lkml.org 
[lkml]   [2004]   [Nov]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] Fix O_SYNC speedup for generic_file_write_nolock

The O_SYNC speedup patches missed the generic_file_xxx_nolock cases,
which means that pages weren't actually getting sync'ed in those
cases. This patch fixes that.

Signed-off-by: Suparna Bhattacharya <suparna@in.ibm.com>


include/linux/writeback.h | 2 +
mm/filemap.c | 67 +++++++++++++++++++++++++++++++++++++++++++---
2 files changed, 66 insertions(+), 3 deletions(-)

diff -urp -X dontdiff2 linux-2.6.10-rc1/include/linux/writeback.h linux-2.6.10-rc1-aio/include/linux/writeback.h
--- linux-2.6.10-rc1/include/linux/writeback.h 2004-11-03 12:04:10.000000000 +0530
+++ linux-2.6.10-rc1-aio/include/linux/writeback.h 2004-11-04 10:10:31.000000000 +0530
@@ -106,6 +106,8 @@ int pdflush_operation(void (*fn)(unsigne
int do_writepages(struct address_space *mapping, struct writeback_control *wbc);
int sync_page_range(struct inode *inode, struct address_space *mapping,
loff_t pos, size_t count);
+int sync_page_range_nolock(struct inode *inode, struct address_space
+ *mapping, loff_t pos, size_t count);

/* pdflush.c */
extern int nr_pdflush_threads; /* Global so it can be exported to sysctl
diff -urp -X dontdiff2 linux-2.6.10-rc1/mm/filemap.c linux-2.6.10-rc1-aio/mm/filemap.c
--- linux-2.6.10-rc1/mm/filemap.c 2004-11-03 12:04:24.000000000 +0530
+++ linux-2.6.10-rc1-aio/mm/filemap.c 2004-11-04 10:10:31.000000000 +0530
@@ -283,6 +283,30 @@ int sync_page_range(struct inode *inode,
}
EXPORT_SYMBOL(sync_page_range);

+/*
+ * Note: Holding i_sem across sync_page_range_nolock is not a good idea
+ * as it forces O_SYNC writers to different parts of the same file
+ * to be serialised right until io completion.
+ */
+int sync_page_range_nolock(struct inode *inode, struct address_space *mapping,
+ loff_t pos, size_t count)
+{
+ pgoff_t start = pos >> PAGE_CACHE_SHIFT;
+ pgoff_t end = (pos + count - 1) >> PAGE_CACHE_SHIFT;
+ int ret;
+
+ if (mapping->backing_dev_info->memory_backed || !count)
+ return 0;
+ ret = filemap_fdatawrite_range(mapping, pos, pos + count - 1);
+ if (ret == 0) {
+ ret = generic_osync_inode(inode, mapping, OSYNC_METADATA);
+ }
+ if (ret == 0)
+ ret = wait_on_page_writeback_range(mapping, start, end);
+ return ret;
+}
+EXPORT_SYMBOL(sync_page_range_nolock);
+
/**
* filemap_fdatawait - walk the list of under-writeback pages of the given
* address space and wait for all of them.
@@ -1998,7 +2022,7 @@ generic_file_buffered_write(struct kiocb
EXPORT_SYMBOL(generic_file_buffered_write);

ssize_t
-generic_file_aio_write_nolock(struct kiocb *iocb, const struct iovec *iov,
+__generic_file_aio_write_nolock(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t *ppos)
{
struct file *file = iocb->ki_filp;
@@ -2075,6 +2099,43 @@ out:
EXPORT_SYMBOL(generic_file_aio_write_nolock);

ssize_t
+generic_file_aio_write_nolock(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long nr_segs, loff_t *ppos)
+{
+ struct file *file = iocb->ki_filp;
+ struct address_space *mapping = file->f_mapping;
+ struct inode *inode = mapping->host;
+ ssize_t ret;
+ loff_t pos = *ppos;
+
+ ret = __generic_file_aio_write_nolock(iocb, iov, nr_segs, ppos);
+
+ if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
+ int err;
+
+ err = sync_page_range_nolock(inode, mapping, pos, ret);
+ if (err < 0)
+ ret = err;
+ }
+ return ret;
+}
+
+
+ssize_t
+__generic_file_write_nolock(struct file *file, const struct iovec *iov,
+ unsigned long nr_segs, loff_t *ppos)
+{
+ struct kiocb kiocb;
+ ssize_t ret;
+
+ init_sync_kiocb(&kiocb, file);
+ ret = __generic_file_aio_write_nolock(&kiocb, iov, nr_segs, ppos);
+ if (-EIOCBQUEUED == ret)
+ ret = wait_on_sync_kiocb(&kiocb);
+ return ret;
+}
+
+ssize_t
generic_file_write_nolock(struct file *file, const struct iovec *iov,
unsigned long nr_segs, loff_t *ppos)
{
@@ -2128,7 +2189,7 @@ ssize_t generic_file_write(struct file *
.iov_len = count };

down(&inode->i_sem);
- ret = generic_file_write_nolock(file, &local_iov, 1, ppos);
+ ret = __generic_file_write_nolock(file, &local_iov, 1, ppos);
up(&inode->i_sem);

if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
@@ -2165,7 +2226,7 @@ ssize_t generic_file_writev(struct file
ssize_t ret;

down(&inode->i_sem);
- ret = generic_file_write_nolock(file, iov, nr_segs, ppos);
+ ret = __generic_file_write_nolock(file, iov, nr_segs, ppos);
up(&inode->i_sem);

if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
--
Suparna Bhattacharya (suparna@in.ibm.com)
Linux Technology Center
IBM Software Lab, India
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 14:07    [W:0.033 / U:9.516 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site