ext4: fast commit recovery path
This patch adds fast commit recovery path support for Ext4 file
system. We add several helper functions that are similar in spirit to
e2fsprogs journal recovery path handlers. Example of such functions
include - a simple block allocator, idempotent block bitmap update
function etc. Using these routines and the fast commit log in the fast
commit area, the recovery path (ext4_fc_replay()) performs fast commit
log recovery.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201015203802.3597742-8-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/fast_commit.h b/fs/ext4/fast_commit.h
index 560bc9c..06907d4 100644
--- a/fs/ext4/fast_commit.h
+++ b/fs/ext4/fast_commit.h
@@ -116,4 +116,44 @@ struct ext4_fc_stats {
unsigned long fc_numblks;
};
+#define EXT4_FC_REPLAY_REALLOC_INCREMENT 4
+
+/*
+ * Physical block regions added to different inodes due to fast commit
+ * recovery. These are set during the SCAN phase. During the replay phase,
+ * our allocator excludes these from its allocation. This ensures that
+ * we don't accidentally allocating a block that is going to be used by
+ * another inode.
+ */
+struct ext4_fc_alloc_region {
+ ext4_lblk_t lblk;
+ ext4_fsblk_t pblk;
+ int ino, len;
+};
+
+/*
+ * Fast commit replay state.
+ */
+struct ext4_fc_replay_state {
+ int fc_replay_num_tags;
+ int fc_replay_expected_off;
+ int fc_current_pass;
+ int fc_cur_tag;
+ int fc_crc;
+ struct ext4_fc_alloc_region *fc_regions;
+ int fc_regions_size, fc_regions_used, fc_regions_valid;
+ int *fc_modified_inodes;
+ int fc_modified_inodes_used, fc_modified_inodes_size;
+};
+
+#define region_last(__region) (((__region)->lblk) + ((__region)->len) - 1)
+
+#define fc_for_each_tl(__start, __end, __tl) \
+ for (tl = (struct ext4_fc_tl *)start; \
+ (u8 *)tl < (u8 *)end; \
+ tl = (struct ext4_fc_tl *)((u8 *)tl + \
+ sizeof(struct ext4_fc_tl) + \
+ + le16_to_cpu(tl->fc_len)))
+
+
#endif /* __FAST_COMMIT_H__ */