From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f45.google.com ([74.125.82.45]:42137 "EHLO mail-wg0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751824Ab3FZQo1 (ORCPT ); Wed, 26 Jun 2013 12:44:27 -0400 Received: by mail-wg0-f45.google.com with SMTP id j13so10853191wgh.24 for ; Wed, 26 Jun 2013 09:44:26 -0700 (PDT) From: Filipe David Borba Manana To: linux-btrfs@vger.kernel.org Cc: Filipe David Borba Manana Subject: [PATCH v2 5/5] Btrfs-progs: Validate super block checksum Date: Wed, 26 Jun 2013 17:42:46 +0100 Message-Id: <1372264966-10251-1-git-send-email-fdmanana@gmail.com> In-Reply-To: <1370893895-24884-1-git-send-email-fdmanana@gmail.com> References: <1370893895-24884-1-git-send-email-fdmanana@gmail.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: After finding a super block in a device also validate its checksum. This validation is done in the kernel but it was missing in btrfs-progs. The function btrfs_check_super_csum() is imported from the file fs/btrfs/disk-io.c in the kernel source tree. v2: When finding the super block for a device ignore checksum validation failures if we're running the btrfsck tool, the restore or check commands of the btrfs tool, btrfs-debug-tree or btrfs-find-root tools. For all cases, print a warning message whenever the checksum validation fails, mentioning the superblock offset and device path. Signed-off-by: Filipe David Borba Manana --- btrfs-debug-tree.c | 2 +- btrfs-find-root.c | 8 ++-- cmds-check.c | 2 +- cmds-device.c | 2 +- cmds-filesystem.c | 2 +- cmds-replace.c | 2 +- cmds-restore.c | 2 +- disk-io.c | 103 ++++++++++++++++++++++++++++++++++++++++------------ disk-io.h | 7 +++- utils.c | 15 ++++---- utils.h | 4 +- volumes.c | 6 ++- volumes.h | 3 +- 13 files changed, 110 insertions(+), 48 deletions(-) diff --git a/btrfs-debug-tree.c b/btrfs-debug-tree.c index 74d4d66..6fa9e83 100644 --- a/btrfs-debug-tree.c +++ b/btrfs-debug-tree.c @@ -166,7 +166,7 @@ int main(int ac, char **av) if (ac != 1) print_usage(); - info = open_ctree_fs_info(av[optind], 0, 0, 0, 1); + info = open_ctree_fs_info(av[optind], 0, 0, 0, 1, 1); if (!info) { fprintf(stderr, "unable to open %s\n", av[optind]); exit(1); diff --git a/btrfs-find-root.c b/btrfs-find-root.c index 810d835..d7abc8a 100644 --- a/btrfs-find-root.c +++ b/btrfs-find-root.c @@ -102,7 +102,7 @@ static struct btrfs_root *open_ctree_broken(int fd, const char *device) u64 features; ret = btrfs_scan_one_device(fd, device, &fs_devices, - &total_devs, BTRFS_SUPER_INFO_OFFSET); + &total_devs, BTRFS_SUPER_INFO_OFFSET, 1); if (ret) { fprintf(stderr, "No valid Btrfs found on %s\n", device); @@ -110,7 +110,7 @@ static struct btrfs_root *open_ctree_broken(int fd, const char *device) } if (total_devs != 1) { - ret = btrfs_scan_for_fsid(fs_devices, total_devs, 1); + ret = btrfs_scan_for_fsid(fs_devices, total_devs, 1, 1); if (ret) goto out; } @@ -149,8 +149,8 @@ static struct btrfs_root *open_ctree_broken(int fd, const char *device) fs_info->super_bytenr = BTRFS_SUPER_INFO_OFFSET; disk_super = fs_info->super_copy; - ret = btrfs_read_dev_super(fs_devices->latest_bdev, - disk_super, BTRFS_SUPER_INFO_OFFSET); + ret = btrfs_read_dev_super(fs_devices->latest_bdev, device, + disk_super, BTRFS_SUPER_INFO_OFFSET, 