Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:43301 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755016Ab0I3SPu (ORCPT ); Thu, 30 Sep 2010 14:15:50 -0400 From: David Howells Subject: [PATCH 04/17] CIFS: Use d_automount() rather than abusing follow_link() To: viro@ftp.linux.org.uk, jmoyer@redhat.com Cc: linux-fs@vger.kernel.org, autofs@linux.kernel.org, linux-kernel@vger.kernel.org, linux-afs@lists.infradead.org, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, David Howells , Steve French Date: Thu, 30 Sep 2010 19:15:16 +0100 Message-ID: <20100930181515.30939.57129.stgit@warthog.procyon.org.uk> In-Reply-To: <20100930181455.30939.53914.stgit@warthog.procyon.org.uk> References: <20100930181455.30939.53914.stgit@warthog.procyon.org.uk> Content-Type: text/plain; charset="utf-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Make CIFS use the new d_automount() dentry operation rather than abusing follow_link() on directories. [NOTE: THIS IS UNTESTED!] [Question: Why does cifs_dfs_do_refmount() when the caller has already done that and could pass the result through?] Signed-off-by: David Howells Cc: Steve French --- fs/cifs/cifs_dfs_ref.c | 134 +++++++++++++++++++++++------------------------- fs/cifs/cifsfs.h | 6 ++ fs/cifs/dir.c | 2 + fs/cifs/inode.c | 8 ++- 4 files changed, 78 insertions(+), 72 deletions(-) diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c index d6ced7a..8fc4943 100644 --- a/fs/cifs/cifs_dfs_ref.c +++ b/fs/cifs/cifs_dfs_ref.c @@ -256,35 +256,6 @@ static struct vfsmount *cifs_dfs_do_refmount(struct cifs_sb_info *cifs_sb, } -static int add_mount_helper(struct vfsmount *newmnt, struct nameidata *nd, - struct list_head *mntlist) -{ - /* stolen from afs code */ - int err; - - mntget(newmnt); - err = do_add_mount(newmnt, &nd->path, nd->path.mnt->mnt_flags | MNT_SHRINKABLE, mntlist); - switch (err) { - case 0: - path_put(&nd->path); - nd->path.mnt = newmnt; - nd->path.dentry = dget(newmnt->mnt_root); - schedule_delayed_work(&cifs_dfs_automount_task, - cifs_dfs_mountpoint_expiry_timeout); - break; - case -EBUSY: - /* someone else made a mount here whilst we were busy */ - while (d_mountpoint(nd->path.dentry) && - follow_down(&nd->path)) - ; - err = 0; - default: - mntput(newmnt); - break; - } - return err; -} - static void dump_referral(const struct dfs_info3_param *ref) { cFYI(1, "DFS: ref path: %s", ref->path_name); @@ -294,34 +265,30 @@ static void dump_referral(const struct dfs_info3_param *ref) ref->path_consumed); } - -static void* -cifs_dfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd) +/* + * Create a vfsmount that we can automount + */ +static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt) { struct dfs_info3_param *referrals = NULL; unsigned int num_referrals = 0; struct cifs_sb_info *cifs_sb; struct cifsSesInfo *ses; - char *full_path = NULL; + char *full_path; int xid, i; - int rc = 0; - struct vfsmount *mnt = ERR_PTR(-ENOENT); + int rc; + struct vfsmount *mnt; cFYI(1, "in %s", __func__); - BUG_ON(IS_ROOT(dentry)); + BUG_ON(IS_ROOT(mntpt)); xid = GetXid(); - dput(nd->path.dentry); - nd->path.dentry = dget(dentry); - - cifs_sb = CIFS_SB(dentry->d_inode->i_sb); + cifs_sb = CIFS_SB(mntpt->d_inode->i_sb); + mnt = ERR_PTR(-EINVAL); ses = cifs_sb->tcon->ses; - - if (!ses) { - rc = -EINVAL; - goto out_err; - } + if (!ses) + goto free_xid; /* * The MSDFS spec states that paths in DFS referral requests and @@ -329,56 +296,85 @@ cifs_dfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd) * the double backslashes usually used in the UNC. This function * gives us the latter, so we must adjust the result. */ - full_path = build_path_from_dentry(dentry); - if (full_path == NULL) { - rc = -ENOMEM; - goto out_err; - } + mnt = ERR_PTR(-ENOMEM); + full_path = build_path_from_dentry(mntpt); + if (full_path == NULL) + goto free_xid; rc = get_dfs_path(xid, ses , full_path + 1, cifs_sb->local_nls, &num_referrals, &referrals, cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); + mnt = ERR_PTR(-ENOENT); for (i = 0; i < num_referrals; i++) { int len; - dump_referral(referrals+i); + dump_referral(referrals + i); /* connect to a node */ len = strlen(referrals[i].node_name); if (len < 2) { cERROR(1, "%s: Net Address path too short: %s", __func__, referrals[i].node_name); - rc = -EINVAL; - goto out_err; + mnt = ERR_PTR(-EINVAL); + break; } mnt = cifs_dfs_do_refmount(cifs_sb, full_path, referrals + i); cFYI(1, "%s: cifs_dfs_do_refmount:%s , mnt:%p", __func__, referrals[i].node_name, mnt); - - /* complete mount procedure if we accured submount */ if (!IS_ERR(mnt)) - break; + goto success; } - /* we need it cause for() above could exit without valid submount */ - rc = PTR_ERR(mnt); - if (IS_ERR(mnt)) - goto out_err; - - rc = add_mount_helper(mnt, nd, &cifs_dfs_automount_list); + /* no valid submounts were found; return error from get_dfs_path() by + * preference */ + if (rc != 0) + mnt = ERR_PTR(rc); -out: - FreeXid(xid); +success: free_dfs_info_array(referrals, num_referrals); kfree(full_path); +free_xid: + FreeXid(xid); cFYI(1, "leaving %s" , __func__); return ERR_PTR(rc); -out_err: - path_put(&nd->path); - goto out; +} + +/* + * Attempt to automount the referral + */ +struct vfsmount *cifs_dfs_d_automount(struct path *path) +{ + struct vfsmount *newmnt; + int err; + + cFYI(1, "in %s", __func__); + + newmnt = cifs_dfs_do_automount(path->dentry); + if (IS_ERR(newmnt)) { + cFYI(1, "leaving %s [automount failed]" , __func__); + return newmnt; + } + + mntget(newmnt); + err = do_add_mount(newmnt, path, MNT_SHRINKABLE, + &cifs_dfs_automount_list); + switch (err) { + case 0: + schedule_delayed_work(&cifs_dfs_automount_task, + cifs_dfs_mountpoint_expiry_timeout); + cFYI(1, "leaving %s [ok]" , __func__); + return newmnt; + case -EBUSY: + /* someone else made a mount here whilst we were busy */ + mntput(newmnt); + cFYI(1, "leaving %s [EBUSY]" , __func__); + return NULL; + default: + mntput(newmnt); + cFYI(1, "leaving %s [error %d]" , __func__, err); + return ERR_PTR(err); + } } const struct inode_operations cifs_dfs_referral_inode_operations = { - .follow_link = cifs_dfs_follow_mountpoint, }; - diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h index d82f5fb..34b18a6 100644 --- a/fs/cifs/cifsfs.h +++ b/fs/cifs/cifsfs.h @@ -95,6 +95,12 @@ extern int cifs_readdir(struct file *file, void *direntry, filldir_t filldir); extern const struct dentry_operations cifs_dentry_ops; extern const struct dentry_operations cifs_ci_dentry_ops; +#ifdef CONFIG_CIFS_DFS_UPCALL +extern struct vfsmount *cifs_dfs_d_automount(struct path *path); +#else +#define cifs_dfs_d_automount NULL +#endif + /* Functions related to symlinks */ extern void *cifs_follow_link(struct dentry *direntry, struct nameidata *nd); extern void cifs_put_link(struct dentry *direntry, diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c index f9ed075..fc97233 100644 --- a/fs/cifs/dir.c +++ b/fs/cifs/dir.c @@ -795,6 +795,7 @@ cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd) const struct dentry_operations cifs_dentry_ops = { .d_revalidate = cifs_d_revalidate, + .d_automount = cifs_dfs_d_automount, /* d_delete: cifs_d_delete, */ /* not needed except for debugging */ }; @@ -835,4 +836,5 @@ const struct dentry_operations cifs_ci_dentry_ops = { .d_revalidate = cifs_d_revalidate, .d_hash = cifs_ci_hash, .d_compare = cifs_ci_compare, + .d_automount = cifs_dfs_d_automount, }; diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c index 93f77d4..a1f810c 100644 --- a/fs/cifs/inode.c +++ b/fs/cifs/inode.c @@ -32,7 +32,7 @@ #include "fscache.h" -static void cifs_set_ops(struct inode *inode, const bool is_dfs_referral) +static void cifs_set_ops(struct inode *inode) { struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); @@ -60,7 +60,7 @@ static void cifs_set_ops(struct inode *inode, const bool is_dfs_referral) break; case S_IFDIR: #ifdef CONFIG_CIFS_DFS_UPCALL - if (is_dfs_referral) { + if (IS_AUTOMOUNT(inode)) { inode->i_op = &cifs_dfs_referral_inode_operations; } else { #else /* NO DFS support, treat as a directory */ @@ -167,7 +167,9 @@ cifs_fattr_to_inode(struct inode *inode, struct cifs_fattr *fattr) } spin_unlock(&inode->i_lock); - cifs_set_ops(inode, fattr->cf_flags & CIFS_FATTR_DFS_REFERRAL); + if (fattr->cf_flags & CIFS_FATTR_DFS_REFERRAL) + inode->i_flags |= S_AUTOMOUNT; + cifs_set_ops(inode); } void