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authorDarrick J. Wong <darrick.wong@oracle.com>2018-10-30 10:42:10 +1100
committerDave Chinner <david@fromorbit.com>2018-10-30 10:42:10 +1100
commiteca3654e3cc7d93e9734d0fa96cfb15c7f356244 (patch)
tree00e5f8bd5de34435872d8cb222daaec79ede3961 /include/linux/fs.h
parentdf3658361951e17364f1e1c3fa92862a990ad8bd (diff)
vfs: enable remap callers that can handle short operations
Plumb in a remap flag that enables the filesystem remap handler to shorten remapping requests for callers that can handle it. Now copy_file_range can report partial success (in case we run up against alignment problems, resource limits, etc.). We also enable CAN_SHORTEN for fideduperange to maintain existing userspace-visible behavior where xfs/btrfs shorten the dedupe range to avoid stale post-eof data exposure. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
Diffstat (limited to 'include/linux/fs.h')
-rw-r--r--include/linux/fs.h5
1 files changed, 3 insertions, 2 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 544ab5083b48..34c22d695011 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1727,8 +1727,10 @@ struct block_device_operations;
* See Documentation/filesystems/vfs.txt for more details about this call.
*
* REMAP_FILE_DEDUP: only remap if contents identical (i.e. deduplicate)
+ * REMAP_FILE_CAN_SHORTEN: caller can handle a shortened request
*/
#define REMAP_FILE_DEDUP (1 << 0)
+#define REMAP_FILE_CAN_SHORTEN (1 << 1)
/*
* These flags signal that the caller is ok with altering various aspects of
@@ -1736,9 +1738,8 @@ struct block_device_operations;
* implementation; the vfs remap helper functions can take advantage of them.
* Flags in this category exist to preserve the quirky behavior of the hoisted
* btrfs clone/dedupe ioctls.
- * There are no flags yet, but subsequent commits will add some.
*/
-#define REMAP_FILE_ADVISORY (0)
+#define REMAP_FILE_ADVISORY (REMAP_FILE_CAN_SHORTEN)
struct iov_iter;