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authorDan Williams <dan.j.williams@intel.com>2016-01-15 16:55:56 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-01-15 17:56:32 -0800
commitfe683adabfe6629c0b6db32bbbc1ce6cacbf2117 (patch)
tree16798d03701b19665bcfcdfdf7796c4b52641242 /fs/block_dev.c
parent0e749e54244eec87b2a3cd0a4314e60bc6781115 (diff)
dax: guarantee page aligned results from bdev_direct_access()
If a ->direct_access() implementation ever returns a map count less than PAGE_SIZE, catch the error in bdev_direct_access(). This simplifies error checking in upper layers. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/block_dev.c')
-rw-r--r--fs/block_dev.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 81c0705558be..ddc6cdd1860b 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -494,6 +494,8 @@ long bdev_direct_access(struct block_device *bdev, sector_t sector,
avail = ops->direct_access(bdev, sector, addr, pfn);
if (!avail)
return -ERANGE;
+ if (avail > 0 && avail & ~PAGE_MASK)
+ return -ENXIO;
return min(avail, size);
}
EXPORT_SYMBOL_GPL(bdev_direct_access);