From 731ccf15c952d53a5f8e8bf98cf110f4048e5ded Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Thu, 23 Sep 2021 14:00:08 +0800 Subject: [PATCH] btrfs: make sure btrfs_io_context::fs_info is always initialized Currently btrfs_io_context::fs_info is only initialized in btrfs_map_bio, but there are call sites like btrfs_map_sblock() which calls __btrfs_map_block() directly, leaving bioc::fs_info uninitialized (NULL). Currently this is fine, but later cleanup will rely on bioc::fs_info to grab fs_info, and this can be a hidden problem for such usage. This patch will remove such hidden uninitialized member by always assigning bioc::fs_info at alloc_btrfs_io_context(). Reviewed-by: Nikolay Borisov Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/volumes.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index d7cc24ed9620..316c889a7040 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -5807,7 +5807,8 @@ static void sort_parity_stripes(struct btrfs_io_context *bioc, int num_stripes) } } -static struct btrfs_io_context *alloc_btrfs_io_context(int total_stripes, +static struct btrfs_io_context *alloc_btrfs_io_context(struct btrfs_fs_info *fs_info, + int total_stripes, int real_stripes) { struct btrfs_io_context *bioc = kzalloc( @@ -5827,6 +5828,7 @@ static struct btrfs_io_context *alloc_btrfs_io_context(int total_stripes, atomic_set(&bioc->error, 0); refcount_set(&bioc->refs, 1); + bioc->fs_info = fs_info; bioc->tgtdev_map = (int *)(bioc->stripes + total_stripes); bioc->raid_map = (u64 *)(bioc->tgtdev_map + real_stripes); @@ -5941,7 +5943,7 @@ static int __btrfs_map_block_for_discard(struct btrfs_fs_info *fs_info, &stripe_index); } - bioc = alloc_btrfs_io_context(num_stripes, 0); + bioc = alloc_btrfs_io_context(fs_info, num_stripes, 0); if (!bioc) { ret = -ENOMEM; goto out; @@ -6463,7 +6465,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, tgtdev_indexes = num_stripes; } - bioc = alloc_btrfs_io_context(num_alloc_stripes, tgtdev_indexes); + bioc = alloc_btrfs_io_context(fs_info, num_alloc_stripes, tgtdev_indexes); if (!bioc) { ret = -ENOMEM; goto out; @@ -6699,7 +6701,6 @@ blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio, bioc->orig_bio = first_bio; bioc->private = first_bio->bi_private; bioc->end_io = first_bio->bi_end_io; - bioc->fs_info = fs_info; atomic_set(&bioc->stripes_pending, bioc->num_stripes); if ((bioc->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) &&