akpm at linux-foundation.org
2016-Mar-23 20:12 UTC
[Ocfs2-devel] [patch 08/25] ocfs2: code clean up for direct io
From: Ryan Ding <ryan.ding at oracle.com>
Subject: ocfs2: code clean up for direct io
Clean up ocfs2_file_write_iter & ocfs2_prepare_inode_for_write:
* remove append dio check: it will be checked in ocfs2_direct_IO()
* remove file hole check: file hole is supported for now
* remove inline data check: it will be checked in ocfs2_direct_IO()
* remove the full_coherence check when append dio: we will get the inode_lock
in ocfs2_dio_get_block, there is no need to fall back to buffer io to ensure
the coherence semantics.
Now the drop dio procedure is gone. :)
[akpm at linux-foundation.org: remove unused label]
Signed-off-by: Ryan Ding <ryan.ding at oracle.com>
Reviewed-by: Junxiao Bi <junxiao.bi at oracle.com>
Cc: Joseph Qi <joseph.qi at huawei.com>
Cc: Mark Fasheh <mfasheh at suse.de>
Cc: Joel Becker <jlbec at evilplan.org>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
---
fs/ocfs2/file.c | 138 +--------------------------------------
fs/ocfs2/ocfs2_trace.h | 16 +---
2 files changed, 10 insertions(+), 144 deletions(-)
diff -puN fs/ocfs2/file.c~ocfs2-code-clean-up-for-direct-io fs/ocfs2/file.c
--- a/fs/ocfs2/file.c~ocfs2-code-clean-up-for-direct-io
+++ a/fs/ocfs2/file.c
@@ -1381,44 +1381,6 @@ 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;
@@ -2129,18 +2091,12 @@ out:
static int ocfs2_prepare_inode_for_write(struct file *file,
loff_t pos,
- size_t count,
- int appending,
- int *direct_io,
- int *has_refcount)
+ size_t count)
{
int ret = 0, meta_level = 0;
struct dentry *dentry = file->f_path.dentry;
struct inode *inode = d_inode(dentry);
loff_t end;
- struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
- int full_coherency = !(osb->s_mount_opt &
- OCFS2_MOUNT_COHERENCY_BUFFERED);
/*
* We start with a read level meta lock and only jump to an ex
@@ -2189,10 +2145,6 @@ static int ocfs2_prepare_inode_for_write
pos,
count,
&meta_level);
- if (has_refcount)
- *has_refcount = 1;
- if (direct_io)
- *direct_io = 0;
}
if (ret < 0) {
@@ -2200,67 +2152,12 @@ static int ocfs2_prepare_inode_for_write
goto out_unlock;
}
- /*
- * Skip the O_DIRECT checks if we don't need
- * them.
- */
- if (!direct_io || !(*direct_io))
- break;
-
- /*
- * There's no sane way to do direct writes to an inode
- * with inline data.
- */
- if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
- *direct_io = 0;
- break;
- }
-
- /*
- * Allowing concurrent direct writes means
- * i_size changes wouldn't be synchronized, so
- * one node could wind up truncating another
- * nodes writes.
- */
- if (end > i_size_read(inode) && !full_coherency) {
- *direct_io = 0;
- break;
- }
-
- /*
- * Fallback to old way if the feature bit is not set.
- */
- if (end > i_size_read(inode) &&
- !ocfs2_supports_append_dio(osb)) {
- *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, pos, count);
- if (ret == 1) {
- /*
- * Fallback to old way if the feature bit is not set.
- * Otherwise try dio first and then complete the rest
- * request through buffer io.
