lkml.org 
[lkml]   [2017]   [Sep]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC PATCH 3/3] fs: detect that the i_rwsem has already been taken exclusively
Date
Don't attempt to take the i_rwsem, if it has already been taken
exclusively.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
---
fs/ext2/file.c | 6 ++++--
fs/ext4/file.c | 8 +++++---
fs/xfs/xfs_file.c | 10 ++++++----
3 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/fs/ext2/file.c b/fs/ext2/file.c
index 839095f66d8d..d174b2880929 100644
--- a/fs/ext2/file.c
+++ b/fs/ext2/file.c
@@ -38,9 +38,11 @@ static ssize_t ext2_dax_read_iter(struct kiocb *iocb, struct iov_iter *to,
if (!iov_iter_count(to))
return 0; /* skip atime */

- inode_lock_shared(inode);
+ if (!rwf)
+ inode_lock_shared(inode);
ret = dax_iomap_rw(iocb, to, &ext2_iomap_ops);
- inode_unlock_shared(inode);
+ if (!rwf)
+ inode_unlock_shared(inode);

file_accessed(iocb->ki_filp);
return ret;
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 10789666725e..7d7c0e380add 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -38,7 +38,7 @@ static ssize_t ext4_dax_read_iter(struct kiocb *iocb, struct iov_iter *to,
struct inode *inode = file_inode(iocb->ki_filp);
ssize_t ret;

- if (!inode_trylock_shared(inode)) {
+ if (!rwf && !inode_trylock_shared(inode)) {
if (iocb->ki_flags & IOCB_NOWAIT)
return -EAGAIN;
inode_lock_shared(inode);
@@ -48,12 +48,14 @@ static ssize_t ext4_dax_read_iter(struct kiocb *iocb, struct iov_iter *to,
* change anymore
*/
if (!IS_DAX(inode)) {
- inode_unlock_shared(inode);
+ if (!rwf)
+ inode_unlock_shared(inode);
/* Fallback to buffered IO in case we cannot support DAX */
return generic_file_read_iter(iocb, to, rwf);
}
ret = dax_iomap_rw(iocb, to, &ext4_iomap_ops);
- inode_unlock_shared(inode);
+ if (!rwf)
+ inode_unlock_shared(inode);

file_accessed(iocb->ki_filp);
return ret;
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index cf1ce8961601..0cffca97ed68 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -239,7 +239,7 @@ xfs_file_dax_read(
if (!count)
return 0; /* skip atime */

- if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) {
+ if (!rwf && !xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) {
if (iocb->ki_flags & IOCB_NOWAIT)
return -EAGAIN;
xfs_ilock(ip, XFS_IOLOCK_SHARED);
@@ -247,7 +247,8 @@ xfs_file_dax_read(
ret = dax_iomap_rw(iocb, to, &xfs_iomap_ops);
xfs_iunlock(ip, XFS_IOLOCK_SHARED);

- file_accessed(iocb->ki_filp);
+ if (!rwf)
+ file_accessed(iocb->ki_filp);
return ret;
}

@@ -262,13 +263,14 @@ xfs_file_buffered_aio_read(

trace_xfs_file_buffered_read(ip, iov_iter_count(to), iocb->ki_pos);

- if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) {
+ if (!rwf && !xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) {
if (iocb->ki_flags & IOCB_NOWAIT)
return -EAGAIN;
xfs_ilock(ip, XFS_IOLOCK_SHARED);
}
ret = generic_file_read_iter(iocb, to, rwf);
- xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+ if (!rwf)
+ xfs_iunlock(ip, XFS_IOLOCK_SHARED);

return ret;
}
--
2.7.4
\
 
 \ /
  Last update: 2017-09-28 14:42    [W:0.132 / U:7.376 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site