aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorMiklos Szeredi <mszeredi@suse.cz>2007-10-18 06:07:00 -0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-18 17:37:30 -0400
commitd139d7ffd0c1e81e2a809909b4f8b121a0dc119a (patch)
treee8c9dd746bfd8ae16d17596009608c4c1a153217
parent49d4914fd7c10ae846d0f30d5f6f4732cc68499c (diff)
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: Miklos 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/namei.c6
-rw-r--r--include/linux/fs.h1
2 files changed, 5 insertions, 2 deletions
diff --git a/fs/namei.c b/fs/namei.c
index 464eeccb675b..1e5c71669164 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1659,8 +1659,10 @@ int may_open(struct nameidata *nd, int acc_mode, int flag)
1659 error = locks_verify_locked(inode); 1659 error = locks_verify_locked(inode);
1660 if (!error) { 1660 if (!error) {
1661 DQUOT_INIT(inode); 1661 DQUOT_INIT(inode);
1662 1662
1663 error = do_truncate(dentry, 0, ATTR_MTIME|ATTR_CTIME, NULL); 1663 error = do_truncate(dentry, 0,
1664 ATTR_MTIME|ATTR_CTIME|ATTR_OPEN,
1665 NULL);
1664 } 1666 }
1665 put_write_access(inode); 1667 put_write_access(inode);
1666 if (error) 1668 if (error)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index e3fc5dbb2246..6a4d170ad9a5 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -330,6 +330,7 @@ typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
330#define ATTR_KILL_SGID 4096 330#define ATTR_KILL_SGID 4096
331#define ATTR_FILE 8192 331#define ATTR_FILE 8192
332#define ATTR_KILL_PRIV 16384 332#define ATTR_KILL_PRIV 16384
333#define ATTR_OPEN 32768 /* Truncating from open(O_TRUNC) */
333 334
334/* 335/*
335 * This is the Inode Attributes structure, used for notify_change(). It 336 * This is the Inode Attributes structure, used for notify_change(). It