From 8df9675f8b498d0bfa1f0b5b06f56bf1ff366dd5 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Fri, 1 May 2009 08:50:38 -0400 Subject: ext4: Avoid races caused by on-line resizing and SMP memory reordering Ext4's on-line resizing adds a new block group and then, only at the last step adjusts s_groups_count. However, it's possible on SMP systems that another CPU could see the updated the s_group_count and not see the newly initialized data structures for the just-added block group. For this reason, it's important to insert a SMP read barrier after reading s_groups_count and before reading any (for example) the new block group descriptors allowed by the increased value of s_groups_count. Unfortunately, we rather blatently violate this locking protocol documented in fs/ext4/resize.c. Fortunately, (1) on-line resizes happen relatively rarely, and (2) it seems rare that the filesystem code will immediately try to use just-added block group before any memory ordering issues resolve themselves. So apparently problems here are relatively hard to hit, since ext3 has been vulnerable to the same issue for years with no one apparently complaining. Signed-off-by: "Theodore Ts'o" --- fs/ext4/mballoc.c | 45 ++++++++++++++++++++++++--------------------- 1 file changed, 24 insertions(+), 21 deletions(-) (limited to 'fs/ext4/mballoc.c') diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index f871677a798..c3af9e6b666 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -739,6 +739,7 @@ static void ext4_mb_generate_buddy(struct super_block *sb, static int ext4_mb_init_cache(struct page *page, char *incore) { + ext4_group_t ngroups; int blocksize; int blocks_per_page; int groups_per_page; @@ -757,6 +758,7 @@ static int ext4_mb_init_cache(struct page *page, char *incore) inode = page->mapping->host; sb = inode->i_sb; + ngroups = ext4_get_groups_count(sb); blocksize = 1 << inode->i_blkbits; blocks_per_page = PAGE_CACHE_SIZE / blocksize; @@ -780,7 +782,7 @@ static int ext4_mb_init_cache(struct page *page, char *incore) for (i = 0; i < groups_per_page; i++) { struct ext4_group_desc *desc; - if (first_group + i >= EXT4_SB(sb)->s_groups_count) + if (first_group + i >= ngroups) break; err = -EIO; @@ -852,7 +854,7 @@ static int ext4_mb_init_cache(struct page *page, char *incore) struct ext4_group_info *grinfo; group = (first_block + i) >> 1; - if (group >= EXT4_SB(sb)->s_groups_count) + if (group >= ngroups) break; /* @@ -1788,6 +1790,7 @@ int ext4_mb_get_buddy_cache_lock(struct super_block *sb, ext4_group_t group) int block, pnum; int blocks_per_page; int groups_per_page; + ext4_group_t ngroups = ext4_get_groups_count(sb); ext4_group_t first_group; struct ext4_group_info *grp; @@ -1807,7 +1810,7 @@ int ext4_mb_get_buddy_cache_lock(struct super_block *sb, ext4_group_t group) /* read all groups the page covers into the cache */ for (i = 0; i < groups_per_page; i++) { - if ((first_group + i) >= EXT4_SB(sb)->s_groups_count) + if ((first_group + i) >= ngroups) break; grp = ext4_get_group_info(sb, first_group + i); /* take all groups write allocation @@ -1945,8 +1948,7 @@ err: static noinline_for_stack int ext4_mb_regular_allocator(struct ext4_allocation_context *ac) { - ext4_group_t group; - ext4_group_t i; + ext4_group_t ngroups, group, i; int cr; int err = 0; int bsbits; @@ -1957,6 +1959,7 @@ ext4_mb_regular_allocator(struct ext4_allocation_context *ac) sb = ac->ac_sb; sbi = EXT4_SB(sb); + ngroups = ext4_get_groups_count(sb); BUG_ON(ac->ac_status == AC_STATUS_FOUND); /* first, try the goal */ @@ -2017,11 +2020,11 @@ repeat: */ group = ac->ac_g_ex.fe_group; - for (i = 0; i < EXT4_SB(sb)->s_groups_count; group++, i++) { + for (i = 0; i < ngroups; group++, i++) { struct