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NFS: Fix double d_drop in nfs_instantiate() error path

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If the LOOKUP or GETATTR in nfs_instantiate fail, nfs_instantiate will do a
d_drop before returning.  But some callers already do a d_drop in the case
of an error return.  Make certain we do only one d_drop in all error paths.

This issue was introduced because over time, the symlink proc API diverged
slightly from the create/mkdir/mknod proc API.  To prevent other coding
mistakes of this type, change the symlink proc API to be more like
create/mkdir/mknod and move the nfs_instantiate call into the symlink proc
routines so it is used in exactly the same way for create, mkdir, mknod,
and symlink.

Test plan:
Connectathon, all versions of NFS.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Chuck Lever 2006-08-22 20:06:22 -04:00 committed by Trond Myklebust
parent d3db90e270
commit 4f390c152b
5 changed files with 59 additions and 48 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
fs/nfs/dir.c
View File

@ -1147,23 +1147,20 @@ int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
struct inode *dir = dentry->d_parent->d_inode;
error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
if (error)
goto out_err;
return error;
}
if (!(fattr->valid & NFS_ATTR_FATTR)) {
struct nfs_server *server = NFS_SB(dentry->d_sb);
error = server->nfs_client->rpc_ops->getattr(server, fhandle, fattr);
if (error < 0)
goto out_err;
return error;
}
inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
error = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_err;
return error;
d_instantiate(dentry, inode);
return 0;
out_err:
d_drop(dentry);
return error;
}
/*
@ -1448,8 +1445,6 @@ static int
nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
{
struct iattr attr;
struct nfs_fattr sym_attr;
struct nfs_fh sym_fh;
struct qstr qsymname;
int error;
@ -1473,12 +1468,9 @@ dentry->d_parent->d_name.name, dentry->d_name.name);
lock_kernel();
nfs_begin_data_update(dir);
error = NFS_PROTO(dir)->symlink(dir, &dentry->d_name, &qsymname,
&attr, &sym_fh, &sym_attr);
error = NFS_PROTO(dir)->symlink(dir, dentry, &qsymname, &attr);
nfs_end_data_update(dir);
if (!error)
error = nfs_instantiate(dentry, &sym_fh, &sym_attr);
else
d_drop(dentry);
unlock_kernel();
return error;

26
fs/nfs/nfs3proc.c
View File

@ -544,23 +544,23 @@ nfs3_proc_link(struct inode *inode, struct inode *dir, struct qstr *name)
}
static int
nfs3_proc_symlink(struct inode *dir, struct qstr *name, struct qstr *path,
struct iattr *sattr, struct nfs_fh *fhandle,
struct nfs_fattr *fattr)
nfs3_proc_symlink(struct inode *dir, struct dentry *dentry, struct qstr *path,
struct iattr *sattr)
{
struct nfs_fattr dir_attr;
struct nfs_fh fhandle;
struct nfs_fattr fattr, dir_attr;
struct nfs3_symlinkargs arg = {
.fromfh = NFS_FH(dir),
.fromname = name->name,
.fromlen = name->len,
.fromname = dentry->d_name.name,
.fromlen = dentry->d_name.len,
.topath = path->name,
.tolen = path->len,
.sattr = sattr
};
struct nfs3_diropres res = {
.dir_attr = &dir_attr,
.fh = fhandle,
.fattr = fattr
.fh = &fhandle,
.fattr = &fattr
};
struct rpc_message msg = {
.rpc_proc = &nfs3_procedures[NFS3PROC_SYMLINK],
@ -571,11 +571,17 @@ nfs3_proc_symlink(struct inode *dir, struct qstr *name, struct qstr *path,
if (path->len > NFS3_MAXPATHLEN)
return -ENAMETOOLONG;
dprintk("NFS call symlink %s -> %s\n", name->name, path->name);
dprintk("NFS call symlink %s -> %s\n", dentry->d_name.name,
path->name);
nfs_fattr_init(&dir_attr);
nfs_fattr_init(fattr);
nfs_fattr_init(&fattr);
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
nfs_post_op_update_inode(dir, &dir_attr);
if (status != 0)
goto out;
status = nfs_instantiate(dentry, &fhandle, &fattr);
out:
dprintk("NFS reply symlink: %d\n", status);
return status;
}

