fs: btrfs: Use btrfs_iter_dir() to replace btrfs_readdir()
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 boundary. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Marek Behún <marek.behun@nic.cz>
This commit is contained in:
Qu Wenruo
Tom Rini
parent
c921aa20c3
commit
325dd1f642
157
fs/btrfs/btrfs.c
157
fs/btrfs/btrfs.c
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@ -16,67 +16,102 @@
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struct btrfs_info btrfs_info;
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struct btrfs_fs_info *current_fs_info;
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static int readdir_callback(const struct __btrfs_root *root,
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struct btrfs_dir_item *item)
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static int show_dir(struct btrfs_root *root, struct extent_buffer *eb,
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struct btrfs_dir_item *di)
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{
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static const char typestr[BTRFS_FT_MAX][4] = {
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[BTRFS_FT_UNKNOWN] = " ? ",
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[BTRFS_FT_REG_FILE] = " ",
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[BTRFS_FT_DIR] = "DIR",
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[BTRFS_FT_CHRDEV] = "CHR",
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[BTRFS_FT_BLKDEV] = "BLK",
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[BTRFS_FT_FIFO] = "FIF",
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[BTRFS_FT_SOCK] = "SCK",
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[BTRFS_FT_SYMLINK] = "SYM",
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[BTRFS_FT_XATTR] = " ? ",
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struct btrfs_fs_info *fs_info = root->fs_info;
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struct btrfs_inode_item ii;
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struct btrfs_key key;
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static const char* dir_item_str[] = {
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[BTRFS_FT_REG_FILE] = "FILE",
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[BTRFS_FT_DIR] = "DIR",
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[BTRFS_FT_CHRDEV] = "CHRDEV",
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[BTRFS_FT_BLKDEV] = "BLKDEV",
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[BTRFS_FT_FIFO] = "FIFO",
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[BTRFS_FT_SOCK] = "SOCK",
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[BTRFS_FT_SYMLINK] = "SYMLINK",
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[BTRFS_FT_XATTR] = "XATTR"
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};
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struct btrfs_inode_item inode;
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const char *name = (const char *) (item + 1);
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char filetime[32], *target = NULL;
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u8 type = btrfs_dir_type(eb, di);
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char namebuf[BTRFS_NAME_LEN];
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char *target = NULL;
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char filetime[32];
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time_t mtime;
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int ret;
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if (__btrfs_lookup_inode(root, (struct btrfs_key *)&item->location,
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&inode, NULL)) {
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printf("%s: Cannot find inode item for directory entry %.*s!\n",
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__func__, item->name_len, name);
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return 0;
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btrfs_dir_item_key_to_cpu(eb, di, &key);
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if (key.type == BTRFS_ROOT_ITEM_KEY) {
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struct btrfs_root *subvol;
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/* It's a subvolume, get its mtime from root item */
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subvol = btrfs_read_fs_root(fs_info, &key);
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if (IS_ERR(subvol)) {
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ret = PTR_ERR(subvol);
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error("Can't find root %llu", key.objectid);
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return ret;
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}
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mtime = btrfs_stack_timespec_sec(&subvol->root_item.otime);
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} else {
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struct btrfs_path path;
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/* It's regular inode, get its mtime from inode item */
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btrfs_init_path(&path);
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ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
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if (ret > 0)
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ret = -ENOENT;
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if (ret < 0) {
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error("Can't find inode %llu", key.objectid);
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btrfs_release_path(&path);
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return ret;
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}
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read_extent_buffer(path.nodes[0], &ii,
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btrfs_item_ptr_offset(path.nodes[0], path.slots[0]),
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sizeof(ii));
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btrfs_release_path(&path);
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mtime = btrfs_stack_timespec_sec(&ii.mtime);
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}
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mtime = inode.mtime.sec;
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ctime_r(&mtime, filetime);
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if (item->type == BTRFS_FT_SYMLINK) {
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target = malloc(min(inode.size + 1,
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(u64) btrfs_info.sb.sectorsize));
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if (target && __btrfs_readlink(root, item->location.objectid,
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target)) {
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free(target);
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target = NULL;
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if (type == BTRFS_FT_SYMLINK) {
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target = malloc(fs_info->sectorsize);
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if (!target) {
