jhead lookup using bios

Tells you how many milliseconds map_journal_extents and find_jhead take.

Signed-off-by Abhi Das <[email protected]>

---
 fs/gfs2/bmap.c     | 8 ++++++--
 fs/gfs2/recovery.c | 2 ++
 2 files changed, 8 insertions(+), 2 deletions(-)

fs/gfs2/bmap.c +6 -2

index 5f3ea07..aaf3682 100644
@@ -14,6 +14,7 @@
 #include <linux/gfs2_ondisk.h>
 #include <linux/crc32.h>
 #include <linux/iomap.h>
+#include <linux/ktime.h>
 
 #include "gfs2.h"
 #include "incore.h"

@@ -2248,7 +2249,9 @@ int gfs2_map_journal_extents(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
        unsigned int shift = sdp->sd_sb.sb_bsize_shift;
        u64 size;
        int rc;
+       ktime_t start, end;
 
+       start = ktime_get();
        lblock_stop = i_size_read(jd->jd_inode) >> shift;
        size = (lblock_stop - lblock) << shift;
        jd->nr_extents = 0;

@@ -2268,8 +2271,9 @@ int gfs2_map_journal_extents(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd)
                lblock += (bh.b_size >> ip->i_inode.i_blkbits);
        } while(size > 0);
 
-       fs_info(sdp, "journal %d mapped with %u extents\n", jd->jd_jid,
-               jd->nr_extents);
+       end = ktime_get();
+       fs_info(sdp, "journal %d mapped with %u extents in %lldms\n", jd->jd_jid,
+               jd->nr_extents, ktime_ms_delta(end, start));
        return 0;
 
 fail:

fs/gfs2/recovery.c +2 -1

index 0f501f9..b0717a0 100644
@@ -460,6 +460,8 @@ void gfs2_recover_func(struct work_struct *work)
        if (error)
                goto fail_gunlock_ji;
        t_jhd = ktime_get();
+       fs_info(sdp, "jid=%u: Journal head lookup took %lldms\n", jd->jd_jid,
+               ktime_ms_delta(t_jhd, t_jlck));
 
        if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
                fs_info(sdp, "jid=%u: Acquiring the transaction lock...\n",
--

2.4.11

Move and re-order the error checks and hash/crc computations into another function __get_log_header() so it can be used in scenarios where buffer_heads are not being used for the log header.

Signed-off-by Abhi Das <[email protected]>

---
 fs/gfs2/recovery.c | 53 ++++++++++++++++++++++++++++++++---------------------
 fs/gfs2/recovery.h |  2 ++
 2 files changed, 34 insertions(+), 21 deletions(-)

fs/gfs2/recovery.c +32 -21

index b0717a0..2dac430 100644
@@ -120,6 +120,35 @@ void gfs2_revoke_clean(struct gfs2_jdesc *jd)
        }
 }
 
+int __get_log_header(struct gfs2_sbd *sdp, const struct gfs2_log_header *lh,
+                    unsigned int blkno, struct gfs2_log_header_host *head)
+{
+       u32 hash, crc;
+
+       if (lh->lh_header.mh_magic != cpu_to_be32(GFS2_MAGIC) ||
+           lh->lh_header.mh_type != cpu_to_be32(GFS2_METATYPE_LH) ||
+           (blkno && be32_to_cpu(lh->lh_blkno) != blkno))
+               return 1;
+
+       hash = crc32(~0, lh, LH_V1_SIZE - 4);
+       hash = ~crc32_le_shift(hash, 4); /* assume lh_hash is zero */
+
+       if (be32_to_cpu(lh->lh_hash) != hash)
+               return 1;
+
+       crc = crc32c(~0, (void *)lh + LH_V1_SIZE + 4,
+                    sdp->sd_sb.sb_bsize - LH_V1_SIZE - 4);
+
+       if ((lh->lh_crc != 0 && be32_to_cpu(lh->lh_crc) != crc))
+               return 1;
+
+       head->lh_sequence = be64_to_cpu(lh->lh_sequence);
+       head->lh_flags = be32_to_cpu(lh->lh_flags);
+       head->lh_tail = be32_to_cpu(lh->lh_tail);
+       head->lh_blkno = be32_to_cpu(lh->lh_blkno);
+
+       return 0;
+}
 /**
  * get_log_header - read the log header for a given segment
  * @jd: the journal

