Refactor btrfs_check_super_valid() by the ways:
1) Rename it to btrfs_validate_mount_super()
Now it's more obvious when the function should be called.
2) Extract core check routine into __validate_super()
So later write time check can reuse it, and if needed, we could also
use __validate_super() to check each super block.
3) Add more comment about btrfs_validate_mount_super()
Mostly of what it doesn't check and when it should be called.
Signed-off-by: Qu Wenruo <w...@suse.com>
---
fs/btrfs/disk-io.c | 29 +++++++++++++++++++++++++----
1 file changed, 25 insertions(+), 4 deletions(-)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 13c5f90995aa..b981ecc4b6f9 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2440,9 +2440,19 @@ static int btrfs_read_roots(struct btrfs_fs_info
*fs_info)
return ret;
}
-static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info)
+/*
+ * Real super block validation check
+ * NOTE: super csum type and incompat features will not be checked here.
+ *
+ * @sb: super block to check
+ * @mirror_num: the super block number to check its bytenr:
+ * 0 means the primary (1st) sb,
+ * 1 and 2 means 2nd and 3rd backup copy
+ * -1 means to skip bytenr check
+ */
+static int __validate_super(struct btrfs_fs_info *fs_info,
+ struct btrfs_super_block *sb, int mirror_num)
{
- struct btrfs_super_block *sb = fs_info->super_copy;
u64 nodesize = btrfs_super_nodesize(sb);
u64 sectorsize = btrfs_super_sectorsize(sb);
int ret = 0;
@@ -2545,7 +2555,8 @@ static int btrfs_check_super_valid(struct btrfs_fs_info
*fs_info)
ret = -EINVAL;
}
- if (btrfs_super_bytenr(sb) != BTRFS_SUPER_INFO_OFFSET) {
+ if (mirror_num >= 0 &&
+ btrfs_super_bytenr(sb) != btrfs_sb_offset(mirror_num)) {
btrfs_err(fs_info, "super offset mismatch %llu != %u",
btrfs_super_bytenr(sb), BTRFS_SUPER_INFO_OFFSET);
ret = -EINVAL;
@@ -2589,6 +2600,16 @@ static int btrfs_check_super_valid(struct btrfs_fs_info
*fs_info)
return ret;
}
+/*
+ * Check the validation of super block at mount time.
+ * Some checks already done by early mount, like csum type and incompat flags
+ * will be skipped.
+ */
+static int btrfs_validate_mount_super(struct btrfs_fs_info *fs_info)
+{
+ return __validate_super(fs_info, fs_info->super_copy, 0);
+}
+
int open_ctree(struct super_block *sb,
struct btrfs_fs_devices *fs_devices,
char *options)
@@ -2814,7 +2835,7 @@ int open_ctree(struct super_block *sb,
memcpy(fs_info->fsid, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
- ret = btrfs_check_super_valid(fs_info);
+ ret = btrfs_validate_mount_super(fs_info);
if (ret) {
btrfs_err(fs_info, "superblock contains fatal errors");
err = -EINVAL;
--
2.17.0
--
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