diff options
Diffstat (limited to 'fs/btrfs/super.c')
-rw-r--r-- | fs/btrfs/super.c | 298 |
1 files changed, 198 insertions, 100 deletions
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 15634d4648d..57080dffdfc 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -40,6 +40,7 @@ #include <linux/magic.h> #include <linux/slab.h> #include <linux/cleancache.h> +#include <linux/mnt_namespace.h> #include "compat.h" #include "delayed-inode.h" #include "ctree.h" @@ -58,6 +59,7 @@ #include <trace/events/btrfs.h> static const struct super_operations btrfs_super_ops; +static struct file_system_type btrfs_fs_type; static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno, char nbuf[16]) @@ -162,7 +164,7 @@ enum { Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard, Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed, Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, - Opt_inode_cache, Opt_err, + Opt_inode_cache, Opt_no_space_cache, Opt_recovery, Opt_err, }; static match_table_t tokens = { @@ -195,6 +197,8 @@ static match_table_t tokens = { {Opt_subvolrootid, "subvolrootid=%d"}, {Opt_defrag, "autodefrag"}, {Opt_inode_cache, "inode_cache"}, + {Opt_no_space_cache, "no_space_cache"}, + {Opt_recovery, "recovery"}, {Opt_err, NULL}, }; @@ -206,14 +210,19 @@ int btrfs_parse_options(struct btrfs_root *root, char *options) { struct btrfs_fs_info *info = root->fs_info; substring_t args[MAX_OPT_ARGS]; - char *p, *num, *orig; + char *p, *num, *orig = NULL; + u64 cache_gen; int intarg; int ret = 0; char *compress_type; bool compress_force = false; + cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy); + if (cache_gen) + btrfs_set_opt(info->mount_opt, SPACE_CACHE); + if (!options) - return 0; + goto out; /* * strsep changes the string, duplicate it because parse_options @@ -360,9 +369,12 @@ int btrfs_parse_options(struct btrfs_root *root, char *options) btrfs_set_opt(info->mount_opt, DISCARD); break; case Opt_space_cache: - printk(KERN_INFO "btrfs: enabling disk space caching\n"); btrfs_set_opt(info->mount_opt, SPACE_CACHE); break; + case Opt_no_space_cache: + printk(KERN_INFO "btrfs: disabling disk space caching\n"); + btrfs_clear_opt(info->mount_opt, SPACE_CACHE); + break; case Opt_inode_cache: printk(KERN_INFO "btrfs: enabling inode map caching\n"); btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE); @@ -381,6 +393,10 @@ int btrfs_parse_options(struct btrfs_root *root, char *options) printk(KERN_INFO "btrfs: enabling auto defrag"); btrfs_set_opt(info->mount_opt, AUTO_DEFRAG); break; + case Opt_recovery: + printk(KERN_INFO "btrfs: enabling auto recovery"); + btrfs_set_opt(info->mount_opt, RECOVERY); + break; case Opt_err: printk(KERN_INFO "btrfs: unrecognized mount option " "'%s'\n", p); @@ -391,6 +407,8 @@ int btrfs_parse_options(struct btrfs_root *root, char *options) } } out: + if (!ret && btrfs_test_opt(root, SPACE_CACHE)) + printk(KERN_INFO "btrfs: disk space caching is enabled\n"); kfree(orig); return ret; } @@ -406,12 +424,12 @@ static int btrfs_parse_early_options(const char *options, fmode_t flags, u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices) { substring_t args[MAX_OPT_ARGS]; - char *opts, *orig, *p; + char *device_name, *opts, *orig, *p; int error = 0; int intarg; if (!options) - goto out; + return 0; /* * strsep changes the string, duplicate it because parse_options @@ -457,29 +475,24 @@ static int btrfs_parse_early_options(const char *options, fmode_t flags, } break; case Opt_device: - error = btrfs_scan_one_device(match_strdup(&args[0]), + device_name = match_strdup(&args[0]); + if (!device_name) { + error = -ENOMEM; + goto out; + } + error = btrfs_scan_one_device(device_name, flags, holder, fs_devices); + kfree(device_name); if (error) - goto out_free_opts; + goto out; break; default: break; } } - out_free_opts: +out: kfree(orig); - out: - /* - * If no subvolume name is specified we use the default one. Allocate - * a copy of the string "." here so that code later in the - * mount path doesn't care if it's the default volume or another one. - */ - if (!*subvol_name) { - *subvol_name = kstrdup(".", GFP_KERNEL); - if (!*subvol_name) - return -ENOMEM; - } return error; } @@ -492,7 +505,6 @@ static struct dentry *get_default_root(struct super_block *sb, struct btrfs_path *path; struct btrfs_key location; struct inode *inode; - struct dentry *dentry; u64 dir_id; int new = 0; @@ -517,7 +529,7 @@ static struct dentry *get_default_root(struct super_block *sb, * will mount by default if we haven't been given a specific subvolume * to mount. */ - dir_id = btrfs_super_root_dir(&root->fs_info->super_copy); + dir_id = btrfs_super_root_dir(root->fs_info->super_copy); di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0); if (IS_ERR(di)) { btrfs_free_path(path); @@ -566,29 +578,7 @@ setup_root: return dget(sb->s_root); } - if (new) { - const struct qstr name = { .name = "/", .len = 1 }; - - /* - * New inode, we need to make the dentry a sibling of s_root so - * everything gets cleaned up properly on unmount. - */ - dentry = d_alloc(sb->s_root, &name); - if (!dentry) { - iput(inode); - return ERR_PTR(-ENOMEM); - } - d_splice_alias(inode, dentry); - } else { - /* - * We found the inode in cache, just find a dentry for it and - * put the reference to the inode we just got. - */ - dentry = d_find_alias(inode); - iput(inode); - } - - return dentry; + return d_obtain_alias(inode); } static int btrfs_fill_super(struct super_block *sb, @@ -719,6 +709,8 @@ static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs) seq_puts(seq, ",noacl"); if (btrfs_test_opt(root, SPACE_CACHE)) seq_puts(seq, ",space_cache"); + else + seq_puts(seq, ",no_space_cache"); if (btrfs_test_opt(root, CLEAR_CACHE)) seq_puts(seq, ",clear_cache"); if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED)) @@ -753,6 +745,137 @@ static int btrfs_set_super(struct super_block *s, void *data) return set_anon_super(s, data); } +/* + * subvolumes are identified by ino 256 + */ +static inline int is_subvolume_inode(struct inode *inode) +{ + if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) + return 1; + return 0; +} + +/* + * This will strip out the subvol=%s argument for an argument string and add + * subvolid=0 to make sure we get the actual tree root for path walking to the + * subvol we want. + */ +static char *setup_root_args(char *args) +{ + unsigned copied = 0; + unsigned len = strlen(args) + 2; + char *pos; + char *ret; + + /* + * We need the same args as before, but minus + * + * subvol=a + * + * and add + * + * subvolid=0 + * + * which is a difference of 2 characters, so we allocate strlen(args) + + * 2 characters. + */ + ret = kzalloc(len * sizeof(char), GFP_NOFS); + if (!ret) + return NULL; + pos = strstr(args, "subvol="); + + /* This shouldn't happen, but just in case.. */ + if (!pos) { + kfree(ret); + return NULL; + } + + /* + * The subvol=<> arg is not at the front of the string, copy everybody + * up to that into ret. + */ + if (pos != args) { + *pos = '\0'; + strcpy(ret, args); + copied += strlen(args); + pos++; + } + + strncpy(ret + copied, "subvolid=0", len - copied); + + /* Length of subvolid=0 */ + copied += 10; + + /* + * If there is no , after the subvol= option then we know there's no + * other options and we can just return. + */ + pos = strchr(pos, ','); + if (!pos) + return ret; + + /* Copy the rest of the arguments into our buffer */ + strncpy(ret + copied, pos, len - copied); + copied += strlen(pos); + + return ret; +} + +static struct dentry *mount_subvol(const char *subvol_name, int flags, + const char *device_name, char *data) +{ + struct super_block *s; + struct dentry *root; + struct vfsmount *mnt; + struct mnt_namespace *ns_private; + char *newargs; + struct path path; + int error; + + newargs = setup_root_args(data); + if (!newargs) + return ERR_PTR(-ENOMEM); + mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, + newargs); + kfree(newargs); + if (IS_ERR(mnt)) + return ERR_CAST(mnt); + + ns_private = create_mnt_ns(mnt); + if (IS_ERR(ns_private)) { + mntput(mnt); + return ERR_CAST(ns_private); + } + + /* + * This will trigger the automount of the subvol so we can just + * drop the mnt we have here and return the dentry that we + * found. + */ + error = vfs_path_lookup(mnt->mnt_root, mnt, subvol_name, + LOOKUP_FOLLOW, &path); + put_mnt_ns(ns_private); + if (error) + return ERR_PTR(error); + + if (!is_subvolume_inode(path.dentry->d_inode)) { + path_put(&path); + mntput(mnt); + error = -EINVAL; + printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n", + subvol_name); + return ERR_PTR(-EINVAL); + } + + /* Get a ref to the sb and the dentry we found and return it */ + s = path.mnt->mnt_sb; + atomic_inc(&s->s_active); + root = dget(path.dentry); + path_put(&path); + down_write(&s->s_umount); + + return root; +} /* * Find a superblock for the given device / mount point. @@ -784,13 +907,19 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, if (error) return ERR_PTR(error); + if (subvol_name) { + root = mount_subvol(subvol_name, flags, device_name, data); + kfree(subvol_name); + return root; + } + error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices); if (error) - goto error_free_subvol_name; + return ERR_PTR(error); error = btrfs_open_devices(fs_devices, mode, fs_type); if (error) - goto error_free_subvol_name; + return ERR_PTR(error); if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { error = -EACCES; @@ -813,88 +942,57 @@ static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, fs_info->fs_devices = fs_devices; tree_root->fs_info = fs_info; + fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); + fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); + if (!fs_info->super_copy || !fs_info->super_for_commit) { + error = -ENOMEM; + goto error_close_devices; + } + bdev = fs_devices->latest_bdev; s = sget(fs_type, btrfs_test_super, btrfs_set_super, tree_root); - if (IS_ERR(s)) - goto error_s; + if (IS_ERR(s)) { + error = PTR_ERR(s); + goto error_close_devices; + } if (s->s_root) { if ((flags ^ s->s_flags) & MS_RDONLY) { deactivate_locked_super(s); - error = -EBUSY; - goto error_close_devices; + return ERR_PTR(-EBUSY); } btrfs_close_devices(fs_devices); - kfree(fs_info); + free_fs_info(fs_info); kfree(tree_root); } else { char b[BDEVNAME_SIZE]; s->s_flags = flags | MS_NOSEC; strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); + btrfs_sb(s)->fs_info->bdev_holder = fs_type; error = btrfs_fill_super(s, fs_devices, data, flags & MS_SILENT ? 1 : 0); if (error) { deactivate_locked_super(s); - goto error_free_subvol_name; + return ERR_PTR(error); } - btrfs_sb(s)->fs_info->bdev_holder = fs_type; s->s_flags |= MS_ACTIVE; } - /* if they gave us a subvolume name bind mount into that */ - if (strcmp(subvol_name, ".")) { - struct dentry *new_root; - - root = get_default_root(s, subvol_rootid); - if (IS_ERR(root)) { - error = PTR_ERR(root); - deactivate_locked_super(s); - goto error_free_subvol_name; - } - - mutex_lock(&root->d_inode->i_mutex); - new_root = lookup_one_len(subvol_name, root, - strlen(subvol_name)); - mutex_unlock(&root->d_inode->i_mutex); - - if (IS_ERR(new_root)) { - dput(root); - deactivate_locked_super(s); - error = PTR_ERR(new_root); - goto error_free_subvol_name; - } - if (!new_root->d_inode) { - dput(root); - dput(new_root); - deactivate_locked_super(s); - error = -ENXIO; - goto error_free_subvol_name; - } - dput(root); - root = new_root; - } else { - root = get_default_root(s, subvol_objectid); - if (IS_ERR(root)) { - error = PTR_ERR(root); - deactivate_locked_super(s); - goto error_free_subvol_name; - } + root = get_default_root(s, subvol_objectid); + if (IS_ERR(root)) { + deactivate_locked_super(s); + return root; } - kfree(subvol_name); return root; -error_s: - error = PTR_ERR(s); error_close_devices: btrfs_close_devices(fs_devices); - kfree(fs_info); + free_fs_info(fs_info); kfree(tree_root); -error_free_subvol_name: - kfree(subvol_name); return ERR_PTR(error); } @@ -919,7 +1017,7 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data) if (root->fs_info->fs_devices->rw_devices == 0) return -EACCES; - if (btrfs_super_log_root(&root->fs_info->super_copy) != 0) + if (btrfs_super_log_root(root->fs_info->super_copy) != 0) return -EINVAL; ret = btrfs_cleanup_fs_roots(root->fs_info); @@ -1085,7 +1183,7 @@ static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes) static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) { struct btrfs_root *root = btrfs_sb(dentry->d_sb); - struct btrfs_super_block *disk_super = &root->fs_info->super_copy; + struct btrfs_super_block *disk_super = root->fs_info->super_copy; struct list_head *head = &root->fs_info->space_info; struct btrfs_space_info *found; u64 total_used = 0; |