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error("Can't alloc memory for symlink %llu",
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key.objectid);
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return -ENOMEM;
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}
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if (!target)
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printf("%s: Cannot read symlink target!\n", __func__);
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ret = btrfs_readlink(root, key.objectid, target);
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if (ret < 0) {
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error("Failed to read symlink %llu", key.objectid);
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goto out;
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}
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target[ret] = '\0';
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}
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printf("<%s> ", typestr[item->type]);
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if (item->type == BTRFS_FT_CHRDEV || item->type == BTRFS_FT_BLKDEV)
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printf("%4u,%5u ", (unsigned int) (inode.rdev >> 20),
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(unsigned int) (inode.rdev & 0xfffff));
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if (type < ARRAY_SIZE(dir_item_str) && dir_item_str[type])
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printf("<%s> ", dir_item_str[type]);
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else
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printf("%10llu ", inode.size);
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printf("%24.24s %.*s", filetime, item->name_len, name);
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if (item->type == BTRFS_FT_SYMLINK) {
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printf(" -> %s", target ? target : "?");
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if (target)
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free(target);
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printf("DIR_ITEM.%u", type);
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if (type == BTRFS_FT_CHRDEV || type == BTRFS_FT_BLKDEV) {
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ASSERT(key.type == BTRFS_INODE_ITEM_KEY);
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printf("%4llu,%5llu ", btrfs_stack_inode_rdev(&ii) >> 20,
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btrfs_stack_inode_rdev(&ii) & 0xfffff);
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} else {
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if (key.type == BTRFS_INODE_ITEM_KEY)
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printf("%10llu ", btrfs_stack_inode_size(&ii));
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else
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printf("%10llu ", 0ULL);
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}
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read_extent_buffer(eb, namebuf, (unsigned long)(di + 1),
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btrfs_dir_name_len(eb, di));
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printf("%24.24s %.*s", filetime, btrfs_dir_name_len(eb, di), namebuf);
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if (type == BTRFS_FT_SYMLINK)
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printf(" -> %s", target ? target : "?");
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printf("\n");
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return 0;
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out:
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free(target);
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return ret;
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}
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int btrfs_probe(struct blk_desc *fs_dev_desc,
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@ -125,27 +160,29 @@ int btrfs_probe(struct blk_desc *fs_dev_desc,
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int btrfs_ls(const char *path)
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{
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struct __btrfs_root root = btrfs_info.fs_root;
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u64 inr;
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struct btrfs_fs_info *fs_info = current_fs_info;
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struct btrfs_root *root = fs_info->fs_root;
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u64 ino = BTRFS_FIRST_FREE_OBJECTID;
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u8 type;
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int ret;
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inr = __btrfs_lookup_path(&root, root.root_dirid, path, &type, NULL, 40);
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if (inr == -1ULL) {
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ASSERT(fs_info);
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ret = btrfs_lookup_path(fs_info->fs_root, BTRFS_FIRST_FREE_OBJECTID,
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path, &root, &ino, &type, 40);
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if (ret < 0) {
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printf("Cannot lookup path %s\n", path);
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return -1;
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return ret;
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}
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if (type != BTRFS_FT_DIR) {
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printf("Not a directory: %s\n", path);
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return -1;
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error("Not a directory: %s", path);
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return -ENOENT;
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}
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if (btrfs_readdir(&root, inr, readdir_callback)) {
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printf("An error occured while listing directory %s\n", path);
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return -1;
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ret = btrfs_iter_dir(root, ino, show_dir);
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if (ret < 0) {
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error("An error occured while listing directory %s", path);
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return ret;
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}
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return 0;
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}
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@ -43,13 +43,8 @@ u32 btrfs_decompress(u8 type, const char *, u32, char *, u32);
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int btrfs_read_superblock(void);
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/* dir-item.c */
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typedef int (*btrfs_readdir_callback_t)(const struct __btrfs_root *,
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struct btrfs_dir_item *);
