linux-kernel - [PATCH] [170/223] fuse: fix attributes after open(O

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Date:	Mon, 13 Dec 2010 00:47:54 +0100 (CET)
From:	Andi Kleen <andi@...stfloor.org>
To:	ksumrall@...roid.com, anfei.zhou@...il.com, avati@...ster.com,
	miklos@...redi.hu, akpm@...ux-foundation.org,
	torvalds@...ux-foundation.org, gregkh@...e.de, ak@...ux.intel.com,
	linux-kernel@...r.kernel.org, stable@...nel.org
Subject: [PATCH] [170/223] fuse: fix attributes after open(O_TRUNC)

2.6.35-longterm review patch.  If anyone has any objections, please let me know.

------------------
From: Ken Sumrall <ksumrall@...roid.com>

commit a0822c55779d9319939eac69f00bb729ea9d23da upstream.

The attribute cache for a file was not being cleared when a file is opened
with O_TRUNC.

If the filesystem's open operation truncates the file ("atomic_o_trunc"
feature flag is set) then the kernel should invalidate the cached st_mtime
and st_ctime attributes.

Also i_size should be explicitly be set to zero as it is used sometimes
without refreshing the cache.

Signed-off-by: Ken Sumrall <ksumrall@...roid.com>
Cc: Anfei <anfei.zhou@...il.com>
Cc: "Anand V. Avati" <avati@...ster.com>
Signed-off-by: Miklos Szeredi <miklos@...redi.hu>
Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@...ux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...e.de>
Signed-off-by: Andi Kleen <ak@...ux.intel.com>

---
 fs/fuse/file.c |   10 ++++++++++
 1 file changed, 10 insertions(+)

Index: linux/fs/fuse/file.c
===================================================================
--- linux.orig/fs/fuse/file.c
+++ linux/fs/fuse/file.c
@@ -134,6 +134,7 @@ EXPORT_SYMBOL_GPL(fuse_do_open);
 void fuse_finish_open(struct inode *inode, struct file *file)
 {
 	struct fuse_file *ff = file->private_data;
+	struct fuse_conn *fc = get_fuse_conn(inode);

 	if (ff->open_flags & FOPEN_DIRECT_IO)
 		file->f_op = &fuse_direct_io_file_operations;
@@ -141,6 +142,15 @@ void fuse_finish_open(struct inode *inod
 		invalidate_inode_pages2(inode->i_mapping);
 	if (ff->open_flags & FOPEN_NONSEEKABLE)
 		nonseekable_open(inode, file);
+	if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC)) {
+		struct fuse_inode *fi = get_fuse_inode(inode);
+
+		spin_lock(&fc->lock);
+		fi->attr_version = ++fc->attr_version;
+		i_size_write(inode, 0);
+		spin_unlock(&fc->lock);
+		fuse_invalidate_attr(inode);
+	}
 }

 int fuse_open_common(struct inode *inode, struct file *file, bool isdir)
--
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