| /* |
| * 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/jbd2.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 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 */ |
| 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_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(sbi, block_group, gdp)) { |
| ext4_error(sb, __func__, "Checksum bad for group %u", |
| block_group); |
| ext4_free_blks_set(sb, gdp, 0); |
| ext4_free_inodes_set(sb, gdp, 0); |
| ext4_itable_unused_set(sb, gdp, 0); |
| memset(bh->b_data, 0xff, sb->s_blocksize); |
| return 0; |
| } |
| |
| memset(bh->b_data, 0, (EXT4_INODES_PER_GROUP(sb) + 7) / 8); |
| mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), sb->s_blocksize * 8, |
| bh->b_data); |
| |
| return EXT4_INODES_PER_GROUP(sb); |
| } |
| |
| /* |
| * 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; |
| |
| 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, __func__, |
| "Cannot read inode bitmap - " |
| "block_group = %u, inode_bitmap = %llu", |
| block_group, bitmap_blk); |
| return NULL; |
| } |
| if (bitmap_uptodate(bh)) |
| return bh; |
| |
| lock_buffer(bh); |
| if (bitmap_uptodate(bh)) { |
| unlock_buffer(bh); |
| return bh; |
| } |
| 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); |
| 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); |
| return bh; |
| } |
| /* |
| * submit the buffer_head for read. We can |
| * safely mark the bitmap as uptodate now. |
| * We do it here so the bitmap uptodate bit |
| * get set with buffer lock held. |
| */ |
| set_bitmap_uptodate(bh); |
| if (bh_submit_read(bh) < 0) { |
| put_bh(bh); |
| ext4_error(sb, __func__, |
| "Cannot read inode bitmap - " |
| "block_group = %u, inode_bitmap = %llu", |
| block_group, bitmap_blk); |
| return NULL; |
| } |
| 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; |
| |
| if (atomic_read(&inode->i_count) > 1) { |
| printk(KERN_ERR "ext4_free_inode: inode has count=%d\n", |
| atomic_read(&inode->i_count)); |
| return; |
| } |
| if (inode->i_nlink) { |
| printk(KERN_ERR "ext4_free_inode: inode has nlink=%d\n", |
| inode->i_nlink); |
| return; |
| } |
| if (!sb) { |
| printk(KERN_ERR "ext4_free_inode: inode on " |
| "nonexistent device\n"); |
| 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 */ |
| 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, "ext4_free_inode", |
| "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); |
| if (!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; |
| |
| /* Ok, now we can actually update the inode bitmaps.. */ |
| cleared = ext4_clear_bit_atomic(ext4_group_lock_ptr(sb, block_group), |
| bit, bitmap_bh->b_data); |
| if (!cleared) |
| ext4_error(sb, "ext4_free_inode", |
| "bit already cleared for inode %lu", ino); |
| else { |
| gdp = ext4_get_group_desc(sb, block_group, &bh2); |
| |
| BUFFER_TRACE(bh2, "get_write_access"); |
| fatal = ext4_journal_get_write_access(handle, bh2); |
| if (fatal) goto error_return; |
| |
| if (gdp) { |
| ext4_lock_group(sb, block_group); |
| 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); |
| if (sbi->s_log_groups_per_flex) { |
| ext4_group_t f; |
| |
| f = ext4_flex_group(sbi, block_group); |
| atomic_dec(&sbi->s_flex_groups[f].free_inodes); |
| } |
| |
| } |
| gdp->bg_checksum = ext4_group_desc_csum(sbi, |
| block_group, gdp); |
| ext4_unlock_group(sb, block_group); |
| percpu_counter_inc(&sbi->s_freeinodes_counter); |
| if (is_directory) |
| percpu_counter_dec(&sbi->s_dirs_counter); |
| |
| if (sbi->s_log_groups_per_flex) { |
| ext4_group_t f; |
| |
| f = ext4_flex_group(sbi, block_group); |
| atomic_inc(&sbi->s_flex_groups[f].free_inodes); |
| } |
| } |
| BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata"); |
| err = ext4_handle_dirty_metadata(handle, NULL, bh2); |
| if (!fatal) fatal = err; |
| } |
| BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata"); |
| err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); |
| if (!fatal) |
| fatal = err; |
| sb->s_dirt = 1; |
| error_return: |
| brelse(bitmap_bh); |
| ext4_std_error(sb, fatal); |
| } |
| |
| /* |
| * 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. |
| */ |
| static int find_group_dir(struct super_block *sb, struct inode *parent, |
| ext4_group_t *best_group) |
| { |
| ext4_group_t ngroups = ext4_get_groups_count(sb); |
| unsigned int freei, avefreei; |
| struct ext4_group_desc *desc, *best_desc = NULL; |
