Messages in this thread | | | Subject | Re: [PATCH] Fix bug in FUSE where the attribute cache for a file was not cleared when a file is opened with O_TRUNC. | From | Miklos Szeredi <> | Date | Fri, 12 Nov 2010 10:37:02 +0100 |
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On Thu, 11 Nov 2010, Andrew Morton wrote: > On Sat, 30 Oct 2010 13:31:23 +0200 > Miklos Szeredi <miklos@szeredi.hu> wrote: > > > Subject: fuse: fix attributes after open(O_TRUNC) > > From: Ken Sumrall <ksumrall@android.com> > > > > 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@android.com> > > Cc: Anfei <anfei.zhou@gmail.com> > > Cc: "Anand V. Avati" <avati@gluster.com> > > Signed-off-by: Andrew Morton <akpm@linux-foundation.org> > > Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> > > Cc: stable@kernel.org > > --- > > > > fs/fuse/file.c | 10 ++++++++++ > > 1 file changed, 10 insertions(+) > > > > Index: linux-2.6/fs/fuse/file.c > > =================================================================== > > --- linux-2.6.orig/fs/fuse/file.c 2010-10-27 14:04:02.000000000 +0200 > > +++ linux-2.6/fs/fuse/file.c 2010-10-30 13:14:07.000000000 +0200 > > @@ -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); > > i_size_write() requires that i_mutex be held, as described at the > i_size_write() definition site. > > Is it reliably the case that i_mutex is held here?
No. AFAICS any lock will do, not just i_mutex. Fuse consistently uses fc->lock to protect i_size_write().
Thanks, Miklos
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