From 09d34ee5f93b2e53b64ffba27bc18731e31154e1 Mon Sep 17 00:00:00 2001 From: Eric Van Hensbergen Date: Mon, 2 Aug 2010 14:28:09 -0500 Subject: [PATCH] 9p: Define and implement TLINK for 9P2000.L This patch adds a helper function to get the dentry from inode and uses it in creating a Hardlink SYNOPSIS size[4] Tlink tag[2] dfid[4] oldfid[4] newpath[s] size[4] Rlink tag[2] DESCRIPTION Create a link 'newpath' in directory pointed by dfid linking to oldfid path. [sripathik@in.ibm.com : p9_client_link should not free req structure if p9_client_rpc has returned an error.] Signed-off-by: Venkateswararao Jujjuri Signed-off-by: Eric Van Hensbergen --- fs/9p/vfs_inode.c | 107 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 106 insertions(+), 1 deletion(-) diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index a90324f4546a..e6ece237241f 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -235,6 +235,41 @@ void v9fs_destroy_inode(struct inode *inode) } #endif +/** + * v9fs_get_fsgid_for_create - Helper function to get the gid for creating a + * new file system object. This checks the S_ISGID to determine the owning + * group of the new file system object. + */ + +static gid_t v9fs_get_fsgid_for_create(struct inode *dir_inode) +{ + BUG_ON(dir_inode == NULL); + + if (dir_inode->i_mode & S_ISGID) { + /* set_gid bit is set.*/ + return dir_inode->i_gid; + } + return current_fsgid(); +} + +/** + * v9fs_dentry_from_dir_inode - helper function to get the dentry from + * dir inode. + * + */ + +struct dentry *v9fs_dentry_from_dir_inode(struct inode *inode) +{ + struct dentry *dentry; + + spin_lock(&dcache_lock); + /* Directory should have only one entry. */ + BUG_ON(S_ISDIR(inode->i_mode) && !list_is_singular(&inode->i_dentry)); + dentry = list_entry(inode->i_dentry.next, struct dentry, d_alias); + spin_unlock(&dcache_lock); + return dentry; +} + /** * v9fs_get_inode - helper function to setup an inode * @sb: superblock @@ -1373,6 +1408,76 @@ clunk_fid: return retval; } +/** + * v9fs_vfs_link_dotl - create a hardlink for dotl + * @old_dentry: dentry for file to link to + * @dir: inode destination for new link + * @dentry: dentry for link + * + */ + +static int +v9fs_vfs_link_dotl(struct dentry *old_dentry, struct inode *dir, + struct dentry *dentry) +{ + int err; + struct p9_fid *dfid, *oldfid; + char *name; + struct v9fs_session_info *v9ses; + struct dentry *dir_dentry; + + P9_DPRINTK(P9_DEBUG_VFS, "dir ino: %lu, old_name: %s, new_name: %s\n", + dir->i_ino, old_dentry->d_name.name, + dentry->d_name.name); + + v9ses = v9fs_inode2v9ses(dir); + dir_dentry = v9fs_dentry_from_dir_inode(dir); + dfid = v9fs_fid_lookup(dir_dentry); + if (IS_ERR(dfid)) + return PTR_ERR(dfid); + + oldfid = v9fs_fid_lookup(old_dentry); + if (IS_ERR(oldfid)) + return PTR_ERR(oldfid); + + name = (char *) dentry->d_name.name; + + err = p9_client_link(dfid, oldfid, (char *)dentry->d_name.name); + + if (err < 0) { + P9_DPRINTK(P9_DEBUG_VFS, "p9_client_link failed %d\n", err); + return err; + } + + if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) { + /* Get the latest stat info from server. */ + struct p9_fid *fid; + struct p9_stat_dotl *st; + + fid = v9fs_fid_lookup(old_dentry); + if (IS_ERR(fid)) + return PTR_ERR(fid); + + st = p9_client_getattr_dotl(fid, P9_STATS_BASIC); + if (IS_ERR(st)) + return PTR_ERR(st); + + v9fs_stat2inode_dotl(st, old_dentry->d_inode); + + kfree(st); + } else { + /* Caching disabled. No need to get upto date stat info. + * This dentry will be released immediately. So, just i_count++ + */ + atomic_inc(&old_dentry->d_inode->i_count); + } + + dentry->d_op = old_dentry->d_op; + d_instantiate(dentry, old_dentry->d_inode); + + return err; +} + /** * v9fs_vfs_mknod - create a special file * @dir: inode destination for new link @@ -1422,7 +1527,7 @@ 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, + .link = v9fs_vfs_link_dotl, .unlink = v9fs_vfs_unlink, .mkdir = v9fs_vfs_mkdir, .rmdir = v9fs_vfs_rmdir, -- 2.20.1