]> git.dujemihanovic.xyz Git - u-boot.git/commitdiff
fs: btrfs: Use btrfs_iter_dir() to replace btrfs_readdir()
authorQu Wenruo <wqu@suse.com>
Wed, 24 Jun 2020 16:03:06 +0000 (18:03 +0200)
committerTom Rini <trini@konsulko.com>
Tue, 8 Sep 2020 00:57:27 +0000 (20:57 -0400)
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 BehĂșn <marek.behun@nic.cz>
fs/btrfs/btrfs.c
fs/btrfs/btrfs.h
fs/btrfs/ctree.h
fs/btrfs/dir-item.c

index c967c114ccf5eb1d2edbb97a0a4519ec0040345b..2278b52e4d0e84c4f7decc9eb8fc72d54ae052ea 100644 (file)
 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;
 }
 
index 53d53f310bdce7ecc93fed3e07a4595a62cb5eed..e36bd898271637f9c9d72d040892f6755c22581f 100644 (file)
@@ -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 *);
index 111a5a6a2950f1d68ede25d6ef6b7ca780a22aed..0cf5e63451ce78c5847732c448e67ff7c31927d3 100644 (file)
@@ -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,
index b49aaacbd8fe44468a779b4dbd84dbac57ca856a..1a3929afdc4b9e21fa547202351613ca73ef9d56 100644 (file)
@@ -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;
 }