Use extent buffer based infrastructure to re-implement btrfs_readdir().
Along this rework, some small corner cases fixed: - Subvolume tree mtime Mtime of a subvolume tree is recorded in its root item, since there is no INODE_ITEM for it. This needs extra search from tree root.
- Output the unknown type If the DIR_ITEM is corrupted, at least don't try to access the memory out of bounday.
Signed-off-by: Qu Wenruo wqu@suse.com --- fs/btrfs/btrfs.c | 157 +++++++++++++++++++++++++++----------------- fs/btrfs/btrfs.h | 5 -- fs/btrfs/ctree.h | 5 ++ fs/btrfs/dir-item.c | 68 +++++++++++-------- 4 files changed, 144 insertions(+), 91 deletions(-)
diff --git a/fs/btrfs/btrfs.c b/fs/btrfs/btrfs.c index c967c114ccf5..2278b52e4d0e 100644 --- a/fs/btrfs/btrfs.c +++ b/fs/btrfs/btrfs.c @@ -16,67 +16,102 @@ struct btrfs_info btrfs_info; struct btrfs_fs_info *current_fs_info;
-static int readdir_callback(const struct __btrfs_root *root, - struct btrfs_dir_item *item) +static int show_dir(struct btrfs_root *root, struct extent_buffer *eb, + struct btrfs_dir_item *di) { - static const char typestr[BTRFS_FT_MAX][4] = { - [BTRFS_FT_UNKNOWN] = " ? ", - [BTRFS_FT_REG_FILE] = " ", - [BTRFS_FT_DIR] = "DIR", - [BTRFS_FT_CHRDEV] = "CHR", - [BTRFS_FT_BLKDEV] = "BLK", - [BTRFS_FT_FIFO] = "FIF", - [BTRFS_FT_SOCK] = "SCK", - [BTRFS_FT_SYMLINK] = "SYM", - [BTRFS_FT_XATTR] = " ? ", + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_inode_item ii; + struct btrfs_key key; + static const char* dir_item_str[] = { + [BTRFS_FT_REG_FILE] = "FILE", + [BTRFS_FT_DIR] = "DIR", + [BTRFS_FT_CHRDEV] = "CHRDEV", + [BTRFS_FT_BLKDEV] = "BLKDEV", + [BTRFS_FT_FIFO] = "FIFO", + [BTRFS_FT_SOCK] = "SOCK", + [BTRFS_FT_SYMLINK] = "SYMLINK", + [BTRFS_FT_XATTR] = "XATTR" }; - struct btrfs_inode_item inode; - const char *name = (const char *) (item + 1); - char filetime[32], *target = NULL; + u8 type = btrfs_dir_type(eb, di); + char namebuf[BTRFS_NAME_LEN]; + char *target = NULL; + char filetime[32]; time_t mtime; + int ret;
- if (__btrfs_lookup_inode(root, (struct btrfs_key *)&item->location, - &inode, NULL)) { - printf("%s: Cannot find inode item for directory entry %.*s!\n", - __func__, item->name_len, name); - return 0; - } - - mtime = inode.mtime.sec; - ctime_r(&mtime, filetime); + btrfs_dir_item_key_to_cpu(eb, di, &key);
- if (item->type == BTRFS_FT_SYMLINK) { - target = malloc(min(inode.size + 1, - (u64) btrfs_info.sb.sectorsize)); + if (key.type == BTRFS_ROOT_ITEM_KEY) { + struct btrfs_root *subvol;
- if (target && __btrfs_readlink(root, item->location.objectid, - target)) { - free(target); - target = NULL; + /* It's a subvolume, get its mtime from root item */ + subvol = btrfs_read_fs_root(fs_info, &key); + if (IS_ERR(subvol)) { + ret = PTR_ERR(subvol); + error("Can't find root %llu", key.objectid); + return ret; } + mtime = btrfs_stack_timespec_sec(&subvol->root_item.otime); + } else { + struct btrfs_path path; + + /* It's regular inode, get its mtime from inode item */ + btrfs_init_path(&path); + ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0); + if (ret > 0) + ret = -ENOENT; + if (ret < 0) { + error("Can't find inode %llu", key.objectid); + btrfs_release_path(&path); + return ret; + } + read_extent_buffer(path.nodes[0], &ii, + btrfs_item_ptr_offset(path.nodes[0], path.slots[0]), + sizeof(ii)); + btrfs_release_path(&path); + mtime = btrfs_stack_timespec_sec(&ii.mtime); + } + ctime_r(&mtime, filetime);