ext4_group_info *grp; struct ext4_group_desc *desc; - if (group == EXT4_SB(sb)->s_groups_count) + if (group == ngroups) group = 0; /* quick check to skip empty groups */ @@ -2315,12 +2318,10 @@ static struct file_operations ext4_mb_seq_history_fops = { static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos) { struct super_block *sb = seq->private; - struct ext4_sb_info *sbi = EXT4_SB(sb); ext4_group_t group; - if (*pos < 0 || *pos >= sbi->s_groups_count) + if (*pos < 0 || *pos >= ext4_get_groups_count(sb)) return NULL; - group = *pos + 1; return (void *) ((unsigned long) group); } @@ -2328,11 +2329,10 @@ static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos) static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos) { struct super_block *sb = seq->private; - struct ext4_sb_info *sbi = EXT4_SB(sb); ext4_group_t group; ++*pos; - if (*pos < 0 || *pos >= sbi->s_groups_count) + if (*pos < 0 || *pos >= ext4_get_groups_count(sb)) return NULL; group = *pos + 1; return (void *) ((unsigned long) group); @@ -2587,6 +2587,7 @@ void ext4_mb_update_group_info(struct ext4_group_info *grp, ext4_grpblk_t add) static int ext4_mb_init_backend(struct super_block *sb) { + ext4_group_t ngroups = ext4_get_groups_count(sb); ext4_group_t i; int metalen; struct ext4_sb_info *sbi = EXT4_SB(sb); @@ -2598,7 +2599,7 @@ static int ext4_mb_init_backend(struct super_block *sb) struct ext4_group_desc *desc; /* This is the number of blocks used by GDT */ - num_meta_group_infos = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - + num_meta_group_infos = (ngroups + EXT4_DESC_PER_BLOCK(sb) - 1) >> EXT4_DESC_PER_BLOCK_BITS(sb); /* @@ -2644,7 +2645,7 @@ static int ext4_mb_init_backend(struct super_block *sb) for (i = 0; i < num_meta_group_infos; i++) { if ((i + 1) == num_meta_group_infos) metalen = sizeof(*meta_group_info) * - (sbi->s_groups_count - + (ngroups - (i << EXT4_DESC_PER_BLOCK_BITS(sb))); meta_group_info = kmalloc(metalen, GFP_KERNEL); if (meta_group_info == NULL) { @@ -2655,7 +2656,7 @@ static int ext4_mb_init_backend(struct super_block *sb) sbi->s_group_info[i] = meta_group_info; } - for (i = 0; i < sbi->s_groups_count; i++) { + for (i = 0; i < ngroups; i++) { desc = ext4_get_group_desc(sb, i, NULL); if (desc == NULL) { printk(KERN_ERR @@ -2781,13 +2782,14 @@ static void ext4_mb_cleanup_pa(struct ext4_group_info *grp) int ext4_mb_release(struct super_block *sb) { + ext4_group_t ngroups = ext4_get_groups_count(sb); ext4_group_t i; int num_meta_group_infos; struct ext4_group_info *grinfo; struct ext4_sb_info *sbi = EXT4_SB(sb); if (sbi->s_group_info) { - for (i = 0; i < sbi->s_groups_count; i++) { + for (i = 0; i < ngroups; i++) { grinfo = ext4_get_group_info(sb, i); #ifdef DOUBLE_CHECK kfree(grinfo->bb_bitmap); @@ -2797,7 +2799,7 @@ int ext4_mb_release(struct super_block *sb) ext4_unlock_group(sb, i); kfree(grinfo); } - num_meta_group_infos = (sbi->s_groups_count + + num_meta_group_infos = (ngroups + EXT4_DESC_PER_BLOCK(sb) - 1) >> EXT4_DESC_PER_BLOCK_BITS(sb); for (i = 0; i < num_meta_group_infos; i++) @@ -4121,7 +4123,7 @@ static void ext4_mb_return_to_preallocation(struct inode *inode, static void ext4_mb_show_ac(struct ext4_allocation_context *ac) { struct super_block *sb = ac->ac_sb; - ext4_group_t i; + ext4_group_t ngroups, i; printk(KERN_ERR "EXT4-fs: Can't allocate:" " Allocation context details:\n"); @@ -4145,7 +4147,8 @@ static void ext4_mb_show_ac(struct ext4_allocation_context *ac) printk(KERN_ERR "EXT4-fs: %lu scanned, %d found\n", ac->ac_ex_scanned, ac->ac_found); printk(KERN_ERR "EXT4-fs: groups: \n"); - for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) { + ngroups = ext4_get_groups_count(sb); + for (i = 