Concurrent access to alloc_blocks in hfsplus_inode_info is
protected by extents_lock mutex. This patch fixes two
instances where alloc_blocks modification was not protected
with this lock. This fixes possible allocation bitmap
corruption in race conditions while extending and truncating
files.
Signed-off-by: Sougata Santra <sougata@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
---
fs/hfsplus/extents.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/hfsplus/extents.c b/fs/hfsplus/extents.c
index fbb212f..314c858 100644
--- a/fs/hfsplus/extents.c
+++ b/fs/hfsplus/extents.c
@@ -498,11 +498,13 @@ int hfsplus_file_extend(struct inode *inode)
goto insert_extent;
}
out:
- mutex_unlock(&hip->extents_lock);
if (!res) {
hip->alloc_blocks += len;
+ mutex_unlock(&hip->extents_lock);
hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
+ return 0;
}
+ mutex_unlock(&hip->extents_lock);
return res;
insert_extent:
@@ -592,9 +594,9 @@ void hfsplus_file_truncate(struct inode *inode)
hfs_brec_remove(&fd);
}
hfs_find_exit(&fd);
- mutex_unlock(&hip->extents_lock);
hip->alloc_blocks = blk_cnt;
+ mutex_unlock(&hip->extents_lock);
out:
hip->phys_size = inode->i_size;
hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >>
--
1.8.1.4
--
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