diff options
| -rw-r--r-- | fs/btrfs/Makefile | 2 | ||||
| -rw-r--r-- | fs/btrfs/compat.h | 17 | ||||
| -rw-r--r-- | fs/btrfs/export.c | 208 | ||||
| -rw-r--r-- | fs/btrfs/export.h | 19 | ||||
| -rw-r--r-- | fs/btrfs/super.c | 2 |
5 files changed, 247 insertions, 1 deletions
diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile index a4b38177abdb..75f8818cbfee 100644 --- a/fs/btrfs/Makefile +++ b/fs/btrfs/Makefile @@ -7,7 +7,7 @@ btrfs-y := super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \ transaction.o bit-radix.o inode.o file.o tree-defrag.o \ extent_map.o sysfs.o struct-funcs.o xattr.o ordered-data.o \ extent_io.o volumes.o async-thread.o ioctl.o locking.o orphan.o \ - ref-cache.o + ref-cache.o export.o btrfs-$(CONFIG_FS_POSIX_ACL) += acl.o else diff --git a/fs/btrfs/compat.h b/fs/btrfs/compat.h index b3349a66999d..d45fb37887bc 100644 --- a/fs/btrfs/compat.h +++ b/fs/btrfs/compat.h @@ -5,6 +5,23 @@ #define trylock_page(page) (!TestSetPageLocked(page)) #endif +#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,27) +static inline struct dentry *d_obtain_alias(struct inode *inode) +{ + struct dentry *d; + + if (!inode) + return NULL; + if (IS_ERR(inode)) + return ERR_CAST(inode); + + d = d_alloc_anon(inode); + if (!d) + iput(inode); + return d; +} +#endif + /* * Even if AppArmor isn't enabled, it still has different prototypes. * Add more distro/version pairs here to declare which has AppArmor applied. diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c new file mode 100644 index 000000000000..797b4cbc3786 --- /dev/null +++ b/fs/btrfs/export.c @@ -0,0 +1,208 @@ +#include <linux/fs.h> +#include <linux/types.h> +#include "ctree.h" +#include "disk-io.h" +#include "btrfs_inode.h" +#include "print-tree.h" +#include "export.h" +#include "compat.h" + +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,28) +#define FILEID_BTRFS_WITHOUT_PARENT 0x4d +#define FILEID_BTRFS_WITH_PARENT 0x4e +#define FILEID_BTRFS_WITH_PARENT_ROOT 0x4f +#endif + +#define BTRFS_FID_SIZE_NON_CONNECTABLE (offsetof(struct btrfs_fid, parent_objectid)/4) +#define BTRFS_FID_SIZE_CONNECTABLE (offsetof(struct btrfs_fid, parent_root_objectid)/4) +#define BTRFS_FID_SIZE_CONNECTABLE_ROOT (sizeof(struct btrfs_fid)/4) + +static int btrfs_encode_fh(struct dentry *dentry, u32 *fh, int *max_len, + int connectable) +{ + struct btrfs_fid *fid = (struct btrfs_fid *)fh; + struct inode *inode = dentry->d_inode; + int len = *max_len; + int type; + + if ((len < BTRFS_FID_SIZE_NON_CONNECTABLE) || + (connectable && len < BTRFS_FID_SIZE_CONNECTABLE)) + return 255; + + len = BTRFS_FID_SIZE_NON_CONNECTABLE; + type = FILEID_BTRFS_WITHOUT_PARENT; + + fid->objectid = BTRFS_I(inode)->location.objectid; + fid->root_objectid = BTRFS_I(inode)->root->objectid; + fid->gen = inode->i_generation; + + if (connectable && !S_ISDIR(inode->i_mode)) { + struct inode *parent; + u64 parent_root_id; + + spin_lock(&dentry->d_lock); + + parent = dentry->d_parent->d_inode; + fid->parent_objectid = BTRFS_I(parent)->location.objectid; + fid->parent_gen = parent->i_generation; + parent_root_id = BTRFS_I(parent)->root->objectid; + + spin_unlock(&dentry->d_lock); + + if (parent_root_id != fid->root_objectid) { + fid->parent_root_objectid = parent_root_id; + len = BTRFS_FID_SIZE_CONNECTABLE_ROOT; + type = FILEID_BTRFS_WITH_PARENT_ROOT; + } else { + len = BTRFS_FID_SIZE_CONNECTABLE; + type = FILEID_BTRFS_WITH_PARENT; + } + } + + *max_len = len; + return type; +} + +static struct dentry *btrfs_get_dentry(struct super_block *sb, u64 objectid, + u64 root_objectid, u32 generation) +{ + struct btrfs_root *root; + struct inode *inode; + struct dentry *result; + struct btrfs_key key; + + key.objectid = objectid; + btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); + key.offset = 0; + + root = btrfs_lookup_fs_root(btrfs_sb(sb)->fs_info, root_objectid); + inode = btrfs_iget(sb, &key, root, NULL); + if (IS_ERR(inode)) + return (void *)inode; + + if (generation != inode->i_generation) { + iput(inode); + return ERR_PTR(-ESTALE); + } + + result = d_obtain_alias(inode); + if (!result) + return ERR_PTR(-ENOMEM); + + return result; +} + +static struct dentry *btrfs_fh_to_parent(struct super_block *sb, struct fid *fh, + int fh_len, int fh_type) +{ + struct btrfs_fid *fid = (struct btrfs_fid *) fh; + u64 objectid, root_objectid; + u32 generation; + + if (fh_type == FILEID_BTRFS_WITH_PARENT) { + if (fh_len != BTRFS_FID_SIZE_CONNECTABLE) + return NULL; + root_objectid = fid->root_objectid; + } else if (fh_type == FILEID_BTRFS_WITH_PARENT_ROOT) { + if (fh_len != BTRFS_FID_SIZE_CONNECTABLE_ROOT) + return NULL; + root_objectid = fid->parent_root_objectid; + } else + return NULL; + + objectid = fid->parent_objectid; + generation = fid->parent_gen; + + return btrfs_get_dentry(sb, objectid, root_objectid, generation); +} + +static struct dentry *btrfs_fh_to_dentry(struct super_block *sb, struct fid *fh, + int fh_len, int fh_type) +{ + struct btrfs_fid *fid = (struct btrfs_fid *) fh; + u64 objectid, root_objectid; + u32 generation; + + if ((fh_type != FILEID_BTRFS_WITH_PARENT || + fh_len != BTRFS_FID_SIZE_CONNECTABLE) && + (fh_type != FILEID_BTRFS_WITH_PARENT_ROOT || + fh_len != BTRFS_FID_SIZE_CONNECTABLE_ROOT) && + (fh_type != FILEID_BTRFS_WITHOUT_PARENT || + fh_len != BTRFS_FID_SIZE_NON_CONNECTABLE)) + return NULL; + + objectid = fid->objectid; + root_objectid = fid->root_objectid; + generation = fid->gen; + + return btrfs_get_dentry(sb, objectid, root_objectid, generation); +} + +static struct dentry *btrfs_get_parent(struct dentry *child) +{ + struct inode *dir = child->d_inode; + struct inode *inode; + struct dentry *parent; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct btrfs_key key; + struct btrfs_path *path; + struct extent_buffer *leaf; + u32 nritems; + int slot; + u64 objectid; + int ret; + + path = btrfs_alloc_path(); + + key.objectid = dir->i_ino; + btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY); + key.offset = 0; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + BUG_ON(ret == 0); + ret = 0; + + leaf = path->nodes[0]; + slot = path->slots[0]; + nritems = btrfs_header_nritems(leaf); + if (slot >= nritems) { + ret = btrfs_next_leaf(root, path); + if (ret) { + btrfs_free_path(path); + goto out; + } + leaf = path->nodes[0]; + slot = path->slots[0]; + } + + btrfs_free_path(path); + + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.objectid != dir->i_ino || key.type != BTRFS_INODE_REF_KEY) + goto out; + + objectid = key.offset; + + /* Build a new key for the inode item */ + key.objectid = objectid; + btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); + key.offset = 0; + + inode = btrfs_iget(root->fs_info->sb, &key, root, NULL); + + parent = d_obtain_alias(inode); + if (!parent) + parent = ERR_PTR(-ENOMEM); + + return parent; + +out: + btrfs_free_path(path); + return ERR_PTR(-EINVAL); +} + +const struct export_operations btrfs_export_ops = { + .encode_fh = btrfs_encode_fh, + .fh_to_dentry = btrfs_fh_to_dentry, + .fh_to_parent = btrfs_fh_to_parent, + .get_parent = btrfs_get_parent, +}; diff --git a/fs/btrfs/export.h b/fs/btrfs/export.h new file mode 100644 index 000000000000..074348a95841 --- /dev/null +++ b/fs/btrfs/export.h @@ -0,0 +1,19 @@ +#ifndef BTRFS_EXPORT_H +#define BTRFS_EXPORT_H + +#include <linux/exportfs.h> + +extern const struct export_operations btrfs_export_ops; + +struct btrfs_fid { + u64 objectid; + u64 root_objectid; + u32 gen; + + u64 parent_objectid; + u32 parent_gen; + + u64 parent_root_objectid; +} __attribute__ ((packed)); + +#endif diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index eb4b357d05e1..e830e0ed409a 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -46,6 +46,7 @@ #include "xattr.h" #include "volumes.h" #include "version.h" +#include "export.h" #define BTRFS_SUPER_MAGIC 0x9123683E @@ -303,6 +304,7 @@ static int btrfs_fill_super(struct super_block * sb, sb->s_maxbytes = MAX_LFS_FILESIZE; sb->s_magic = BTRFS_SUPER_MAGIC; sb->s_op = &btrfs_super_ops; + sb->s_export_op = &btrfs_export_ops; sb->s_xattr = btrfs_xattr_handlers; sb->s_time_gran = 1; sb->s_flags |= MS_POSIXACL; |
