--- /dev/null
+Subject: [PATCH] linux-5.14/ext4-mballoc-extra-checks.patch
+
+---
+ fs/ext4/ext4.h | 1 +
+ fs/ext4/mballoc.c | 103 ++++++++++++++++++++++++++++++++++++++++------
+ fs/ext4/mballoc.h | 2 +-
+ 3 files changed, 93 insertions(+), 13 deletions(-)
+
+diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
+index 89e289c..5707cba 100644
+--- a/fs/ext4/ext4.h
++++ b/fs/ext4/ext4.h
+@@ -3424,6 +3424,7 @@ struct ext4_group_info {
+ ext4_grpblk_t bb_largest_free_order;/* order of largest frag in BG */
+ ext4_group_t bb_group; /* Group number */
+ struct list_head bb_prealloc_list;
++ unsigned long bb_prealloc_nr;
+ #ifdef DOUBLE_CHECK
+ void *bb_bitmap;
+ #endif
+diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
+index 06c583d..a2b5d56 100644
+--- a/fs/ext4/mballoc.c
++++ b/fs/ext4/mballoc.c
+@@ -399,7 +399,7 @@ static const char * const ext4_groupinfo_slab_names[NR_GRPINFO_CACHES] = {
+ "ext4_groupinfo_64k", "ext4_groupinfo_128k"
+ };
+
+-static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
++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);
+@@ -1101,7 +1101,7 @@ mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp)
+ }
+
+ static noinline_for_stack
+-void ext4_mb_generate_buddy(struct super_block *sb,
++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);
+@@ -1145,6 +1145,7 @@ 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);
+
+@@ -1154,6 +1155,8 @@ void ext4_mb_generate_buddy(struct super_block *sb,
+ atomic_inc(&sbi->s_mb_buddies_generated);
+ atomic64_add(period, &sbi->s_mb_generation_time);
+ mb_update_avg_fragment_size(sb, grp);
++
++ return 0;
+ }
+
+ /* The buddy information is attached the buddy cache inode
+@@ -1256,7 +1259,7 @@ 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;
+@@ -1300,7 +1303,7 @@ 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 {
+@@ -1315,7 +1318,7 @@ 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);
+
+@@ -1325,7 +1328,8 @@ 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) {
+@@ -2840,9 +2844,11 @@ static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos)
+ static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
+ {
+ struct super_block *sb = PDE_DATA(file_inode(seq->file));
++ struct ext4_group_desc *gdp;
+ ext4_group_t group = (ext4_group_t) ((unsigned long) v);
+ int i;
+ int err, buddy_loaded = 0;
++ int free = 0;
+ struct ext4_buddy e4b;
+ struct ext4_group_info *grinfo;
+ unsigned char blocksize_bits = min_t(unsigned char,
+@@ -2855,7 +2861,7 @@ 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 frags first pa ["
+ " 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");
+
+@@ -2873,13 +2879,19 @@ 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 != NULL)
++ 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);
+@@ -4476,23 +4488,72 @@ static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap,
+ return;
+ }
+
++/*
++ * 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 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 held
+ */
+ static noinline_for_stack
+-void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
++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 skip = 0, count = 0;
++ int err;
+ int len;
+
++ gdp = ext4_get_group_desc(sb, group, NULL);
++ if (gdp == NULL)
++ 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.
+ * we don't need any locking here
+@@ -4508,13 +4569,23 @@ 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(sb, "preallocated %d for group %u\n", preallocated, group);
++ return 0;
+ }
+
+ static void ext4_mb_mark_pa_deleted(struct super_block *sb,
+@@ -4598,6 +4669,7 @@ 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);
+@@ -4689,6 +4761,7 @@ ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)
+ pa->pa_inode = ac->ac_inode;
+
+ list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
++ grp->bb_prealloc_nr++;
+
+ spin_lock(pa->pa_obj_lock);
+ list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list);
+@@ -4744,6 +4817,7 @@ ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
+ pa->pa_inode = NULL;
+
+ list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
++ grp->bb_prealloc_nr++;
+
+ /*
+ * We will later add the new pa to the right bucket
+@@ -4914,6 +4988,8 @@ repeat:
+
+ 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);
+ }
+@@ -5050,7 +5126,7 @@ repeat:
+ if (err) {
+ ext4_error_err(sb, -err, "Error %d loading buddy information for %u",
+ err, group);
+- continue;
++ return;
+ }
+
+ bitmap_bh = ext4_read_block_bitmap(sb, group);
+@@ -5063,6 +5139,8 @@ repeat:
+ }
+
+ 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);
+@@ -5357,6 +5435,7 @@ ext4_mb_discard_lg_preallocations(struct super_block *sb,
+ }
+ 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);
+
+diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h
+index 39da92c..b6c4a30 100644
+--- a/fs/ext4/mballoc.h
++++ b/fs/ext4/mballoc.h
+@@ -66,7 +66,7 @@
+ /*
+ * 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
+--
+2.31.1
+
git://git.whamcloud.com / fs / lustre-release.git / blobdiff