The patch titled
direct-io: sync and invalidate file region when falling back to buffered write
has been added to the -mm tree. Its filename is
direct-io-sync-and-invalidate-file-region-when-falling-back-to-buffered-write.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: direct-io: sync and invalidate file region when falling back to buffered write
From: Jeff Moyer <jmoyer@xxxxxxxxxx>
Cc: Jeff Moyer <jmoyer@xxxxxxxxxx>
Cc: Zach Brown <zach.brown@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
mm/filemap.c | 28 +++++++++++++++++++++++++---
1 files changed, 25 insertions(+), 3 deletions(-)
diff -puN mm/filemap.c~direct-io-sync-and-invalidate-file-region-when-falling-back-to-buffered-write mm/filemap.c
--- a/mm/filemap.c~direct-io-sync-and-invalidate-file-region-when-falling-back-to-buffered-write
+++ a/mm/filemap.c
@@ -2222,13 +2222,13 @@ __generic_file_aio_write_nolock(struct k
unsigned long nr_segs, loff_t *ppos)
{
struct file *file = iocb->ki_filp;
- const struct address_space * mapping = file->f_mapping;
+ struct address_space * mapping = file->f_mapping;
size_t ocount; /* original count */
size_t count; /* after file limit checks */
struct inode *inode = mapping->host;
unsigned long seg;
loff_t pos;
- ssize_t written;
+ ssize_t written, written_direct;
ssize_t err;
ocount = 0;
@@ -2258,7 +2258,7 @@ __generic_file_aio_write_nolock(struct k
/* We can write back this queue in page reclaim */
current->backing_dev_info = mapping->backing_dev_info;
- written = 0;
+ written = written_direct = 0;
err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
if (err)
@@ -2285,10 +2285,32 @@ __generic_file_aio_write_nolock(struct k
*/
pos += written;
count -= written;
+
+ written_direct = written;
}
written = generic_file_buffered_write(iocb, iov, nr_segs,
pos, ppos, count, written);
+
+ /*
+ * When falling through to buffered I/O, we need to ensure that the
+ * page cache pages are written to disk and invalidated to preserve
+ * the expected O_DIRECT semantics.
+ */
+ if (unlikely(file->f_flags & O_DIRECT)) {
+ pgoff_t endbyte = pos + count - 1;
+
+ err = do_sync_file_range(file, pos, endbyte,
+ SYNC_FILE_RANGE_WAIT_BEFORE|
+ SYNC_FILE_RANGE_WRITE|
+ SYNC_FILE_RANGE_WAIT_AFTER);
+ if (err == 0)
+ invalidate_mapping_pages(mapping,
+ pos >> PAGE_CACHE_SHIFT,
+ endbyte >> PAGE_CACHE_SHIFT);
+ else
+ written = written_direct;
+ }
out:
current->backing_dev_info = NULL;
return written ? written : err;
_
Patches currently in -mm which might be from jmoyer@xxxxxxxxxx are
direct-io-sync-and-invalidate-file-region-when-falling-back-to-buffered-write.patch
direct-io-sync-and-invalidate-file-region-when-falling-back-to-buffered-write-fixes.patch
dio-centralize-completion-in-dio_complete.patch
dio-call-blk_run_address_space-once-per-op.patch
dio-formalize-bio-counters-as-a-dio-reference-count.patch
dio-remove-duplicate-bio-wait-code.patch
dio-only-call-aio_complete-after-returning-eiocbqueued.patch
-
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