- */
- if (!ocfs2_supports_append_dio(osb))
- *direct_io = 0;
- ret = 0;
- } else if (ret < 0)
- mlog_errno(ret);
break;
}
out_unlock:
trace_ocfs2_prepare_inode_for_write(OCFS2_I(inode)->ip_blkno,
- pos, appending, count,
- direct_io, has_refcount);
+ pos, count);
if (meta_level >= 0)
ocfs2_inode_unlock(inode, meta_level);
@@ -2272,18 +2169,16 @@ out:
static ssize_t ocfs2_file_write_iter(struct kiocb *iocb,
struct iov_iter *from)
{
- int direct_io, appending, rw_level;
- int can_do_direct, has_refcount = 0;
+ int direct_io, rw_level;
ssize_t written = 0;
ssize_t ret;
- size_t count = iov_iter_count(from), orig_count;
+ size_t count = iov_iter_count(from);
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
int full_coherency = !(osb->s_mount_opt &
OCFS2_MOUNT_COHERENCY_BUFFERED);
int unaligned_dio = 0;
- int dropped_dio = 0;
int append_write = ((iocb->ki_pos + count) > i_size_read(inode) ? 1 :
0);
@@ -2296,12 +2191,10 @@ static ssize_t ocfs2_file_write_iter(str
if (count == 0)
return 0;
- appending = iocb->ki_flags & IOCB_APPEND ? 1 : 0;
direct_io = iocb->ki_flags & IOCB_DIRECT ? 1 : 0;
inode_lock(inode);
-relock:
/*
* Concurrent O_DIRECT writes are allowed with
* mount_option "coherency=buffered".
@@ -2334,7 +2227,6 @@ relock:
ocfs2_inode_unlock(inode, 1);
}
- orig_count = iov_iter_count(from);
ret = generic_write_checks(iocb, from);
if (ret <= 0) {
if (ret)
@@ -2343,9 +2235,7 @@ relock:
}
count = ret;
- can_do_direct = direct_io;
- ret = ocfs2_prepare_inode_for_write(file, iocb->ki_pos, count, appending,
- &can_do_direct, &has_refcount);
+ ret = ocfs2_prepare_inode_for_write(file, iocb->ki_pos, count);
if (ret < 0) {
mlog_errno(ret);
goto out;
@@ -2354,22 +2244,6 @@ relock:
if (direct_io && !is_sync_kiocb(iocb))
unaligned_dio = ocfs2_is_io_unaligned(inode, count, iocb->ki_pos);
- /*
- * We can't complete the direct I/O as requested, fall back to
- * buffered I/O.
- */
- if (direct_io && !can_do_direct) {
- ocfs2_rw_unlock(inode, rw_level);
-
- rw_level = -1;
-
- direct_io = 0;
- iocb->ki_flags &= ~IOCB_DIRECT;
- iov_iter_reexpand(from, orig_count);
- dropped_dio = 1;
- goto relock;
- }
-
if (unaligned_dio) {
/*
* Wait on previous unaligned aio to complete before
@@ -2405,7 +2279,7 @@ relock:
goto no_sync;
if (((file->f_flags & O_DSYNC) && !direct_io) ||
- IS_SYNC(inode) || dropped_dio) {
+ IS_SYNC(inode)) {
ret = filemap_fdatawrite_range(file->f_mapping,
iocb->ki_pos - written,
iocb->ki_pos - 1);
diff -puN fs/ocfs2/ocfs2_trace.h~ocfs2-code-clean-up-for-direct-io
fs/ocfs2/ocfs2_trace.h
--- a/fs/ocfs2/ocfs2_trace.h~ocfs2-code-clean-up-for-direct-io
+++ a/fs/ocfs2/ocfs2_trace.h
@@ -1450,28 +1450,20 @@ DEFINE_OCFS2_ULL_ULL_ULL_EVENT(ocfs2_rem
TRACE_EVENT(ocfs2_prepare_inode_for_write,
TP_PROTO(unsigned long long ino, unsigned long long saved_pos,
- int appending, unsigned long count,
- int *direct_io, int *has_refcount),
- TP_ARGS(ino, saved_pos, appending, count, direct_io, has_refcount),
+ unsigned long count),
+ TP_ARGS(ino, saved_pos, count),
TP_STRUCT__entry(
__field(unsigned long long, ino)
__field(unsigned long long, saved_pos)
- __field(int, appending)
__field(unsigned long, count)
- __field(int, direct_io)
- __field(int, has_refcount)
),
TP_fast_assign(
__entry->ino = ino;
__entry->saved_pos = saved_pos;
- __entry->appending = appending;
__entry->count = count;
- __entry->direct_io = direct_io ? *direct_io : -1;
- __entry->has_refcount = has_refcount ? *has_refcount : -1;
),
- TP_printk("%llu %llu %d %lu %d %d", __entry->ino,
- __entry->saved_pos, __entry->appending, __entry->count,
- __entry->direct_io, __entry->has_refcount)
+ TP_printk("%llu %llu %lu", __entry->ino,
+ __entry->saved_pos, __entry->count)
);
DEFINE_OCFS2_INT_EVENT(generic_file_aio_read_ret);
_