From 5cf06ea56ee67209d4e9a0b381641fb062ecd2c3 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 8 Jan 2026 15:19:07 +0100 Subject: [PATCH] fs: add a ->sync_lazytime method Allow the file system to explicitly implement lazytime syncing instead of pigging back on generic inode dirtying. This allows to simplify the XFS implementation and prepares for non-blocking lazytime timestamp updates. Signed-off-by: Christoph Hellwig Link: https://patch.msgid.link/20260108141934.2052404-8-hch@lst.de Reviewed-by: Chaitanya Kulkarni Reviewed-by: Jeff Layton Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- Documentation/filesystems/locking.rst | 2 ++ Documentation/filesystems/vfs.rst | 6 ++++++ fs/fs-writeback.c | 13 +++++++++++-- include/linux/fs.h | 1 + 4 files changed, 20 insertions(+), 2 deletions(-) diff --git a/Documentation/filesystems/locking.rst b/Documentation/filesystems/locking.rst index 37a4a7fa8094c..0312fba6d73bc 100644 --- a/Documentation/filesystems/locking.rst +++ b/Documentation/filesystems/locking.rst @@ -82,6 +82,7 @@ prototypes:: int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start, u64 len); void (*update_time)(struct inode *inode, enum fs_update_time type, int flags); + void (*sync_lazytime)(struct inode *inode); int (*atomic_open)(struct inode *, struct dentry *, struct file *, unsigned open_flag, umode_t create_mode); @@ -118,6 +119,7 @@ getattr: no listxattr: no fiemap: no update_time: no +sync_lazytime: no atomic_open: shared (exclusive if O_CREAT is set in open flags) tmpfile: no fileattr_get: no or exclusive diff --git a/Documentation/filesystems/vfs.rst b/Documentation/filesystems/vfs.rst index 51aa9db64784f..d8cb181f69f83 100644 --- a/Documentation/filesystems/vfs.rst +++ b/Documentation/filesystems/vfs.rst @@ -487,6 +487,7 @@ As of kernel 2.6.22, the following members are defined: ssize_t (*listxattr) (struct dentry *, char *, size_t); void (*update_time)(struct inode *inode, enum fs_update_time type, int flags); + void (*sync_lazytime)(struct inode *inode); int (*atomic_open)(struct inode *, struct dentry *, struct file *, unsigned open_flag, umode_t create_mode); int (*tmpfile) (struct mnt_idmap *, struct inode *, struct file *, umode_t); @@ -643,6 +644,11 @@ otherwise noted. an inode. If this is not defined the VFS will update the inode itself and call mark_inode_dirty_sync. +``sync_lazytime``: + called by the writeback code to update the lazy time stamps to + regular time stamp updates that get syncing into the on-disk + inode. + ``atomic_open`` called on the last component of an open. Using this optional method the filesystem can look up, possibly create and open the diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 3d68b757136c8..62658be2578ba 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -1717,7 +1717,10 @@ bool sync_lazytime(struct inode *inode) return false; trace_writeback_lazytime(inode); - mark_inode_dirty_sync(inode); + if (inode->i_op->sync_lazytime) + inode->i_op->sync_lazytime(inode); + else + mark_inode_dirty_sync(inode); return true; } @@ -2569,6 +2572,8 @@ void __mark_inode_dirty(struct inode *inode, int flags) trace_writeback_mark_inode_dirty(inode, flags); if (flags & I_DIRTY_INODE) { + bool was_dirty_time = false; + /* * Inode timestamp update will piggback on this dirtying. * We tell ->dirty_inode callback that timestamps need to @@ -2579,6 +2584,7 @@ void __mark_inode_dirty(struct inode *inode, int flags) if (inode_state_read(inode) & I_DIRTY_TIME) { inode_state_clear(inode, I_DIRTY_TIME); flags |= I_DIRTY_TIME; + was_dirty_time = true; } spin_unlock(&inode->i_lock); } @@ -2591,9 +2597,12 @@ void __mark_inode_dirty(struct inode *inode, int flags) * for just I_DIRTY_PAGES or I_DIRTY_TIME. */ trace_writeback_dirty_inode_start(inode, flags); - if (sb->s_op->dirty_inode) + if (sb->s_op->dirty_inode) { sb->s_op->dirty_inode(inode, flags & (I_DIRTY_INODE | I_DIRTY_TIME)); + } else if (was_dirty_time && inode->i_op->sync_lazytime) { + inode->i_op->sync_lazytime(inode); + } trace_writeback_dirty_inode(inode, flags); /* I_DIRTY_INODE supersedes I_DIRTY_TIME. */ diff --git a/include/linux/fs.h b/include/linux/fs.h index 77985b4ed6ffc..9cce8b9a29ace 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2024,6 +2024,7 @@ struct inode_operations { u64 len); int (*update_time)(struct inode *inode, enum fs_update_time type, unsigned int flags); + void (*sync_lazytime)(struct inode *inode); int (*atomic_open)(struct inode *, struct dentry *, struct file *, unsigned open_flag, umode_t create_mode); -- 2.47.3