Some images produced by btrfs-image cause a mount crash in rmap block
when excluding superblock extents. Handle the errors gracefully.
Signed-off-by: David Sterba <dste...@suse.cz>
---
fs/btrfs/extent-tree.c | 19 ++++++++++++++++---
fs/btrfs/volumes.c | 20 +++++++++++++++++---
2 files changed, 33 insertions(+), 6 deletions(-)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 0bdb9fa..8055d58 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -250,10 +250,17 @@ static int exclude_super_stripes(struct btrfs_root *root,
for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
bytenr = btrfs_sb_offset(i);
+ if (bytenr <= cache->key.objectid + cache->key.offset)
+ break;
+ logical = NULL;
ret = btrfs_rmap_block(&root->fs_info->mapping_tree,
cache->key.objectid, bytenr,
0, &logical, &nr, &stripe_len);
- BUG_ON(ret); /* -ENOMEM */
+ if (ret < 0) {
+ kfree(logical);
+ free_excluded_extents(root, cache);
+ goto out;
+ }
while (nr--) {
cache->bytes_super += stripe_len;
@@ -264,7 +271,9 @@ static int exclude_super_stripes(struct btrfs_root *root,
kfree(logical);
}
- return 0;
+
+out:
+ return ret;
}
static struct btrfs_caching_control *
@@ -7665,7 +7674,11 @@ int btrfs_read_block_groups(struct btrfs_root *root)
* info has super bytes accounted for, otherwise we'll think
* we have more space than we actually do.
*/
- exclude_super_stripes(root, cache);
+ ret = exclude_super_stripes(root, cache);
+ if (ret < 0) {
+ kfree(cache);
+ goto error;
+ }
/*
* check for two cases, either we are full, and therefore
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index f818f48..3400fbd 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3911,12 +3911,22 @@ int btrfs_rmap_block(struct btrfs_mapping_tree
*map_tree,
u64 length;
u64 stripe_nr;
int i, j, nr = 0;
+ int ret = 0;
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, chunk_start, 1);
read_unlock(&em_tree->lock);
- BUG_ON(!em || em->start != chunk_start);
+ if (!em)
+ return -ENOENT;
+
+ if (em->start != chunk_start) {
+ printk(KERN_DEBUG "btrfs: rmap em->start %llu != %llu\n",
+ em->start, chunk_start);
+ ret = -EINVAL;
+ goto out_error;
+ }
+
map = (struct map_lookup *)em->bdev;
length = em->len;
@@ -3926,7 +3936,10 @@ int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
do_div(length, map->num_stripes);
buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
- BUG_ON(!buf); /* -ENOMEM */
+ if (!buf) {
+ ret = -ENOMEM;
+ goto out_error;
+ }
for (i = 0; i < map->num_stripes; i++) {
if (devid && map->stripes[i].dev->devid != devid)
@@ -3960,8 +3973,9 @@ int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
*naddrs = nr;
*stripe_len = map->stripe_len;
+out_error:
free_extent_map(em);
- return 0;
+ return ret;
}
static void btrfs_end_bio(struct bio *bio, int err)
--
1.7.9
--
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