From: Paulo Alcantara (SUSE) pc@cjr.nz
[ Upstream commit 5739375ee4230980166807d347cc21c305532bbc ]
Starting from 4a367dc04435, we must set the mount options based on the DFS full path rather than the resolved target, that is, cifs_mount() will be responsible for resolving the DFS link (cached) as well as performing failover to any other targets in the referral.
Signed-off-by: Paulo Alcantara (SUSE) pc@cjr.nz Reported-by: Martijn de Gouw martijn.de.gouw@prodrive-technologies.com Fixes: 4a367dc04435 ("cifs: Add support for failover in cifs_mount()") Link: https://lore.kernel.org/linux-cifs/39643d7d-2abb-14d3-ced6-c394fab9a777@prod... Tested-by: Martijn de Gouw martijn.de.gouw@prodrive-technologies.com Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/cifs/cifs_dfs_ref.c | 97 +++++++++++++++++++----------------------- 1 file changed, 43 insertions(+), 54 deletions(-)
diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c index 41957b82d7960..606f26d862dc1 100644 --- a/fs/cifs/cifs_dfs_ref.c +++ b/fs/cifs/cifs_dfs_ref.c @@ -120,17 +120,17 @@ cifs_build_devname(char *nodename, const char *prepath)
/** - * cifs_compose_mount_options - creates mount options for refferral + * cifs_compose_mount_options - creates mount options for referral * @sb_mountdata: parent/root DFS mount options (template) * @fullpath: full path in UNC format - * @ref: server's referral + * @ref: optional server's referral * @devname: optional pointer for saving device name * * creates mount options for submount based on template options sb_mountdata * and replacing unc,ip,prefixpath options with ones we've got form ref_unc. * * Returns: pointer to new mount options or ERR_PTR. - * Caller is responcible for freeing retunrned value if it is not error. + * Caller is responsible for freeing returned value if it is not error. */ char *cifs_compose_mount_options(const char *sb_mountdata, const char *fullpath, @@ -150,18 +150,27 @@ char *cifs_compose_mount_options(const char *sb_mountdata, if (sb_mountdata == NULL) return ERR_PTR(-EINVAL);
- if (strlen(fullpath) - ref->path_consumed) { - prepath = fullpath + ref->path_consumed; - /* skip initial delimiter */ - if (*prepath == '/' || *prepath == '\') - prepath++; - } + if (ref) { + if (strlen(fullpath) - ref->path_consumed) { + prepath = fullpath + ref->path_consumed; + /* skip initial delimiter */ + if (*prepath == '/' || *prepath == '\') + prepath++; + }
- name = cifs_build_devname(ref->node_name, prepath); - if (IS_ERR(name)) { - rc = PTR_ERR(name); - name = NULL; - goto compose_mount_options_err; + name = cifs_build_devname(ref->node_name, prepath); + if (IS_ERR(name)) { + rc = PTR_ERR(name); + name = NULL; + goto compose_mount_options_err; + } + } else { + name = cifs_build_devname((char *)fullpath, NULL); + if (IS_ERR(name)) { + rc = PTR_ERR(name); + name = NULL; + goto compose_mount_options_err; + } }
rc = dns_resolve_server_name_to_ip(name, &srvIP); @@ -225,6 +234,8 @@ char *cifs_compose_mount_options(const char *sb_mountdata,
if (devname) *devname = name; + else + kfree(name);
/*cifs_dbg(FYI, "%s: parent mountdata: %s\n", __func__, sb_mountdata);*/ /*cifs_dbg(FYI, "%s: submount mountdata: %s\n", __func__, mountdata );*/ @@ -241,23 +252,23 @@ compose_mount_options_err: }
/** - * cifs_dfs_do_refmount - mounts specified path using provided refferal + * cifs_dfs_do_mount - mounts specified path using DFS full path + * + * Always pass down @fullpath to smb3_do_mount() so we can use the root server + * to perform failover in case we failed to connect to the first target in the + * referral. + * * @cifs_sb: parent/root superblock * @fullpath: full path in UNC format - * @ref: server's referral */ -static struct vfsmount *cifs_dfs_do_refmount(struct dentry *mntpt, - struct cifs_sb_info *cifs_sb, - const char *fullpath, const struct dfs_info3_param *ref) +static struct vfsmount *cifs_dfs_do_mount(struct dentry *mntpt, + struct cifs_sb_info *cifs_sb, + const char *fullpath) { struct vfsmount *mnt; char *mountdata; char *devname;
- /* - * Always pass down the DFS full path to smb3_do_mount() so we - * can use it later for failover. - */ devname = kstrndup(fullpath, strlen(fullpath), GFP_KERNEL); if (!devname) return ERR_PTR(-ENOMEM); @@ -266,7 +277,7 @@ static struct vfsmount *cifs_dfs_do_refmount(struct dentry *mntpt,
/* strip first '' from fullpath */ mountdata = cifs_compose_mount_options(cifs_sb->mountdata, - fullpath + 1, ref, NULL); + fullpath + 1, NULL, NULL); if (IS_ERR(mountdata)) { kfree(devname); return (struct vfsmount *)mountdata; @@ -278,28 +289,16 @@ static struct vfsmount *cifs_dfs_do_refmount(struct dentry *mntpt, return mnt; }
-static void dump_referral(const struct dfs_info3_param *ref) -{ - cifs_dbg(FYI, "DFS: ref path: %s\n", ref->path_name); - cifs_dbg(FYI, "DFS: node path: %s\n", ref->node_name); - cifs_dbg(FYI, "DFS: fl: %d, srv_type: %d\n", - ref->flags, ref->server_type); - cifs_dbg(FYI, "DFS: ref_flags: %d, path_consumed: %d\n", - ref->ref_flag, ref->path_consumed); -} - /* * Create a vfsmount that we can automount */ static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt) { - struct dfs_info3_param referral = {0}; struct cifs_sb_info *cifs_sb; struct cifs_ses *ses; struct cifs_tcon *tcon; char *full_path, *root_path; unsigned int xid; - int len; int rc; struct vfsmount *mnt;
@@ -357,7 +356,7 @@ static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt) if (!rc) { rc = dfs_cache_find(xid, ses, cifs_sb->local_nls, cifs_remap(cifs_sb), full_path + 1, - &referral, NULL); + NULL, NULL); }
free_xid(xid); @@ -366,26 +365,16 @@ static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt) mnt = ERR_PTR(rc); goto free_root_path; } - - dump_referral(&referral); - - len = strlen(referral.node_name); - if (len < 2) { - cifs_dbg(VFS, "%s: Net Address path too short: %s\n", - __func__, referral.node_name); - mnt = ERR_PTR(-EINVAL); - goto free_dfs_ref; - } /* - * cifs_mount() will retry every available node server in case - * of failures. + * OK - we were able to get and cache a referral for @full_path. + * + * Now, pass it down to cifs_mount() and it will retry every available + * node server in case of failures - no need to do it here. */ - mnt = cifs_dfs_do_refmount(mntpt, cifs_sb, full_path, &referral); - cifs_dbg(FYI, "%s: cifs_dfs_do_refmount:%s , mnt:%p\n", __func__, - referral.node_name, mnt); + mnt = cifs_dfs_do_mount(mntpt, cifs_sb, full_path); + cifs_dbg(FYI, "%s: cifs_dfs_do_mount:%s , mnt:%p\n", __func__, + full_path + 1, mnt);
-free_dfs_ref: - free_dfs_info_param(&referral); free_root_path: kfree(root_path); free_full_path: