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From: Goldwyn Rodrigues <rgoldwyn@suse.de>
To: linux-btrfs@vger.kernel.org
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>,
	Nikolay Borisov <nborisov@suse.com>,
	Johannes Thumshirn <jth@kernel.org>
Subject: [PATCH 7/9] btrfs: remove BTRFS_INODE_READDIO_NEED_LOCK
Date: Thu, 26 Mar 2020 16:02:52 -0500
Message-ID: <20200326210254.17647-8-rgoldwyn@suse.de> (raw)
In-Reply-To: <20200326210254.17647-1-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 4e12a477d32e..cd8f378ed8e7 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -27,7 +27,6 @@ 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,
 };
@@ -317,23 +316,6 @@ struct btrfs_dio_private {
 			blk_status_t);
 };
 
-/*
- * 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 7bda178afa87..97ff3a38d704 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4701,10 +4701,7 @@ 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: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-26 21:02 [PATCH 0/9 v7] btrfs direct-io using iomap Goldwyn Rodrigues
2020-03-26 21:02 ` [PATCH 1/9] fs: Export generic_file_buffered_read() Goldwyn Rodrigues
2020-03-26 21:02 ` [PATCH 2/9] iomap: add a filesystem hook for direct I/O bio submission Goldwyn Rodrigues
2020-03-26 21:02 ` [PATCH 3/9] iomap: Remove lockdep_assert_held() Goldwyn Rodrigues
2020-03-26 21:02 ` [PATCH 4/9] btrfs: Switch to iomap_dio_rw() for dio Goldwyn Rodrigues
2020-03-27  8:10   ` Christoph Hellwig
2020-03-27 16:13     ` Goldwyn Rodrigues
2020-03-26 21:02 ` [PATCH 5/9] btrfs: Use ->iomap_end() instead of btrfs_dio_data Goldwyn Rodrigues
2020-03-27  8:16   ` Christoph Hellwig
2020-03-27 16:11     ` Goldwyn Rodrigues
2020-03-26 21:02 ` [PATCH 6/9] fs: Remove dio_end_io() Goldwyn Rodrigues
2020-03-26 21:02 ` Goldwyn Rodrigues [this message]
2020-03-26 21:02 ` [PATCH 8/9] btrfs: btrfs: split btrfs_direct_IO Goldwyn Rodrigues
2020-03-26 21:02 ` [PATCH 9/9] btrfs: unlock extents in ->iomap_end() for DIO reads Goldwyn Rodrigues
2020-03-27 15:56 ` [PATCH 0/9 v7] btrfs direct-io using iomap David Sterba

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