Messages in this thread Patch in this message | | | Date | Wed, 4 Feb 2009 10:46:12 -0800 | From | Greg KH <> | Subject | [patch 12/41] nfsd: Ensure nfsv4 calls the underlying filesystem on LOCKT |
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2.6.27-stable review patch. If anyone has any objections, please let us know.
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From: J. Bruce Fields <bfields@citi.umich.edu>
commit 55ef1274dddd4de387c54d110e354ffbb6cdc706 upstream.
Since nfsv4 allows LOCKT without an open, but the ->lock() method is a file method, we fake up a struct file in the nfsv4 code with just the fields we need initialized. But we forgot to initialize the file operations, with the result that LOCKT never results in a call to the filesystem's ->lock() method (if it exists).
We could just add that one more initialization. But this hack of faking up a struct file with only some fields initialized seems the kind of thing that might cause more problems in the future. We should either do an open and get a real struct file, or make lock-testing an inode (not a file) method.
This patch does the former.
Reported-by: Marc Eshel <eshel@almaden.ibm.com> Tested-by: Marc Eshel <eshel@almaden.ibm.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- fs/nfsd/nfs4state.c | 30 ++++++++++++++++++++---------- 1 file changed, 20 insertions(+), 10 deletions(-)
--- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -2767,6 +2767,25 @@ out: } /* + * The NFSv4 spec allows a client to do a LOCKT without holding an OPEN, + * so we do a temporary open here just to get an open file to pass to + * vfs_test_lock. (Arguably perhaps test_lock should be done with an + * inode operation.) + */ +static int nfsd_test_lock(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file_lock *lock) +{ + struct file *file; + int err; + + err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file); + if (err) + return err; + err = vfs_test_lock(file, lock); + nfsd_close(file); + return err; +} + +/* * LOCKT operation */ __be32 @@ -2774,7 +2793,6 @@ nfsd4_lockt(struct svc_rqst *rqstp, stru struct nfsd4_lockt *lockt) { struct inode *inode; - struct file file; struct file_lock file_lock; int error; __be32 status; @@ -2832,16 +2850,8 @@ nfsd4_lockt(struct svc_rqst *rqstp, stru nfs4_transform_lock_offset(&file_lock); - /* vfs_test_lock uses the struct file _only_ to resolve the inode. - * since LOCKT doesn't require an OPEN, and therefore a struct - * file may not exist, pass vfs_test_lock a struct file with - * only the dentry:inode set. - */ - memset(&file, 0, sizeof (struct file)); - file.f_path.dentry = cstate->current_fh.fh_dentry; - status = nfs_ok; - error = vfs_test_lock(&file, &file_lock); + error = nfsd_test_lock(rqstp, &cstate->current_fh, &file_lock); if (error) { status = nfserrno(error); goto out;
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