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int __btrfs_lookup_dir_item(const struct __btrfs_root *, u64, const char *, int,
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struct btrfs_dir_item *);
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int btrfs_readdir(const struct __btrfs_root *, u64, btrfs_readdir_callback_t);
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/* root.c */
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int btrfs_find_root(u64, struct __btrfs_root *, struct btrfs_root_item *);
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u64 btrfs_lookup_root_ref(u64, struct btrfs_root_ref *, char *);
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@ -1285,6 +1285,11 @@ struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
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struct btrfs_path *path, u64 dir,
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const char *name, int name_len,
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int mod);
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typedef int (*btrfs_iter_dir_callback_t)(struct btrfs_root *root,
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struct extent_buffer *eb,
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struct btrfs_dir_item *di);
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int btrfs_iter_dir(struct btrfs_root *root, u64 ino,
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btrfs_iter_dir_callback_t callback);
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/* inode.c */
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int btrfs_lookup_path(struct btrfs_root *root, u64 ino, const char *filename,
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struct btrfs_root **root_ret, u64 *ino_ret,
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@ -193,39 +193,55 @@ out:
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return res ? 0 : -1;
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}
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int btrfs_readdir(const struct __btrfs_root *root, u64 dir,
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btrfs_readdir_callback_t callback)
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int btrfs_iter_dir(struct btrfs_root *root, u64 ino,
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btrfs_iter_dir_callback_t callback)
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{
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struct __btrfs_path path;
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struct btrfs_key key, *found_key;
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struct btrfs_dir_item *item;
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int res = 0;
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struct btrfs_path path;
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struct btrfs_key key;
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int ret;
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key.objectid = dir;
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btrfs_init_path(&path);
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key.objectid = ino;
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key.type = BTRFS_DIR_INDEX_KEY;
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key.offset = 0;
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if (btrfs_search_tree(root, &key, &path))
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return -1;
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ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
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if (ret < 0)
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return ret;
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/* Should not happen */
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if (ret == 0) {
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ret = -EUCLEAN;
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goto out;
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}
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if (path.slots[0] >= btrfs_header_nritems(path.nodes[0])) {
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ret = btrfs_next_leaf(root, &path);
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if (ret < 0)
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goto out;
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if (ret > 0) {
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ret = 0;
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goto out;
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}
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}
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do {
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found_key = btrfs_path_leaf_key(&path);
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if (btrfs_comp_keys_type(&key, found_key))
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struct btrfs_dir_item *di;
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btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
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if (key.objectid != ino || key.type != BTRFS_DIR_INDEX_KEY)
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break;
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di = btrfs_item_ptr(path.nodes[0], path.slots[0],
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struct btrfs_dir_item);
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if (verify_dir_item(root, path.nodes[0], di)) {
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ret = -EUCLEAN;
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goto out;
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}
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ret = callback(root, path.nodes[0], di);
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if (ret < 0)
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goto out;
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} while (!(ret = btrfs_next_item(root, &path)));
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item = btrfs_path_item_ptr(&path, struct btrfs_dir_item);
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btrfs_dir_item_to_cpu(item);
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if (__verify_dir_item(item, 0, sizeof(*item) + item->name_len))
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continue;
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if (item->type == BTRFS_FT_XATTR)
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continue;
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if (callback(root, item))
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break;
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} while (!(res = btrfs_next_slot(&path)));
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__btrfs_free_path(&path);
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return res < 0 ? -1 : 0;
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if (ret > 0)
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ret = 0;
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out:
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btrfs_release_path(&path);
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return ret;
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}
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