linux/fs/ext4/fast_commit.h
Harshad Shirwadkar a7ba36bc94 ext4: fix fast commit alignment issues
Fast commit recovery data on disk may not be aligned. So, when the
recovery code reads it, this patch makes sure that fast commit info
found on-disk is first memcpy-ed into an aligned variable before
accessing it. As a consequence of it, we also remove some macros that
could resulted in unaligned accesses.

Cc: stable@kernel.org
Fixes: 8016e29f43 ("ext4: fast commit recovery path")
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20210519215920.2037527-1-harshads@google.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-06-06 10:10:23 -04:00

183 lines
4.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __FAST_COMMIT_H__
#define __FAST_COMMIT_H__
/*
* Note this file is present in e2fsprogs/lib/ext2fs/fast_commit.h and
* linux/fs/ext4/fast_commit.h. These file should always be byte identical.
*/
/* Fast commit tags */
#define EXT4_FC_TAG_ADD_RANGE 0x0001
#define EXT4_FC_TAG_DEL_RANGE 0x0002
#define EXT4_FC_TAG_CREAT 0x0003
#define EXT4_FC_TAG_LINK 0x0004
#define EXT4_FC_TAG_UNLINK 0x0005
#define EXT4_FC_TAG_INODE 0x0006
#define EXT4_FC_TAG_PAD 0x0007
#define EXT4_FC_TAG_TAIL 0x0008
#define EXT4_FC_TAG_HEAD 0x0009
#define EXT4_FC_SUPPORTED_FEATURES 0x0
/* On disk fast commit tlv value structures */
/* Fast commit on disk tag length structure */
struct ext4_fc_tl {
__le16 fc_tag;
__le16 fc_len;
};
/* Value structure for tag EXT4_FC_TAG_HEAD. */
struct ext4_fc_head {
__le32 fc_features;
__le32 fc_tid;
};
/* Value structure for EXT4_FC_TAG_ADD_RANGE. */
struct ext4_fc_add_range {
__le32 fc_ino;
__u8 fc_ex[12];
};
/* Value structure for tag EXT4_FC_TAG_DEL_RANGE. */
struct ext4_fc_del_range {
__le32 fc_ino;
__le32 fc_lblk;
__le32 fc_len;
};
/*
* This is the value structure for tags EXT4_FC_TAG_CREAT, EXT4_FC_TAG_LINK
* and EXT4_FC_TAG_UNLINK.
*/
struct ext4_fc_dentry_info {
__le32 fc_parent_ino;
__le32 fc_ino;
__u8 fc_dname[0];
};
/* Value structure for EXT4_FC_TAG_INODE and EXT4_FC_TAG_INODE_PARTIAL. */
struct ext4_fc_inode {
__le32 fc_ino;
__u8 fc_raw_inode[0];
};
/* Value structure for tag EXT4_FC_TAG_TAIL. */
struct ext4_fc_tail {
__le32 fc_tid;
__le32 fc_crc;
};
/*
* Fast commit reason codes
*/
enum {
/*
* Commit status codes:
*/
EXT4_FC_REASON_OK = 0,
EXT4_FC_REASON_INELIGIBLE,
EXT4_FC_REASON_ALREADY_COMMITTED,
EXT4_FC_REASON_FC_START_FAILED,
EXT4_FC_REASON_FC_FAILED,
/*
* Fast commit ineligiblity reasons:
*/
EXT4_FC_REASON_XATTR = 0,
EXT4_FC_REASON_CROSS_RENAME,
EXT4_FC_REASON_JOURNAL_FLAG_CHANGE,
EXT4_FC_REASON_NOMEM,
EXT4_FC_REASON_SWAP_BOOT,
EXT4_FC_REASON_RESIZE,
EXT4_FC_REASON_RENAME_DIR,
EXT4_FC_REASON_FALLOC_RANGE,
EXT4_FC_REASON_INODE_JOURNAL_DATA,
EXT4_FC_COMMIT_FAILED,
EXT4_FC_REASON_MAX
};
#ifdef __KERNEL__
/*
* In memory list of dentry updates that are performed on the file
* system used by fast commit code.
*/
struct ext4_fc_dentry_update {
int fcd_op; /* Type of update create / unlink / link */
int fcd_parent; /* Parent inode number */
int fcd_ino; /* Inode number */
struct qstr fcd_name; /* Dirent name */
unsigned char fcd_iname[DNAME_INLINE_LEN]; /* Dirent name string */
struct list_head fcd_list;
};
struct ext4_fc_stats {
unsigned int fc_ineligible_reason_count[EXT4_FC_REASON_MAX];
unsigned long fc_num_commits;
unsigned long fc_ineligible_commits;
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)
#endif
static inline const char *tag2str(__u16 tag)
{
switch (tag) {
case EXT4_FC_TAG_LINK:
return "ADD_ENTRY";
case EXT4_FC_TAG_UNLINK:
return "DEL_ENTRY";
case EXT4_FC_TAG_ADD_RANGE:
return "ADD_RANGE";
case EXT4_FC_TAG_CREAT:
return "CREAT_DENTRY";
case EXT4_FC_TAG_DEL_RANGE:
return "DEL_RANGE";
case EXT4_FC_TAG_INODE:
return "INODE";
case EXT4_FC_TAG_PAD:
return "PAD";
case EXT4_FC_TAG_TAIL:
return "TAIL";
case EXT4_FC_TAG_HEAD:
return "HEAD";
default:
return "ERROR";
}
}
#endif /* __FAST_COMMIT_H__ */