diff options
| -rw-r--r-- | fs/btrfs/disk-io.c | 25 | ||||
| -rw-r--r-- | fs/btrfs/disk-io.h | 4 | ||||
| -rw-r--r-- | fs/btrfs/super.c | 60 | ||||
| -rw-r--r-- | fs/btrfs/volumes.c | 2 |
4 files changed, 83 insertions, 8 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 74c30deba8bc..bb87b5697aff 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2598,8 +2598,8 @@ out: * 1, 2 2nd and 3rd backup copy * -1 skip bytenr check */ -static int validate_super(struct btrfs_fs_info *fs_info, - struct btrfs_super_block *sb, int mirror_num) +int btrfs_validate_super(struct btrfs_fs_info *fs_info, + struct btrfs_super_block *sb, int mirror_num) { u64 nodesize = btrfs_super_nodesize(sb); u64 sectorsize = btrfs_super_sectorsize(sb); @@ -2783,7 +2783,7 @@ static int validate_super(struct btrfs_fs_info *fs_info, */ static int btrfs_validate_mount_super(struct btrfs_fs_info *fs_info) { - return validate_super(fs_info, fs_info->super_copy, 0); + return btrfs_validate_super(fs_info, fs_info->super_copy, 0); } /* @@ -2797,7 +2797,7 @@ static int btrfs_validate_write_super(struct btrfs_fs_info *fs_info, { int ret; - ret = validate_super(fs_info, sb, -1); + ret = btrfs_validate_super(fs_info, sb, -1); if (ret < 0) goto out; if (!btrfs_supported_super_csum(btrfs_super_csum_type(sb))) { @@ -3844,7 +3844,7 @@ static void btrfs_end_super_write(struct bio *bio) } struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev, - int copy_num) + int copy_num, bool drop_cache) { struct btrfs_super_block *super; struct page *page; @@ -3862,6 +3862,19 @@ struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev, if (bytenr + BTRFS_SUPER_INFO_SIZE >= bdev_nr_bytes(bdev)) return ERR_PTR(-EINVAL); + if (drop_cache) { + /* This should only be called with the primary sb. */ + ASSERT(copy_num == 0); + + /* + * Drop the page of the primary superblock, so later read will + * always read from the device. + */ + invalidate_inode_pages2_range(mapping, + bytenr >> PAGE_SHIFT, + (bytenr + BTRFS_SUPER_INFO_SIZE) >> PAGE_SHIFT); + } + page = read_cache_page_gfp(mapping, bytenr >> PAGE_SHIFT, GFP_NOFS); if (IS_ERR(page)) return ERR_CAST(page); @@ -3893,7 +3906,7 @@ struct btrfs_super_block *btrfs_read_dev_super(struct block_device *bdev) * later supers, using BTRFS_SUPER_MIRROR_MAX instead */ for (i = 0; i < 1; i++) { - super = btrfs_read_dev_one_super(bdev, i); + super = btrfs_read_dev_one_super(bdev, i, false); if (IS_ERR(super)) continue; diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h index 47ad8e0a2d33..aef981de672c 100644 --- a/fs/btrfs/disk-io.h +++ b/fs/btrfs/disk-io.h @@ -46,10 +46,12 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_devices, char *options); void __cold close_ctree(struct btrfs_fs_info *fs_info); +int btrfs_validate_super(struct btrfs_fs_info *fs_info, + struct btrfs_super_block *sb, int mirror_num); int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors); struct btrfs_super_block *btrfs_read_dev_super(struct block_device *bdev); struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev, - int copy_num); + int copy_num, bool drop_cache); int btrfs_commit_super(struct btrfs_fs_info *fs_info); struct btrfs_root *btrfs_read_tree_root(struct btrfs_root *tree_root, struct btrfs_key *key); diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 01dd3c9d713e..51449619a023 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -2553,11 +2553,71 @@ static int btrfs_freeze(struct super_block *sb) return btrfs_commit_transaction(trans); } +static int check_dev_super(struct btrfs_device *dev) +{ + struct btrfs_fs_info *fs_info = dev->fs_info; + struct btrfs_super_block *sb; + int ret = 0; + + /* This should be called with fs still frozen. */ + ASSERT(test_bit(BTRFS_FS_FROZEN, &fs_info->flags)); + + /* Missing dev, no need to check. */ + if (!dev->bdev) + return 0; + + /* Only need to check the primary super block. */ + sb = btrfs_read_dev_one_super(dev->bdev, 0, true); + if (IS_ERR(sb)) + return PTR_ERR(sb); + + /* Btrfs_validate_super() includes fsid check against super->fsid. */ + ret = btrfs_validate_super(fs_info, sb, 0); + if (ret < 0) + goto out; + + if (btrfs_super_generation(sb) != fs_info->last_trans_committed) { + btrfs_err(fs_info, "transid mismatch, has %llu expect %llu", + btrfs_super_generation(sb), + fs_info->last_trans_committed); + ret = -EUCLEAN; + goto out; + } +out: + btrfs_release_disk_super(sb); + return ret; +} + static int btrfs_unfreeze(struct super_block *sb) { struct btrfs_fs_info *fs_info = btrfs_sb(sb); + struct btrfs_device *device; + int ret = 0; + /* + * Make sure the fs is not changed by accident (like hibernation then + * modified by other OS). + * If we found anything wrong, we mark the fs error immediately. + * + * And since the fs is frozen, no one can modify the fs yet, thus + * we don't need to hold device_list_mutex. + */ + list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) { + ret = check_dev_super(device); + if (ret < 0) { + btrfs_handle_fs_error(fs_info, ret, + "super block on devid %llu got modified unexpectedly", + device->devid); + break; + } + } clear_bit(BTRFS_FS_FROZEN, &fs_info->flags); + + /* + * We still return 0, to allow VFS layer to unfreeze the fs even the + * above checks failed. Since the fs is either fine or read-only, we're + * safe to continue, without causing further damage. + */ return 0; } diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 1153a850038c..94ba46d57920 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -2019,7 +2019,7 @@ void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info, struct page *page; int ret; - disk_super = btrfs_read_dev_one_super(bdev, copy_num); + disk_super = btrfs_read_dev_one_super(bdev, copy_num, false); if (IS_ERR(disk_super)) continue; |