- if (!target) - printf("%s: Cannot read symlink target!\n", __func__); + if (type == BTRFS_FT_SYMLINK) { + target = malloc(fs_info->sectorsize); + if (!target) { + error("Can't alloc memory for symlink %llu", + key.objectid); + return -ENOMEM; + } + ret = btrfs_readlink(root, key.objectid, target); + if (ret < 0) { + error("Failed to read symlink %llu", key.objectid); + goto out; + } + target[ret] = '\0'; }
- printf("<%s> ", typestr[item->type]); - if (item->type == BTRFS_FT_CHRDEV || item->type == BTRFS_FT_BLKDEV) - printf("%4u,%5u ", (unsigned int) (inode.rdev >> 20), - (unsigned int) (inode.rdev & 0xfffff)); + if (type < ARRAY_SIZE(dir_item_str) && dir_item_str[type]) + printf("<%s> ", dir_item_str[type]); else - printf("%10llu ", inode.size); - - printf("%24.24s %.*s", filetime, item->name_len, name); - - if (item->type == BTRFS_FT_SYMLINK) { - printf(" -> %s", target ? target : "?"); - if (target) - free(target); + printf("DIR_ITEM.%u", type); + if (type == BTRFS_FT_CHRDEV || type == BTRFS_FT_BLKDEV) { + ASSERT(key.type == BTRFS_INODE_ITEM_KEY); + printf("%4llu,%5llu ", btrfs_stack_inode_rdev(&ii) >> 20, + btrfs_stack_inode_rdev(&ii) & 0xfffff); + } else { + if (key.type == BTRFS_INODE_ITEM_KEY) + printf("%10llu ", btrfs_stack_inode_size(&ii)); + else + printf("%10llu ", 0ULL); }
+ read_extent_buffer(eb, namebuf, (unsigned long)(di + 1), + btrfs_dir_name_len(eb, di)); + printf("%24.24s %.*s", filetime, btrfs_dir_name_len(eb, di), namebuf); + if (type == BTRFS_FT_SYMLINK) + printf(" -> %s", target ? target : "?"); printf("\n"); - - return 0; +out: + free(target); + return ret; }
int btrfs_probe(struct blk_desc *fs_dev_desc, @@ -125,27 +160,29 @@ int btrfs_probe(struct blk_desc *fs_dev_desc,
int btrfs_ls(const char *path) { - struct __btrfs_root root = btrfs_info.fs_root; - u64 inr; + struct btrfs_fs_info *fs_info = current_fs_info; + struct btrfs_root *root = fs_info->fs_root; + u64 ino = BTRFS_FIRST_FREE_OBJECTID; u8 type; + int ret;
- inr = __btrfs_lookup_path(&root, root.root_dirid, path, &type, NULL, 40); - - if (inr == -1ULL) { + ASSERT(fs_info); + ret = btrfs_lookup_path(fs_info->fs_root, BTRFS_FIRST_FREE_OBJECTID, + path, &root, &ino, &type, 40); + if (ret < 0) { printf("Cannot lookup path %s\n", path); - return -1; + return ret; }
if (type != BTRFS_FT_DIR) { - printf("Not a directory: %s\n", path); - return -1; + error("Not a directory: %s", path); + return -ENOENT; } - - if (btrfs_readdir(&root, inr, readdir_callback)) { - printf("An error occured while listing directory %s\n", path); - return -1; + ret = btrfs_iter_dir(root, ino, show_dir); + if (ret < 0) { + error("An error occured while listing directory %s", path); + return ret; } - return 0; }
diff --git a/fs/btrfs/btrfs.h b/fs/btrfs/btrfs.h index 53d53f310bdc..e36bd8982716 100644 --- a/fs/btrfs/btrfs.h +++ b/fs/btrfs/btrfs.h @@ -43,13 +43,8 @@ u32 btrfs_decompress(u8 type, const char *, u32, char *, u32); int btrfs_read_superblock(void);