0; i < ngroups; i++) { struct ext4_group_info *grp = ext4_get_group_info(sb, i); struct ext4_prealloc_space *pa; ext4_grpblk_t start; @@ -4469,13 +4472,13 @@ static int ext4_mb_release_context(struct ext4_allocation_context *ac) static int ext4_mb_discard_preallocations(struct super_block *sb, int needed) { - ext4_group_t i; + ext4_group_t i, ngroups = ext4_get_groups_count(sb); int ret; int freed = 0; trace_mark(ext4_mb_discard_preallocations, "dev %s needed %d", sb->s_id, needed); - for (i = 0; i < EXT4_SB(sb)->s_groups_count && needed > 0; i++) { + for (i = 0; i < ngroups && needed > 0; i++) { ret = ext4_mb_discard_group_preallocations(sb, i, needed); freed += ret; needed -= ret; -- cgit v1.2.3 From 75507efb1372b6acf1aa6bf00ebd49ce196fd994 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Fri, 1 May 2009 12:58:36 -0400 Subject: ext4: Don't avoid using BLOCK_UNINIT block groups in mballoc By avoiding the use of not-yet-used block groups (i.e., block groups with the BLOCK_UNINIT flag), mballoc had a tendency to create large files with large non-contiguous gaps. In addition avoiding the use of new block groups had a tendency to push regular file data into the first block group in a flex_bg group, which slows down the speed of e2fsck pass 2, since it has a tendency to seek much more. For example: Before Patch After Patch Time in seconds Time in seconds Real / User/ Sys MB/s Real / User/ Sys MB/s Pass 1 8.52 / 2.21 / 0.46 20.43 8.84 / 4.97 / 1.11 19.68 Pass 2 21.16 / 1.02 / 1.86 11.30 6.54 / 1.77 / 1.78 36.39 Pass 3 0.01 / 0.00 / 0.00 139.00 0.01 / 0.01 / 0.00 128.90 Pass 4 0.16 / 0.15 / 0.00 0.00 0.17 / 0.17 / 0.00 0.00 Pass 5 2.52 / 1.99 / 0.09 0.79 2.31 / 1.78 / 0.06 0.86 Total 32.40 / 5.11 / 2.49 12.81 17.99 / 8.75 / 2.98 23.01 This was on a sample 80 gig root filesystem which was approximately 50% full. Note the improved e2fsck pass 2 performance, by over a factor of 3, due to a decreased number of seeks. (The total amount of I/O in pass 2 was unchanged; the layout of the directory blocks was simply much better from e2fsck's's perspective.) Other changes as a result of this patch on this sample filesystem: Before Patch After Patch # of non-contig files 762 779 # of non-contig directories 571 570 # of BLOCK_UNINIT bg's 307 293 # of INODE_UNINIT bg's 503 503 Out of 640 block groups, of which 333 were in use, this patch caused an extra 14 block groups to be utilized. The number of non-contiguous files did go up slightly, but when measured against the 99.9% of the files (603,154) which were contiguously allocated, this is pretty insignificant. Signed-off-by: "Theodore Ts'o" Signed-off-by: Andreas Dilger --- fs/ext4/mballoc.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) (limited to 'fs/ext4/mballoc.c') diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index c3af9e6b666..dbd47eac13e 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -1728,7 +1728,6 @@ static int ext4_mb_good_group(struct ext4_allocation_context *ac, unsigned free, fragments; unsigned i, bits; int flex_size = ext4_flex_bg_size(EXT4_SB(ac->ac_sb)); - struct ext4_group_desc *desc; struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group); BUG_ON(cr < 0 || cr >= 4); @@ -1744,10 +1743,6 @@ static int ext4_mb_good_group(struct ext4_allocation_context *ac, switch (cr) { case 0: BUG_ON(ac->ac_2order == 0); - /* If this group is uninitialized, skip it initially */ - desc = ext4_get_group_desc(ac->ac_sb, group, NULL); - if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) - return 0; /* Avoid using the first bg of a flexgroup for data files */ if ((ac->ac_flags & EXT4_MB_HINT_DATA) && @@ -2067,9 +2062,7 @@ repeat: ac->ac_groups_scanned++; desc = ext4_get_group_desc(sb, group, NULL); - if (cr == 0 || (desc->bg_flags & - cpu_to_le16(EXT4_BG_BLOCK_UNINIT) && - ac->ac_2order != 0)) + if (cr == 0) ext4_mb_simple_scan_group(ac, &e4b); else if (cr == 1 && ac->ac_g_ex.fe_len == sbi->s_stripe) -- cgit v1.2.3 From f40339031b04279c3fdde7ac5fe97db33b2a7694 Mon Sep 17 00:00:00 2001 From: Curt Wohlgemuth Date: Fri, 1 May 2009 20:27:20 -0400 Subject: ext4: Make the length of the mb_history file tunable In memory-constrained systems with many partitions, the ~68K for each partition for the mb_history buffer can be excessive. This patch adds a new mount option, mb_history_length, as well as a way of setting the default via a module parameter (or via a sysfs parameter in /sys/module/ext4/parameter/default_mb_history_length). If the mb_history_length is set to zero, the mb_history facility is disabled entirely. Signed-off-by: Curt Wohlgemuth Signed-off-by: "Theodore Ts'o" --- fs/ext4/mballoc.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'fs/ext4/mballoc.c') diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index dbd47eac13e..df75855ae6f 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2413,7 +2413,8 @@ static void ext4_mb_history_release(struct super_block *sb) if (sbi->s_proc != NULL) { remove_proc_entry("mb_groups", sbi->s_proc); - remove_proc_entry("mb_history", sbi->s_proc); + if (sbi->s_mb_history_max) + remove_proc_entry("mb_history", sbi->s_proc); } kfree(sbi->s_mb_history); } @@ -2424,17 +2425,17 @@ static void ext4_mb_history_init(struct super_block *sb) int i; if (sbi->s_proc != NULL) { - proc_create_data("mb_history", S_IRUGO, sbi->s_proc, - &ext4_mb_seq_history_fops, sb); + if (sbi->s_mb_history_max) + proc_create_data("mb_history", S_IRUGO, sbi->s_proc, + &ext4_mb_seq_history_fops, sb); proc_create_data("mb_groups", S_IRUGO, sbi->s_proc, &ext4_mb_seq_groups_fops, sb); } - sbi->s_mb_history_max = 1000; sbi->s_mb_history_cur = 0; spin_lock_init(&sbi->s_mb_history_lock); i = sbi->s_mb_history_max * sizeof(struct ext4_mb_history); - sbi->s_mb_history = kzalloc(i, GFP_KERNEL); + sbi->s_mb_history = i ? kzalloc(i, GFP_KERNEL) : NULL; /* if we can't allocate history, then we simple won't use it */ } @@ -2444,7 +2445,7 @@ ext4_mb_store_history(struct ext4_allocation_context *ac) struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); struct ext4_mb_history h; - if (unlikely(sbi->s_mb_history == NULL)) + if (sbi->s_mb_history == NULL) return; if (!(ac->ac_op & sbi->s_mb_history_filter)) -- cgit v1.2.3 From 955ce5f5be67dfe0d1d096b543af33fe8a1ce3dd Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Sat, 2 May 2009 20:35:09 -0400 Subject: ext4: Convert ext4_lock_group to use sb_bgl_lock We have sb_bgl_lock() and ext4_group_info.bb_state bit spinlock to protech group information. The later is only used within mballoc code. Consolidate them to use sb_bgl_lock(). This makes the mballoc.c code much simpler and also avoid confusion with two locks protecting same info. Signed-off-by: Aneesh Kumar K.V Signed-off-by: "Theodore Ts'o" --- fs/ext4/mballoc.c | 78 +++++++++++++++++++------------------------------------ 1 file changed, 27 insertions(+), 51 deletions(-) (limited to 'fs/ext4/mballoc.c') diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index df75855ae6f..e76459cedcd 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -372,24 +372,12 @@ static inline void mb_set_bit(int bit, void *addr) ext4_set_bit(bit, addr); } -static inline void mb_set_bit_atomic(spinlock_t *lock, int bit, void *addr) -{ - addr = mb_correct_addr_and_bit(&bit, addr); - ext4_set_bit_atomic(lock, bit, addr); -} - static inline void mb_clear_bit(int bit, void *addr) { addr = mb_correct_addr_and_bit(&bit, addr); ext4_clear_bit(bit, addr); } -static inline void mb_clear_bit_atomic(spinlock_t *lock, int bit, void *addr) -{ - addr = mb_correct_addr_and_bit(&bit, addr); - ext4_clear_bit_atomic(lock, bit, addr); -} - static inline int mb_find_next_zero_bit(void *addr, int max, int start) { int fix = 0, ret, tmpmax; @@ -803,17 +791,17 @@ static int ext4_mb_init_cache(struct page *page, char *incore) unlock_buffer(bh[i]); continue; } - spin_lock(sb_bgl_lock(EXT4_SB(sb), first_group + i)); + ext4_lock_group(sb, first_group + i); if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { ext4_init_block_bitmap(sb, bh[i], first_group + i, desc); set_bitmap_uptodate(bh[i]); set_buffer_uptodate(bh[i]); - spin_unlock(sb_bgl_lock(EXT4_SB(sb), first_group + i)); + ext4_unlock_group(sb, first_group + i); unlock_buffer(bh[i]); continue; } - spin_unlock(sb_bgl_lock(EXT4_SB(sb), first_group + i)); + ext4_unlock_group(sb, first_group + i); if (buffer_uptodate(bh[i])) { /* * if not uninit if bh is uptodate, @@ -1080,7 +1068,7 @@ static int mb_find_order_for_block(struct ext4_buddy *e4b, int block) return 0; } -static void mb_clear_bits(spinlock_t *lock, void *bm, int cur, int len) +static void mb_clear_bits(void *bm, int cur, int len) { __u32 *addr; @@ -1093,15 +1081,12 @@ static void mb_clear_bits(spinlock_t *lock, void *bm, int cur, int len) cur += 32; continue; } - if (lock) - mb_clear_bit_atomic(lock, cur, bm); - else - mb_clear_bit(cur, bm); + mb_clear_bit(cur, bm); cur++; } } -static void mb_set_bits(spinlock_t *lock, void *bm, int cur, int len) +static void mb_set_bits(void *bm, int cur, int len) { __u32 *addr; @@ -1114,10 +1099,7 @@ static void mb_set_bits(spinlock_t *lock, void *bm, int cur, int len) cur += 32; continue; } - if (lock) - mb_set_bit_atomic(lock, cur, bm); - else - mb_set_bit(cur, bm); + mb_set_bit(cur, bm); cur++; } } @@ -1332,8 +1314,7 @@ static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex) e4b->bd_info->bb_counters[ord]++; } - mb_set_bits(sb_bgl_lock(EXT4_SB(e4b->bd_sb), ex->fe_group), - EXT4_MB_BITMAP(e4b), ex->fe_start, len0); + mb_set_bits(EXT4_MB_BITMAP(e4b), ex->fe_start, len0); mb_check_buddy(e4b); return ret; @@ -2756,7 +2737,7 @@ int ext4_mb_init(struct super_block *sb, int needs_recovery) return 0; } -/* need to called with ext4 group lock (ext4_lock_group) */ +/* need to called with the ext4 group lock held */ static void ext4_mb_cleanup_pa(struct ext4_group_info *grp) { struct ext4_prealloc_space *pa; @@ -2993,14 +2974,17 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac, * Fix the bitmap and repeat the block allocation * We leak some of the blocks here. */ - mb_set_bits(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group), - bitmap_bh->b_data, ac->ac_b_ex.fe_start, - ac->ac_b_ex.fe_len); + ext4_lock_group(sb, ac->ac_b_ex.fe_group); + mb_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start, + ac->ac_b_ex.fe_len); + ext4_unlock_group(sb, ac->ac_b_ex.fe_group); err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); if (!err) err = -EAGAIN; goto out_err; } + + ext4_lock_group(sb, ac->ac_b_ex.fe_group); #ifdef AGGRESSIVE_CHECK { int i; @@ -3010,9 +2994,7 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac, } } #endif - spin_lock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group)); - mb_set_bits(NULL, bitmap_bh->b_data, - ac->ac_b_ex.fe_start, ac->ac_b_ex.fe_len); + mb_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start,ac->ac_b_ex.fe_len); if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT); ext4_free_blks_set(sb, gdp, @@ -3022,7 +3004,8 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac, len = ext4_free_blks_count(sb, gdp) - ac->ac_b_ex.fe_len; ext4_free_blks_set(sb, gdp, len); gdp->bg_checksum = ext4_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp); - spin_unlock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group)); + + ext4_unlock_group(sb, ac->ac_b_ex.fe_group); percpu_counter_sub(&sbi->s_freeblocks_counter, ac->ac_b_ex.fe_len); /* * Now reduce the dirty block count also. Should not go negative @@ -3455,7 +3438,7 @@ ext4_mb_use_preallocated(struct ext4_allocation_context *ac) * the function goes through all block freed in the group * but not yet committed and marks them used in in-core bitmap. * buddy must be generated from this bitmap - * Need to be called with ext4 group lock (ext4_lock_group) + * Need to be called with the ext4 group lock held */ static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap, ext4_group_t group) @@ -3469,9 +3452,7 @@ static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap, while (n) { entry = rb_entry(n, struct ext4_free_data, node); - mb_set_bits(sb_bgl_lock(EXT4_SB(sb), group), - bitmap, entry->start_blk, - entry->count); + mb_set_bits(bitmap, entry->start_blk, entry->count); n = rb_next(n); } return; @@ -3480,7 +3461,7 @@ static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap, /* * the function goes through all preallocation in this group and marks them * used in in-core bitmap. buddy must be generated from this bitmap - * Need to be called with ext4 group lock (ext4_lock_group) + * Need to be called with ext4 group lock held */ static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap, ext4_group_t group) @@ -3512,8 +3493,7 @@ static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap, if (unlikely(len == 0)) continue; BUG_ON(groupnr != group); - mb_set_bits(sb_bgl_lock(EXT4_SB(sb), group), - bitmap, start, len); + mb_set_bits(bitmap, start, len); preallocated += len; count++; } @@ -4856,29 +4836,25 @@ do_more: new_entry->group = block_group; new_entry->count = count; new_entry->t_tid = handle->h_transaction->t_tid; + ext4_lock_group(sb, block_group); - mb_clear_bits(sb_bgl_lock(sbi, block_group), bitmap_bh->b_data, - bit, count); + mb_clear_bits(bitmap_bh->b_data, bit, count); ext4_mb_free_metadata(handle, &e4b, new_entry); - ext4_unlock_group(sb, block_group); } else { - ext4_lock_group(sb, block_group); /* need to update group_info->bb_free and bitmap * with group lock held. generate_buddy look at * them with group lock_held */ - mb_clear_bits(sb_bgl_lock(sbi, block_group), bitmap_bh->b_data, - bit, count); + ext4_lock_group(sb, block_group); + mb_clear_bits(bitmap_bh->b_data, bit, count); mb_free_blocks(inode, &e4b, bit, count); ext4_mb_return_to_preallocation(inode, &e4b, block, count); - ext4_unlock_group(sb, block_group); } - spin_lock(sb_bgl_lock(sbi, block_group)); ret = ext4_free_blks_count(sb, gdp) + count; ext4_free_blks_set(sb, gdp, ret); gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp); - spin_unlock(sb_bgl_lock(sbi, block_group)); + ext4_unlock_group(sb, block_group); percpu_counter_add(&sbi->s_freeblocks_counter, count); if (sbi->s_log_groups_per_flex) { -- cgit v1.2.3 From bc8e67409ccdcff72c3f1656b1fb1aad7ff396db Mon Sep 17 00:00:00 2001 From: Vincent Minet Date: Fri, 15 May 2009 08:33:18 -0400 Subject: ext4: Fix spinlock assertions on UP systems On UP systems without DEBUG_SPINLOCK, ext4_is_group_locked always fails which triggers a BUG_ON() call. This patch fixes it by using assert_spin_locked instead. Signed-off-by: Vincent Minet Signed-off-by: "Theodore Ts'o" --- fs/ext4/mballoc.