| Message ID | 20181115142103.24617-2-aaptel@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | DFS failover | expand |
After I rereviewed this - I updated with minor changes and remerged to cifs-2.6.git for-next. $ diff -a saved-0015-cifs-Refactor-out-cifs_mount.patch 0015-cifs-Refactor-out-cifs_mount.patch 180c180 < + tlink = kzalloc(sizeof *tlink, GFP_KERNEL); --- > + tlink = kzalloc(sizeof(*tlink), GFP_KERNEL); 259c259 < + return -ENOSYS; --- > + return -EOPNOTSUPP; 365c365 < + if (rc == -EACCES || rc == -EOPNOTSUPP) --- > + if ((rc == -EACCES) || (rc == -EOPNOTSUPP) || (ses == NULL) || (server == NULL)) Updated patch attached On Thu, Nov 15, 2018 at 8:21 AM Aurelien Aptel <aaptel@suse.com> wrote: > > From: Paulo Alcantara <paulo@paulo.ac> > > * Split and refactor the very large function cifs_mount() in multiple > functions: > > - tcp, ses and tcon setup to mount_get_conns() > - tcp, ses and tcon cleanup in mount_put_conns() > - tcon tlink setup to mount_setup_tlink() > - remote path checking to is_path_remote() > > * Implement 2 version of cifs_mount() for DFS-enabled builds and > non-DFS-enabled builds (CONFIG_CIFS_DFS_UPCALL). > > In preparation for DFS failover support. > > Signed-off-by: Paulo Alcantara <palcantara@suse.de> > Signed-off-by: Aurelien Aptel <aaptel@suse.com> > --- > fs/cifs/cifsproto.h | 4 +- > fs/cifs/connect.c | 441 ++++++++++++++++++++++++++++++---------------------- > 2 files changed, 262 insertions(+), 183 deletions(-) > > diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h > index fa361bc00602..f4dd2a3795dd 100644 > --- a/fs/cifs/cifsproto.h > +++ b/fs/cifs/cifsproto.h > @@ -213,7 +213,7 @@ extern int cifs_match_super(struct super_block *, void *); > extern void cifs_cleanup_volume_info(struct smb_vol *pvolume_info); > extern struct smb_vol *cifs_get_volume_info(char *mount_data, > const char *devname, bool is_smb3); > -extern int cifs_mount(struct cifs_sb_info *, struct smb_vol *); > +extern int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *vol); > extern void cifs_umount(struct cifs_sb_info *); > extern void cifs_mark_open_files_invalid(struct cifs_tcon *tcon); > extern void cifs_reopen_persistent_handles(struct cifs_tcon *tcon); > @@ -524,6 +524,8 @@ extern int E_md4hash(const unsigned char *passwd, unsigned char *p16, > const struct nls_table *codepage); > extern int SMBencrypt(unsigned char *passwd, const unsigned char *c8, > unsigned char *p24); > +extern void > +cifs_cleanup_volume_info_contents(struct smb_vol *volume_info); > > void cifs_readdata_release(struct kref *refcount); > int cifs_async_readv(struct cifs_readdata *rdata); > diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c > index 6f24f129a751..3caa2021a5d6 100644 > --- a/fs/cifs/connect.c > +++ b/fs/cifs/connect.c > @@ -3746,8 +3746,8 @@ int cifs_setup_cifs_sb(struct smb_vol *pvolume_info, > return 0; > } > > -static void > -cleanup_volume_info_contents(struct smb_vol *volume_info) > +void > +cifs_cleanup_volume_info_contents(struct smb_vol *volume_info) > { > kfree(volume_info->username); > kzfree(volume_info->password); > @@ -3762,10 +3762,136 @@ cifs_cleanup_volume_info(struct smb_vol *volume_info) > { > if (!volume_info) > return; > - cleanup_volume_info_contents(volume_info); > + cifs_cleanup_volume_info_contents(volume_info); > kfree(volume_info); > } > > +/* Release all succeed connections */ > +static inline void mount_put_conns(struct cifs_sb_info *cifs_sb, > + unsigned int xid, > + struct TCP_Server_Info *server, > + struct cifs_ses *ses, struct cifs_tcon *tcon) > +{ > + int rc = 0; > + > + if (tcon) > + cifs_put_tcon(tcon); > + else if (ses) > + cifs_put_smb_ses(ses); > + else if (server) > + cifs_put_tcp_session(server, 0); > + cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS; > + free_xid(xid); > +} > + > +/* Get connections for tcp, ses and tcon */ > +static int mount_get_conns(struct smb_vol *vol, struct cifs_sb_info *cifs_sb, > + unsigned int *xid, > + struct TCP_Server_Info **nserver, > + struct cifs_ses **nses, struct