1); if (ret) { printk("No valid btrfs found\n"); goto out_devices; diff --git a/cmds-check.c b/cmds-check.c index 68cdd52..7aa5e82 100644 --- a/cmds-check.c +++ b/cmds-check.c @@ -5185,7 +5185,7 @@ int cmd_check(int argc, char **argv) return -EBUSY; } - info = open_ctree_fs_info(argv[optind], bytenr, 0, rw, 1); + info = open_ctree_fs_info(argv[optind], bytenr, 0, rw, 1, 1); if (!info) { fprintf(stderr, "Couldn't open file system\n"); return -EIO; diff --git a/cmds-device.c b/cmds-device.c index 41e79d3..723ce2e 100644 --- a/cmds-device.c +++ b/cmds-device.c @@ -203,7 +203,7 @@ static int cmd_scan_dev(int argc, char **argv) printf("Scanning for Btrfs filesystems\n"); if(checklist) - ret = btrfs_scan_block_devices(1); + ret = btrfs_scan_block_devices(1, 0); else ret = btrfs_scan_one_dir("/dev", 1); if (ret){ diff --git a/cmds-filesystem.c b/cmds-filesystem.c index f41a72a..2178986 100644 --- a/cmds-filesystem.c +++ b/cmds-filesystem.c @@ -257,7 +257,7 @@ static int cmd_show(int argc, char **argv) usage(cmd_show_usage); if(checklist) - ret = btrfs_scan_block_devices(0); + ret = btrfs_scan_block_devices(0, 0); else ret = btrfs_scan_one_dir("/dev", 0); diff --git a/cmds-replace.c b/cmds-replace.c index 6397bb5..16b17f0 100644 --- a/cmds-replace.c +++ b/cmds-replace.c @@ -280,7 +280,7 @@ static int cmd_start_replace(int argc, char **argv) goto leave_with_error; } ret = btrfs_scan_one_device(fddstdev, dstdev, &fs_devices_mnt, - &total_devs, BTRFS_SUPER_INFO_OFFSET); + &total_devs, BTRFS_SUPER_INFO_OFFSET, 0); if (ret >= 0 && !force_using_targetdev) { fprintf(stderr, "Error, target device %s contains filesystem, use '-f' to force overwriting.\n", diff --git a/cmds-restore.c b/cmds-restore.c index eca528d..39f19cd 100644 --- a/cmds-restore.c +++ b/cmds-restore.c @@ -842,7 +842,7 @@ static struct btrfs_root *open_fs(const char *dev, u64 root_location, for (i = super_mirror; i < BTRFS_SUPER_MIRROR_MAX; i++) { bytenr = btrfs_sb_offset(i); - fs_info = open_ctree_fs_info(dev, bytenr, root_location, 0, 1); + fs_info = open_ctree_fs_info(dev, bytenr, root_location, 0, 1, 1); if (fs_info) break; fprintf(stderr, "Could not open root, trying backup super\n"); diff --git a/disk-io.c b/disk-io.c index 768adda..350daa1 100644 --- a/disk-io.c +++ b/disk-io.c @@ -801,7 +801,8 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info, static struct btrfs_fs_info *__open_ctree_fd(int fp, const char *path, u64 sb_bytenr, u64 root_tree_bytenr, int writes, - int partial) + int partial, + int ignore_sb_csum) { u32 sectorsize; u32 nodesize; @@ -830,7 +831,7 @@ static struct btrfs_fs_info *__open_ctree_fd(int fp, const char *path, fprintf(stderr, "Warning, could not drop caches\n"); ret = btrfs_scan_one_device(fp, path, &fs_devices, - &total_devs, sb_bytenr); + &total_devs, sb_bytenr, ignore_sb_csum); if (ret) { fprintf(stderr, "No valid Btrfs found on %s\n", path); @@ -838,7 +839,7 @@ static struct btrfs_fs_info *__open_ctree_fd(int fp, const char *path, } if (total_devs != 1) { - ret = btrfs_scan_for_fsid(fs_devices, total_devs, 1); + ret = btrfs_scan_for_fsid(fs_devices, total_devs, 1, ignore_sb_csum); if (ret) goto out; } @@ -881,8 +882,8 @@ static struct btrfs_fs_info *__open_ctree_fd(int fp, const char *path, fs_info->super_bytenr = sb_bytenr; disk_super = fs_info->super_copy; - ret = btrfs_read_dev_super(fs_devices->latest_bdev, - disk_super, sb_bytenr); + ret = btrfs_read_dev_super(fs_devices->latest_bdev, path, + disk_super, sb_bytenr, ignore_sb_csum); if (ret) { printk("No valid btrfs found\n"); goto out_devices; @@ -1048,7 +1049,8 @@ out: struct btrfs_fs_info *open_ctree_fs_info(const char *filename, u64 sb_bytenr, u64 root_tree_bytenr, - int writes, int partial) + int writes, int partial, + int ignore_sb_csum) { int fp; struct btrfs_fs_info *info; @@ -1063,7 +1065,7 @@ struct btrfs_fs_info *open_ctree_fs_info(const char *filename, return NULL; } info = __open_ctree_fd(fp, filename, sb_bytenr, root_tree_bytenr, - writes, partial); + writes, partial, ignore_sb_csum); close(fp); return info; } @@ -1072,7 +1074,7 @@ struct btrfs_root *open_ctree(const char *filename, u64 sb_bytenr, int writes) { struct btrfs_fs_info *info; - info = open_ctree_fs_info(filename, sb_bytenr, 0, writes, 0); + info = open_ctree_fs_info(filename, sb_bytenr, 0, writes, 0, 0); if (!info) return NULL; return info->fs_root; @@ -1082,53 +1084,106 @@ struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr, int writes) { struct btrfs_fs_info *info; - info = __open_ctree_fd(fp, path, sb_bytenr, 0, writes, 0); + info = __open_ctree_fd(fp, path, sb_bytenr, 0, writes, 0, 0); if (!info) return NULL; return info->fs_root; } -int btrfs_read_dev_super(int fd, struct btrfs_super_block *sb, u64 sb_bytenr) +static int btrfs_check_super_csum(char *raw_disk_sb, const char *path) +{ + struct btrfs_super_block *disk_sb = + (struct btrfs_super_block *)raw_disk_sb; + u16 csum_type = btrfs_super_csum_type(disk_sb); + int ret = 0; + + if (csum_type == BTRFS_CSUM_TYPE_CRC32) { + u32 crc = ~(u32)0; + const int csum_size = sizeof(crc); + char result[csum_size]; + + /* + * The super_block structure does not span the whole + * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space + * is filled with zeros and is included in the checkum. + */ + crc = btrfs_csum_data(NULL, raw_disk_sb + BTRFS_CSUM_SIZE, + crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE); + btrfs_csum_final(crc, result); + + if (memcmp(raw_disk_sb, result, csum_size)) + ret = 1; + + if (ret && btrfs_super_generation(disk_sb) < 1) { + fprintf(stderr, "Super block CRCs don't match, " + "older mkfs detected\n"); + ret = 0; + } + } + + if (ret) { + fprintf(stderr, + "Super block checksum validation failed, offset %llu," + " device %s\n", + (unsigned long long)btrfs_super_bytenr(disk_sb), path); + } + + if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) { + fprintf(stderr, "Unsupported super block checksum algorithm %u\n", + csum_type); + ret = 1; + } + + return ret; +} + +int btrfs_read_dev_super(int fd, const char *path, + struct btrfs_super_block *sb, u64 sb_bytenr, + int ignore_sb_csum) { u8 fsid[BTRFS_FSID_SIZE]; int fsid_is_initialized = 0; - struct btrfs_super_block buf; + char buf[BTRFS_SUPER_INFO_SIZE]; + struct btrfs_super_block *tmp_sb = (struct btrfs_super_block *)buf; int i; int ret; u64 transid = 0; u64 bytenr; if (sb_bytenr != BTRFS_SUPER_INFO_OFFSET) { - ret = pread64(fd, &buf, sizeof(buf), sb_bytenr); + ret = pread64(fd, buf, sizeof(buf), sb_bytenr); if (ret < sizeof(buf)) return -1; - if (btrfs_super_bytenr(&buf) != sb_bytenr || - buf.magic != cpu_to_le64(BTRFS_MAGIC)) + if (btrfs_super_bytenr(tmp_sb) != sb_bytenr || + tmp_sb->magic != cpu_to_le64(BTRFS_MAGIC) || + (btrfs_check_super_csum(buf, path) && !ignore_sb_csum)) return -1; - memcpy(sb, &buf, sizeof(*sb)); + memcpy(sb, buf, sizeof(*sb)); return 0; } for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) { bytenr = btrfs_sb_offset(i); - ret = pread64(fd, &buf, sizeof(buf), bytenr); + ret = pread64(fd, buf, sizeof(buf), bytenr); if (ret < sizeof(buf)) break; - if (btrfs_super_bytenr(&buf) != bytenr ) + if (btrfs_super_bytenr(tmp_sb) != bytenr ) continue; /* if magic is NULL, the device was removed */ - if (buf.magic == 0 && i == 0) + if (tmp_sb->magic == 0 && i == 0) return -1; - if (buf.magic != cpu_to_le64(BTRFS_MAGIC)) + if (tmp_sb->magic != cpu_to_le64(BTRFS_MAGIC)) + continue; + if (btrfs_check_super_csum(buf, path) && !ignore_sb_csum) continue; if (!fsid_is_initialized) { - memcpy(fsid, buf.fsid, sizeof(fsid)); + memcpy(fsid, tmp_sb->fsid, sizeof(fsid)); fsid_is_initialized = 1; - } else if (memcmp(fsid, buf.fsid, sizeof(fsid))) { + } else if (memcmp(fsid, tmp_sb->fsid, sizeof(fsid))) { /* * the superblocks (the original one and * its backups) contain data of different @@ -1137,9 +1192,9 @@ int btrfs_read_dev_super(int fd, struct btrfs_super_block *sb, u64 sb_bytenr) continue; } - if (btrfs_super_generation(&buf) > transid) { - memcpy(sb, &buf, sizeof(*sb)); - transid = btrfs_super_generation(&buf); + if (btrfs_super_generation(tmp_sb) > transid) { + memcpy(sb, buf, sizeof(*sb)); + transid = btrfs_super_generation(tmp_sb); } } diff --git a/disk-io.h b/disk-io.h index c29ee8e..f061998 100644 --- a/disk-io.h +++ b/disk-io.h @@ -52,12 +52,15 @@ struct btrfs_root *open_ctree_fd(int fp, const char *path, u64 sb_bytenr, int writes); struct btrfs_fs_info *open_ctree_fs_info(const char *filename, u64 sb_bytenr, u64 root_tree_bytenr, - int writes, int partial); + int writes, int partial, + int ignore_sb_csum); int close_ctree(struct btrfs_root *root); int write_all_supers(struct btrfs_root *root); int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root *root); -int btrfs_read_dev_super(int fd, struct btrfs_super_block *sb, u64 sb_bytenr); +int btrfs_read_dev_super(int fd, const char *path, + struct btrfs_super_block *sb, u64 sb_bytenr, + int ignore_sb_csum); int btrfs_map_bh_to_logical(struct btrfs_root *root, struct extent_buffer *bh, u64 logical); struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root, diff --git a/utils.c b/utils.c index 7b4cd74..4c9e89a 100644 --- a/utils.c +++ b/utils.c @@ -923,12 +923,12 @@ int check_mounted_where(int fd, const char *file, char *where, int size, /* scan the initial device */ ret = btrfs_scan_one_device(fd, file, &fs_devices_mnt, - &total_devs, BTRFS_SUPER_INFO_OFFSET); + &total_devs, BTRFS_SUPER_INFO_OFFSET, 1); is_btrfs = (ret >= 0); /* scan other devices */ if (is_btrfs && total_devs > 1) { - if((ret = btrfs_scan_for_fsid(fs_devices_mnt, total_devs, 1))) + if((ret = btrfs_scan_for_fsid(fs_devices_mnt, total_devs, 1, 1))) return ret; } @@ -1085,7 +1085,7 @@ again: } ret = btrfs_scan_one_device(fd, fullpath, &tmp_devices, &num_devices, - BTRFS_SUPER_INFO_OFFSET); + BTRFS_SUPER_INFO_OFFSET, 0); if (ret == 0 && run_ioctl > 0) { btrfs_register_one_device(fullpath); } @@ -1111,11 +1111,11 @@ fail: } int btrfs_scan_for_fsid(struct btrfs_fs_devices *fs_devices, u64 total_devs, - int run_ioctls) + int run_ioctls, int ignore_sb_csum) { int ret; - ret = btrfs_scan_block_devices(run_ioctls); + ret = btrfs_scan_block_devices(run_ioctls, ignore_sb_csum); if (ret) ret = btrfs_scan_one_dir("/dev", run_ioctls); return ret; @@ -1350,7 +1350,7 @@ int set_label(const char *btrfs_dev, const char *label) set_label_mounted(btrfs_dev, label); } -int btrfs_scan_block_devices(int run_ioctl) +int btrfs_scan_block_devices(int run_ioctl, int ignore_sb_csum) { struct stat st; @@ -1416,7 +1416,8 @@ scan_again: } ret = btrfs_scan_one_device(fd, fullpath, &tmp_devices, &num_devices, - BTRFS_SUPER_INFO_OFFSET); + BTRFS_SUPER_INFO_OFFSET, + ignore_sb_csum); if (ret == 0 && run_ioctl > 0) { btrfs_register_one_device(fullpath); } diff --git a/utils.h b/utils.h index 3c17e14..9c1a98e 100644 --- a/utils.h +++ b/utils.h @@ -36,7 +36,7 @@ int btrfs_add_to_fsid(struct btrfs_trans_handle *trans, u64 block_count, u32 io_width, u32 io_align, u32 sectorsize); int btrfs_scan_for_fsid(struct btrfs_fs_devices *fs_devices, u64 total_devs, - int run_ioctls); + int run_ioctls, int ignore_sb_csum); void btrfs_register_one_device(char *fname); int btrfs_scan_one_dir(char *dirname, int run_ioctl); int check_mounted(const char *devicename); @@ -46,7 +46,7 @@ int btrfs_device_already_in_root(struct btrfs_root *root, int fd, int super_offset); char *pretty_sizes(u64 size); int get_mountpt(char *dev, char *mntpt, size_t size); -int btrfs_scan_block_devices(int run_ioctl); +int btrfs_scan_block_devices(int run_ioctl, int ignore_sb_csum); u64 parse_size(char *s); int open_file_or_dir(const char *fname); int get_device_info(int fd, u64 devid, diff --git a/volumes.c b/volumes.c index 061f094..3178281 100644 --- a/volumes.c +++ b/volumes.c @@ -213,7 +213,8 @@ fail: int btrfs_scan_one_device(int fd, const char *path, struct btrfs_fs_devices **fs_devices_ret, - u64 *total_devs, u64 super_offset) + u64 *total_devs, u64 super_offset, + int ignore_sb_csum) { struct btrfs_super_block *disk_super; char *buf; @@ -227,7 +228,8 @@ int btrfs_scan_one_device(int fd, const char *path, goto error; } disk_super = (struct btrfs_super_block *)buf; - ret = btrfs_read_dev_super(fd, disk_super, super_offset); + ret = btrfs_read_dev_super(fd, path, + disk_super, super_offset, ignore_sb_csum); if (ret < 0) { ret = -EIO; goto error_brelse; diff --git a/volumes.h b/volumes.h index 911f788..e8d1534 100644 --- a/volumes.h +++ b/volumes.h @@ -179,7 +179,8 @@ int btrfs_update_device(struct btrfs_trans_handle *trans, struct btrfs_device *device); int btrfs_scan_one_device(int fd, const char *path, struct btrfs_fs_devices **fs_devices_ret, - u64 *total_devs, u64 super_offset); + u64 *total_devs, u64 super_offset, + int ignore_sb_csum); int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len); int btrfs_bootstrap_super_map(struct btrfs_mapping_tree *map_tree, struct btrfs_fs_devices *fs_devices); -- 1.7.9.5