7 files changed, 250 insertions, 46 deletions

diff --git a/fs/afs/cell.c b/fs/afs/cell.c
index d0765883430..0d5eeadf612 100644
--- a/fs/afs/cell.c
+++ b/fs/afs/cell.c
@@ -31,21 +31,20 @@ static struct afs_cell *afs_cell_root;
  * allocate a cell record and fill in its name, VL server address list and
  * allocate an anonymous key
  */
-static struct afs_cell *afs_cell_alloc(const char *name, char *vllist)
+static struct afs_cell *afs_cell_alloc(const char *name, unsigned namelen,
+                                       char *vllist)
 {
         struct afs_cell *cell;
         struct key *key;
-        size_t namelen;
         char keyname[4 + AFS_MAXCELLNAME + 1], *cp, *dp, *next;
         char  *dvllist = NULL, *_vllist = NULL;
         char  delimiter = ':';
         int ret;
 
-        _enter("%s,%s", name, vllist);
+        _enter("%*.*s,%s", namelen, namelen, name ?: "", vllist);
 
         BUG_ON(!name); /* TODO: want to look up "this cell" in the cache */
 
-        namelen = strlen(name);
         if (namelen > AFS_MAXCELLNAME) {
                 _leave(" = -ENAMETOOLONG");
                 return ERR_PTR(-ENAMETOOLONG);
@@ -142,26 +141,29 @@ error:
 }
 
 /*
- * create a cell record
- * - "name" is the name of the cell
- * - "vllist" is a colon separated list of IP addresses in "a.b.c.d" format
+ * afs_cell_crate() - create a cell record
+ * @name:       is the name of the cell.
+ * @namsesz:    is the strlen of the cell name.
+ * @vllist:     is a colon separated list of IP addresses in "a.b.c.d" format.
+ * @retref:     is T to return the cell reference when the cell exists.
  */
-struct afs_cell *afs_cell_create(const char *name, char *vllist)
+struct afs_cell *afs_cell_create(const char *name, unsigned namesz,
+                                 char *vllist, bool retref)
 {
         struct afs_cell *cell;
         int ret;
 
-        _enter("%s,%s", name, vllist);
+        _enter("%*.*s,%s", namesz, namesz, name ?: "", vllist);
 
         down_write(&afs_cells_sem);
         read_lock(&afs_cells_lock);
         list_for_each_entry(cell, &afs_cells, link) {
-                if (strcasecmp(cell->name, name) == 0)
+                if (strncasecmp(cell->name, name, namesz) == 0)
                         goto duplicate_name;
         }
         read_unlock(&afs_cells_lock);
 
-        cell = afs_cell_alloc(name, vllist);
+        cell = afs_cell_alloc(name, namesz, vllist);
         if (IS_ERR(cell)) {
                 _leave(" = %ld", PTR_ERR(cell));
                 up_write(&afs_cells_sem);
@@ -201,8 +203,18 @@ error:
         return ERR_PTR(ret);
 
 duplicate_name:
+        if (retref && !IS_ERR(cell))
+                afs_get_cell(cell);
+
         read_unlock(&afs_cells_lock);
         up_write(&afs_cells_sem);
+
+        if (retref) {
+                _leave(" = %p", cell);
+                return cell;
+        }
+
+        _leave(" = -EEXIST");
         return ERR_PTR(-EEXIST);
 }
 
@@ -233,7 +245,7 @@ int afs_cell_init(char *rootcell)
                 *cp++ = 0;
 
         /* allocate a cell record for the root cell */
-        new_root = afs_cell_create(rootcell, cp);
+        new_root = afs_cell_create(rootcell, strlen(rootcell), cp, false);
         if (IS_ERR(new_root)) {
                 _leave(" = %ld", PTR_ERR(new_root));
                 return PTR_ERR(new_root);
@@ -253,11 +265,12 @@ int afs_cell_init(char *rootcell)
 /*
  * lookup a cell record
  */
-struct afs_cell *afs_cell_lookup(const char *name, unsigned namesz)
+struct afs_cell *afs_cell_lookup(const char *name, unsigned namesz,
+                                 bool dns_cell)
 {
         struct afs_cell *cell;
 
-        _enter("\"%*.*s\",", namesz, namesz, name ? name : "");
+        _enter("\"%*.*s\",", namesz, namesz, name ?: "");
 
         down_read(&afs_cells_sem);
         read_lock(&afs_cells_lock);
@@ -271,6 +284,8 @@ struct afs_cell *afs_cell_lookup(const char *name, unsigned namesz)
                         }
                 }
                 cell = ERR_PTR(-ENOENT);
+                if (dns_cell)
+                        goto create_cell;
         found:
                 ;
         } else {
@@ -293,6 +308,15 @@ struct afs_cell *afs_cell_lookup(const char *name, unsigned namesz)
         up_read(&afs_cells_sem);
         _leave(" = %p", cell);
         return cell;
+
+create_cell:
+        read_unlock(&afs_cells_lock);
+        up_read(&afs_cells_sem);
+
+        cell = afs_cell_create(name, namesz, NULL, true);
+
+        _leave(" = %p", cell);
+        return cell;
 }
 
 #if 0
diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index b42d5cc1d6d..0d38c09bd55 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -477,6 +477,40 @@ static int afs_do_lookup(struct inode *dir, struct dentry *dentry,
 }
 
 /*
+ * Try to auto mount the mountpoint with pseudo directory, if the autocell
+ * operation is setted.
+ */
+static struct inode *afs_try_auto_mntpt(
+        int ret, struct dentry *dentry, struct inode *dir, struct key *key,
+        struct afs_fid *fid)
+{
+        const char *devname = dentry->d_name.name;
+        struct afs_vnode *vnode = AFS_FS_I(dir);
+        struct inode *inode;
+
+        _enter("%d, %p{%s}, {%x:%u}, %p",
+               ret, dentry, devname, vnode->fid.vid, vnode->fid.vnode, key);
+
+        if (ret != -ENOENT ||
+            !test_bit(AFS_VNODE_AUTOCELL, &vnode->flags))
+                goto out;
+
+        inode = afs_iget_autocell(dir, devname, strlen(devname), key);
+        if (IS_ERR(inode)) {
+                ret = PTR_ERR(inode);
+                goto out;
+        }
+
+        *fid = AFS_FS_I(inode)->fid;
+        _leave("= %p", inode);
+        return inode;
+
+out:
+        _leave("= %d", ret);
+        return ERR_PTR(ret);
+}
+
+/*
  * look up an entry in a directory
  */
 static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
@@ -520,6 +554,13 @@ static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
 
         ret = afs_do_lookup(dir, dentry, &fid, key);
         if (ret < 0) {
+                inode = afs_try_auto_mntpt(ret, dentry, dir, key, &fid);
+                if (!IS_ERR(inode)) {
+                        key_put(key);
+                        goto success;
+                }
+
+                ret = PTR_ERR(inode);
                 key_put(key);
                 if (ret == -ENOENT) {
                         d_add(dentry, NULL);
@@ -539,6 +580,7 @@ static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
                 return ERR_CAST(inode);
         }
 
+success:
         dentry->d_op = &afs_fs_dentry_operations;
 
         d_add(dentry, inode);
@@ -696,8 +738,9 @@ static int afs_d_delete(struct dentry *dentry)
                 goto zap;
 
         if (dentry->d_inode &&
-            test_bit(AFS_VNODE_DELETED, &AFS_FS_I(dentry->d_inode)->flags))
-                        goto zap;
+            (test_bit(AFS_VNODE_DELETED,   &AFS_FS_I(dentry->d_inode)->flags) ||
+             test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(dentry->d_inode)->flags)))
+                goto zap;
 
         _leave(" = 0 [keep]");
         return 0;
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 320ffef1157..0747339011c 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -19,6 +19,8 @@
 #include <linux/fs.h>
 #include <linux/pagemap.h>
 #include <linux/sched.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
 #include "internal.h"
 
 struct afs_iget_data {
@@ -102,6 +104,16 @@ static int afs_iget5_test(struct inode *inode, void *opaque)
 }
 
 /*
+ * iget5() comparator for inode created by autocell operations
+ *
+ * These pseudo inodes don't match anything.
+ */
+static int afs_iget5_autocell_test(struct inode *inode, void *opaque)
+{
+        return 0;
+}
+
+/*
  * iget5() inode initialiser
  */
 static int afs_iget5_set(struct inode *inode, void *opaque)
@@ -118,6 +130,67 @@ static int afs_iget5_set(struct inode *inode, void *opaque)
 }
 
 /*
+ * inode retrieval for autocell
+ */
+struct inode *afs_iget_autocell(struct inode *dir, const char *dev_name,
+                                int namesz, struct key *key)
+{
+        struct afs_iget_data data;
+        struct afs_super_info *as;
+        struct afs_vnode *vnode;
+        struct super_block *sb;
+        struct inode *inode;
+        static atomic_t afs_autocell_ino;
+
+        _enter("{%x:%u},%*.*s,",
+               AFS_FS_I(dir)->fid.vid, AFS_FS_I(dir)->fid.vnode,
+               namesz, namesz, dev_name ?: "");
+
+        sb = dir->i_sb;
+        as = sb->s_fs_info;
+        data.volume = as->volume;
+        data.fid.vid = as->volume->vid;
+        data.fid.unique = 0;
+        data.fid.vnode = 0;
+
+        inode = iget5_locked(sb, atomic_inc_return(&afs_autocell_ino),
+                             afs_iget5_autocell_test, afs_iget5_set,
+                             &data);
+        if (!inode) {
+                _leave(" = -ENOMEM");
+                return ERR_PTR(-ENOMEM);
+        }
+
+        _debug("GOT INODE %p { ino=%lu, vl=%x, vn=%x, u=%x }",
+               inode, inode->i_ino, data.fid.vid, data.fid.vnode,
+               data.fid.unique);
+
+        vnode = AFS_FS_I(inode);
+
+        /* there shouldn't be an existing inode */
+        BUG_ON(!(inode->i_state & I_NEW));
+
+        inode->i_size           = 0;
+        inode->i_mode           = S_IFDIR | S_IRUGO | S_IXUGO;
+        inode->i_op             = &afs_autocell_inode_operations;
+        inode->i_nlink          = 2;
+        inode->i_uid            = 0;
+        inode->i_gid            = 0;
+        inode->i_ctime.tv_sec   = get_seconds();
+        inode->i_ctime.tv_nsec  = 0;
+        inode->i_atime          = inode->i_mtime = inode->i_ctime;
+        inode->i_blocks         = 0;
+        inode->i_version        = 0;
+        inode->i_generation     = 0;
+
+        set_bit(AFS_VNODE_PSEUDODIR, &vnode->flags);
+        inode->i_flags |= S_NOATIME;
+        unlock_new_inode(inode);
+        _leave(" = %p", inode);
+        return inode;
+}
+
+/*
  * inode retrieval
  */
 struct inode *afs_iget(struct super_block *sb, struct key *key,
@@ -314,6 +387,19 @@ int afs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 }
 
 /*
+ * discard an AFS inode
+ */
+int afs_drop_inode(struct inode *inode)
+{
+        _enter("");
+
+        if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
+                return generic_delete_inode(inode);
+        else
+                return generic_drop_inode(inode);
+}
+
+/*
  * clear an AFS inode
  */
 void afs_evict_inode(struct inode *inode)
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 8679089ce9a..ce12a2b06f8 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -42,6 +42,7 @@ typedef enum {
 struct afs_mount_params {
         bool                    rwpath;         /* T if the parent should be considered R/W */
         bool                    force;          /* T to force cell type */
+        bool                    autocell;       /* T if set auto mount operation */
         afs_voltype_t           type;           /* type of volume requested */
         int                     volnamesz;      /* size of volume name */
         const char              *volname;       /* name of volume to mount */
@@ -358,6 +359,8 @@ struct afs_vnode {
 #define AFS_VNODE_READLOCKED    7               /* set if vnode is read-locked on the server */
 #define AFS_VNODE_WRITELOCKED   8               /* set if vnode is write-locked on the server */
 #define AFS_VNODE_UNLOCKING     9               /* set if vnode is being unlocked on the server */
+#define AFS_VNODE_AUTOCELL      10              /* set if Vnode is an auto mount point */
+#define AFS_VNODE_PSEUDODIR     11              /* set if Vnode is a pseudo directory */
 
         long                    acl_order;      /* ACL check count (callback break count) */
 
@@ -468,8 +471,8 @@ extern struct list_head afs_proc_cells;
 
 #define afs_get_cell(C) do { atomic_inc(&(C)->usage); } while(0)
 extern int afs_cell_init(char *);
-extern struct afs_cell *afs_cell_create(const char *, char *);
-extern struct afs_cell *afs_cell_lookup(const char *, unsigned);
+extern struct afs_cell *afs_cell_create(const char *, unsigned, char *, bool);
+extern struct afs_cell *afs_cell_lookup(const char *, unsigned, bool);
 extern struct afs_cell *afs_grab_cell(struct afs_cell *);
 extern void afs_put_cell(struct afs_cell *);
 extern void afs_cell_purge(void);
@@ -558,6 +561,8 @@ extern int afs_fs_release_lock(struct afs_server *, struct key *,
 /*
  * inode.c
  */
+extern struct inode *afs_iget_autocell(struct inode *, const char *, int,
+                                       struct key *);
 extern struct inode *afs_iget(struct super_block *, struct key *,
                               struct afs_fid *, struct afs_file_status *,
                               struct afs_callback *);
@@ -566,6 +571,7 @@ extern int afs_validate(struct afs_vnode *, struct key *);
 extern int afs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
 extern int afs_setattr(struct dentry *, struct iattr *);
 extern void afs_evict_inode(struct inode *);
+extern int afs_drop_inode(struct inode *);
 
 /*
  * main.c
@@ -581,6 +587,7 @@ extern int afs_abort_to_error(u32);
  * mntpt.c
  */
 extern const struct inode_operations afs_mntpt_inode_operations;
+extern const struct inode_operations afs_autocell_inode_operations;
 extern const struct file_operations afs_mntpt_file_operations;
 
 extern int afs_mntpt_check_symlink(struct afs_vnode *, struct key *);
diff --git a/fs/afs/mntpt.c b/fs/afs/mntpt.c
index a9e23039ea3..6d552686c49 100644
--- a/fs/afs/mntpt.c
+++ b/fs/afs/mntpt.c
@@ -38,6 +38,11 @@ const struct inode_operations afs_mntpt_inode_operations = {
         .getattr        = afs_getattr,
 };
 
+const struct inode_operations afs_autocell_inode_operations = {
+        .follow_link    = afs_mntpt_follow_link,
+        .getattr        = afs_getattr,
+};
+
 static LIST_HEAD(afs_vfsmounts);
 static DECLARE_DELAYED_WORK(afs_mntpt_expiry_timer, afs_mntpt_expiry_timed_out);
 
@@ -136,20 +141,16 @@ static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt)
 {
         struct afs_super_info *super;
         struct vfsmount *mnt;
+        struct afs_vnode *vnode;
         struct page *page;
-        size_t size;
-        char *buf, *devname, *options;
+        char *devname, *options;
+        bool rwpath = false;
         int ret;
 
         _enter("{%s}", mntpt->d_name.name);
 
         BUG_ON(!mntpt->d_inode);
 
-        ret = -EINVAL;
-        size = mntpt->d_inode->i_size;
-        if (size > PAGE_SIZE - 1)
-                goto error_no_devname;
-
         ret = -ENOMEM;
         devname = (char *) get_zeroed_page(GFP_KERNEL);
         if (!devname)
@@ -159,28 +160,59 @@ static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt)
         if (!options)
                 goto error_no_options;
 
-        /* read the contents of the AFS special symlink */
-        page = read_mapping_page(mntpt->d_inode->i_mapping, 0, NULL);
-        if (IS_ERR(page)) {
-                ret = PTR_ERR(page);
-                goto error_no_page;
+        vnode = AFS_FS_I(mntpt->d_inode);
+        if (test_bit(AFS_VNODE_PSEUDODIR, &vnode->flags)) {
+                /* if the directory is a pseudo directory, use the d_name */
+                static const char afs_root_cell[] = ":root.cell.";
+                unsigned size = mntpt->d_name.len;
+
+                ret = -ENOENT;
+                if (size < 2 || size > AFS_MAXCELLNAME)
+                        goto error_no_page;
+
+                if (mntpt->d_name.name[0] == '.') {
+                        devname[0] = '#';
+                        memcpy(devname + 1, mntpt->d_name.name, size - 1);
+                        memcpy(devname + size, afs_root_cell,
+                               sizeof(afs_root_cell));
+                        rwpath = true;
+                } else {
+                        devname[0] = '%';
+                        memcpy(devname + 1, mntpt->d_name.name, size);
+                        memcpy(devname + size + 1, afs_root_cell,
+                               sizeof(afs_root_cell));
+                }
+        } else {
+                /* read the contents of the AFS special symlink */
+                loff_t size = i_size_read(mntpt->d_inode);
+                char *buf;
+
+                ret = -EINVAL;
+                if (size > PAGE_SIZE - 1)
+                        goto error_no_page;
+
+                page = read_mapping_page(mntpt->d_inode->i_mapping, 0, NULL);
+                if (IS_ERR(page)) {
+                        ret = PTR_ERR(page);
+                        goto error_no_page;
+                }
+
+                ret = -EIO;
+                if (PageError(page))
+                        goto error;
+
+                buf = kmap_atomic(page, KM_USER0);
+                memcpy(devname, buf, size);
+                kunmap_atomic(buf, KM_USER0);
+                page_cache_release(page);
+                page = NULL;
         }
 
-        ret = -EIO;
-        if (PageError(page))
-                goto error;
-
-        buf = kmap_atomic(page, KM_USER0);
-        memcpy(devname, buf, size);
-        kunmap_atomic(buf, KM_USER0);
-        page_cache_release(page);
-        page = NULL;
-
         /* work out what options we want */
         super = AFS_FS_S(mntpt->d_sb);
         memcpy(options, "cell=", 5);
         strcpy(options + 5, super->volume->cell->name);
-        if (super->volume->type == AFSVL_RWVOL)
+        if (super->volume->type == AFSVL_RWVOL || rwpath)
                 strcat(options, ",rwpath");
 
         /* try and do the mount */
diff --git a/fs/afs/proc.c b/fs/afs/proc.c
index 852739d262a..096b23f821a 100644
--- a/fs/afs/proc.c
+++ b/fs/afs/proc.c
@@ -294,7 +294,7 @@ static ssize_t afs_proc_cells_write(struct file *file, const char __user *buf,
         if (strcmp(kbuf, "add") == 0) {
                 struct afs_cell *cell;
 
-                cell = afs_cell_create(name, args);
+                cell = afs_cell_create(name, strlen(name), args, false);
                 if (IS_ERR(cell)) {
                         ret = PTR_ERR(cell);
                         goto done;
diff --git a/fs/afs/super.c b/fs/afs/super.c
index 9cf80f02da1..77e1e5a6115 100644
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -16,6 +16,7 @@
 
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/mount.h>
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/smp_lock.h>
@@ -48,6 +49,7 @@ struct file_system_type afs_fs_type = {
 static const struct super_operations afs_super_ops = {
         .statfs         = afs_statfs,
         .alloc_inode    = afs_alloc_inode,
+        .drop_inode     = afs_drop_inode,
         .destroy_inode  = afs_destroy_inode,
         .evict_inode    = afs_evict_inode,
         .put_super      = afs_put_super,
@@ -62,12 +64,14 @@ enum {
         afs_opt_cell,
         afs_opt_rwpath,
         afs_opt_vol,
+        afs_opt_autocell,
 };
 
 static const match_table_t afs_options_list = {
         { afs_opt_cell,         "cell=%s"       },
         { afs_opt_rwpath,       "rwpath"        },
         { afs_opt_vol,          "vol=%s"        },
+        { afs_opt_autocell,     "autocell"      },
         { afs_no_opt,           NULL            },
 };
 
@@ -151,7 +155,8 @@ static int afs_parse_options(struct afs_mount_params *params,
                 switch (token) {
                 case afs_opt_cell:
                         cell = afs_cell_lookup(args[0].from,
-                                               args[0].to - args[0].from);
+                                               args[0].to - args[0].from,
+                                               false);
                         if (IS_ERR(cell))
                                 return PTR_ERR(cell);
                         afs_put_cell(params->cell);
@@ -166,6 +171,10 @@ static int afs_parse_options(struct afs_mount_params *params,
                         *devname = args[0].from;
                         break;
 
+                case afs_opt_autocell:
+                        params->autocell = 1;
+                        break;
+
                 default:
                         printk(KERN_ERR "kAFS:"
                                " Unknown or invalid mount option: '%s'\n", p);
@@ -252,10 +261,10 @@ static int afs_parse_device_name(struct afs_mount_params *params,
 
         /* lookup the cell record */
         if (cellname || !params->cell) {
-                cell = afs_cell_lookup(cellname, cellnamesz);
+                cell = afs_cell_lookup(cellname, cellnamesz, true);
                 if (IS_ERR(cell)) {
-                        printk(KERN_ERR "kAFS: unable to lookup cell '%s'\n",
-                               cellname ?: "");
+                        printk(KERN_ERR "kAFS: unable to lookup cell '%*.*s'\n",
+                               cellnamesz, cellnamesz, cellname ?: "");
                         return PTR_ERR(cell);
                 }
                 afs_put_cell(params->cell);
@@ -321,6 +330,9 @@ static int afs_fill_super(struct super_block *sb, void *data)
         if (IS_ERR(inode))
                 goto error_inode;
 
+        if (params->autocell)
+                set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags);
+
         ret = -ENOMEM;
         root = d_alloc_root(inode);
         if (!root)