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| author | Elena Reshetova <elena.reshetova@intel.com> | 2017-03-03 10:55:20 +0200 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2017-04-18 14:07:24 +0200 |
| commit | a50299ae7cc4ba7268749e144e7c16321c25e3b3 (patch) | |
| tree | a45b465fe4ab70575256e611adc9db97e4500647 /fs | |
| parent | b7ac31b7b2ebd735b7b67c85711ef6d16648051a (diff) | |
| download | linux-a50299ae7cc4ba7268749e144e7c16321c25e3b3.tar.bz2 | |
btrfs: convert compressed_bio.pending_bios from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/compression.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index c7721a6aa3bb..10e6b282d09d 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -44,7 +44,7 @@ struct compressed_bio { /* number of bios pending for this compressed extent */ - atomic_t pending_bios; + refcount_t pending_bios; /* the pages with the compressed data on them */ struct page **compressed_pages; @@ -161,7 +161,7 @@ static void end_compressed_bio_read(struct bio *bio) /* if there are more bios still pending for this compressed * extent, just exit */ - if (!atomic_dec_and_test(&cb->pending_bios)) + if (!refcount_dec_and_test(&cb->pending_bios)) goto out; inode = cb->inode; @@ -274,7 +274,7 @@ static void end_compressed_bio_write(struct bio *bio) /* if there are more bios still pending for this compressed * extent, just exit */ - if (!atomic_dec_and_test(&cb->pending_bios)) + if (!refcount_dec_and_test(&cb->pending_bios)) goto out; /* ok, we're the last bio for this extent, step one is to @@ -342,7 +342,7 @@ int btrfs_submit_compressed_write(struct inode *inode, u64 start, cb = kmalloc(compressed_bio_size(fs_info, compressed_len), GFP_NOFS); if (!cb) return -ENOMEM; - atomic_set(&cb->pending_bios, 0); + refcount_set(&cb->pending_bios, 0); cb->errors = 0; cb->inode = inode; cb->start = start; @@ -363,7 +363,7 @@ int btrfs_submit_compressed_write(struct inode *inode, u64 start, bio_set_op_attrs(bio, REQ_OP_WRITE, 0); bio->bi_private = cb; bio->bi_end_io = end_compressed_bio_write; - atomic_inc(&cb->pending_bios); + refcount_set(&cb->pending_bios, 1); /* create and submit bios for the compressed pages */ bytes_left = compressed_len; @@ -388,7 +388,7 @@ int btrfs_submit_compressed_write(struct inode *inode, u64 start, * we inc the count. Otherwise, the cb might get * freed before we're done setting it up */ - atomic_inc(&cb->pending_bios); + refcount_inc(&cb->pending_bios); ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA); BUG_ON(ret); /* -ENOMEM */ @@ -607,7 +607,7 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, if (!cb) goto out; - atomic_set(&cb->pending_bios, 0); + refcount_set(&cb->pending_bios, 0); cb->errors = 0; cb->inode = inode; cb->mirror_num = mirror_num; @@ -656,7 +656,7 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, bio_set_op_attrs (comp_bio, REQ_OP_READ, 0); comp_bio->bi_private = cb; comp_bio->bi_end_io = end_compressed_bio_read; - atomic_inc(&cb->pending_bios); + refcount_set(&cb->pending_bios, 1); for (pg_index = 0; pg_index < nr_pages; pg_index++) { page = cb->compressed_pages[pg_index]; @@ -685,7 +685,7 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, * we inc the count. Otherwise, the cb might get * freed before we're done setting it up */ - atomic_inc(&cb->pending_bios); + refcount_inc(&cb->pending_bios); if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) { ret = btrfs_lookup_bio_sums(inode, comp_bio, |