| ext4_group_t group; |
| int ret = -1; |
| |
| freei = percpu_counter_read_positive(&EXT4_SB(sb)->s_freeinodes_counter); |
| avefreei = freei / ngroups; |
| |
| for (group = 0; group < ngroups; group++) { |
| desc = ext4_get_group_desc(sb, group, NULL); |
| if (!desc || !ext4_free_inodes_count(sb, desc)) |
| continue; |
| if (ext4_free_inodes_count(sb, desc) < avefreei) |
| continue; |
| if (!best_desc || |
| (ext4_free_blks_count(sb, desc) > |
| ext4_free_blks_count(sb, best_desc))) { |
| *best_group = group; |
| best_desc = desc; |
| ret = 0; |
| } |
| } |
| return ret; |
| } |
| |
| #define free_block_ratio 10 |
| |
| static int find_group_flex(struct super_block *sb, struct inode *parent, |
| ext4_group_t *best_group) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| struct ext4_group_desc *desc; |
| struct flex_groups *flex_group = sbi->s_flex_groups; |
| ext4_group_t parent_group = EXT4_I(parent)->i_block_group; |
| ext4_group_t parent_fbg_group = ext4_flex_group(sbi, parent_group); |
| ext4_group_t ngroups = ext4_get_groups_count(sb); |
| int flex_size = ext4_flex_bg_size(sbi); |
| ext4_group_t best_flex = parent_fbg_group; |
| int blocks_per_flex = sbi->s_blocks_per_group * flex_size; |
| int flexbg_free_blocks; |
| int flex_freeb_ratio; |
| ext4_group_t n_fbg_groups; |
| ext4_group_t i; |
| |
| n_fbg_groups = (ngroups + flex_size - 1) >> |
| sbi->s_log_groups_per_flex; |
| |
| find_close_to_parent: |
| flexbg_free_blocks = atomic_read(&flex_group[best_flex].free_blocks); |
| flex_freeb_ratio = flexbg_free_blocks * 100 / blocks_per_flex; |
| if (atomic_read(&flex_group[best_flex].free_inodes) && |
| flex_freeb_ratio > free_block_ratio) |
| goto found_flexbg; |
| |
| if (best_flex && best_flex == parent_fbg_group) { |
| best_flex--; |
| goto find_close_to_parent; |
| } |
| |
| for (i = 0; i < n_fbg_groups; i++) { |
| if (i == parent_fbg_group || i == parent_fbg_group - 1) |
| continue; |
| |
| flexbg_free_blocks = atomic_read(&flex_group[i].free_blocks); |
| flex_freeb_ratio = flexbg_free_blocks * 100 / blocks_per_flex; |
| |
| if (flex_freeb_ratio > free_block_ratio && |
| (atomic_read(&flex_group[i].free_inodes))) { |
| best_flex = i; |
| goto found_flexbg; |
| } |
| |
| if ((atomic_read(&flex_group[best_flex].free_inodes) == 0) || |
| ((atomic_read(&flex_group[i].free_blocks) > |
| atomic_read(&flex_group[best_flex].free_blocks)) && |
| atomic_read(&flex_group[i].free_inodes))) |
| best_flex = i; |
| } |
| |
| if (!atomic_read(&flex_group[best_flex].free_inodes) || |
| !atomic_read(&flex_group[best_flex].free_blocks)) |
| return -1; |
| |
| found_flexbg: |
| for (i = best_flex * flex_size; i < ngroups && |
| i < (best_flex + 1) * flex_size; i++) { |
| desc = ext4_get_group_desc(sb, i, NULL); |
| if (ext4_free_inodes_count(sb, desc)) { |
| *best_group = i; |
| goto out; |
| } |
| } |
| |
| return -1; |
| out: |
| return 0; |
| } |
| |
| struct orlov_stats { |
| __u32 free_inodes; |
| __u32 free_blocks; |
| __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. |
| */ |
| 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_blocks = atomic_read(&flex_group[g].free_blocks); |
| 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_blocks = ext4_free_blks_count(sb, desc); |
| stats->used_dirs = ext4_used_dirs_count(sb, desc); |
| } else { |
| stats->free_inodes = 0; |
| stats->free_blocks = 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, int 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; |
| ext4_fsblk_t freeb, avefreeb; |
| unsigned int ndirs; |
| int max_dirs, min_inodes; |
| ext4_grpblk_t min_blocks; |
| 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 = percpu_counter_read_positive(&sbi->s_freeblocks_counter); |
| avefreeb = freeb; |
| do_div(avefreeb, ngroups); |
| ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter); |
| |
| if (S_ISDIR(mode) && |
| ((parent == sb->s_root->d_inode) || |
| (EXT4_I(parent)->i_flags & EXT4_TOPDIR_FL))) { |
| 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 |
| get_random_bytes(&grp, sizeof(grp)); |
| 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_blocks < avefreeb) |
| 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_blocks = avefreeb - EXT4_BLOCKS_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_blocks < min_blocks) |
| 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 && ext4_free_inodes_count(sb, desc) && |