31
fs/nfs/nfs4proc.c
View File

@ -2084,24 +2084,24 @@ static int nfs4_proc_link(struct inode *inode, struct inode *dir, struct qstr *n
return err;
}
static int _nfs4_proc_symlink(struct inode *dir, struct qstr *name,
struct qstr *path, struct iattr *sattr, struct nfs_fh *fhandle,
struct nfs_fattr *fattr)
static int _nfs4_proc_symlink(struct inode *dir, struct dentry *dentry,
struct qstr *path, struct iattr *sattr)
{
struct nfs_server *server = NFS_SERVER(dir);
struct nfs_fattr dir_fattr;
struct nfs_fh fhandle;
struct nfs_fattr fattr, dir_fattr;
struct nfs4_create_arg arg = {
.dir_fh = NFS_FH(dir),
.server = server,
.name = name,
.name = &dentry->d_name,
.attrs = sattr,
.ftype = NF4LNK,
.bitmask = server->attr_bitmask,
};
struct nfs4_create_res res = {
.server = server,
.fh = fhandle,
.fattr = fattr,
.fh = &fhandle,
.fattr = &fattr,
.dir_fattr = &dir_fattr,
};
struct rpc_message msg = {
@ -2113,27 +2113,28 @@ static int _nfs4_proc_symlink(struct inode *dir, struct qstr *name,
if (path->len > NFS4_MAXPATHLEN)
return -ENAMETOOLONG;
arg.u.symlink = path;
nfs_fattr_init(fattr);
nfs_fattr_init(&fattr);
nfs_fattr_init(&dir_fattr);
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
if (!status)
if (!status) {
update_changeattr(dir, &res.dir_cinfo);
nfs_post_op_update_inode(dir, res.dir_fattr);
nfs_post_op_update_inode(dir, res.dir_fattr);
status = nfs_instantiate(dentry, &fhandle, &fattr);
}
return status;
}
static int nfs4_proc_symlink(struct inode *dir, struct qstr *name,
struct qstr *path, struct iattr *sattr, struct nfs_fh *fhandle,
struct nfs_fattr *fattr)
static int nfs4_proc_symlink(struct inode *dir, struct dentry *dentry,
struct qstr *path, struct iattr *sattr)
{
struct nfs4_exception exception = { };
int err;
do {
err = nfs4_handle_exception(NFS_SERVER(dir),
_nfs4_proc_symlink(dir, name, path, sattr,
fhandle, fattr),
_nfs4_proc_symlink(dir, dentry, path, sattr),
&exception);
} while (exception.retry);
return err;

29
fs/nfs/proc.c
View File

@ -425,14 +425,15 @@ nfs_proc_link(struct inode *inode, struct inode *dir, struct qstr *name)
}
static int
nfs_proc_symlink(struct inode *dir, struct qstr *name, struct qstr *path,
struct iattr *sattr, struct nfs_fh *fhandle,
struct nfs_fattr *fattr)
nfs_proc_symlink(struct inode *dir, struct dentry *dentry, struct qstr *path,
struct iattr *sattr)
{
struct nfs_fh fhandle;
struct nfs_fattr fattr;
struct nfs_symlinkargs arg = {
.fromfh = NFS_FH(dir),
.fromname = name->name,
.fromlen = name->len,
.fromname = dentry->d_name.name,
.fromlen = dentry->d_name.len,
.topath = path->name,
.tolen = path->len,
.sattr = sattr
@ -445,11 +446,23 @@ nfs_proc_symlink(struct inode *dir, struct qstr *name, struct qstr *path,
if (path->len > NFS2_MAXPATHLEN)
return -ENAMETOOLONG;
dprintk("NFS call symlink %s -> %s\n", name->name, path->name);
nfs_fattr_init(fattr);
fhandle->size = 0;
dprintk("NFS call symlink %s -> %s\n", dentry->d_name.name,
path->name);
status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
nfs_mark_for_revalidate(dir);
/*
* V2 SYMLINK requests don't return any attributes. Setting the
* filehandle size to zero indicates to nfs_instantiate that it
* should fill in the data with a LOOKUP call on the wire.
*/
if (status == 0) {
nfs_fattr_init(&fattr);
fhandle.size = 0;
status = nfs_instantiate(dentry, &fhandle, &fattr);
}
dprintk("NFS reply symlink: %d\n", status);
return status;
}

5
include/linux/nfs_xdr.h
View File

@ -793,9 +793,8 @@ struct nfs_rpc_ops {
int (*rename) (struct inode *, struct qstr *,
struct inode *, struct qstr *);
int (*link) (struct inode *, struct inode *, struct qstr *);
int (*symlink) (struct inode *, struct qstr *, struct qstr *,
struct iattr *, struct nfs_fh *,
struct nfs_fattr *);
int (*symlink) (struct inode *, struct dentry *, struct qstr *,
struct iattr *);
int (*mkdir) (struct inode *, struct dentry *, struct iattr *);
int (*rmdir) (struct inode *, struct qstr *);
int (*readdir) (struct dentry *, struct rpc_cred *,