From: yangyun <yangyun50@huawei.com> mainline inclusion from mainline-v6.12-rc1 commit ac5cffec53be0b0231b89470a357bd3a5814f599 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IC4GP7 CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit ac5cffec53be0b0231b89470a357bd3a5814f599 ] In some cases, the fi->writepages may be empty. And there is no need to check fi->writepages with spin_lock, which may have an impact on performance due to lock contention. For example, in scenarios where multiple readers read the same file without any writers, or where the page cache is not enabled. Also remove the outdated comment since commit 6b2fb79963fb ("fuse: optimize writepages search") has optimize the situation by replacing list with rb-tree. Signed-off-by: yangyun <yangyun50@huawei.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> --- fs/fuse/file.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index e0aac6019cdb..3ee8da27a202 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -421,9 +421,6 @@ static struct fuse_writepage_args *fuse_find_writeback(struct fuse_inode *fi, /* * Check if any page in a range is under writeback - * - * This is currently done by walking the list of writepage requests - * for the inode, which can be pretty inefficient. */ static bool fuse_range_is_writeback(struct inode *inode, pgoff_t idx_from, pgoff_t idx_to) @@ -431,6 +428,9 @@ static bool fuse_range_is_writeback(struct inode *inode, pgoff_t idx_from, struct fuse_inode *fi = get_fuse_inode(inode); bool found; + if (RB_EMPTY_ROOT(&fi->writepages)) + return false; + spin_lock(&fi->lock); found = fuse_find_writeback(fi, idx_from, idx_to); spin_unlock(&fi->lock); -- 2.33.0