diff options
| -rw-r--r-- | fs/afs/cell.c | 2 | ||||
| -rw-r--r-- | fs/afs/dir.c | 53 | ||||
| -rw-r--r-- | fs/afs/proc.c | 35 |
3 files changed, 89 insertions, 1 deletions
diff --git a/fs/afs/cell.c b/fs/afs/cell.c index 721425b98b31..fdf4c36cff79 100644 --- a/fs/afs/cell.c +++ b/fs/afs/cell.c @@ -130,6 +130,8 @@ static struct afs_cell *afs_alloc_cell(struct afs_net *net, _leave(" = -ENAMETOOLONG"); return ERR_PTR(-ENAMETOOLONG); } + if (namelen == 5 && memcmp(name, "@cell", 5) == 0) + return ERR_PTR(-EINVAL); _enter("%*.*s,%s", namelen, namelen, name, vllist); diff --git a/fs/afs/dir.c b/fs/afs/dir.c index 3ebd741b74d0..b073976db8d2 100644 --- a/fs/afs/dir.c +++ b/fs/afs/dir.c @@ -909,6 +909,55 @@ success: } /* + * Look up @cell in a dynroot directory. This is a substitution for the + * local cell name for the net namespace. + */ +static struct dentry *afs_lookup_atcell(struct dentry *dentry) +{ + struct afs_cell *cell; + struct afs_net *net = afs_d2net(dentry); + struct dentry *ret; + unsigned int seq = 0; + char *name; + int len; + + if (!net->ws_cell) + return ERR_PTR(-ENOENT); + + ret = ERR_PTR(-ENOMEM); + name = kmalloc(AFS_MAXCELLNAME + 1, GFP_KERNEL); + if (!name) + goto out_p; + + rcu_read_lock(); + do { + read_seqbegin_or_lock(&net->cells_lock, &seq); + cell = rcu_dereference_raw(net->ws_cell); + if (cell) { + len = cell->name_len; + memcpy(name, cell->name, len + 1); + } + } while (need_seqretry(&net->cells_lock, seq)); + done_seqretry(&net->cells_lock, seq); + rcu_read_unlock(); + + ret = ERR_PTR(-ENOENT); + if (!cell) + goto out_n; + + ret = lookup_one_len(name, dentry->d_parent, len); + + /* We don't want to d_add() the @cell dentry here as we don't want to + * the cached dentry to hide changes to the local cell name. + */ + +out_n: + kfree(name); +out_p: + return ret; +} + +/* * Look up an entry in a dynroot directory. */ static struct dentry *afs_dynroot_lookup(struct inode *dir, struct dentry *dentry, @@ -929,6 +978,10 @@ static struct dentry *afs_dynroot_lookup(struct inode *dir, struct dentry *dentr return ERR_PTR(-ENAMETOOLONG); } + if (dentry->d_name.len == 5 && + memcmp(dentry->d_name.name, "@cell", 5) == 0) + return afs_lookup_atcell(dentry); + inode = afs_try_auto_mntpt(dentry, dir); if (IS_ERR(inode)) { ret = PTR_ERR(inode); diff --git a/fs/afs/proc.c b/fs/afs/proc.c index 15650cd59404..76f6df32cde0 100644 --- a/fs/afs/proc.c +++ b/fs/afs/proc.c @@ -334,7 +334,40 @@ inval: static ssize_t afs_proc_rootcell_read(struct file *file, char __user *buf, size_t size, loff_t *_pos) { - return 0; + struct afs_cell *cell; + struct afs_net *net = afs_proc2net(file); + unsigned int seq = 0; + char name[AFS_MAXCELLNAME + 1]; + int len; + + if (*_pos > 0) + return 0; + if (!net->ws_cell) + return 0; + + rcu_read_lock(); + do { + read_seqbegin_or_lock(&net->cells_lock, &seq); + len = 0; + cell = rcu_dereference_raw(net->ws_cell); + if (cell) { + len = cell->name_len; + memcpy(name, cell->name, len); + } + } while (need_seqretry(&net->cells_lock, seq)); + done_seqretry(&net->cells_lock, seq); + rcu_read_unlock(); + + if (!len) + return 0; + + name[len++] = '\n'; + if (len > size) + len = size; + if (copy_to_user(buf, name, len) != 0) + return -EFAULT; + *_pos = 1; + return len; } /* |