From 50cc42ff3d7bc48a436c5a0413459ca7841b505f Mon Sep 17 00:00:00 2001 From: "Venkateswararao Jujjuri (JV)" Date: Wed, 9 Jun 2010 15:59:31 -0700 Subject: [PATCH] 9p: Define and implement TSYMLINK for 9P2000.L Create a symbolic link SYNOPSIS size[4] Tsymlink tag[2] fid[4] name[s] symtgt[s] gid[4] size[4] Rsymlink tag[2] qid[13] DESCRIPTION Create a symbolic link named 'name' pointing to 'symtgt'. gid represents the effective group id of the caller. The permissions of a symbolic link are irrelevant hence it is omitted from the protocol. Signed-off-by: Venkateswararao Jujjuri Reviewed-by: Sripathi Kodi Signed-off-by: Eric Van Hensbergen --- fs/9p/vfs_inode.c | 101 ++++++++++++++++++++++++++++++++++++++-- include/net/9p/9p.h | 4 ++ include/net/9p/client.h | 2 + net/9p/client.c | 34 ++++++++++++++ 4 files changed, 137 insertions(+), 4 deletions(-) diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index e6ece237241f..a7319364544b 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -1245,7 +1245,7 @@ static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen) if (IS_ERR(fid)) return PTR_ERR(fid); - if (!v9fs_proto_dotu(v9ses)) + if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) return -EBADF; st = p9_client_stat(fid); @@ -1350,6 +1350,99 @@ static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry, return 0; } +/** + * v9fs_vfs_symlink_dotl - helper function to create symlinks + * @dir: directory inode containing symlink + * @dentry: dentry for symlink + * @symname: symlink data + * + * See Also: 9P2000.L RFC for more information + * + */ + +static int +v9fs_vfs_symlink_dotl(struct inode *dir, struct dentry *dentry, + const char *symname) +{ + struct v9fs_session_info *v9ses; + struct p9_fid *dfid; + struct p9_fid *fid = NULL; + struct inode *inode; + struct p9_qid qid; + char *name; + int err; + gid_t gid; + + name = (char *) dentry->d_name.name; + P9_DPRINTK(P9_DEBUG_VFS, "v9fs_vfs_symlink_dotl : %lu,%s,%s\n", + dir->i_ino, name, symname); + v9ses = v9fs_inode2v9ses(dir); + + dfid = v9fs_fid_lookup(dentry->d_parent); + if (IS_ERR(dfid)) { + err = PTR_ERR(dfid); + P9_DPRINTK(P9_DEBUG_VFS, "fid lookup failed %d\n", err); + return err; + } + + gid = v9fs_get_fsgid_for_create(dir); + + if (gid < 0) { + P9_DPRINTK(P9_DEBUG_VFS, "v9fs_get_egid failed %d\n", gid); + goto error; + } + + /* Server doesn't alter fid on TSYMLINK. Hence no need to clone it. */ + err = p9_client_symlink(dfid, name, (char *)symname, gid, &qid); + + if (err < 0) { + P9_DPRINTK(P9_DEBUG_VFS, "p9_client_symlink failed %d\n", err); + goto error; + } + + if (v9ses->cache) { + /* Now walk from the parent so we can get an unopened fid. */ + fid = p9_client_walk(dfid, 1, &name, 1); + if (IS_ERR(fid)) { + err = PTR_ERR(fid); + P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", + err); + fid = NULL; + goto error; + } + + /* instantiate inode and assign the unopened fid to dentry */ + inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + P9_DPRINTK(P9_DEBUG_VFS, "inode creation failed %d\n", + err); + goto error; + } + dentry->d_op = &v9fs_cached_dentry_operations; + d_instantiate(dentry, inode); + err = v9fs_fid_add(dentry, fid); + if (err < 0) + goto error; + fid = NULL; + } else { + /* Not in cached mode. No need to populate inode with stat */ + inode = v9fs_get_inode(dir->i_sb, S_IFLNK); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto