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From: Goldwyn Rodrigues <rgoldwyn@suse.de>
To: linux-btrfs@vger.kernel.org
Cc: hch@infradead.org, dsterba@suse.cz,
	Goldwyn Rodrigues <rgoldwyn@suse.com>,
	Nikolay Borisov <nborisov@suse.com>,
	Johannes Thumshirn <jth@kernel.org>
Subject: [PATCH 6/7] btrfs: remove BTRFS_INODE_READDIO_NEED_LOCK
Date: Fri, 22 May 2020 07:38:36 -0500
Message-ID: <20200522123837.1196-7-rgoldwyn@suse.de> (raw)
In-Reply-To: <20200522123837.1196-1-rgoldwyn@suse.de>

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.

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

diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index e7d709505cb1..aeff56a0e105 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -28,7 +28,6 @@ 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,
 };
@@ -313,23 +312,6 @@ 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 ebf97286b110..a975d2c61d68 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4752,10 +4752,7 @@ 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) {
-- 
2.25.0


  parent reply index

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-22 12:38 [PATCH 0/7 v8] btrfs direct-io using iomap Goldwyn Rodrigues
2020-05-22 12:38 ` [PATCH 1/7] fs: Export generic_file_buffered_read() Goldwyn Rodrigues
2020-05-25 12:25   ` David Sterba
2020-05-22 12:38 ` [PATCH 2/7] iomap: add a filesystem hook for direct I/O bio submission Goldwyn Rodrigues
2020-05-22 12:38 ` [PATCH 3/7] iomap: Remove lockdep_assert_held() Goldwyn Rodrigues
2020-05-28 15:40   ` Darrick J. Wong
2020-05-28 16:45     ` Goldwyn Rodrigues
2020-05-22 12:38 ` [PATCH 4/7] btrfs: Switch to iomap_dio_rw() for dio Goldwyn Rodrigues
2020-05-26 15:03   ` Johannes Thumshirn
2020-05-26 16:44     ` Goldwyn Rodrigues
2020-05-28 15:13       ` Filipe Manana
2020-05-28 16:34         ` Goldwyn Rodrigues
2020-05-28 16:45           ` Filipe Manana
2020-05-28 18:38             ` Goldwyn Rodrigues
2020-06-03 11:35               ` Filipe Manana
2020-06-05 15:17                 ` Filipe Manana
2020-06-05 20:43                   ` Goldwyn Rodrigues
2020-05-22 12:38 ` [PATCH 5/7] fs: Remove dio_end_io() Goldwyn Rodrigues
2020-05-22 12:38 ` Goldwyn Rodrigues [this message]
2020-05-22 12:38 ` [PATCH 7/7] btrfs: btrfs: split btrfs_direct_IO Goldwyn Rodrigues

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