/* dir-item.c */ -typedef int (*btrfs_readdir_callback_t)(const struct __btrfs_root *, - struct btrfs_dir_item *); - int __btrfs_lookup_dir_item(const struct __btrfs_root *, u64, const char *, int, struct btrfs_dir_item *); -int btrfs_readdir(const struct __btrfs_root *, u64, btrfs_readdir_callback_t); - /* root.c */ int btrfs_find_root(u64, struct __btrfs_root *, struct btrfs_root_item *); u64 btrfs_lookup_root_ref(u64, struct btrfs_root_ref *, char *); diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 992b7187339a..3430659c8874 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1285,6 +1285,11 @@ struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, struct btrfs_path *path, u64 dir, const char *name, int name_len, int mod); +typedef int (*btrfs_iter_dir_callback_t)(struct btrfs_root *root, + struct extent_buffer *eb, + struct btrfs_dir_item *di); +int btrfs_iter_dir(struct btrfs_root *root, u64 ino, + btrfs_iter_dir_callback_t callback); /* inode.c */ int btrfs_lookup_path(struct btrfs_root *root, u64 ino, const char *filename, struct btrfs_root **root_ret, u64 *ino_ret, diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c index 4bf45c2fa925..a6c66a021896 100644 --- a/fs/btrfs/dir-item.c +++ b/fs/btrfs/dir-item.c @@ -193,39 +193,55 @@ out: return res ? 0 : -1; }
-int btrfs_readdir(const struct __btrfs_root *root, u64 dir, - btrfs_readdir_callback_t callback) +int btrfs_iter_dir(struct btrfs_root *root, u64 ino, + btrfs_iter_dir_callback_t callback) { - struct __btrfs_path path; - struct btrfs_key key, *found_key; - struct btrfs_dir_item *item; - int res = 0; + struct btrfs_path path; + struct btrfs_key key; + int ret;
- key.objectid = dir; + btrfs_init_path(&path); + key.objectid = ino; key.type = BTRFS_DIR_INDEX_KEY; key.offset = 0;
- if (btrfs_search_tree(root, &key, &path)) - return -1; - + ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0); + if (ret < 0) + return ret; + /* Should not happen */ + if (ret == 0) { + ret = -EUCLEAN; + goto out; + } + if (path.slots[0] >= btrfs_header_nritems(path.nodes[0])) { + ret = btrfs_next_leaf(root, &path); + if (ret < 0) + goto out; + if (ret > 0) { + ret = 0; + goto out; + } + } do { - found_key = btrfs_path_leaf_key(&path); - if (btrfs_comp_keys_type(&key, found_key)) - break; - - item = btrfs_path_item_ptr(&path, struct btrfs_dir_item); - btrfs_dir_item_to_cpu(item); + struct btrfs_dir_item *di;
- if (__verify_dir_item(item, 0, sizeof(*item) + item->name_len)) - continue; - if (item->type == BTRFS_FT_XATTR) - continue; - - if (callback(root, item)) + btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]); + if (key.objectid != ino || key.type != BTRFS_DIR_INDEX_KEY) break; - } while (!(res = btrfs_next_slot(&path))); - - __btrfs_free_path(&path); + di = btrfs_item_ptr(path.nodes[0], path.slots[0], + struct btrfs_dir_item); + if (verify_dir_item(root, path.nodes[0], di)) { + ret = -EUCLEAN; + goto out; + } + ret = callback(root, path.nodes[0], di); + if (ret < 0) + goto out; + } while (!(ret = btrfs_next_item(root, &path)));
- return res < 0 ? -1 : 0; + if (ret > 0) + ret = 0; +out: + btrfs_release_path(&path); + return ret; }