Commit d139d7ff authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Linus Torvalds
Browse files

VFS: allow filesystems to implement atomic open+truncate



Add a new attribute flag ATTR_OPEN, with the meaning: "truncation was
initiated by open() due to the O_TRUNC flag".

This way filesystems wanting to implement truncation within their ->open()
method can ignore such truncate requests.

This is a quick & dirty hack, but it comes for free.
Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger@clusterfs.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 49d4914f
......@@ -1659,8 +1659,10 @@ int may_open(struct nameidata *nd, int acc_mode, int flag)
error = locks_verify_locked(inode);
if (!error) {
DQUOT_INIT(inode);
error = do_truncate(dentry, 0, ATTR_MTIME|ATTR_CTIME, NULL);
error = do_truncate(dentry, 0,
ATTR_MTIME|ATTR_CTIME|ATTR_OPEN,
NULL);
}
put_write_access(inode);
if (error)
......
......@@ -330,6 +330,7 @@ typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
#define ATTR_KILL_SGID 4096
#define ATTR_FILE 8192
#define ATTR_KILL_PRIV 16384
#define ATTR_OPEN 32768 /* Truncating from open(O_TRUNC) */
/*
* This is the Inode Attributes structure, used for notify_change(). It
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment