diff options
| -rw-r--r-- | fs/cifs/cifs_fs_sb.h | 7 | ||||
| -rw-r--r-- | fs/cifs/cifsglob.h | 32 | ||||
| -rw-r--r-- | fs/cifs/connect.c | 268 |
3 files changed, 279 insertions, 28 deletions
diff --git a/fs/cifs/cifs_fs_sb.h b/fs/cifs/cifs_fs_sb.h index e04e6923d35..5ce57bdf186 100644 --- a/fs/cifs/cifs_fs_sb.h +++ b/fs/cifs/cifs_fs_sb.h @@ -15,6 +15,8 @@ * the GNU Lesser General Public License for more details. * */ +#include <linux/radix-tree.h> + #ifndef _CIFS_FS_SB_H #define _CIFS_FS_SB_H @@ -40,8 +42,9 @@ #define CIFS_MOUNT_MULTIUSER 0x20000 /* multiuser mount */ struct cifs_sb_info { - struct cifsTconInfo *ptcon; /* primary mount */ - struct list_head nested_tcon_q; + struct radix_tree_root tlink_tree; +#define CIFS_TLINK_MASTER_TAG 0 /* is "master" (mount) tcon */ + spinlock_t tlink_tree_lock; struct nls_table *local_nls; unsigned int rsize; unsigned int wsize; diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index d5324853203..9a7c472a153 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -317,42 +317,36 @@ struct cifsTconInfo { * "get" on the container. */ struct tcon_link { - spinlock_t tl_lock; - u32 tl_count; - u64 tl_time; + unsigned long tl_index; + unsigned long tl_flags; +#define TCON_LINK_MASTER 0 +#define TCON_LINK_PENDING 1 +#define TCON_LINK_IN_TREE 2 + unsigned long tl_time; + atomic_t tl_count; struct cifsTconInfo *tl_tcon; }; -static inline struct tcon_link * -cifs_sb_tlink(struct cifs_sb_info *cifs_sb) -{ - return (struct tcon_link *)cifs_sb->ptcon; -} +extern struct tcon_link *cifs_sb_tlink(struct cifs_sb_info *cifs_sb); static inline struct cifsTconInfo * tlink_tcon(struct tcon_link *tlink) { - return (struct cifsTconInfo *)tlink; + return tlink->tl_tcon; } -static inline void -cifs_put_tlink(struct tcon_link *tlink) -{ - return; -} +extern void cifs_put_tlink(struct tcon_link *tlink); static inline struct tcon_link * cifs_get_tlink(struct tcon_link *tlink) { + if (tlink && !IS_ERR(tlink)) + atomic_inc(&tlink->tl_count); return tlink; } /* This function is always expected to succeed */ -static inline struct cifsTconInfo * -cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb) -{ - return cifs_sb->ptcon; -} +extern struct cifsTconInfo *cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb); /* * This info hangs off the cifsFileInfo structure, pointed to by llist. diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index f6a3091c287..3156a9de947 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -109,6 +109,9 @@ struct smb_vol { struct nls_table *local_nls; }; +#define TLINK_ERROR_EXPIRE (1 * HZ) + + static int ipv4_connect(struct TCP_Server_Info *server); static int ipv6_connect(struct TCP_Server_Info *server); @@ -1959,6 +1962,23 @@ out_fail: return ERR_PTR(rc); } +void +cifs_put_tlink(struct tcon_link *tlink) +{ + if (!tlink || IS_ERR(tlink)) + return; + + if (!atomic_dec_and_test(&tlink->tl_count) || + test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) { + tlink->tl_time = jiffies; + return; + } + + if (!IS_ERR(tlink_tcon(tlink))) + cifs_put_tcon(tlink_tcon(tlink)); + kfree(tlink); + return; +} int get_dfs_path(int xid, struct cifsSesInfo *pSesInfo, const char *old_path, @@ -2641,6 +2661,7 @@ cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb, struct TCP_Server_Info *srvTcp; char *full_path; char *mount_data = mount_data_global; + struct tcon_link *tlink; #ifdef CONFIG_CIFS_DFS_UPCALL struct dfs_info3_param *referrals = NULL; unsigned int num_referrals = 0; @@ -2652,6 +2673,7 @@ try_mount_again: pSesInfo = NULL; srvTcp = NULL; full_path = NULL; + tlink = NULL; xid = GetXid(); @@ -2727,8 +2749,6 @@ try_mount_again: goto remote_path_check; } - cifs_sb->ptcon = tcon; - /* do not care if following two calls succeed - informational */ if (!tcon->ipc) { CIFSSMBQFSDeviceInfo(xid, tcon); @@ -2837,6 +2857,35 @@ remote_path_check: #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; + } + + tlink->tl_index = pSesInfo->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); + + rc = radix_tree_preload(GFP_KERNEL); + if (rc == -ENOMEM) { + kfree(tlink); + goto mount_fail_check; + } + + spin_lock(&cifs_sb->tlink_tree_lock); + radix_tree_insert(&cifs_sb->tlink_tree, pSesInfo->linux_uid, tlink); + radix_tree_tag_set(&cifs_sb->tlink_tree, pSesInfo->linux_uid, + CIFS_TLINK_MASTER_TAG); + spin_unlock(&cifs_sb->tlink_tree_lock); + radix_tree_preload_end(); + mount_fail_check: /* on error free sesinfo and tcon struct if needed */ if (rc) { @@ -3023,19 +3072,37 @@ CIFSTCon(unsigned int xid, struct cifsSesInfo *ses, int cifs_umount(struct super_block *sb, struct cifs_sb_info *cifs_sb) { - int rc = 0; + int i, ret; char *tmp; - struct cifsTconInfo *tcon = cifs_sb_master_tcon(cifs_sb); + struct tcon_link *tlink[8]; + unsigned long index = 0; + + do { + spin_lock(&cifs_sb->tlink_tree_lock); + ret = radix_tree_gang_lookup(&cifs_sb->tlink_tree, + (void **)tlink, index, + ARRAY_SIZE(tlink)); + /* increment index for next pass */ + if (ret > 0) + index = tlink[ret - 1]->tl_index + 1; + for (i = 0; i < ret; i++) { + cifs_get_tlink(tlink[i]); + clear_bit(TCON_LINK_IN_TREE, &tlink[i]->tl_flags); + radix_tree_delete(&cifs_sb->tlink_tree, + tlink[i]->tl_index); + } + spin_unlock(&cifs_sb->tlink_tree_lock); - cifs_put_tcon(tcon); + for (i = 0; i < ret; i++) + cifs_put_tlink(tlink[i]); + } while (ret != 0); - cifs_sb->ptcon = NULL; tmp = cifs_sb->prepath; cifs_sb->prepathlen = 0; cifs_sb->prepath = NULL; kfree(tmp); - return rc; + return 0; } int cifs_negotiate_protocol(unsigned int xid, struct cifsSesInfo *ses) @@ -3096,3 +3163,190 @@ int cifs_setup_session(unsigned int xid, struct cifsSesInfo *ses, return rc; } +struct cifsTconInfo * +cifs_construct_tcon(struct cifs_sb_info *cifs_sb, uid_t fsuid) +{ + struct cifsTconInfo *master_tcon = cifs_sb_master_tcon(cifs_sb); + struct cifsSesInfo *ses; + struct cifsTconInfo *tcon = NULL; + struct smb_vol *vol_info; + char username[MAX_USERNAME_SIZE + 1]; + + vol_info = kzalloc(sizeof(*vol_info), GFP_KERNEL); + if (vol_info == NULL) { + tcon = ERR_PTR(-ENOMEM); + goto out; + } + + snprintf(username, MAX_USERNAME_SIZE, "krb50x%x", fsuid); + vol_info->username = username; + vol_info->local_nls = cifs_sb->local_nls; + vol_info->linux_uid = fsuid; + vol_info->cred_uid = fsuid; + vol_info->UNC = master_tcon->treeName; + vol_info->retry = master_tcon->retry; + vol_info->nocase = master_tcon->nocase; + vol_info->local_lease = master_tcon->local_lease; + vol_info->no_linux_ext = !master_tcon->unix_ext; + + /* FIXME: allow for other secFlg settings */ + vol_info->secFlg = CIFSSEC_MUST_KRB5; + + /* get a reference for the same TCP session */ + write_lock(&cifs_tcp_ses_lock); + ++master_tcon->ses->server->srv_count; + write_unlock(&cifs_tcp_ses_lock); + + ses = cifs_get_smb_ses(master_tcon->ses->server, vol_info); + if (IS_ERR(ses)) { + tcon = (struct cifsTconInfo *)ses; + cifs_put_tcp_session(master_tcon->ses->server); + goto out; + } + + tcon = cifs_get_tcon(ses, vol_info); + if (IS_ERR(tcon)) { + cifs_put_smb_ses(ses); + goto out; + } + + if (ses->capabilities & CAP_UNIX) + reset_cifs_unix_caps(0, tcon, NULL, vol_info); +out: + kfree(vol_info); + + return tcon; +} + +static struct tcon_link * +cifs_sb_master_tlink(struct