cifs_tcon **ntcon) > +{ > + int rc = 0; > + struct TCP_Server_Info *server; > + struct cifs_ses *ses; > + struct cifs_tcon *tcon; > + > + *nserver = NULL; > + *nses = NULL; > + *ntcon = NULL; > + > + *xid = get_xid(); > + > + /* get a reference to a tcp session */ > + server = cifs_get_tcp_session(vol); > + if (IS_ERR(server)) { > + rc = PTR_ERR(server); > + return rc; > + } > + > + *nserver = server; > + > + if ((vol->max_credits < 20) || (vol->max_credits > 60000)) > + server->max_credits = SMB2_MAX_CREDITS_AVAILABLE; > + else > + server->max_credits = vol->max_credits; > + > + /* get a reference to a SMB session */ > + ses = cifs_get_smb_ses(server, vol); > + if (IS_ERR(ses)) { > + rc = PTR_ERR(ses); > + return rc; > + } > + > + *nses = ses; > + > + if ((vol->persistent == true) && (!(ses->server->capabilities & > + SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) { > + cifs_dbg(VFS, "persistent handles not supported by server\n"); > + return -EOPNOTSUPP; > + } > + > + /* search for existing tcon to this server share */ > + tcon = cifs_get_tcon(ses, vol); > + if (IS_ERR(tcon)) { > + rc = PTR_ERR(tcon); > + return rc; > + } > + > + *ntcon = tcon; > + > + /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */ > + if (tcon->posix_extensions) > + cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS; > + > + /* tell server which Unix caps we support */ > + if (cap_unix(tcon->ses)) { > + /* > + * reset of caps checks mount to see if unix extensions disabled > + * for just this mount. > + */ > + reset_cifs_unix_caps(*xid, tcon, cifs_sb, vol); > + if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) && > + (le64_to_cpu(tcon->fsUnixInfo.Capability) & > + CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) > + return -EACCES; > + } else > + tcon->unix_ext = 0; /* server does not support them */ > + > + /* do not care if a following call succeed - informational */ > + if (!tcon->pipe && server->ops->qfs_tcon) > + server->ops->qfs_tcon(*xid, tcon); > + > + cifs_sb->wsize = server->ops->negotiate_wsize(tcon, vol); > + cifs_sb->rsize = server->ops->negotiate_rsize(tcon, vol); > + > + return 0; > +} > + > +static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses, > + struct cifs_tcon *tcon) > +{ > + struct tcon_link *tlink; > + > + /* hang the tcon off of the superblock */ > + tlink = kzalloc(sizeof *tlink, GFP_KERNEL); > + if (tlink == NULL) > + return -ENOMEM; > + > + tlink->tl_uid = ses->linux_uid; > + tlink->tl_tcon = tcon; > + tlink->tl_time = jiffies; > + set_bit(TCON_LINK_MASTER, &tlink->tl_flags); > + set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags); > + > + cifs_sb->master_tlink = tlink; > + spin_lock(&cifs_sb->tlink_tree_lock); > + tlink_rb_insert(&cifs_sb->tlink_tree, tlink); > + spin_unlock(&cifs_sb->tlink_tree_lock); > + > + queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks, > + TLINK_IDLE_EXPIRE); > + return 0; > +} > > #ifdef CONFIG_CIFS_DFS_UPCALL > /* > @@ -3845,7 +3971,7 @@ expand_dfs_referral(const unsigned int xid, struct cifs_ses *ses, > rc = PTR_ERR(mdata); > mdata = NULL; > } else { > - cleanup_volume_info_contents(volume_info); > + cifs_cleanup_volume_info_contents(volume_info); > rc = cifs_setup_volume_info(volume_info, mdata, > fake_devname, false); > } > @@ -3954,107 +4080,77 @@ cifs_are_all_path_components_accessible(struct TCP_Server_Info *server, > return rc; > } > > -int > -cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *volume_info) > +/* > + * Check if path is remote (e.g. a DFS share). Return -EREMOTE if it is, > + * otherwise 0. > + */ > +static int is_path_remote(struct cifs_sb_info *cifs_sb, struct smb_vol *vol, > + const unsigned int xid, > + struct TCP_Server_Info *server, > + struct cifs_tcon *tcon) > { > int rc; > - unsigned int xid; > - struct cifs_ses *ses; > - struct cifs_tcon *tcon; > - struct TCP_Server_Info *server; > - char *full_path; > - struct tcon_link *tlink; > -#ifdef CONFIG_CIFS_DFS_UPCALL > - int referral_walks_count = 0; > -#endif > - > -#ifdef CONFIG_CIFS_DFS_UPCALL > -try_mount_again: > - /* cleanup activities if we're chasing a referral */ > - if (referral_walks_count) { > - if (tcon) > - cifs_put_tcon(tcon); > - else if (ses) > - cifs_put_smb_ses(ses); > - > - cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS; > + char *full_path; > > - free_xid(xid); > - } > -#endif > - rc = 0; > - tcon = NULL; > - ses = NULL; > - server = NULL; > - full_path = NULL; > - tlink = NULL; > + if (!server->ops->is_path_accessible) > + return -ENOSYS; > > - xid = get_xid(); > + /* > + * cifs_build_path_to_root works only when we have a valid tcon > + */ > + full_path = cifs_build_path_to_root(vol, cifs_sb, tcon, > + tcon->Flags & SMB_SHARE_IS_IN_DFS); > + if (full_path == NULL) > + return -ENOMEM; > > - /* get a reference to a tcp session */ > - server = cifs_get_tcp_session(volume_info); > - if (IS_ERR(server)) { > - rc = PTR_ERR(server); > - goto out; > - } > - if ((volume_info->max_credits < 20) || > - (volume_info->max_credits > 60000)) > - server->max_credits = SMB2_MAX_CREDITS_AVAILABLE; > - else > - server->max_credits = volume_info->max_credits; > - /* get a reference to a SMB session */ > - ses = cifs_get_smb_ses(server, volume_info); > - if (IS_ERR(ses)) { > - rc = PTR_ERR(ses); > - ses = NULL; > - goto mount_fail_check; > - } > + cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path); > > - if ((volume_info->persistent == true) && ((ses->server->capabilities & > - SMB2_GLOBAL_CAP_PERSISTENT_HANDLES) == 0)) { > - cifs_dbg(VFS, "persistent handles not supported by server\n"); > - rc = -EOPNOTSUPP; > - goto mount_fail_check; > + rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, > + full_path); > + if (rc != 0 && rc != -EREMOTE) { > + kfree(full_path); > + return rc; > } > > - /* search for existing tcon to this server share */ > - tcon = cifs_get_tcon(ses, volume_info); > - if (IS_ERR(tcon)) { > - rc = PTR_ERR(tcon); > - tcon = NULL; > - if (rc == -EACCES) > - goto mount_fail_check; > - > - goto remote_path_check; > + if (rc != -EREMOTE) { > + rc = cifs_are_all_path_components_accessible(server, xid, tcon, > + cifs_sb, > + full_path); > + if (rc != 0) { > + cifs_dbg(VFS, "cannot query dirs between root and final path, " > + "enabling CIFS_MOUNT_USE_PREFIX_PATH\n"); > + cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; > + rc = 0; > + } > } > > - /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */ > - if (tcon->posix_extensions) > - cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS; > + kfree(full_path); > + return rc; > +} > > - /* tell server which Unix caps we support */ > - if (cap_unix(tcon->ses)) { > - /* reset of caps checks mount to see if unix extensions > - disabled for just this mount */ > - reset_cifs_unix_caps(xid, tcon, cifs_sb, volume_info); > - if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) && > - (le64_to_cpu(tcon->fsUnixInfo.Capability) & > - CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) { > - rc = -EACCES; > - goto mount_fail_check; > - } > - } else > - tcon->unix_ext = 0; /* server does not support them */ > +#ifdef CONFIG_CIFS_DFS_UPCALL > +int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *vol) > +{ > + int rc = 0; > + unsigned int xid; > + struct cifs_ses *ses; > + struct cifs_tcon *tcon = NULL; > + struct TCP_Server_Info *server; > + char *old_mountdata; > + int count; > > - /* do not care if a following call succeed - informational */ > - if (!tcon->pipe && server->ops->qfs_tcon) > - server->ops->qfs_tcon(xid, tcon); > + rc = mount_get_conns(vol, cifs_sb, &xid, &server, &ses, &tcon); > + if (!rc && tcon) { > + rc = is_path_remote(cifs_sb, vol, xid, server, tcon); > + if (!rc) > + goto out; > + if (rc != -EREMOTE) > + goto error; > + } > + if (rc == -EACCES || rc == -EOPNOTSUPP) > + goto error; > > - cifs_sb->wsize = server->ops->negotiate_wsize(tcon, volume_info); > - cifs_sb->rsize = server->ops->negotiate_rsize(tcon, volume_info); > > -remote_path_check: > -#ifdef CONFIG_CIFS_DFS_UPCALL > /* > * Perform an unconditional check for whether there are DFS > * referrals for this path without prefix, to provide support > @@ -4062,119 +4158,100 @@ cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *volume_info) > * with PATH_NOT_COVERED to requests that include the prefix. > * Chase the referral if found, otherwise continue normally. > */ > - if (referral_walks_count == 0) { > - int refrc = expand_dfs_referral(xid, ses, volume_info, cifs_sb, > - false); > - if (!refrc) { > - referral_walks_count++; > - goto try_mount_again; > - } > + old_mountdata = cifs_sb->mountdata; > + (void)expand_dfs_referral(xid, ses, vol, cifs_sb, false); > + > + if (cifs_sb->mountdata == NULL) { > + rc = -ENOENT; > + goto error; > } > -#endif > > - /* check if a whole path is not remote */ > - if (!rc && tcon) { > - if (!server->ops->is_path_accessible) { > - rc = -ENOSYS; > - goto mount_fail_check; > + if (cifs_sb->mountdata != old_mountdata) { > + /* If we were redirected, reconnect to new target server */ > + mount_put_conns(cifs_sb, xid, server, ses, tcon); > + rc = mount_get_conns(vol, cifs_sb, &xid, &server, &ses, &tcon); > + } > + if (rc) { > + if (rc == -EACCES || rc == -EOPNOTSUPP) > + goto error; > + } > + > + for (count = 1; ;) { > + if (!rc && tcon) { > + rc = is_path_remote(cifs_sb, vol, xid, server, tcon); > + if (!rc || rc != -EREMOTE) > + break; > } > /* > - * cifs_build_path_to_root works only when we have a valid tcon > + * BB: when we implement proper loop detection, > + * we will remove this check. But now we need it > + * to prevent an indefinite loop if 'DFS tree' is > + * misconfigured (i.e. has loops). > */ > - full_path = cifs_build_path_to_root(volume_info, cifs_sb, tcon, > - tcon->Flags & SMB_SHARE_IS_IN_DFS); > - if (full_path == NULL) { > - rc = -ENOMEM; > - goto mount_fail_check; > - } > - rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, > - full_path); > - if (rc != 0 && rc != -EREMOTE) { > - kfree(full_path); > - goto mount_fail_check; > - } > - > - if (rc != -EREMOTE) { > - rc = cifs_are_all_path_components_accessible(server, > - xid, tcon, cifs_sb, > - full_path); > - if (rc != 0) { > - cifs_dbg(VFS, "cannot query dirs between root and final path, " > - "enabling CIFS_MOUNT_USE_PREFIX_PATH\n"); > - cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; > - rc = 0; > - } > - } > - kfree(full_path); > - } > - > - /* get referral if needed */ > - if (rc == -EREMOTE) { > -#ifdef CONFIG_CIFS_DFS_UPCALL > - if (referral_walks_count > MAX_NESTED_LINKS) { > - /* > - * BB: when we implement proper loop detection, > - * we will remove this check. But now we need it > - * to prevent an indefinite loop if 'DFS tree' is > - * misconfigured (i.e. has loops). > - */ > + if (count++ > MAX_NESTED_LINKS) { > rc = -ELOOP; > - goto mount_fail_check; > + break; > } > > - rc = expand_dfs_referral(xid, ses, volume_info, cifs_sb, true); > + old_mountdata = cifs_sb->mountdata; > + rc = expand_dfs_referral(xid, tcon->ses, vol, cifs_sb, > + true); > + if (rc) > + break; > > - if (!rc) { > - referral_walks_count++; > - goto try_mount_again; > + if (cifs_sb->mountdata != old_mountdata) { > + mount_put_conns(cifs_sb, xid, server, ses, tcon); > + rc = mount_get_conns(vol, cifs_sb, &xid, &server, &ses, > + &tcon); > + } > + if (rc) { > + if (rc == -EACCES || rc == -EOPNOTSUPP || !server || > + !ses) > + goto error; > } > - goto mount_fail_check; > -#else /* No DFS support, return error on mount */ > - rc = -EOPNOTSUPP; > -#endif > } > > if (rc) > - goto mount_fail_check; > - > - /* now, hang the tcon off of the superblock */ > - tlink = kzalloc(sizeof *tlink, GFP_KERNEL); > - if (tlink == NULL) { > - rc = -ENOMEM; > - goto mount_fail_check; > - } > + goto error; > > - tlink->tl_uid = ses->linux_uid; > - tlink->tl_tcon = tcon; > - tlink->tl_time = jiffies; > - set_bit(TCON_LINK_MASTER, &tlink->tl_flags); > - set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags); > +out: > + free_xid(xid); > + return mount_setup_tlink(cifs_sb, ses, tcon); > > - cifs_sb->master_tlink = tlink; > - spin_lock(&cifs_sb->tlink_tree_lock); > - tlink_rb_insert(&cifs_sb->tlink_tree, tlink); > - spin_unlock(&cifs_sb->tlink_tree_lock); > +error: > + mount_put_conns(cifs_sb, xid, server, ses, tcon); > + return rc; > +} > +#else > +int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *vol) > +{ > + int rc = 0; > + unsigned int xid; > + struct cifs_ses *ses; > + struct cifs_tcon *tcon; > + struct TCP_Server_Info *server; > > - queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks, > - TLINK_IDLE_EXPIRE); > + rc = mount_get_conns(vol, cifs_sb, &xid, &server, &ses, &tcon); > + if (rc) > + goto error; > > -mount_fail_check: > - /* on error free sesinfo and tcon struct if needed */ > - if (rc) { > - /* If find_unc succeeded then rc == 0 so we can not end */ > - /* up accidentally freeing someone elses tcon struct */ > - if (tcon) > - cifs_put_tcon(tcon); > - else if (ses) > - cifs_put_smb_ses(ses); > - else > - cifs_put_tcp_session(server, 0); > + if (tcon) { > + rc = is_path_remote(cifs_sb, vol, xid, server, tcon); > + if (rc == -EREMOTE) > + rc = -EOPNOTSUPP; > + if (rc) > + goto error; > } > > -out: > free_xid(xid); > + > + return mount_setup_tlink(cifs_sb, ses, tcon); > + > +error: > + mount_put_conns(cifs_sb, xid, server, ses, tcon); > return rc; > } > +#endif > > /* > * Issue a TREE_CONNECT request. > -- > 2.13.7 >
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index fa361bc00602..f4dd2a3795dd 100644 --- a/fs/cifs/cifsproto.h +++ b/fs/cifs/cifsproto.h @@ -213,7 +213,7 @@ extern int cifs_match_super(struct super_block *, void *); extern void cifs_cleanup_volume_info(struct smb_vol *pvolume_info); extern struct smb_vol *cifs_get_volume_info(char *mount_data, const char *devname, bool is_smb3); -extern int cifs_mount(struct cifs_sb_info *, struct smb_vol *); +extern int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *vol); extern void cifs_umount(struct cifs_sb_info *); extern void cifs_mark_open_files_invalid(struct cifs_tcon *tcon); extern void cifs_reopen_persistent_handles(struct cifs_tcon *tcon); @@ -524,6 +524,8 @@ extern int E_md4hash(const unsigned char *passwd, unsigned char *p16, const struct nls_table *codepage); extern int SMBencrypt(unsigned char *passwd, const unsigned char *c8, unsigned char *p24); +extern void +cifs_cleanup_volume_info_contents(struct smb_vol *volume_info); void cifs_readdata_release(struct kref *refcount); int cifs_async_readv(struct cifs_readdata *rdata); diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 6f24f129a751..3caa2021a5d6 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -3746,8 +3746,8 @@ int cifs_setup_cifs_sb(struct smb_vol *pvolume_info, return 0; } -static void -cleanup_volume_info_contents(struct smb_vol *volume_info) +void +cifs_cleanup_volume_info_contents(struct smb_vol *volume_info) { kfree(volume_info->username); kzfree(volume_info->password); @@ -3762,10 +3762,136 @@ cifs_cleanup_volume_info(struct smb_vol *volume_info) { if (!volume_info) return; - cleanup_volume_info_contents(volume_info); + cifs_cleanup_volume_info_contents(volume_info); kfree(volume_info); } +/* Release all succeed connections */ +static inline void mount_put_conns(struct cifs_sb_info *cifs_sb, + unsigned int xid, + struct TCP_Server_Info *server, + struct cifs_ses *ses, struct cifs_tcon *tcon) +{ + int rc = 0; + + if (tcon) + cifs_put_tcon(tcon); + else if (ses) + cifs_put_smb_ses(ses); + else if (server) + cifs_put_tcp_session(server, 0); + cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS; + free_xid(xid); +} + +/* Get connections for tcp, ses and tcon */ +static int mount_get_conns(struct smb_vol *vol, struct cifs_sb_info *cifs_sb, + unsigned int *xid, + struct TCP_Server_Info **nserver, + struct cifs_ses **nses, struct cifs_tcon **ntcon) +{ + int rc = 0; + struct TCP_Server_Info *server; + struct cifs_ses *ses; + struct cifs_tcon *tcon; + + *nserver = NULL; + *nses = NULL; + *ntcon = NULL; + + *xid = get_xid(); + + /* get a reference to a tcp session */ + server = cifs_get_tcp_session(vol); + if (IS_ERR(server)) { + rc = PTR_ERR(server); + return rc; + } + + *nserver = server; + + if ((vol->max_credits < 20) || (vol->max_credits > 60000)) + server->max_credits = SMB2_MAX_CREDITS_AVAILABLE; + else + server->max_credits = vol->max_credits; + + /* get a reference to a SMB session */ + ses = cifs_get_smb_ses(server, vol); + if (IS_ERR(ses)) { + rc = PTR_ERR(ses); + return rc; + } + + *nses = ses; + + if ((vol->persistent == true) && (!