diff options
Diffstat (limited to 'kernel/fs/ext4/ialloc.c')
| -rw-r--r-- | kernel/fs/ext4/ialloc.c | 1350 |
1 files changed, 1350 insertions, 0 deletions
diff --git a/kernel/fs/ext4/ialloc.c b/kernel/fs/ext4/ialloc.c new file mode 100644 index 000000000..1eaa6cb96 --- /dev/null +++ b/kernel/fs/ext4/ialloc.c @@ -0,0 +1,1350 @@ +/* + * 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 <linux/time.h> +#include <linux/fs.h> +#include <linux/stat.h> +#include <linux/string.h> +#include <linux/quotaops.h> +#include <linux/buffer_head.h> +#include <linux/random.h> +#include <linux/bitops.h> +#include <linux/blkdev.h> +#include <asm/byteorder.h> + +#include "ext4.h" +#include "ext4_jbd2.h" +#include "xattr.h" +#include "acl.h" + +#include <trace/events/ext4.h> + +/* + * 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); +} + +/* Initializes an uninitialized inode bitmap */ +static unsigned ext4_init_inode_bitmap(struct super_block *sb, + struct buffer_head *bh, + ext4_group_t block_group, + struct ext4_group_desc *gdp) +{ + struct ext4_group_info *grp; + struct ext4_sb_info *sbi = EXT4_SB(sb); + J_ASSERT_BH(bh, buffer_locked(bh)); + + /* If checksum is bad mark all blocks and inodes use to prevent + * allocation, essentially implementing a per-group read-only flag. */ + if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) { + ext4_error(sb, "Checksum bad for group %u", block_group); + grp = ext4_get_group_info(sb, block_group); + if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp)) + percpu_counter_sub(&sbi->s_freeclusters_counter, + grp->bb_free); + set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &grp->bb_state); + if (!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); + return 0; + } + + 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); + ext4_inode_bitmap_csum_set(sb, block_group, gdp, bh, + EXT4_INODES_PER_GROUP(sb) / 8); + ext4_group_desc_csum_set(sb, block_group, gdp); + + return EXT4_INODES_PER_GROUP(sb); +} + +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); +} + +/* + * 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 buffer_head *bh = NULL; + ext4_fsblk_t bitmap_blk; + struct ext4_group_info *grp; + struct ext4_sb_info *sbi = EXT4_SB(sb); + + desc = ext4_get_group_desc(sb, block_group, NULL); + if (!desc) + return NULL; + + bitmap_blk = ext4_inode_bitmap(sb, desc); + 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 NULL; + } + 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 (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) { + ext4_init_inode_bitmap(sb, bh, block_group, desc); + 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(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 NULL; + } + +verify: + ext4_lock_group(sb, block_group); + if (!buffer_verified(bh) && + !ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh, + EXT4_INODES_PER_GROUP(sb) / 8)) { + ext4_unlock_group(sb, block_group); + put_bh(bh); + ext4_error(sb, "Corrupt inode bitmap - block_group = %u, " + "inode_bitmap = %llu", block_group, bitmap_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 NULL; + } + ext4_unlock_group(sb, block_group); + set_buffer_verified(bh); + return bh; +} + +/* + * 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 (unlikely(EXT4_MB_GRP_IBITMAP_CORRUPT(grp)) || !bitmap_bh) + 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) { + ext4_group_t f = ext4_flex_group(sbi, block_group); + + atomic_inc(&sbi->s_flex_groups[f].free_inodes); + if (is_directory) + atomic_dec(&sbi->s_flex_groups[f].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; + struct flex_groups *flex_group = EXT4_SB(sb)->s_flex_groups; + + if (flex_size > 1) { + stats->free_inodes = atomic_read(&flex_group[g].free_inodes); + stats->free_clusters = atomic64_read(&flex_group[g].free_clusters); + stats->used_dirs = atomic_read(&flex_group[g].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 = 0; + struct inode *ret; + ext4_group_t i; + ext4_group_t flex_group; + struct ext4_group_info *grp; + + /* Cannot create files in a deleted directory */ + if (!dir || !dir->i_nlink) + return ERR_PTR(-EPERM); + + 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); + + /* + * Initalize 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); + dquot_initialize(inode); + + 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) || !inode_bitmap_bh) { + 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 (!block_bitmap_bh) { + err = -EIO; + 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 (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->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->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; + + /* If the directory encrypted, then we should encrypt the inode. */ + if ((S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) && + (ext4_encrypted_inode(dir) || + DUMMY_ENCRYPTION_ENABLED(sbi))) + ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT); + + 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; +#ifdef CONFIG_EXT4_FS_ENCRYPTION + if ((sbi->s_file_encryption_mode == EXT4_ENCRYPTION_MODE_INVALID) && + (sbi->s_dir_encryption_mode == EXT4_ENCRYPTION_MODE_INVALID)) { + ei->i_inline_off = 0; + if (EXT4_HAS_INCOMPAT_FEATURE(sb, + EXT4_FEATURE_INCOMPAT_INLINE_DATA)) + ext4_set_inode_state(inode, + EXT4_STATE_MAY_INLINE_DATA); + } else { + /* Inline data and encryption are incompatible + * We turn off inline data since encryption is enabled */ + ei->i_inline_off = 1; + if (EXT4_HAS_INCOMPAT_FEATURE(sb, + EXT4_FEATURE_INCOMPAT_INLINE_DATA)) + ext4_clear_inode_state(inode, + EXT4_STATE_MAY_INLINE_DATA); + } +#else + ei->i_inline_off = 0; + if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_INLINE_DATA)) + ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA); +#endif + ret = inode; + err = dquot_alloc_inode(inode); + if (err) + goto fail_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_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) { + /* 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; + struct inode *inode = NULL; + long err = -EIO; + + /* Error cases - e2fsck has already cleaned up for us */ + if (ino > max_ino) { + ext4_warning(sb, "bad orphan ino %lu! e2fsck was run?", ino); + goto error; + } + + 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 (!bitmap_bh) { + ext4_warning(sb, "inode bitmap error for orphan %lu", ino); + goto error; + } + + /* 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); + if (IS_ERR(inode)) + goto iget_failed; + + /* + * 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. + */ + if (inode->i_nlink && !ext4_can_truncate(inode)) + goto bad_orphan; + + if (NEXT_ORPHAN(inode) > max_ino) + goto bad_orphan; + brelse(bitmap_bh); + return inode; + +iget_failed: + err = PTR_ERR(inode); + inode = NULL; +bad_orphan: + ext4_warning(sb, "bad orphan inode %lu! e2fsck was run?", ino); + printk(KERN_WARNING "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)); + printk(KERN_WARNING "inode=%p\n", inode); + if (inode) { + printk(KERN_WARNING "is_bad_inode(inode)=%d\n", + is_bad_inode(inode)); + printk(KERN_WARNING "NEXT_ORPHAN(inode)=%u\n", + NEXT_ORPHAN(inode)); + printk(KERN_WARNING "max_ino=%lu\n", max_ino); + printk(KERN_WARNING "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); +error: + 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 (!bitmap_bh) + 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)) { + 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; +} |