From: Harshad Shirwadkar <[email protected]>
Add fast_commit.h that contains the necessary helpers needed for fast
commit replay. Note that this file is also byte by byte identical with
kernel's fast_commit.h. Also, we introduce the
"e2fsck_fc_replay_state" structure which is needed for ext4 fast
commit replay.
Signed-off-by: Harshad Shirwadkar <[email protected]>
Reviewed-by: Theodore Ts'o <[email protected]>
---
e2fsck/e2fsck.h | 16 +++
e2fsck/journal.c | 15 +++
lib/ext2fs/ext2_fs.h | 1 +
lib/ext2fs/ext2fs.h | 3 +
lib/ext2fs/fast_commit.h | 203 +++++++++++++++++++++++++++++++++++++++
5 files changed, 238 insertions(+)
create mode 100644 lib/ext2fs/fast_commit.h
diff --git a/e2fsck/e2fsck.h b/e2fsck/e2fsck.h
index 3b9c1874..f75cc343 100644
--- a/e2fsck/e2fsck.h
+++ b/e2fsck/e2fsck.h
@@ -68,6 +68,7 @@
#endif
#include "support/quotaio.h"
+#include "ext2fs/fast_commit.h"
/*
* Exit codes used by fsck-type programs
@@ -239,6 +240,18 @@ struct extent_list {
errcode_t retval;
ext2_ino_t ino;
};
+
+/* State structure for fast commit replay */
+struct e2fsck_fc_replay_state {
+ struct extent_list fc_extent_list;
+ int fc_replay_num_tags;
+ int fc_replay_expected_off;
+ int fc_current_pass;
+ int fc_cur_tag;
+ int fc_crc;
+ __u16 fc_super_state;
+};
+
struct e2fsck_struct {
ext2_filsys fs;
const char *program_name;
@@ -431,6 +444,9 @@ struct e2fsck_struct {
/* Undo file */
char *undo_file;
+
+ /* Fast commit replay state */
+ struct e2fsck_fc_replay_state fc_replay_state;
};
/* Data structures to evaluate whether an extent tree needs rebuilding. */
diff --git a/e2fsck/journal.c b/e2fsck/journal.c
index 2adef76a..56e48385 100644
--- a/e2fsck/journal.c
+++ b/e2fsck/journal.c
@@ -278,6 +278,17 @@ static int process_journal_block(ext2_filsys fs,
return 0;
}
+/*
+ * Main recovery path entry point. This function returns JBD2_FC_REPLAY_CONTINUE
+ * to indicate that it is expecting more fast commit blocks. It returns
+ * JBD2_FC_REPLAY_STOP to indicate that replay is done.
+ */
+static int ext4_fc_replay(journal_t *journal, struct buffer_head *bh,
+ enum passtype pass, int off, tid_t expected_tid)
+{
+ return JBD2_FC_REPLAY_STOP;
+}
+
static errcode_t e2fsck_get_journal(e2fsck_t ctx, journal_t **ret_journal)
{
struct process_block_struct pb;
@@ -514,6 +525,10 @@ static errcode_t e2fsck_get_journal(e2fsck_t ctx, journal_t **ret_journal)
journal->j_sb_buffer = bh;
journal->j_superblock = (journal_superblock_t *)bh->b_data;
+ if (ext2fs_has_feature_fast_commit(ctx->fs->super))
+ journal->j_fc_replay_callback = ext4_fc_replay;
+ else
+ journal->j_fc_replay_callback = NULL;
#ifdef USE_INODE_IO
if (j_inode)
diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h
index bfc30c29..b1e4329c 100644
--- a/lib/ext2fs/ext2_fs.h
+++ b/lib/ext2fs/ext2_fs.h
@@ -543,6 +543,7 @@ struct ext2_inode *EXT2_INODE(struct ext2_inode_large *large_inode)
#define EXT2_VALID_FS 0x0001 /* Unmounted cleanly */
#define EXT2_ERROR_FS 0x0002 /* Errors detected */
#define EXT3_ORPHAN_FS 0x0004 /* Orphans being recovered */
+#define EXT4_FC_REPLAY 0x0020 /* Ext4 fast commit replay ongoing */
/*
* Misc. filesystem flags
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index fdcb28f6..eb2e6549 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -2148,4 +2148,7 @@ static inline unsigned int ext2_dir_htree_level(ext2_filsys fs)
}
#endif
+/* Commonly used helpers */
+#define max(a, b) ((a) > (b) ? (a) : (b))
+
#endif /* _EXT2FS_EXT2FS_H */
diff --git a/lib/ext2fs/fast_commit.h b/lib/ext2fs/fast_commit.h
new file mode 100644
index 00000000..b83e1810
--- /dev/null
+++ b/lib/ext2fs/fast_commit.h
@@ -0,0 +1,203 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __FAST_COMMIT_H__
+#define __FAST_COMMIT_H__
+
+#include "jfs_compat.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
+
+#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)))
+
+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";
+ }
+}
+
+/* Get length of a particular tlv */
+static inline int ext4_fc_tag_len(struct ext4_fc_tl *tl)
+{
+ return le16_to_cpu(tl->fc_len);
+}
+
+/* Get a pointer to "value" of a tlv */
+static inline __u8 *ext4_fc_tag_val(struct ext4_fc_tl *tl)
+{
+ return (__u8 *)tl + sizeof(*tl);
+}
+
+#endif /* __FAST_COMMIT_H__ */
--
2.30.0.284.gd98b1dd5eaa7-goog
On Wed, Jan 20, 2021 at 01:26:34PM -0800, Harshad Shirwadkar wrote:
> diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
> index fdcb28f6..eb2e6549 100644
> --- a/lib/ext2fs/ext2fs.h
> +++ b/lib/ext2fs/ext2fs.h
> @@ -2148,4 +2148,7 @@ static inline unsigned int ext2_dir_htree_level(ext2_filsys fs)
> }
> #endif
>
> +/* Commonly used helpers */
> +#define max(a, b) ((a) > (b) ? (a) : (b))
> +
> #endif /* _EXT2FS_EXT2FS_H */
It's better not to add this to a publically exported file, such as
lib/ext2fs/ext2fs.h, since it may conflict with other userspace
application which may define their own max file.
Something which we might want to do is to add something like
linux/minmax.h from the kernel sources to libsupport. This defines a
max() macro which does paranoid typechecking to make sure we don't
accidentally compare an unsigned int to an signed int, which can
potential security problems with maliciously fuzzed file system
images. :-)
- Ted