| ext4_free_inodes_count(sb, desc) >= 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, int 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, 0); |
| } |
| |
| /* |
| * 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_blks_count(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_blks_count(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; |
| } |
| |
| /* |
| * claim the inode from the inode bitmap. If the group |
| * is uninit we need to take the groups's ext4_group_lock |
| * and clear the uninit flag. The inode bitmap update |
| * and group desc uninit flag clear should be done |
| * after holding ext4_group_lock so that ext4_read_inode_bitmap |
| * doesn't race with the ext4_claim_inode |
| */ |
| static int ext4_claim_inode(struct super_block *sb, |
| struct buffer_head *inode_bitmap_bh, |
| unsigned long ino, ext4_group_t group, int mode) |
| { |
| int free = 0, retval = 0, count; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL); |
| |
| ext4_lock_group(sb, group); |
| if (ext4_set_bit(ino, inode_bitmap_bh->b_data)) { |
| /* not a free inode */ |
| retval = 1; |
| goto err_ret; |
| } |
| ino++; |
| if ((group == 0 && ino < EXT4_FIRST_INO(sb)) || |
| ino > EXT4_INODES_PER_GROUP(sb)) { |
| ext4_unlock_group(sb, group); |
| ext4_error(sb, __func__, |
| "reserved inode or inode > inodes count - " |
| "block_group = %u, inode=%lu", group, |
| ino + group * EXT4_INODES_PER_GROUP(sb)); |
| return 1; |
| } |
| /* If we didn't allocate from within the initialized part of the inode |
| * table then we need to initialize up to this inode. */ |
| if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) { |
| |
| if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) { |
| gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT); |
| /* When marking the block group with |
| * ~EXT4_BG_INODE_UNINIT we don't want to depend |
| * on the value of bg_itable_unused even though |
| * mke2fs could have initialized the same for us. |
| * Instead we calculated the value below |
| */ |
| |
| free = 0; |
| } else { |
| free = EXT4_INODES_PER_GROUP(sb) - |
| ext4_itable_unused_count(sb, gdp); |
| } |
| |
| /* |
| * 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)); |
| } |
| count = ext4_free_inodes_count(sb, gdp) - 1; |
| ext4_free_inodes_set(sb, gdp, count); |
| if (S_ISDIR(mode)) { |
| count = ext4_used_dirs_count(sb, gdp) + 1; |
| ext4_used_dirs_set(sb, gdp, count); |
| if (sbi->s_log_groups_per_flex) { |
| ext4_group_t f = ext4_flex_group(sbi, group); |
| |
| atomic_inc(&sbi->s_flex_groups[f].free_inodes); |
| } |
| } |
| gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp); |
| err_ret: |
| ext4_unlock_group(sb, group); |
| return retval; |
| } |
| |
| /* |
| * 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, int mode, |
| const struct qstr *qstr, __u32 goal) |
| { |
| 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; |
| int free = 0; |
| static int once = 1; |
| ext4_group_t flex_group; |
| |
| /* 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); |
| |
| 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 (sbi->s_log_groups_per_flex && test_opt(sb, OLDALLOC)) { |
| ret2 = find_group_flex(sb, dir, &group); |
| if (ret2 == -1) { |
| ret2 = find_group_other(sb, dir, &group, mode); |
| if (ret2 == 0 && once) { |
| once = 0; |
| printk(KERN_NOTICE "ext4: find_group_flex " |
| "failed, fallback succeeded dir %lu\n", |
| dir->i_ino); |
| } |
| } |
| goto got_group; |
| } |
| |
| if (S_ISDIR(mode)) { |
| if (test_opt(sb, OLDALLOC)) |
| ret2 = find_group_dir(sb, dir, &group); |
| else |
| 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; |
| |
| for (i = 0; i < ngroups; i++, ino = 0) { |
| err = -EIO; |
| |
| gdp = ext4_get_group_desc(sb, group, &group_desc_bh); |
| if (!gdp) |
| goto fail; |
| |
| brelse(inode_bitmap_bh); |
| inode_bitmap_bh = ext4_read_inode_bitmap(sb, group); |
| if (!inode_bitmap_bh) |
| goto fail; |
| |
| 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)) { |
| |
| BUFFER_TRACE(inode_bitmap_bh, "get_write_access"); |
| err = ext4_journal_get_write_access(handle, |
| inode_bitmap_bh); |
| if (err) |
| goto fail; |
| |
| BUFFER_TRACE(group_desc_bh, "get_write_access"); |
| err = ext4_journal_get_write_access(handle, |
| group_desc_bh); |
| if (err) |
| goto fail; |
| if (!ext4_claim_inode(sb, inode_bitmap_bh, |
| ino, group, mode)) { |
| /* we won it */ |
