From 4a30131e7dbb17e5fec6958bfac9da9aff1fa29b Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Sun, 8 Jan 2006 01:02:39 -0800 Subject: [PATCH] Fix some problems with truncate and mtime semantics. SUS requires that when truncating a file to the size that it currently is: truncate and ftruncate should NOT modify ctime or mtime O_TRUNC SHOULD modify ctime and mtime. Currently mtime and ctime are always modified on most local filesystems (side effect of ->truncate) or never modified (on NFS). With this patch: ATTR_CTIME|ATTR_MTIME are sent with ATTR_SIZE precisely when an update of these times is required whether size changes or not (via a new argument to do_truncate). This allows NFS to do the right thing for O_TRUNC. inode_setattr nolonger forces ATTR_MTIME|ATTR_CTIME when the ATTR_SIZE sets the size to it's current value. This allows local filesystems to do the right thing for f?truncate. Also, the logic in inode_setattr is changed a bit so there are two return points. One returns the error from vmtruncate if it failed, the other returns 0 (there can be no other failure). Finally, if vmtruncate succeeds, and ATTR_SIZE is the only change requested, we now fall-through and mark_inode_dirty. If a filesystem did not have a ->truncate function, then vmtruncate will have changed i_size, without marking the inode as 'dirty', and I think this is wrong. Signed-off-by: Neil Brown Cc: Christoph Hellwig Cc: Trond Myklebust Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/fs.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux/fs.h') diff --git a/include/linux/fs.h b/include/linux/fs.h index ef29500b5df..74c01aabd4a 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1344,7 +1344,8 @@ static inline int break_lease(struct inode *inode, unsigned int mode) /* fs/open.c */ -extern int do_truncate(struct dentry *, loff_t start, struct file *filp); +extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs, + struct file *filp); extern long do_sys_open(const char __user *filename, int flags, int mode); extern struct file *filp_open(const char *, int, int); extern struct file * dentry_open(struct dentry *, struct vfsmount *, int); -- cgit v1.2.3