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Date: Fri, 14 Mar 2008 19:42:05 -0400
From: "J. Bruce Fields" <bfields@...ldses.org>
To: Lukas Hejtmanek <xhejtman@....muni.cz>
Cc: nfsv4@...ux-nfs.org, linux-kernel@...r.kernel.org,
Neil Brown <neilb@...e.de>
Subject: Re: Oops in NFSv4 server in 2.6.23.17
On Fri, Mar 14, 2008 at 04:05:10PM -0400, bfields wrote:
> I find that a little contorted. So I'll go ahead and submit this small
> patch to 2.6.25 and stable now (I have since managed to reproduce what I
> believe is your bug, though my symptoms were a little different), and
> then submit to 2.6.26 some cleanup which makes this more understandable,
Here's an attempt. We could break up fh_verify even more, though.--b.
>From ce83cbd34a40153aed8bf559f24576a06e3e378a Mon Sep 17 00:00:00 2001
From: J. Bruce Fields <bfields@...i.umich.edu>
Date: Fri, 14 Mar 2008 17:51:12 -0400
Subject: [PATCH] nfsd: move most of fh_verify to separate function
Move the code that actually parses the filehandle and looks up the
dentry and export to a separate function. This simplifies the reference
counting a little and moves fh_verify() a little closer to the kernel
ideal of small, minimally-indentended functions. Clean up a few other
minor style sins along the way.
Signed-off-by: J. Bruce Fields <bfields@...i.umich.edu>
---
fs/nfsd/nfsfh.c | 223 +++++++++++++++++++++++++++++--------------------------
1 files changed, 118 insertions(+), 105 deletions(-)
diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index 3e6b3f4..fc1d98b 100644
--- a/fs/nfsd/nfsfh.c
+++ b/fs/nfsd/nfsfh.c
@@ -112,6 +112,119 @@ static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
return nfserrno(nfsd_setuser(rqstp, exp));
}
+static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
+{
+ struct knfsd_fh *fh = &fhp->fh_handle;
+ struct fid *fid = NULL, sfid;
+ struct svc_export *exp;
+ struct dentry *dentry;
+ int fileid_type;
+ int data_left = fh->fh_size/4;
+ __be32 error;
+
+ error = nfserr_stale;
+ if (rqstp->rq_vers > 2)
+ error = nfserr_badhandle;
+ if (rqstp->rq_vers == 4 && fh->fh_size == 0)
+ return nfserr_nofilehandle;
+
+ if (fh->fh_version == 1) {
+ int len;
+
+ if (--data_left < 0)
+ return error;
+ if (fh->fh_auth_type != 0)
+ return error;
+ len = key_len(fh->fh_fsid_type) / 4;
+ if (len == 0)
+ return error;
+ if (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
+ /* deprecated, convert to type 3 */
+ len = key_len(FSID_ENCODE_DEV)/4;
+ fh->fh_fsid_type = FSID_ENCODE_DEV;
+ fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
+ fh->fh_fsid[1] = fh->fh_fsid[2];
+ }
+ data_left -= len;
+ if (data_left < 0)
+ return error;
+ exp = rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_auth);
+ fid = (struct fid *)(fh->fh_auth + len);
+ } else {
+ __u32 tfh[2];
+ dev_t xdev;
+ ino_t xino;
+
+ if (fh->fh_size != NFS_FHSIZE)
+ return error;
+ /* assume old filehandle format */
+ xdev = old_decode_dev(fh->ofh_xdev);
+ xino = u32_to_ino_t(fh->ofh_xino);
+ mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
+ exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
+ }
+
+ error = nfserr_stale;
+ if (PTR_ERR(exp) == -ENOENT)
+ return error;
+
+ if (IS_ERR(exp))
+ return nfserrno(PTR_ERR(exp));
+
+ error = nfsd_setuser_and_check_port(rqstp, exp);
+ if (error)
+ goto out;
+
+ /*
+ * Look up the dentry using the NFS file handle.
+ */
+ error = nfserr_stale;
+ if (rqstp->rq_vers > 2)
+ error = nfserr_badhandle;
+
+ if (fh->fh_version != 1) {
+ sfid.i32.ino = fh->ofh_ino;
+ sfid.i32.gen = fh->ofh_generation;
+ sfid.i32.parent_ino = fh->ofh_dirino;
+ fid = &sfid;
+ data_left = 3;
+ if (fh->ofh_dirino == 0)
+ fileid_type = FILEID_INO32_GEN;
+ else
+ fileid_type = FILEID_INO32_GEN_PARENT;
+ } else
+ fileid_type = fh->fh_fileid_type;
+
+ if (fileid_type == FILEID_ROOT)
+ dentry = dget(exp->ex_path.dentry);
+ else {
+ dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
+ data_left, fileid_type,
+ nfsd_acceptable, exp);
+ }
+ if (dentry == NULL)
+ goto out;
+ if (IS_ERR(dentry)) {
+ if (PTR_ERR(dentry) != -EINVAL)
+ error = nfserrno(PTR_ERR(dentry));
+ goto out;
+ }
+
+ if (S_ISDIR(dentry->d_inode->i_mode) &&
+ (dentry->d_flags & DCACHE_DISCONNECTED)) {
+ printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
+ dentry->d_parent->d_name.name, dentry->d_name.name);
+ }
+
+ fhp->fh_dentry = dentry;
+ fhp->fh_export = exp;
+ nfsd_nr_verified++;
+ return 0;
+out:
+ exp_put(exp);
+ return error;
+}
+
/*
* Perform sanity checks on the dentry in a client's file handle.
