The patch titled
Subject: ocfs2: do not fallback to buffer I/O write if filling holes
has been removed from the -mm tree. Its filename was
ocfs2-do-not-fallback-to-buffer-i-o-write-if-fill-holes.patch
This patch was dropped because an updated version will be merged
------------------------------------------------------
From: WeiWei Wang <wangww631@xxxxxxxxxx>
Subject: ocfs2: do not fallback to buffer I/O write if filling holes
In this commit, direct-io to a hole will go direct-io first, then fall
through to buffered I/O for completing the rest of the request.
Signed-off-by: Weiwei Wang <wangww631@xxxxxxxxxx>
Cc: Mark Fasheh <mfasheh@xxxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/ocfs2/file.c | 87 +++++++++++++++++++---------------------------
1 file changed, 36 insertions(+), 51 deletions(-)
diff -puN fs/ocfs2/file.c~ocfs2-do-not-fallback-to-buffer-i-o-write-if-fill-holes fs/ocfs2/file.c
--- a/fs/ocfs2/file.c~ocfs2-do-not-fallback-to-buffer-i-o-write-if-fill-holes
+++ a/fs/ocfs2/file.c
@@ -1352,44 +1352,6 @@ out:
return ret;
}
-/*
- * Will look for holes and unwritten extents in the range starting at
- * pos for count bytes (inclusive).
- */
-static int ocfs2_check_range_for_holes(struct inode *inode, loff_t pos,
- size_t count)
-{
- int ret = 0;
- unsigned int extent_flags;
- u32 cpos, clusters, extent_len, phys_cpos;
- struct super_block *sb = inode->i_sb;
-
- cpos = pos >> OCFS2_SB(sb)->s_clustersize_bits;
- clusters = ocfs2_clusters_for_bytes(sb, pos + count) - cpos;
-
- while (clusters) {
- ret = ocfs2_get_clusters(inode, cpos, &phys_cpos, &extent_len,
- &extent_flags);
- if (ret < 0) {
- mlog_errno(ret);
- goto out;
- }
-
- if (phys_cpos == 0 || (extent_flags & OCFS2_EXT_UNWRITTEN)) {
- ret = 1;
- break;
- }
-
- if (extent_len > clusters)
- extent_len = clusters;
-
- clusters -= extent_len;
- cpos += extent_len;
- }
-out:
- return ret;
-}
-
static int ocfs2_write_remove_suid(struct inode *inode)
{
int ret;
@@ -2190,19 +2152,6 @@ static int ocfs2_prepare_inode_for_write
*direct_io = 0;
break;
}
-
- /*
- * We don't fill holes during direct io, so
- * check for them here. If any are found, the
- * caller will have to retake some cluster
- * locks and initiate the io as buffered.
- */
- ret = ocfs2_check_range_for_holes(inode, saved_pos, count);
- if (ret == 1) {
- *direct_io = 0;
- ret = 0;
- } else if (ret < 0)
- mlog_errno(ret);
break;
}
@@ -2232,6 +2181,7 @@ static ssize_t ocfs2_file_write_iter(str
u32 old_clusters;
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
+ struct address_space *mapping = file->f_mapping;
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
int full_coherency = !(osb->s_mount_opt &
OCFS2_MOUNT_COHERENCY_BUFFERED);
@@ -2346,11 +2296,46 @@ relock:
iov_iter_truncate(from, count);
if (direct_io) {
+ loff_t endbyte;
+ ssize_t written_buffered;
written = generic_file_direct_write(iocb, from, *ppos);
if (written < 0) {
ret = written;
goto out_dio;
}
+ /*
+ * direct-io write to a hole: fall through to buffered I/O
+ * for completing the rest of the request.
+ */
+ *ppos += written;
+ count -= written;
+ written_buffered = generic_perform_write(file, from, *ppos);
+ /*
+ * If generic_file_buffered_write() retuned a synchronous error
+ * then we want to return the number of bytes which were
+ * direct-written, or the error code if that was zero. Note
+ * that this differs from normal direct-io semantics, which
+ * will return -EFOO even if some bytes were written.
+ */
+ if (written_buffered < 0) {
+ ret = written_buffered;
+ goto out;
+ }
+
+ /*
+ * We need to ensure that the page cache pages are written to
+ * disk and invalidated to preserve the expected O_DIRECT
+ * semantics.
+ */
+ endbyte = *ppos + written_buffered - written - 1;
+ ret = filemap_write_and_wait_range(file->f_mapping, *ppos,
+ endbyte);
+ if (ret == 0) {
+ written = written_buffered;
+ invalidate_mapping_pages(mapping,
+ *ppos >> PAGE_CACHE_SHIFT,
+ endbyte >> PAGE_CACHE_SHIFT);
+ }
} else {
current->backing_dev_info = file->f_mapping->backing_dev_info;
written = generic_perform_write(file, from, *ppos);
_
Patches currently in -mm which might be from wangww631@xxxxxxxxxx are
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