diff mbox series

[02/15] btrfs: remove BTRFS_INODE_READDIO_NEED_LOCK

Message ID 20200921144353.31319-3-rgoldwyn@suse.de
State New
Headers show
Series BTRFS DIO inode locking/D_SYNC fix | expand

Commit Message

Goldwyn Rodrigues Sept. 21, 2020, 2:43 p.m. UTC
From: Goldwyn Rodrigues <rgoldwyn@suse.com>

Since we now perform direct reads using i_rwsem, we can remove this
inode flag used to co-ordinate unlocked reads.

The truncate call takes i_rwsem. This means it is correctly synchronized
with concurrent direct reads.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
---
 fs/btrfs/btrfs_inode.h | 18 ------------------
 fs/btrfs/inode.c       |  3 ---
 2 files changed, 21 deletions(-)

Comments

Christoph Hellwig Sept. 22, 2020, 1:18 p.m. UTC | #1
On Mon, Sep 21, 2020 at 09:43:40AM -0500, Goldwyn Rodrigues wrote:
> From: Goldwyn Rodrigues <rgoldwyn@suse.com>
> 
> Since we now perform direct reads using i_rwsem, we can remove this
> inode flag used to co-ordinate unlocked reads.
> 
> The truncate call takes i_rwsem. This means it is correctly synchronized
> with concurrent direct reads.
> 
> Reviewed-by: Nikolay Borisov <nborisov@suse.com>
> Reviewed-by: Johannes Thumshirn <jth@kernel.org>
> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>
Josef Bacik Sept. 22, 2020, 2:17 p.m. UTC | #2
On 9/21/20 10:43 AM, Goldwyn Rodrigues wrote:
> From: Goldwyn Rodrigues <rgoldwyn@suse.com>
> 
> Since we now perform direct reads using i_rwsem, we can remove this
> inode flag used to co-ordinate unlocked reads.
> 
> The truncate call takes i_rwsem. This means it is correctly synchronized
> with concurrent direct reads.
> 
> Reviewed-by: Nikolay Borisov <nborisov@suse.com>
> Reviewed-by: Johannes Thumshirn <jth@kernel.org>
> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef
diff mbox series

Patch

diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index 6fdb46d58299..738009a22320 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -33,7 +33,6 @@  enum {
 	BTRFS_INODE_NEEDS_FULL_SYNC,
 	BTRFS_INODE_COPY_EVERYTHING,
 	BTRFS_INODE_IN_DELALLOC_LIST,
-	BTRFS_INODE_READDIO_NEED_LOCK,
 	BTRFS_INODE_HAS_PROPS,
 	BTRFS_INODE_SNAPSHOT_FLUSH,
 };
@@ -334,23 +333,6 @@  struct btrfs_dio_private {
 	u8 csums[];
 };
 
-/*
- * Disable DIO read nolock optimization, so new dio readers will be forced
- * to grab i_mutex. It is used to avoid the endless truncate due to
- * nonlocked dio read.
- */
-static inline void btrfs_inode_block_unlocked_dio(struct btrfs_inode *inode)
-{
-	set_bit(BTRFS_INODE_READDIO_NEED_LOCK, &inode->runtime_flags);
-	smp_mb();
-}
-
-static inline void btrfs_inode_resume_unlocked_dio(struct btrfs_inode *inode)
-{
-	smp_mb__before_atomic();
-	clear_bit(BTRFS_INODE_READDIO_NEED_LOCK, &inode->runtime_flags);
-}
-
 /* Array of bytes with variable length, hexadecimal format 0x1234 */
 #define CSUM_FMT				"0x%*phN"
 #define CSUM_FMT_VALUE(size, bytes)		size, bytes
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 18d171b2d544..3db4697ff1ba 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4855,10 +4855,7 @@  static int btrfs_setsize(struct inode *inode, struct iattr *attr)
 
 		truncate_setsize(inode, newsize);
 
-		/* Disable nonlocked read DIO to avoid the endless truncate */
-		btrfs_inode_block_unlocked_dio(BTRFS_I(inode));
 		inode_dio_wait(inode);
-		btrfs_inode_resume_unlocked_dio(BTRFS_I(inode));
 
 		ret = btrfs_truncate(inode, newsize == oldsize);
 		if (ret && inode->i_nlink) {