@@ -2957,6 +2957,7 @@ struct ext4_group_info {
ext4_grpblk_t bb_fragments; /* nr of freespace fragments */
ext4_grpblk_t bb_largest_free_order;/* order of largest frag in BG */
struct list_head bb_prealloc_list;
+ unsigned long bb_prealloc_nr;
#ifdef DOUBLE_CHECK
void *bb_bitmap;
#endif
@@ -352,8 +352,8 @@
"ext4_groupinfo_64k", "ext4_groupinfo_128k"
};
-static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
- ext4_group_t group);
+static int ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
+ ext4_group_t group);
static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
ext4_group_t group);
@@ -708,8 +708,8 @@ static void ext4_mb_mark_free_simple(struct super_block *sb,
}
static noinline_for_stack
-void ext4_mb_generate_buddy(struct super_block *sb,
- void *buddy, void *bitmap, ext4_group_t group)
+int ext4_mb_generate_buddy(struct super_block *sb,
+ void *buddy, void *bitmap, ext4_group_t group)
{
struct ext4_group_info *grp = ext4_get_group_info(sb, group);
struct ext4_sb_info *sbi = EXT4_SB(sb);
@@ -752,6 +752,7 @@ void ext4_mb_generate_buddy(struct super_block *sb,
grp->bb_free = free;
ext4_mark_group_bitmap_corrupted(sb, group,
EXT4_GROUP_INFO_BBITMAP_CORRUPT);
+ return -EIO;
}
mb_set_largest_free_order(sb, grp);
@@ -762,6 +763,8 @@ void ext4_mb_generate_buddy(struct super_block *sb,
sbi->s_mb_buddies_generated++;
sbi->s_mb_generation_time += period;
spin_unlock(&sbi->s_bal_lock);
+
+ return 0;
}
static void mb_regenerate_buddy(struct ext4_buddy *e4b)
@@ -882,7 +885,7 @@ static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
}
first_block = page->index * blocks_per_page;
- for (i = 0; i < blocks_per_page; i++) {
+ for (i = 0; i < blocks_per_page && err == 0; i++) {
group = (first_block + i) >> 1;
if (group >= ngroups)
break;
@@ -926,7 +929,7 @@ static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
ext4_lock_group(sb, group);
/* init the buddy */
memset(data, 0xff, blocksize);
- ext4_mb_generate_buddy(sb, data, incore, group);
+ err = ext4_mb_generate_buddy(sb, data, incore, group);
ext4_unlock_group(sb, group);
incore = NULL;
} else {
@@ -941,7 +944,7 @@ static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
memcpy(data, bitmap, blocksize);
/* mark all preallocated blks used in in-core bitmap */
- ext4_mb_generate_from_pa(sb, data, group);
+ err = ext4_mb_generate_from_pa(sb, data, group);
ext4_mb_generate_from_freelist(sb, data, group);
ext4_unlock_group(sb, group);
@@ -951,8 +954,8 @@ static int ext4_mb_init_cache(struct page *page, char *incore, gfp_t gfp)
incore = data;
}
}
- SetPageUptodate(page);
-
+ if (likely(err == 0))
+ SetPageUptodate(page);
out:
if (bh) {
for (i = 0; i < groups_per_page; i++)
@@ -2281,7 +2284,8 @@ static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
{
struct super_block *sb = PDE_DATA(file_inode(seq->file));
ext4_group_t group = (ext4_group_t) ((unsigned long) v);
- int i;
+ struct ext4_group_desc *gdp;
+ int free = 0, i;
int err, buddy_loaded = 0;
struct ext4_buddy e4b;
struct ext4_group_info *grinfo;
@@ -2295,7 +2299,7 @@ static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
group--;
if (group == 0)
- seq_puts(seq, "#group: free frags first ["
+ seq_puts(seq, "#group: bfree gfree free frags first ["
" 2^0 2^1 2^2 2^3 2^4 2^5 2^6 "
" 2^7 2^8 2^9 2^10 2^11 2^12 2^13 ]\n");
@@ -2313,13 +2317,19 @@ static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
buddy_loaded = 1;
}
+ gdp = ext4_get_group_desc(sb, group, NULL);
+ if (gdp)
+ free = ext4_free_group_clusters(sb, gdp);
+
memcpy(&sg, ext4_get_group_info(sb, group), i);
if (buddy_loaded)
ext4_mb_unload_buddy(&e4b);
- seq_printf(seq, "#%-5u: %-5u %-5u %-5u [", group, sg.info.bb_free,
- sg.info.bb_fragments, sg.info.bb_first_free);
+ seq_printf(seq, "#%-5lu: %-5u %-5u %-5u %-5u %-5lu [",
+ (long unsigned int)group, sg.info.bb_free, free,
+ sg.info.bb_fragments, sg.info.bb_first_free,
+ sg.info.bb_prealloc_nr);
for (i = 0; i <= 13; i++)
seq_printf(seq, " %-5u", i <= blocksize_bits + 1 ?
sg.info.bb_counters[i] : 0);
@@ -3593,6 +3603,42 @@ static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
}
/*
+ * check free blocks in bitmap match free block in group descriptor
+ * do this before taking preallocated blocks into account to be able
+ * to detect on-disk corruptions. The group lock should be hold by the
+ * caller.
