; i < ngroups; i <<= 1) { *group += i; if (*group >= ngroups) *group -= ngroups; desc = ext4_get_group_desc(sb, *group, NULL); if (desc && ext4_free_inodes_count(sb, desc) && ext4_free_group_clusters(sb, desc)) return 0; } /* * That failed: try linear search for a free inode, even if that group * has no free blocks. */ *group = parent_group; for (i = 0; i < ngroups; i++) { if (++*group >= ngroups) *group = 0; desc = ext4_get_group_desc(sb, *group, NULL); if (desc && ext4_free_inodes_count(sb, desc)) return 0; } return -1; } /* * In no journal mode, if an inode has recently been deleted, we want * to avoid reusing it until we're reasonably sure the inode table * block has been written back to disk. (Yes, these values are * somewhat arbitrary...) */ #define RECENTCY_MIN 5 #define RECENTCY_DIRTY 30 static int recently_deleted(struct super_block *sb, ext4_group_t group, int ino) { struct ext4_group_desc *gdp; struct ext4_inode *raw_inode; struct buffer_head *bh; unsigned long dtime, now; int inodes_per_block = EXT4_SB(sb)->s_inodes_per_block; int offset, ret = 0, recentcy = RECENTCY_MIN; gdp = ext4_get_group_desc(sb, group, NULL); if (unlikely(!gdp)) return 0; bh = sb_getblk(sb, ext4_inode_table(sb, gdp) + (ino / inodes_per_block)); if (unlikely(!bh) || !buffer_uptodate(bh)) /* * If the block is not in the buffer cache, then it * must have been written out. */ goto out; offset = (ino % inodes_per_block) * EXT4_INODE_SIZE(sb); raw_inode = (struct ext4_inode *) (bh->b_data + offset); dtime = le32_to_cpu(raw_inode->i_dtime); now = get_seconds(); if (buffer_dirty(bh)) recentcy += RECENTCY_DIRTY; if (dtime && (dtime < now) && (now < dtime + recentcy)) ret = 1; out: brelse(bh); return ret; } /* * There are two policies for allocating an inode. If the new inode is * a directory, then a forward search is made for a block group with both * free space and a low directory-to-inode ratio; if that fails, then of * the groups with above-average free space, that group with the fewest * directories already is chosen. * * For other inodes, search forward from the parent directory's block * group to find a free inode. */ struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir, umode_t mode, const struct qstr *qstr, __u32 goal, uid_t *owner, int handle_type, unsigned int line_no, int nblocks) { struct super_block *sb; struct buffer_head *inode_bitmap_bh = NULL; struct buffer_head *group_desc_bh; ext4_group_t ngroups, group = 0; unsigned long ino = 0; struct inode *inode; struct ext4_group_desc *gdp = NULL; struct ext4_inode_info *ei; struct ext4_sb_info *sbi; int ret2, err; struct inode *ret; ext4_group_t i; ext4_group_t flex_group; struct ext4_group_info *grp; int encrypt = 0; /* Cannot create files in a deleted directory */ if (!dir || !dir->i_nlink) return ERR_PTR(-EPERM); if ((ext4_encrypted_inode(dir) || DUMMY_ENCRYPTION_ENABLED(EXT4_SB(dir->i_sb))) && (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) { err = fscrypt_get_encryption_info(dir); if (err) return ERR_PTR(err); if (!fscrypt_has_encryption_key(dir)) return ERR_PTR(-ENOKEY); if (!handle) nblocks += EXT4_DATA_TRANS_BLOCKS(dir->i_sb); encrypt = 1; } sb = dir->i_sb; ngroups = ext4_get_groups_count(sb); trace_ext4_request_inode(dir, mode); inode = new_inode(sb); if (!inode) return ERR_PTR(-ENOMEM); ei = EXT4_I(inode); sbi = EXT4_SB(sb); /* * Initialize owners and quota early so that we don't have to account * for quota initialization worst case in standard inode creating * transaction */ if (owner) { inode->i_mode = mode; i_uid_write(inode, owner[0]); i_gid_write(inode, owner[1]); } else if (test_opt(sb, GRPID)) { inode->i_mode = mode; inode->i_uid = current_fsuid(); inode->i_gid = dir->i_gid; } else inode_init_owner(inode, dir, mode); if (ext4_has_feature_project(sb) && ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) ei->i_projid = EXT4_I(dir)->i_projid; else ei->i_projid = make_kprojid(&init_user_ns, EXT4_DEF_PROJID); err = dquot_initialize(inode); if (err) goto out; if (!goal) goal = sbi->s_inode_goal; if (goal && goal <= le32_to_cpu(sbi->s_es->s_inodes_count)) { group = (goal - 1) / EXT4_INODES_PER_GROUP(sb); ino = (goal - 1) % EXT4_INODES_PER_GROUP(sb); ret2 = 0; goto got_group; } if (S_ISDIR(mode)) ret2 = find_group_orlov(sb, dir, &group, mode, qstr); else ret2 = find_group_other(sb, dir, &group, mode); got_group: EXT4_I(dir)->i_last_alloc_group = group; err = -ENOSPC; if (ret2 == -1) goto out; /* * Normally we will only go through one pass of this loop, * unless we get unlucky and it turns out the group we selected * had its last inode grabbed by someone else. */ for (i = 0; i < ngroups; i++, ino = 0) { err = -EIO; gdp = ext4_get_group_desc(sb, group, &group_desc_bh); if (!gdp) goto out; /* * Check free inodes count before loading bitmap. */ if (ext4_free_inodes_count(sb, gdp) == 0) { if (++group == ngroups) group = 0; continue; } grp = ext4_get_group_info(sb, group); /* Skip groups with already-known suspicious inode tables */ if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) { if (++group == ngroups) group = 0; continue; } brelse(inode_bitmap_bh); inode_bitmap_bh = ext4_read_inode_bitmap(sb, group); /* Skip groups with suspicious inode tables */ if (EXT4_MB_GRP_IBITMAP_CORRUPT(grp) || IS_ERR(inode_bitmap_bh)) { inode_bitmap_bh = NULL; if (++group == ngroups) group = 0; continue; } repeat_in_this_group: ino = ext4_find_next_zero_bit((unsigned long *) inode_bitmap_bh->b_data, EXT4_INODES_PER_GROUP(sb), ino); if (ino >= EXT4_INODES_PER_GROUP(sb)) goto next_group; if (group == 0 && (ino+1) < EXT4_FIRST_INO(sb)) { ext4_error(sb, "reserved inode found cleared - " "inode=%lu", ino + 1); continue; } if ((EXT4_SB(sb)->s_journal == NULL) && recently_deleted(sb, group, ino)) { ino++; goto next_inode; } if (!handle) { BUG_ON(nblocks <= 0); handle = __ext4_journal_start_sb(dir->i_sb, line_no, handle_type, nblocks, 0); if (IS_ERR(handle)) { err = PTR_ERR(handle); ext4_std_error(sb, err); goto out; } } BUFFER_TRACE(inode_bitmap_bh, "get_write_access"); err = ext4_journal_get_write_access(handle, inode_bitmap_bh); if (err) { ext4_std_error(sb, err); goto out; } ext4_lock_group(sb, group); ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data); ext4_unlock_group(sb, group); ino++; /* the inode bitmap is zero-based */ if (!ret2) goto got; /* we grabbed the inode! */ next_inode: if (ino < EXT4_INODES_PER_GROUP(sb)) goto repeat_in_this_group; next_group: if (++group == ngroups) group = 0; } err = -ENOSPC; goto out; got: BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata"); err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh); if (err) { ext4_std_error(sb, err); goto out; } BUFFER_TRACE(group_desc_bh, "get_write_access"); err = ext4_journal_get_write_access(handle, group_desc_bh); if (err) { ext4_std_error(sb, err); goto out; } /* We may have to initialize the block bitmap if it isn't already */ if (ext4_has_group_desc_csum(sb) && gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { struct buffer_head *block_bitmap_bh; block_bitmap_bh = ext4_read_block_bitmap(sb, group); if (IS_ERR(block_bitmap_bh)) { err = PTR_ERR(block_bitmap_bh); goto out; } BUFFER_TRACE(block_bitmap_bh, "get block bitmap access"); err = ext4_journal_get_write_access(handle, block_bitmap_bh); if (err) { brelse(block_bitmap_bh); ext4_std_error(sb, err); goto out; } BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap"); err = ext4_handle_dirty_metadata(handle, NULL, block_bitmap_bh); /* recheck and clear flag under lock if we still need to */ ext4_lock_group(sb, group); if (ext4_has_group_desc_csum(sb) && (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) { gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT); ext4_free_group_clusters_set(sb, gdp, ext4_free_clusters_after_init(sb, group, gdp)); ext4_block_bitmap_csum_set(sb, group, gdp, block_bitmap_bh); ext4_group_desc_csum_set(sb, group, gdp); } ext4_unlock_group(sb, group); brelse(block_bitmap_bh); if (err) { ext4_std_error(sb, err); goto out; } } /* Update the relevant bg descriptor fields */ if (ext4_has_group_desc_csum(sb)) { int free; struct ext4_group_info *grp = ext4_get_group_info(sb, group); down_read(&grp->alloc_sem); /* protect vs itable lazyinit */ ext4_lock_group(sb, group); /* while we modify the bg desc */ free = EXT4_INODES_PER_GROUP(sb) - ext4_itable_unused_count(sb, gdp); if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) { gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT); free = 0; } /* * Check the relative inode number against the last used * relative inode number in this group. if it is greater * we need to update the bg_itable_unused count */ if (ino > free) ext4_itable_unused_set(sb, gdp, (EXT4_INODES_PER_GROUP(sb) - ino)); up_read(&grp->alloc_sem); } else { ext4_lock_group(sb, group); } ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1); if (S_ISDIR(mode)) { ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1); if (sbi->s_log_groups_per_flex) { ext4_group_t f = ext4_flex_group(sbi, group); atomic_inc(&sbi_array_rcu_deref(sbi, s_flex_groups, f)->used_dirs); } } if (ext4_has_group_desc_csum(sb)) { ext4_inode_bitmap_csum_set(sb, group, gdp, inode_bitmap_bh, EXT4_INODES_PER_GROUP(sb) / 8); ext4_group_desc_csum_set(sb, group, gdp); } ext4_unlock_group(sb, group); BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata"); err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh); if (err) { ext4_std_error(sb, err); goto out; } percpu_counter_dec(&sbi->s_freeinodes_counter); if (S_ISDIR(mode)) percpu_counter_inc(&sbi->s_dirs_counter); if (sbi->s_log_groups_per_flex) { flex_group = ext4_flex_group(sbi, group); atomic_dec(&sbi_array_rcu_deref(sbi, s_flex_groups, flex_group)->free_inodes); } inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb); /* This is the optimal IO size (for stat), not the fs block size */ inode->i_blocks = 0; inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime = ext4_current_time(inode); memset(ei->i_data, 0, sizeof(ei->i_data)); ei->i_dir_start_lookup = 0; ei->i_disksize = 0; /* Don't inherit extent flag from directory, amongst others. */ ei->i_flags = ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED); ei->i_file_acl = 0; ei->i_dtime = 0; ei->i_block_group = group; ei->i_last_alloc_group = ~0; ext4_set_inode_flags(inode); if (IS_DIRSYNC(inode)) ext4_handle_sync(handle); if (insert_inode_locked(inode) < 0) { /* * Likely a bitmap corruption causing inode to be allocated * twice. */ err = -EIO; ext4_error(sb, "failed to insert inode %lu: doubly allocated?", inode->i_ino); goto out; } spin_lock(&sbi->s_next_gen_lock); inode->i_generation = sbi->s_next_generation++; spin_unlock(&sbi->s_next_gen_lock); /* Precompute checksum seed for inode metadata */ if (ext4_has_metadata_csum(sb)) { __u32 csum; __le32 inum = cpu_to_le32(inode->i_ino); __le32 gen = cpu_to_le32(inode->i_generation); csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum, sizeof(inum)); ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen, sizeof(gen)); } ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */ ext4_set_inode_state(inode, EXT4_STATE_NEW); ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize; ei->i_inline_off = 0; if (ext4_has_feature_inline_data(sb)) ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA); ret = inode; err = dquot_alloc_inode(inode); if (err) goto fail_drop; /* * Since the encryption xattr will always be unique, create it first so * that it's less likely to end up in an external xattr block and * prevent its deduplication. */ if (encrypt) { err = fscrypt_inherit_context(dir, inode, handle, true); if (err) goto fail_free_drop; } err = ext4_init_acl(handle, inode, dir); if (err) goto fail_free_drop; err = ext4_init_security(handle, inode, dir, qstr); if (err) goto fail_free_drop; if (ext4_has_feature_extents(sb)) { /* set extent flag only for directory, file and normal symlink*/ if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) { ext4_set_inode_flag(inode, EXT4_INODE_EXTENTS); ext4_ext_tree_init(handle, inode); } } if (ext4_handle_valid(handle)) { ei->i_sync_tid = handle->h_transaction->t_tid; ei->i_datasync_tid = handle->h_transaction->t_tid; } err = ext4_mark_inode_dirty(handle, inode); if (err) { ext4_std_error(sb, err); goto fail_free_drop; } ext4_debug("allocating inode %lu\n", inode->i_ino); trace_ext4_allocate_inode(inode, dir, mode); brelse(inode_bitmap_bh); return ret; fail_free_drop: dquot_free_inode(inode); fail_drop: clear_nlink(inode); unlock_new_inode(inode); out: dquot_drop(inode); inode->i_flags |= S_NOQUOTA; iput(inode); brelse(inode_bitmap_bh); return ERR_PTR(err); } /* Verify that we are loading a valid orphan from disk */ struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino) { unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count); ext4_group_t block_group; int bit; struct buffer_head *bitmap_bh = NULL; struct inode *inode = NULL; int err = -EFSCORRUPTED; if (ino < EXT4_FIRST_INO(sb) || ino > max_ino) goto bad_orphan; block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb); bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb); bitmap_bh = ext4_read_inode_bitmap(sb, block_group); if (IS_ERR(bitmap_bh)) { ext4_error(sb, "inode bitmap error %ld for orphan %lu", ino, PTR_ERR(bitmap_bh)); return (struct inode *) bitmap_bh; } /* Having the inode bit set should be a 100% indicator that this * is a valid orphan (no e2fsck run on fs). Orphans also include * inodes that were being truncated, so we can't check i_nlink==0. */ if (!ext4_test_bit(bit, bitmap_bh->b_data)) goto bad_orphan; inode = ext4_iget(sb, ino, EXT4_IGET_NORMAL); if (IS_ERR(inode)) { err = PTR_ERR(inode); ext4_error(sb, "couldn't read orphan inode %lu (err %d)", ino, err); return inode; } /* * If the orphans has i_nlinks > 0 then it should be able to * be truncated, otherwise it won't be removed from the orphan * list during processing and an infinite loop will result. * Similarly, it must not be a bad inode. */ if ((inode->i_nlink && !ext4_can_truncate(inode)) || is_bad_inode(inode)) goto bad_orphan; if (NEXT_ORPHAN(inode) > max_ino) goto bad_orphan; brelse(bitmap_bh); return inode; bad_orphan: ext4_error(sb, "bad orphan inode %lu", ino); if (bitmap_bh) printk(KERN_ERR "ext4_test_bit(bit=%d, block=%llu) = %d\n", bit, (unsigned long long)bitmap_bh->b_blocknr, ext4_test_bit(bit, bitmap_bh->b_data)); if (inode) { printk(KERN_ERR "is_bad_inode(inode)=%d\n", is_bad_inode(inode)); printk(KERN_ERR "NEXT_ORPHAN(inode)=%u\n", NEXT_ORPHAN(inode)); printk(KERN_ERR "max_ino=%lu\n", max_ino); printk(KERN_ERR "i_nlink=%u\n", inode->i_nlink); /* Avoid freeing blocks if we got a bad deleted inode */ if (inode->i_nlink == 0) inode->i_blocks = 0; iput(inode); } brelse(bitmap_bh); return ERR_PTR(err); } unsigned long ext4_count_free_inodes(struct super_block *sb) { unsigned long desc_count; struct ext4_group_desc *gdp; ext4_group_t i, ngroups = ext4_get_groups_count(sb); #ifdef EXT4FS_DEBUG struct ext4_super_block *es; unsigned long bitmap_count, x; struct buffer_head *bitmap_bh = NULL; es = EXT4_SB(sb)->s_es; desc_count = 0; bitmap_count = 0; gdp = NULL; for (i = 0; i < ngroups; i++) { gdp = ext4_get_group_desc(sb, i, NULL); if (!gdp) continue; desc_count += ext4_free_inodes_count(sb, gdp); brelse(bitmap_bh); bitmap_bh = ext4_read_inode_bitmap(sb, i); if (IS_ERR(bitmap_bh)) { bitmap_bh = NULL; continue; } x = ext4_count_free(bitmap_bh->b_data, EXT4_INODES_PER_GROUP(sb) / 8); printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n", (unsigned long) i, ext4_free_inodes_count(sb, gdp), x); bitmap_count += x; } brelse(bitmap_bh); printk(KERN_DEBUG "ext4_count_free_inodes: " "stored = %u, computed = %lu, %lu\n", le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count); return desc_count; #else desc_count = 0; for (i = 0; i < ngroups; i++) { gdp = ext4_get_group_desc(sb, i, NULL); if (!gdp) continue; desc_count += ext4_free_inodes_count(sb, gdp); cond_resched(); } return desc_count; #endif } /* Called at mount-time, super-block is locked */ unsigned long ext4_count_dirs(struct super_block * sb) { unsigned long count = 0; ext4_group_t i, ngroups = ext4_get_groups_count(sb); for (i = 0; i < ngroups; i++) { struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL); if (!gdp) continue; count += ext4_used_dirs_count(sb, gdp); } return count; } /* * Zeroes not yet zeroed inode table - just write zeroes through the whole * inode table. Must be called without any spinlock held. The only place * where it is called from on active part of filesystem is ext4lazyinit * thread, so we do not need any special locks, however we have to prevent * inode allocation from the current group, so we take alloc_sem lock, to * block ext4_new_inode() until we are finished. */ int ext4_init_inode_table(struct super_block *sb, ext4_group_t group, int barrier) { struct ext4_group_info *grp = ext4_get_group_info(sb, group); struct ext4_sb_info *sbi = EXT4_SB(sb); struct ext4_group_desc *gdp = NULL; struct buffer_head *group_desc_bh; handle_t *handle; ext4_fsblk_t blk; int num, ret = 0, used_blks = 0; /* This should not happen, but just to be sure check this */ if (sb->s_flags & MS_RDONLY) { ret = 1; goto out; } gdp = ext4_get_group_desc(sb, group, &group_desc_bh); if (!gdp) goto out; /* * We do not need to lock this, because we are the only one * handling this flag. */ if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)) goto out; handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1); if (IS_ERR(handle)) { ret = PTR_ERR(handle); goto out; } down_write(&grp->alloc_sem); /* * If inode bitmap was already initialized there may be some * used inodes so we need to skip blocks with used inodes in * inode table. */ if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT))) used_blks = DIV_ROUND_UP((EXT4_INODES_PER_GROUP(sb) - ext4_itable_unused_count(sb, gdp)), sbi->s_inodes_per_block); if ((used_blks < 0) || (used_blks > sbi->s_itb_per_group) || ((group == 0) && ((EXT4_INODES_PER_GROUP(sb) - ext4_itable_unused_count(sb, gdp)) < EXT4_FIRST_INO(sb)))) { ext4_error(sb, "Something is wrong with group %u: " "used itable blocks: %d; " "itable unused count: %u", group, used_blks, ext4_itable_unused_count(sb, gdp)); ret = 1; goto err_out; } blk = ext4_inode_table(sb, gdp) + used_blks; num = sbi->s_itb_per_group - used_blks; BUFFER_TRACE(group_desc_bh, "get_write_access"); ret = ext4_journal_get_write_access(handle, group_desc_bh); if (ret) goto err_out; /* * Skip zeroout if the inode table is full. But we set the ZEROED * flag anyway, because obviously, when it is full it does not need * further zeroing. */ if (unlikely(num == 0)) goto skip_zeroout; ext4_debug("going to zero out inode table in group %d\n", group); ret = sb_issue_zeroout(sb, blk, num, GFP_NOFS); if (ret < 0) goto err_out; if (barrier) blkdev_issue_flush(sb->s_bdev, GFP_NOFS, NULL); skip_zeroout: ext4_lock_group(sb, group); gdp->bg_flags |= cpu_to_le16(EXT4_BG_INODE_ZEROED); ext4_group_desc_csum_set(sb, group, gdp); ext4_unlock_group(sb, group); BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata"); ret = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh); err_out: up_write(&grp->alloc_sem); ext4_journal_stop(handle); out: return ret; }