cifs_sb_info *cifs_sb) +{ + struct tcon_link *tlink; + unsigned int ret; + + spin_lock(&cifs_sb->tlink_tree_lock); + ret = radix_tree_gang_lookup_tag(&cifs_sb->tlink_tree, (void **)&tlink, + 0, 1, CIFS_TLINK_MASTER_TAG); + spin_unlock(&cifs_sb->tlink_tree_lock); + + /* the master tcon should always be present */ + if (ret == 0) + BUG(); + + return tlink; +} + +struct cifsTconInfo * +cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb) +{ + return tlink_tcon(cifs_sb_master_tlink(cifs_sb)); +} + +static int +cifs_sb_tcon_pending_wait(void *unused) +{ + schedule(); + return signal_pending(current) ? -ERESTARTSYS : 0; +} + +/* + * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the + * current task. + * + * If the superblock doesn't refer to a multiuser mount, then just return + * the master tcon for the mount. + * + * First, search the radix tree for an existing tcon for this fsuid. If one + * exists, then check to see if it's pending construction. If it is then wait + * for construction to complete. Once it's no longer pending, check to see if + * it failed and either return an error or retry construction, depending on + * the timeout. + * + * If one doesn't exist then insert a new tcon_link struct into the tree and + * try to construct a new one. + */ +struct tcon_link * +cifs_sb_tlink(struct cifs_sb_info *cifs_sb) +{ + int ret; + unsigned long fsuid = (unsigned long) current_fsuid(); + struct tcon_link *tlink, *newtlink; + + if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER)) + return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb)); + + spin_lock(&cifs_sb->tlink_tree_lock); + tlink = radix_tree_lookup(&cifs_sb->tlink_tree, fsuid); + if (tlink) + cifs_get_tlink(tlink); + spin_unlock(&cifs_sb->tlink_tree_lock); + + if (tlink == NULL) { + newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL); + if (newtlink == NULL) + return ERR_PTR(-ENOMEM); + newtlink->tl_index = fsuid; + newtlink->tl_tcon = ERR_PTR(-EACCES); + set_bit(TCON_LINK_PENDING, &newtlink->tl_flags); + set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags); + cifs_get_tlink(newtlink); + + ret = radix_tree_preload(GFP_KERNEL); + if (ret != 0) { + kfree(newtlink); + return ERR_PTR(ret); + } + + spin_lock(&cifs_sb->tlink_tree_lock); + /* was one inserted after previous search? */ + tlink = radix_tree_lookup(&cifs_sb->tlink_tree, fsuid); + if (tlink) { + cifs_get_tlink(tlink); + spin_unlock(&cifs_sb->tlink_tree_lock); + radix_tree_preload_end(); + kfree(newtlink); + goto wait_for_construction; + } + ret = radix_tree_insert(&cifs_sb->tlink_tree, fsuid, newtlink); + spin_unlock(&cifs_sb->tlink_tree_lock); + radix_tree_preload_end(); + if (ret) { + kfree(newtlink); + return ERR_PTR(ret); + } + tlink = newtlink; + } else { +wait_for_construction: + ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING, + cifs_sb_tcon_pending_wait, + TASK_INTERRUPTIBLE); + if (ret) { + cifs_put_tlink(tlink); + return ERR_PTR(ret); + } + + /* if it's good, return it */ + if (!IS_ERR(tlink->tl_tcon)) + return tlink; + + /* return error if we tried this already recently */ + if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) { + cifs_put_tlink(tlink); + return ERR_PTR(-EACCES); + } + + if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags)) + goto wait_for_construction; + } + + tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid); + clear_bit(TCON_LINK_PENDING, &tlink->tl_flags); + wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING); + + if (IS_ERR(tlink->tl_tcon)) { + cifs_put_tlink(tlink); + return ERR_PTR(-EACCES); + } + + return tlink; +} |