| BUFFER_TRACE(inode_bitmap_bh, |
| "call ext4_handle_dirty_metadata"); |
| err = ext4_handle_dirty_metadata(handle, |
| inode, |
| inode_bitmap_bh); |
| if (err) |
| goto fail; |
| /* zero bit is inode number 1*/ |
| ino++; |
| goto got; |
| } |
| /* we lost it */ |
| ext4_handle_release_buffer(handle, inode_bitmap_bh); |
| ext4_handle_release_buffer(handle, group_desc_bh); |
| |
| if (++ino < EXT4_INODES_PER_GROUP(sb)) |
| goto repeat_in_this_group; |
| } |
| |
| /* |
| * This case is possible in concurrent environment. It is very |
| * rare. We cannot repeat the find_group_xxx() call because |
| * that will simply return the same blockgroup, because the |
| * group descriptor metadata has not yet been updated. |
| * So we just go onto the next blockgroup. |
| */ |
| if (++group == ngroups) |
| group = 0; |
| } |
| err = -ENOSPC; |
| goto out; |
| |
| got: |
| /* We may have to initialize the block bitmap if it isn't already */ |
| if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM) && |
| 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); |
| 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); |
| goto fail; |
| } |
| |
| free = 0; |
| ext4_lock_group(sb, group); |
| /* recheck and clear flag under lock if we still need to */ |
| if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { |
| free = ext4_free_blocks_after_init(sb, group, gdp); |
| gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT); |
| ext4_free_blks_set(sb, gdp, free); |
| gdp->bg_checksum = ext4_group_desc_csum(sbi, group, |
| gdp); |
| } |
| ext4_unlock_group(sb, group); |
| |
| /* Don't need to dirty bitmap block if we didn't change it */ |
| if (free) { |
| BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap"); |
| err = ext4_handle_dirty_metadata(handle, |
| NULL, block_bitmap_bh); |
| } |
| |
| brelse(block_bitmap_bh); |
| if (err) |
| goto fail; |
| } |
| BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata"); |
| err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh); |
| if (err) |
| goto fail; |
| |
| percpu_counter_dec(&sbi->s_freeinodes_counter); |
| if (S_ISDIR(mode)) |
| percpu_counter_inc(&sbi->s_dirs_counter); |
| sb->s_dirt = 1; |
| |
| 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_uid = current_fsuid(); |
| if (test_opt(sb, GRPID)) |
| inode->i_gid = dir->i_gid; |
| else if (dir->i_mode & S_ISGID) { |
| inode->i_gid = dir->i_gid; |
| if (S_ISDIR(mode)) |
| mode |= S_ISGID; |
| } else |
| inode->i_gid = current_fsgid(); |
| inode->i_mode = mode; |
| |
| 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. We set |
| * extent flag on newly created directory and file only if -o extent |
| * mount option is specified |
| */ |
| 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) { |
| err = -EINVAL; |
| goto fail_drop; |
| } |
| spin_lock(&sbi->s_next_gen_lock); |
| inode->i_generation = sbi->s_next_generation++; |
| spin_unlock(&sbi->s_next_gen_lock); |
| |
| ei->i_state = EXT4_STATE_NEW; |
| |
| ei->i_extra_isize = EXT4_SB(sb)->s_want_extra_isize; |
| |
| ret = inode; |
| dquot_initialize(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); |
| 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_I(inode)->i_flags |= EXT4_EXTENTS_FL; |
| ext4_ext_tree_init(handle, inode); |
| } |
| } |
| |
| 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); |
| goto really_out; |
| fail: |
| ext4_std_error(sb, err); |
| out: |
| iput(inode); |
| ret = ERR_PTR(err); |
| really_out: |
| brelse(inode_bitmap_bh); |
| return ret; |
| |
| fail_free_drop: |
| dquot_free_inode(inode); |
| |
| fail_drop: |
| dquot_drop(inode); |
| inode->i_flags |= S_NOQUOTA; |
| inode->i_nlink = 0; |
| unlock_new_inode(inode); |
| 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, __func__, |
| "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, __func__, |
| "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, __func__, |
| "bad orphan inode %lu! e2fsck was run?", ino); |
| printk(KERN_NOTICE "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_NOTICE "inode=%p\n", inode); |
| if (inode) { |
| printk(KERN_NOTICE "is_bad_inode(inode)=%d\n", |
| is_bad_inode(inode)); |
| printk(KERN_NOTICE "NEXT_ORPHAN(inode)=%u\n", |
| NEXT_ORPHAN(inode)); |
| printk(KERN_NOTICE "max_ino=%lu\n", max_ino); |
| printk(KERN_NOTICE "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, 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; |
| } |