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authorDave Chinner <dchinner@redhat.com>2019-10-17 23:12:01 +0300
committerDarrick J. Wong <darrick.wong@oracle.com>2019-10-17 23:12:01 +0300
commit7684e2c4384d5d1f884b01ab8bff2369e4db0bff (patch)
tree38603082924ece0934d128b7ed08be6a39fa3d23 /include/linux/iomap.h
parent906753befc4d2610194cd4d3d2ed15dff1ed1ca0 (diff)
downloadlinux-7684e2c4384d5d1f884b01ab8bff2369e4db0bff.tar.xz
iomap: iomap that extends beyond EOF should be marked dirty
When doing a direct IO that spans the current EOF, and there are written blocks beyond EOF that extend beyond the current write, the only metadata update that needs to be done is a file size extension. However, we don't mark such iomaps as IOMAP_F_DIRTY to indicate that there is IO completion metadata updates required, and hence we may fail to correctly sync file size extensions made in IO completion when O_DSYNC writes are being used and the hardware supports FUA. Hence when setting IOMAP_F_DIRTY, we need to also take into account whether the iomap spans the current EOF. If it does, then we need to mark it dirty so that IO completion will call generic_write_sync() to flush the inode size update to stable storage correctly. Fixes: 3460cac1ca76 ("iomap: Use FUA for pure data O_DSYNC DIO writes") Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> [darrick: removed the ext4 part; they'll handle it separately] Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'include/linux/iomap.h')
-rw-r--r--include/linux/iomap.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 76b14cb729dc..4b25ad6b5edd 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -32,6 +32,8 @@ struct vm_fault;
*
* IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access
* written data and requires fdatasync to commit them to persistent storage.
+ * This needs to take into account metadata changes that *may* be made at IO
+ * completion, such as file size updates from direct IO.
*/
#define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */
#define IOMAP_F_DIRTY 0x02 /* uncommitted metadata */