From e3c57805f8f2215a1586741009111b92930cc6ac Mon Sep 17 00:00:00 2001 From: Goldwyn Rodrigues Date: Thu, 24 Sep 2020 11:39:09 -0500 Subject: [PATCH] btrfs: remove BTRFS_INODE_READDIO_NEED_LOCK 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 Reviewed-by: Johannes Thumshirn Reviewed-by: Josef Bacik Reviewed-by: Christoph Hellwig Signed-off-by: Goldwyn Rodrigues Reviewed-by: David Sterba Signed-off-by: David Sterba --- 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 6fdb46d..738009a 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 d526833..36efed0 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4844,10 +4844,7 @@ 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) { -- 2.7.4