(ses->server->capabilities & + SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) { + cifs_dbg(VFS, "persistent handles not supported by server\n"); + return -EOPNOTSUPP; + } + + /* search for existing tcon to this server share */ + tcon = cifs_get_tcon(ses, vol); + if (IS_ERR(tcon)) { + rc = PTR_ERR(tcon); + return rc; + } + + *ntcon = tcon; + + /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */ + if (tcon->posix_extensions) + cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS; + + /* tell server which Unix caps we support */ + if (cap_unix(tcon->ses)) { + /* + * reset of caps checks mount to see if unix extensions disabled + * for just this mount. + */ + reset_cifs_unix_caps(*xid, tcon, cifs_sb, vol); + if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) && + (le64_to_cpu(tcon->fsUnixInfo.Capability) & + CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) + return -EACCES; + } else + tcon->unix_ext = 0; /* server does not support them */ + + /* do not care if a following call succeed - informational */ + if (!tcon->pipe && server->ops->qfs_tcon) + server->ops->qfs_tcon(*xid, tcon); + + cifs_sb->wsize = server->ops->negotiate_wsize(tcon, vol); + cifs_sb->rsize = server->ops->negotiate_rsize(tcon, vol); + + return 0; +} + +static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses, + struct cifs_tcon *tcon) +{ + struct tcon_link *tlink; + + /* hang the tcon off of the superblock */ + tlink = kzalloc(sizeof *tlink, GFP_KERNEL); + if (tlink == NULL) + return -ENOMEM; + + tlink->tl_uid = ses->linux_uid; + tlink->tl_tcon = tcon; + tlink->tl_time = jiffies; + set_bit(TCON_LINK_MASTER, &tlink->tl_flags); + set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags); + + cifs_sb->master_tlink = tlink; + spin_lock(&cifs_sb->tlink_tree_lock); + tlink_rb_insert(&cifs_sb->tlink_tree, tlink); + spin_unlock(&cifs_sb->tlink_tree_lock); + + queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks, + TLINK_IDLE_EXPIRE); + return 0; +} #ifdef CONFIG_CIFS_DFS_UPCALL /* @@ -3845,7 +3971,7 @@ expand_dfs_referral(const unsigned int xid, struct cifs_ses *ses, rc = PTR_ERR(mdata); mdata = NULL; } else { - cleanup_volume_info_contents(volume_info); + cifs_cleanup_volume_info_contents(volume_info); rc = cifs_setup_volume_info(volume_info, mdata, fake_devname, false); } @@ -3954,107 +4080,77 @@ cifs_are_all_path_components_accessible(struct TCP_Server_Info *server, return rc; } -int -cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *volume_info) +/* + * Check if path is remote (e.g. a DFS share). Return -EREMOTE if it is, + * otherwise 0. + */ +static int is_path_remote(struct cifs_sb_info *cifs_sb, struct smb_vol *vol, + const unsigned int xid, + struct TCP_Server_Info *server, + struct cifs_tcon *tcon) { int rc; - unsigned int xid; - struct cifs_ses *ses; - struct cifs_tcon *tcon; - struct TCP_Server_Info *server; - char *full_path; - struct tcon_link *tlink; -#ifdef CONFIG_CIFS_DFS_UPCALL - int referral_walks_count = 0; -#endif - -#ifdef CONFIG_CIFS_DFS_UPCALL -try_mount_again: - /* cleanup activities if we're chasing a referral */ - if (referral_walks_count) { - if (tcon) - cifs_put_tcon(tcon); - else if (ses) - cifs_put_smb_ses(ses); - - cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS; + char *full_path; - free_xid(xid); - } -#endif - rc = 0; - tcon = NULL; - ses = NULL; - server = NULL; - full_path = NULL; - tlink = NULL; + if (!server->ops->is_path_accessible) + return -ENOSYS; - xid = get_xid(); + /* + * cifs_build_path_to_root works only when we have a valid tcon + */ + full_path = cifs_build_path_to_root(vol, cifs_sb, tcon, + tcon->Flags & SMB_SHARE_IS_IN_DFS); + if (full_path == NULL) + return -ENOMEM; - /* get a reference to a tcp session */ - server = cifs_get_tcp_session(volume_info); - if (IS_ERR(server)) { - rc = PTR_ERR(server); - goto out; - } - if ((volume_info->max_credits < 20) || - (volume_info->max_credits > 60000)) - server->max_credits = SMB2_MAX_CREDITS_AVAILABLE; - else - server->max_credits = volume_info->max_credits; - /* get a reference to a SMB session */ - ses = cifs_get_smb_ses(server, volume_info); - if (IS_ERR(ses)) { - rc = PTR_ERR(ses); - ses = NULL; - goto mount_fail_check; - } + cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path); - if ((volume_info->persistent == true) && ((ses->server->capabilities & - SMB2_GLOBAL_CAP_PERSISTENT_HANDLES) == 0)) { - cifs_dbg(VFS, "persistent handles not supported by server\n"); - rc = -EOPNOTSUPP; - goto mount_fail_check; + rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, + full_path); + if (rc != 0 && rc != -EREMOTE) { + kfree(full_path); + return rc; } - /* search for existing tcon to this server share */ - tcon = cifs_get_tcon(ses, volume_info); - if (IS_ERR(tcon)) { - rc = PTR_ERR(tcon); - tcon = NULL; - if (rc == -EACCES) - goto mount_fail_check; - - goto remote_path_check; + if (rc != -EREMOTE) { + rc = cifs_are_all_path_components_accessible(server, xid, tcon, + cifs_sb, + full_path); + if (rc != 0) { + cifs_dbg(VFS, "cannot query dirs between root and final path, " + "enabling CIFS_MOUNT_USE_PREFIX_PATH\n"); + cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; + rc = 0; + } } - /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */ - if (tcon->posix_extensions) - cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS; + kfree(full_path); + return rc; +} - /* tell server which Unix caps we support */ - if (cap_unix(tcon->ses)) { - /* reset of caps checks mount to see if unix extensions - disabled for just this mount */ - reset_cifs_unix_caps(xid, tcon, cifs_sb, volume_info); - if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) && - (le64_to_cpu(tcon->fsUnixInfo.Capability) & - CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) { - rc = -EACCES; - goto mount_fail_check; - } - } else - tcon->unix_ext = 0; /* server does not support them */ +#ifdef CONFIG_CIFS_DFS_UPCALL +int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *vol) +{ + int rc = 0; + unsigned int xid; + struct cifs_ses *ses; + struct cifs_tcon *tcon = NULL; + struct TCP_Server_Info *server; + char *old_mountdata; + int count; - /* do not care if a following call succeed - informational */ - if (!tcon->pipe && server->ops->qfs_tcon) - server->ops->qfs_tcon(xid, tcon); + rc = mount_get_conns(vol, cifs_sb, &xid, &server, &ses, &tcon); + if (!rc && tcon) { + rc = is_path_remote(cifs_sb, vol, xid, server, tcon); + if (!rc) + goto out; + if (rc != -EREMOTE) + goto error; + } + if (rc == -EACCES || rc == -EOPNOTSUPP) + goto error; - cifs_sb->wsize = server->ops->negotiate_wsize(tcon, volume_info); - cifs_sb->rsize = server->ops->negotiate_rsize(tcon, volume_info); -remote_path_check: -#ifdef CONFIG_CIFS_DFS_UPCALL /* * Perform an unconditional check for whether there are DFS * referrals for this path without prefix, to provide support @@ -4062,119 +4158,100 @@ cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *volume_info) * with PATH_NOT_COVERED to requests that include the prefix. * Chase the referral if found, otherwise continue normally. */ - if (referral_walks_count == 0) { - int refrc = expand_dfs_referral(xid, ses, volume_info, cifs_sb, - false); - if (!refrc) { - referral_walks_count++; - goto try_mount_again; - } + old_mountdata = cifs_sb->mountdata; + (void)expand_dfs_referral(xid, ses, vol, cifs_sb, false); + + if (cifs_sb->mountdata == NULL) { + rc = -ENOENT; + goto error; } -#endif - /* check if a whole path is not remote */ - if (!rc && tcon) { - if (!server->ops->is_path_accessible) { - rc = -ENOSYS; - goto mount_fail_check; + if (cifs_sb->mountdata != old_mountdata) { + /* If we were redirected, reconnect to new target server */ + mount_put_conns(cifs_sb, xid, server, ses, tcon); + rc = mount_get_conns(vol, cifs_sb, &xid, &server, &ses, &tcon); + } + if (rc) { + if (rc == -EACCES || rc == -EOPNOTSUPP) + goto error; + } + + for (count = 1; ;) { + if (!rc && tcon) { + rc = is_path_remote(cifs_sb, vol, xid, server, tcon); + if (!rc || rc != -EREMOTE) + break; } /* - * cifs_build_path_to_root works only when we have a valid tcon + * BB: when we implement proper loop detection, + * we will remove this check. But now we need it + * to prevent an indefinite loop if 'DFS tree' is + * misconfigured (i.e. has loops). */ - full_path = cifs_build_path_to_root(volume_info, cifs_sb, tcon, - tcon->Flags & SMB_SHARE_IS_IN_DFS); - if (full_path == NULL) { - rc = -ENOMEM; - goto mount_fail_check; - } - rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, - full_path); - if (rc != 0 && rc != -EREMOTE) { - kfree(full_path); - goto mount_fail_check; - } - - if (rc != -EREMOTE) { - rc = cifs_are_all_path_components_accessible(server, - xid, tcon, cifs_sb, - full_path); - if (rc != 0) { - cifs_dbg(VFS, "cannot query dirs between root and final path, " - "enabling CIFS_MOUNT_USE_PREFIX_PATH\n"); - cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH; - rc = 0; - } - } - kfree(full_path); - } - - /* get referral if needed */ - if (rc == -EREMOTE) { -#ifdef CONFIG_CIFS_DFS_UPCALL - if (referral_walks_count > MAX_NESTED_LINKS) { - /* - * BB: when we implement proper loop detection, - * we will remove this check. But now we need it - * to prevent an indefinite loop if 'DFS tree' is - * misconfigured (i.e. has loops). - */ + if (count++ > MAX_NESTED_LINKS) { rc = -ELOOP; - goto mount_fail_check; + break; } - rc = expand_dfs_referral(xid, ses, volume_info, cifs_sb, true); + old_mountdata = cifs_sb->mountdata; + rc = expand_dfs_referral(xid, tcon->ses, vol, cifs_sb, + true); + if (rc) + break; - if (!rc) { - referral_walks_count++; - goto try_mount_again; + if (cifs_sb->mountdata != old_mountdata) { + mount_put_conns(cifs_sb, xid, server, ses, tcon); + rc = mount_get_conns(vol, cifs_sb, &xid, &server, &ses, + &tcon); + } + if (rc) { + if (rc == -EACCES || rc == -EOPNOTSUPP || !server || + !ses) + goto error; } - goto mount_fail_check; -#else /* No DFS support, return error on mount */ - rc = -EOPNOTSUPP; -#endif } if (rc) - goto mount_fail_check; - - /* now, hang the tcon off of the superblock */ - tlink = kzalloc(sizeof *tlink, GFP_KERNEL); - if (tlink == NULL) { - rc = -ENOMEM; - goto mount_fail_check; - } + goto error; - tlink->tl_uid = ses->linux_uid; - tlink->tl_tcon = tcon; - tlink->tl_time = jiffies; - set_bit(TCON_LINK_MASTER, &tlink->tl_flags); - set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags); +out: + free_xid(xid); + return mount_setup_tlink(cifs_sb, ses, tcon); - cifs_sb->master_tlink = tlink; - spin_lock(&cifs_sb->tlink_tree_lock); - tlink_rb_insert(&cifs_sb->tlink_tree, tlink); - spin_unlock(&cifs_sb->tlink_tree_lock); +error: + mount_put_conns(cifs_sb, xid, server, ses, tcon); + return rc; +} +#else +int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *vol) +{ + int rc = 0; + unsigned int xid; + struct cifs_ses *ses; + struct cifs_tcon *tcon; + struct TCP_Server_Info *server; - queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks, - TLINK_IDLE_EXPIRE); + rc = mount_get_conns(vol, cifs_sb, &xid, &server, &ses, &tcon); + if (rc) + goto error; -mount_fail_check: - /* on error free sesinfo and tcon struct if needed */ - if (rc) { - /* If find_unc succeeded then rc == 0 so we can not end */ - /* up accidentally freeing someone elses tcon struct */ - if (tcon) - cifs_put_tcon(tcon); - else if (ses) - cifs_put_smb_ses(ses); - else - cifs_put_tcp_session(server, 0); + if (tcon) { + rc = is_path_remote(cifs_sb, vol, xid, server, tcon); + if (rc == -EREMOTE) + rc = -EOPNOTSUPP; + if (rc) + goto error; } -out: free_xid(xid); + + return mount_setup_tlink(cifs_sb, ses, tcon); + +error: + mount_put_conns(cifs_sb, xid, server, ses, tcon); return rc; } +#endif /* * Issue a TREE_CONNECT request.