error; + } + dentry->d_op = &v9fs_dentry_operations; + d_instantiate(dentry, inode); + } + +error: + if (fid) + p9_client_clunk(fid); + + return err; +} + /** * v9fs_vfs_symlink - helper function to create symlinks * @dir: directory inode containing symlink @@ -1527,7 +1620,7 @@ static const struct inode_operations v9fs_dir_inode_operations_dotu = { .create = v9fs_vfs_create, .lookup = v9fs_vfs_lookup, .symlink = v9fs_vfs_symlink, - .link = v9fs_vfs_link_dotl, + .link = v9fs_vfs_link, .unlink = v9fs_vfs_unlink, .mkdir = v9fs_vfs_mkdir, .rmdir = v9fs_vfs_rmdir, @@ -1540,8 +1633,8 @@ static const struct inode_operations v9fs_dir_inode_operations_dotu = { static const struct inode_operations v9fs_dir_inode_operations_dotl = { .create = v9fs_vfs_create, .lookup = v9fs_vfs_lookup, - .symlink = v9fs_vfs_symlink, - .link = v9fs_vfs_link, + .link = v9fs_vfs_link_dotl, + .symlink = v9fs_vfs_symlink_dotl, .unlink = v9fs_vfs_unlink, .mkdir = v9fs_vfs_mkdir, .rmdir = v9fs_vfs_rmdir, diff --git a/include/net/9p/9p.h b/include/net/9p/9p.h index 5985c0f83db3..44a6883d7144 100644 --- a/include/net/9p/9p.h +++ b/include/net/9p/9p.h @@ -88,6 +88,8 @@ do { \ * enum p9_msg_t - 9P message types * @P9_TSTATFS: file system status request * @P9_RSTATFS: file system status response + * @P9_TSYMLINK: make symlink request + * @P9_RSYMLINK: make symlink response * @P9_TRENAME: rename request * @P9_RRENAME: rename response * @P9_TVERSION: version handshake request @@ -131,6 +133,8 @@ do { \ enum p9_msg_t { P9_TSTATFS = 8, P9_RSTATFS, + P9_TSYMLINK = 16, + P9_RSYMLINK, P9_TRENAME = 20, P9_RRENAME, P9_TGETATTR = 24, diff --git a/include/net/9p/client.h b/include/net/9p/client.h index e36f11650e99..2e039730920e 100644 --- a/include/net/9p/client.h +++ b/include/net/9p/client.h @@ -227,6 +227,8 @@ int p9_client_open(struct p9_fid *fid, int mode); int p9_client_fcreate(struct p9_fid *fid, char *name, u32 perm, int mode, char *extension); int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, char *newname); +int p9_client_symlink(struct p9_fid *fid, char *name, char *symname, gid_t gid, + struct p9_qid *qid); int p9_client_clunk(struct p9_fid *fid); int p9_client_remove(struct p9_fid *fid); int p9_client_read(struct p9_fid *fid, char *data, char __user *udata, diff --git a/net/9p/client.c b/net/9p/client.c index ad1c4489ab4d..e37e64cb9394 100644 --- a/net/9p/client.c +++ b/net/9p/client.c @@ -1095,6 +1095,40 @@ error: } EXPORT_SYMBOL(p9_client_fcreate); +int p9_client_symlink(struct p9_fid *dfid, char *name, char *symtgt, gid_t gid, + struct p9_qid *qid) +{ + int err = 0; + struct p9_client *clnt; + struct p9_req_t *req; + + P9_DPRINTK(P9_DEBUG_9P, ">>> TSYMLINK dfid %d name %s symtgt %s\n", + dfid->fid, name, symtgt); + clnt = dfid->clnt; + + req = p9_client_rpc(clnt, P9_TSYMLINK, "dssd", dfid->fid, name, symtgt, + gid); + if (IS_ERR(req)) { + err = PTR_ERR(req); + goto error; + } + + err = p9pdu_readf(req->rc, clnt->proto_version, "Q", qid); + if (err) { + p9pdu_dump(1, req->rc); + goto free_and_error; + } + + P9_DPRINTK(P9_DEBUG_9P, "<<< RSYMLINK qid %x.%llx.%x\n", + qid->type, (unsigned long long)qid->path, qid->version); + +free_and_error: + p9_free_req(clnt, req); +error: + return err; +} +EXPORT_SYMBOL(p9_client_symlink); + int p9_client_link(struct p9_fid *dfid, struct p9_fid *oldfid, char *newname) { struct p9_client *clnt; -- 2.30.2