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ocfs2: Provide a splice-read wrapper

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Provide a splice_read wrapper for ocfs2.  This emits trace lines and does
an atime lock/update before calling filemap_splice_read().  Splicing from
direct I/O is handled by the caller.

A couple of new tracepoints are added for this purpose.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
cc: Christoph Hellwig <hch@lst.de>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: Jens Axboe <axboe@kernel.dk>
cc: Mark Fasheh <mark@fasheh.com>
cc: Joel Becker <jlbec@evilplan.org>
cc: ocfs2-devel@oss.oracle.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-block@vger.kernel.org
cc: linux-mm@kvack.org
Link: https://lore.kernel.org/r/20230522135018.2742245-23-dhowells@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
David Howells 2023-05-22 14:50:09 +01:00 committed by Jens Axboe
parent 5149439880
commit 94aca682a4
2 changed files with 42 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

41
fs/ocfs2/file.c
View file

@ -2552,7 +2552,7 @@ static ssize_t ocfs2_file_read_iter(struct kiocb *iocb,
*
* Take and drop the meta data lock to update inode fields
* like i_size. This allows the checks down below
* generic_file_read_iter() a chance of actually working.
* copy_splice_read() a chance of actually working.
*/
ret = ocfs2_inode_lock_atime(inode, filp->f_path.mnt, &lock_level,
!nowait);
@ -2581,6 +2581,43 @@ static ssize_t ocfs2_file_read_iter(struct kiocb *iocb,
return ret;
}
static ssize_t ocfs2_file_splice_read(struct file *in, loff_t *ppos,
struct pipe_inode_info *pipe,
size_t len, unsigned int flags)
{
struct inode *inode = file_inode(in);
ssize_t ret = 0;
int lock_level = 0;
trace_ocfs2_file_splice_read(inode, in, in->f_path.dentry,
(unsigned long long)OCFS2_I(inode)->ip_blkno,
in->f_path.dentry->d_name.len,
in->f_path.dentry->d_name.name,
flags);
/*
* We're fine letting folks race truncates and extending writes with
* read across the cluster, just like they can locally. Hence no
* rw_lock during read.
*
* Take and drop the meta data lock to update inode fields like i_size.
* This allows the checks down below filemap_splice_read() a chance of
* actually working.
*/
ret = ocfs2_inode_lock_atime(inode, in->f_path.mnt, &lock_level, 1);
if (ret < 0) {
if (ret != -EAGAIN)
mlog_errno(ret);
goto bail;
}
ocfs2_inode_unlock(inode, lock_level);
ret = filemap_splice_read(in, ppos, pipe, len, flags);
trace_filemap_splice_read_ret(ret);
bail:
return ret;
}
/* Refer generic_file_llseek_unlocked() */
static loff_t ocfs2_file_llseek(struct file *file, loff_t offset, int whence)
{
@ -2744,7 +2781,7 @@ const struct file_operations ocfs2_fops = {
#endif
.lock = ocfs2_lock,
.flock = ocfs2_flock,
.splice_read = generic_file_splice_read,
.splice_read = ocfs2_file_splice_read,
.splice_write = iter_file_splice_write,
.fallocate = ocfs2_fallocate,
.remap_file_range = ocfs2_remap_file_range,

3
fs/ocfs2/ocfs2_trace.h
View file

@ -1319,6 +1319,8 @@ DEFINE_OCFS2_FILE_OPS(ocfs2_file_splice_write);
DEFINE_OCFS2_FILE_OPS(ocfs2_file_read_iter);
DEFINE_OCFS2_FILE_OPS(ocfs2_file_splice_read);
DEFINE_OCFS2_ULL_ULL_ULL_EVENT(ocfs2_truncate_file);
DEFINE_OCFS2_ULL_ULL_EVENT(ocfs2_truncate_file_error);
@ -1470,6 +1472,7 @@ TRACE_EVENT(ocfs2_prepare_inode_for_write,
);
DEFINE_OCFS2_INT_EVENT(generic_file_read_iter_ret);
DEFINE_OCFS2_INT_EVENT(filemap_splice_read_ret);
/* End of trace events for fs/ocfs2/file.c. */