| | Date | Fri, 12 Mar 2010 16:25:59 -0800 | | From | Greg KH <> | | Subject | [026/145] vfs: take f_lock on modifying f_mode after open time |
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2.6.32-stable review patch. If anyone has any objections, please let me know.
---------------- From: Wu Fengguang <fengguang.wu@intel.com> commit 42e49608683ab25fbbbf9c40edb944601e543882 upstream.
We'll introduce FMODE_RANDOM which will be runtime modified. So protect all runtime modification to f_mode with f_lock to avoid races.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- fs/file_table.c | 2 ++ fs/nfsd/nfs4state.c | 2 ++ 2 files changed, 4 insertions(+) --- a/fs/file_table.c +++ b/fs/file_table.c @@ -420,7 +420,9 @@ retry: continue; if (!(f->f_mode & FMODE_WRITE)) continue; + spin_lock(&f->f_lock); f->f_mode &= ~FMODE_WRITE; + spin_unlock(&f->f_lock); if (file_check_writeable(f) != 0) continue; file_release_write(f); --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -2002,7 +2002,9 @@ nfs4_file_downgrade(struct file *filp, u { if (share_access & NFS4_SHARE_ACCESS_WRITE) { drop_file_write_access(filp); + spin_lock(&filp->f_lock); filp->f_mode = (filp->f_mode | FMODE_READ) & ~FMODE_WRITE; + spin_unlock(&filp->f_lock); } }
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