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'fs/ext4/mballoc.c') diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index e76459cedcd..541bd9adffa 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -436,7 +436,7 @@ static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b, if (unlikely(e4b->bd_info->bb_bitmap == NULL)) return; - BUG_ON(!ext4_is_group_locked(sb, e4b->bd_group)); + assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group)); for (i = 0; i < count; i++) { if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) { ext4_fsblk_t blocknr; @@ -460,7 +460,7 @@ static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count) if (unlikely(e4b->bd_info->bb_bitmap == NULL)) return; - BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group)); + assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group)); for (i = 0; i < count; i++) { BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap)); mb_set_bit(first + i, e4b->bd_info->bb_bitmap); @@ -1115,7 +1115,7 @@ static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b, struct super_block *sb = e4b->bd_sb; BUG_ON(first + count > (sb->s_blocksize << 3)); - BUG_ON(!ext4_is_group_locked(sb, e4b->bd_group)); + assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group)); mb_check_buddy(e4b); mb_free_blocks_double(inode, e4b, first, count); @@ -1196,7 +1196,7 @@ static int mb_find_extent(struct ext4_buddy *e4b, int order, int block, int ord; void *buddy; - BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group)); + assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group)); BUG_ON(ex == NULL); buddy = mb_find_buddy(e4b, order, &max); @@ -1260,7 +1260,7 @@ static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex) BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3)); BUG_ON(e4b->bd_group != ex->fe_group); - BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group)); + assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group)); mb_check_buddy(e4b); mb_mark_used_double(e4b, start, len); -- cgit v1.2.3 From 6fd058f7791087648c683eb8572edf3be3c4c23c Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sun, 17 May 2009 15:38:01 -0400 Subject: ext4: Add a comprehensive block validity check to ext4_get_blocks() To catch filesystem bugs or corruption which could lead to the filesystem getting severly damaged, this patch adds a facility for tracking all of the filesystem metadata blocks by contiguous regions in a red-black tree. This allows quick searching of the tree to locate extents which might overlap with filesystem metadata blocks. This facility is also used by the multi-block allocator to assure that it is not allocating blocks out of the system zone, as well as by the routines used when reading indirect blocks and extents information from disk to make sure their contents are valid. Signed-off-by: "Theodore Ts'o" --- fs/ext4/mballoc.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) (limited to 'fs/ext4/mballoc.c') diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 541bd9adffa..ed8482e22c0 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2961,15 +2961,10 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac, + le32_to_cpu(es->s_first_data_block); len = ac->ac_b_ex.fe_len; - if (in_range(ext4_block_bitmap(sb, gdp), block, len) || - in_range(ext4_inode_bitmap(sb, gdp), block, len) || - in_range(block, ext4_inode_table(sb, gdp), - EXT4_SB(sb)->s_itb_per_group) || - in_range(block + len - 1, ext4_inode_table(sb, gdp), - EXT4_SB(sb)->s_itb_per_group)) { + if (!ext4_data_block_valid(sbi, block, len)) { ext4_error(sb, __func__, - "Allocating block %llu in system zone of %d group\n", - block, ac->ac_b_ex.fe_group); + "Allocating blocks %llu-%llu which overlap " + "fs metadata\n", block, block+len); /* File system mounted not to panic on error * Fix the bitmap and repeat the block allocation * We leak some of the blocks here. -- cgit v1.2.3