+ */
+int ext4_mb_check_ondisk_bitmap(struct super_block *sb, void *bitmap,
+ struct ext4_group_desc *gdp, int group)
+{
+ unsigned short max = EXT4_CLUSTERS_PER_GROUP(sb);
+ unsigned short i, first, free = 0;
+ unsigned short free_in_gdp = ext4_free_group_clusters(sb, gdp);
+
+ if (free_in_gdp == 0 && gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))
+ return 0;
+
+ i = mb_find_next_zero_bit(bitmap, max, 0);
+
+ while (i < max) {
+ first = i;
+ i = mb_find_next_bit(bitmap, max, i);
+ if (i > max)
+ i = max;
+ free += i - first;
+ if (i < max)
+ i = mb_find_next_zero_bit(bitmap, max, i);
+ }
+
+ if (free != free_in_gdp) {
+ ext4_error(sb, "on-disk bitmap for group %d corrupted: %u blocks free in bitmap, %u - in gd\n",
+ group, free, free_in_gdp);
+ return -EIO;
+ }
+ return 0;
+}
+
+/*
* 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
@@ -3622,16 +3668,27 @@ static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
* Need to be called with ext4 group lock held
*/
static noinline_for_stack
-void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
- ext4_group_t group)
+int ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
+ ext4_group_t group)
{
struct ext4_group_info *grp = ext4_get_group_info(sb, group);
struct ext4_prealloc_space *pa;
+ struct ext4_group_desc *gdp;
struct list_head *cur;
ext4_group_t groupnr;
ext4_grpblk_t start;
int preallocated = 0;
- int len;
+ int skip = 0, count = 0;
+ int err, len;
+
+ gdp = ext4_get_group_desc(sb, group, NULL);
+ if (!gdp)
+ return -EIO;
+
+ /* before applying preallocations, check bitmap consistency */
+ err = ext4_mb_check_ondisk_bitmap(sb, bitmap, gdp, group);
+ if (err)
+ return err;
/* all form of preallocation discards first load group,
* so the only competing code is preallocation use.
@@ -3648,13 +3705,22 @@ void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
&groupnr, &start);
len = pa->pa_len;
spin_unlock(&pa->pa_lock);
- if (unlikely(len == 0))
+ if (unlikely(len == 0)) {
+ skip++;
continue;
+ }
BUG_ON(groupnr != group);
ext4_set_bits(bitmap, start, len);
preallocated += len;
+ count++;
+ }
+ if (count + skip != grp->bb_prealloc_nr) {
+ ext4_error(sb, "lost preallocations: count %d, bb_prealloc_nr %lu, skip %d\n",
+ count, grp->bb_prealloc_nr, skip);
+ return -EIO;
}
mb_debug(1, "preallocated %u for group %u\n", preallocated, group);
+ return 0;
}
static void ext4_mb_pa_callback(struct rcu_head *head)
@@ -3718,6 +3784,7 @@ static void ext4_mb_put_pa(struct ext4_allocation_context *ac,
*/
ext4_lock_group(sb, grp);
list_del(&pa->pa_group_list);
+ ext4_get_group_info(sb, grp)->bb_prealloc_nr--;
ext4_unlock_group(sb, grp);
spin_lock(pa->pa_obj_lock);
@@ -3812,6 +3879,7 @@ static void ext4_mb_put_pa(struct ext4_allocation_context *ac,
ext4_lock_group(sb, ac->ac_b_ex.fe_group);
list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
+ grp->bb_prealloc_nr++;
ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
spin_lock(pa->pa_obj_lock);
@@ -3873,6 +3941,7 @@ static void ext4_mb_put_pa(struct ext4_allocation_context *ac,
ext4_lock_group(sb, ac->ac_b_ex.fe_group);
list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
+ grp->bb_prealloc_nr++;
ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
/*
@@ -4044,6 +4113,8 @@ static int ext4_mb_new_preallocation(struct ext4_allocation_context *ac)
spin_unlock(&pa->pa_lock);
+ BUG_ON(grp->bb_prealloc_nr == 0);
+ grp->bb_prealloc_nr--;
list_del(&pa->pa_group_list);
list_add(&pa->u.pa_tmp_list, &list);
}
@@ -4174,7 +4245,7 @@ void ext4_discard_preallocations(struct inode *inode)
if (err) {
ext4_error(sb, "Error %d loading buddy information for %u",
err, group);
- continue;
+ return;
}
bitmap_bh = ext4_read_block_bitmap(sb, group);
@@ -4187,6 +4258,8 @@ void ext4_discard_preallocations(struct inode *inode)
}
ext4_lock_group(sb, group);
+ BUG_ON(e4b.bd_info->bb_prealloc_nr == 0);
+ e4b.bd_info->bb_prealloc_nr--;
list_del(&pa->pa_group_list);
ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
ext4_unlock_group(sb, group);
@@ -4448,6 +4521,7 @@ static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
}
ext4_lock_group(sb, group);
list_del(&pa->pa_group_list);
+ ext4_get_group_info(sb, group)->bb_prealloc_nr--;
ext4_mb_release_group_pa(&e4b, pa);
ext4_unlock_group(sb, group);
@@ -70,7 +70,7 @@
/*
* for which requests use 2^N search using buddies
*/
-#define MB_DEFAULT_ORDER2_REQS 2
+#define MB_DEFAULT_ORDER2_REQS 8
/*
* default group prealloc size 512 blocks
Handle mballoc corruptions. Signed-off-by: James Simmons <jsimmons@infradead.org> --- fs/ext4/ext4.h | 1 + fs/ext4/mballoc.c | 110 +++++++++++++++++++++++++++++++++++++++++++++--------- fs/ext4/mballoc.h | 2 +- 3 files changed, 94 insertions(+), 19 deletions(-)