*
@@ -124,115 +237,18 @@ static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
__be32
fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
{
- struct knfsd_fh *fh = &fhp->fh_handle;
- struct svc_export *exp = NULL;
+ struct svc_export *exp;
struct dentry *dentry;
- __be32 error = 0;
+ __be32 error;
dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
if (!fhp->fh_dentry) {
- struct fid *fid = NULL, sfid;
- int fileid_type;
- int data_left = fh->fh_size/4;
-
- error = nfserr_stale;
- if (rqstp->rq_vers > 2)
- error = nfserr_badhandle;
- if (rqstp->rq_vers == 4 && fh->fh_size == 0)
- return nfserr_nofilehandle;
-
- if (fh->fh_version == 1) {
- int len;
- if (--data_left<0) goto out;
- switch (fh->fh_auth_type) {
- case 0: break;
- default: goto out;
- }
- len = key_len(fh->fh_fsid_type) / 4;
- if (len == 0) goto out;
- if (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
- /* deprecated, convert to type 3 */
- len = key_len(FSID_ENCODE_DEV)/4;
- fh->fh_fsid_type = FSID_ENCODE_DEV;
- fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
- fh->fh_fsid[1] = fh->fh_fsid[2];
- }
- if ((data_left -= len)<0) goto out;
- exp = rqst_exp_find(rqstp, fh->fh_fsid_type,
- fh->fh_auth);
- fid = (struct fid *)(fh->fh_auth + len);
- } else {
- __u32 tfh[2];
- dev_t xdev;
- ino_t xino;
- if (fh->fh_size != NFS_FHSIZE)
- goto out;
- /* assume old filehandle format */
- xdev = old_decode_dev(fh->ofh_xdev);
- xino = u32_to_ino_t(fh->ofh_xino);
- mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
- exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
- }
-
- error = nfserr_stale;
- if (PTR_ERR(exp) == -ENOENT)
- goto out;
-
- if (IS_ERR(exp)) {
- error = nfserrno(PTR_ERR(exp));
- goto out;
- }
-
- error = nfsd_setuser_and_check_port(rqstp, exp);
+ error = nfsd_set_fh_dentry(rqstp, fhp);
if (error)
goto out;
-
- /*
- * Look up the dentry using the NFS file handle.
- */
- error = nfserr_stale;
- if (rqstp->rq_vers > 2)
- error = nfserr_badhandle;
-
- if (fh->fh_version != 1) {
- sfid.i32.ino = fh->ofh_ino;
- sfid.i32.gen = fh->ofh_generation;
- sfid.i32.parent_ino = fh->ofh_dirino;
- fid = &sfid;
- data_left = 3;
- if (fh->ofh_dirino == 0)
- fileid_type = FILEID_INO32_GEN;
- else
- fileid_type = FILEID_INO32_GEN_PARENT;
- } else
- fileid_type = fh->fh_fileid_type;
-
- if (fileid_type == FILEID_ROOT)
- dentry = dget(exp->ex_path.dentry);
- else {
- dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
- data_left, fileid_type,
- nfsd_acceptable, exp);
- }
- if (dentry == NULL)
- goto out;
- if (IS_ERR(dentry)) {
- if (PTR_ERR(dentry) != -EINVAL)
- error = nfserrno(PTR_ERR(dentry));
- goto out;
- }
-
- if (S_ISDIR(dentry->d_inode->i_mode) &&
- (dentry->d_flags & DCACHE_DISCONNECTED)) {
- printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
- dentry->d_parent->d_name.name, dentry->d_name.name);
- }
-
- fhp->fh_dentry = dentry;
- fhp->fh_export = exp;
- nfsd_nr_verified++;
- cache_get(&exp->h);
+ dentry = fhp->fh_dentry;
+ exp = fhp->fh_export;
} else {
/*
* just rechecking permissions
@@ -242,7 +258,6 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
dprintk("nfsd: fh_verify - just checking\n");
dentry = fhp->fh_dentry;
exp = fhp->fh_export;
- cache_get(&exp->h);
/*
* Set user creds for this exportpoint; necessary even
* in the "just checking" case because this may be a
@@ -281,8 +296,6 @@ fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
access, ntohl(error));
}
out:
- if (exp && !IS_ERR(exp))
- exp_put(exp);
if (error == nfserr_stale)
nfsdstats.fh_stale++;
return error;
--
1.5.4.rc2.60.gb2e62
--
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