From 31b2ebc0929e964f4edfbfa7129d43f7e3c17165 Mon Sep 17 00:00:00 2001 From: "Ritesh Harjani (IBM)" Date: Fri, 21 Apr 2023 15:16:12 +0530 Subject: fs/buffer.c: Add generic_buffers_fsync*() implementation Some of the higher layers like iomap takes inode_lock() when calling generic_write_sync(). Also writeback already happens from other paths without inode lock, so it's difficult to say that we really need sync_mapping_buffers() to take any inode locking here. Having said that, let's add generic_buffers_fsync/_noflush() implementation in buffer.c with no inode_lock/unlock() for now so that filesystems like ext2 and ext4's nojournal mode can use it. Ext4 when got converted to iomap for direct-io already copied it's own variant of __generic_file_fsync() without lock. This patch adds generic_buffers_fsync() & generic_buffers_fsync_noflush() implementations for use in filesystems like ext2 & ext4 respectively. Later we can review other filesystems as well to see if we can make generic_buffers_fsync/_noflush() which does not take any inode_lock() as the default path. Tested-by: Disha Goel Reviewed-by: Christoph Hellwig Signed-off-by: Ritesh Harjani (IBM) Signed-off-by: Jan Kara Message-Id: --- include/linux/buffer_head.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include') diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index 1520793c72da..1bd73cefd311 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -217,6 +217,10 @@ int inode_has_buffers(struct inode *); void invalidate_inode_buffers(struct inode *); int remove_inode_buffers(struct inode *inode); int sync_mapping_buffers(struct address_space *mapping); +int generic_buffers_fsync_noflush(struct file *file, loff_t start, loff_t end, + bool datasync); +int generic_buffers_fsync(struct file *file, loff_t start, loff_t end, + bool datasync); void clean_bdev_aliases(struct block_device *bdev, sector_t block, sector_t len); static inline void clean_bdev_bh_alias(struct buffer_head *bh) -- cgit v1.2.3 From 576215cffdefc1f0ceebffd87abb390926e6b037 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Thu, 25 May 2023 16:17:10 +0200 Subject: fs: Drop wait_unfrozen wait queue wait_unfrozen waitqueue is used only in quota code to wait for filesystem to become unfrozen. In that place we can just use sb_start_write() - sb_end_write() pair to achieve the same. So just remove the waitqueue. Reviewed-by: Christian Brauner Message-Id: <20230525141710.7595-1-jack@suse.cz> Signed-off-by: Jan Kara --- fs/quota/quota.c | 5 +++-- fs/super.c | 4 ---- include/linux/fs.h | 1 - 3 files changed, 3 insertions(+), 7 deletions(-) (limited to 'include') diff --git a/fs/quota/quota.c b/fs/quota/quota.c index 052f143e2e0e..0e41fb84060f 100644 --- a/fs/quota/quota.c +++ b/fs/quota/quota.c @@ -895,8 +895,9 @@ retry: up_write(&sb->s_umount); else up_read(&sb->s_umount); - wait_event(sb->s_writers.wait_unfrozen, - sb->s_writers.frozen == SB_UNFROZEN); + /* Wait for sb to unfreeze */ + sb_start_write(sb); + sb_end_write(sb); put_super(sb); goto retry; } diff --git a/fs/super.c b/fs/super.c index 34afe411cf2b..6283cea67280 100644 --- a/fs/super.c +++ b/fs/super.c @@ -236,7 +236,6 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags, &type->s_writers_key[i])) goto fail; } - init_waitqueue_head(&s->s_writers.wait_unfrozen); s->s_bdi = &noop_backing_dev_info; s->s_flags = flags; if (s->s_user_ns != &init_user_ns) @@ -1706,7 +1705,6 @@ int freeze_super(struct super_block *sb) if (ret) { sb->s_writers.frozen = SB_UNFROZEN; sb_freeze_unlock(sb, SB_FREEZE_PAGEFAULT); - wake_up(&sb->s_writers.wait_unfrozen); deactivate_locked_super(sb); return ret; } @@ -1722,7 +1720,6 @@ int freeze_super(struct super_block *sb) "VFS:Filesystem freeze failed\n"); sb->s_writers.frozen = SB_UNFROZEN; sb_freeze_unlock(sb, SB_FREEZE_FS); - wake_up(&sb->s_writers.wait_unfrozen); deactivate_locked_super(sb); return ret; } @@ -1768,7 +1765,6 @@ static int thaw_super_locked(struct super_block *sb) sb->s_writers.frozen = SB_UNFROZEN; sb_freeze_unlock(sb, SB_FREEZE_FS); out: - wake_up(&sb->s_writers.wait_unfrozen); deactivate_locked_super(sb); return 0; } diff --git a/include/linux/fs.h b/include/linux/fs.h index 21a981680856..3b65a6194485 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1146,7 +1146,6 @@ enum { struct sb_writers { int frozen; /* Is sb frozen? */ - wait_queue_head_t wait_unfrozen; /* wait for thaw */ struct percpu_rw_semaphore rw_sem[SB_FREEZE_LEVELS]; }; -- cgit v1.2.3