@@ -137,36 +166,18 @@ void gfs2_revoke_clean(struct gfs2_jdesc *jd)
 static int get_log_header(struct gfs2_jdesc *jd, unsigned int blk,
                          struct gfs2_log_header_host *head)
 {
-       struct gfs2_log_header *lh;
+       struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
        struct buffer_head *bh;
-       u32 hash, crc;
        int error;
 
        error = gfs2_replay_read_block(jd, blk, &bh);
        if (error)
                return error;
-       lh = (void *)bh->b_data;
-
-       hash = crc32(~0, lh, LH_V1_SIZE - 4);
-       hash = ~crc32_le_shift(hash, 4);  /* assume lh_hash is zero */
-
-       crc = crc32c(~0, (void *)lh + LH_V1_SIZE + 4,
-                    bh->b_size - LH_V1_SIZE - 4);
-
-       error = lh->lh_header.mh_magic != cpu_to_be32(GFS2_MAGIC) ||
-               lh->lh_header.mh_type != cpu_to_be32(GFS2_METATYPE_LH) ||
-               be32_to_cpu(lh->lh_blkno) != blk ||
-               be32_to_cpu(lh->lh_hash) != hash ||
-               (lh->lh_crc != 0 && be32_to_cpu(lh->lh_crc) != crc);
 
+       error = __get_log_header(sdp, (const struct gfs2_log_header *)bh->b_data,
+                                blk, head);
        brelse(bh);
 
-       if (!error) {
-               head->lh_sequence = be64_to_cpu(lh->lh_sequence);
-               head->lh_flags = be32_to_cpu(lh->lh_flags);
-               head->lh_tail = be32_to_cpu(lh->lh_tail);
-               head->lh_blkno = be32_to_cpu(lh->lh_blkno);
-       }
        return error;
 }
 

fs/gfs2/recovery.h +2 -1

index 11fdfab..943a67c 100644
@@ -31,6 +31,8 @@ extern int gfs2_find_jhead(struct gfs2_jdesc *jd,
                    struct gfs2_log_header_host *head);
 extern int gfs2_recover_journal(struct gfs2_jdesc *gfs2_jd, bool wait);
 extern void gfs2_recover_func(struct work_struct *work);
+extern int __get_log_header(struct gfs2_sbd *sdp, const struct gfs2_log_header *lh,
+                           unsigned int blkno, struct gfs2_log_header_host *head);
 
 #endif /* __RECOVERY_DOT_H__ */
 
--

2.4.11

fs/gfs2/lops.c +7 -0

+/**
+ * gfs2_end_log_read - end I/O callback for reads from the log
+ * @bio: The bio
+ *
+ * Simply unlock the pages in the bio. The main thread will wait on them and
+ * process them in order as necessary.
+ */

Quoted 5 lines

+/**
+ * gfs2_end_log_read - end I/O callback for reads from the log
+ * @bio: The bio
+ *
+ * Simply unlock the pages in the bio. The main thread will wait on

them and

fs/gfs2/lops.c void gfs2_log_write_page(struct gfs2_sbd *sdp, struct page *page)

Quoted 12 lines

+ * process them in order as necessary.
+ */

fs/gfs2/lops.c +10 -0

+
+static void gfs2_end_log_read(struct bio *bio)
+{
+     struct gfs2_sbd *sdp = bio->bi_private;
+     struct page *page;
+     struct bio_vec *bvec;
+     int i;
+
+     if (bio->bi_status)
+             fs_err(sdp, "Error %d reading from journal\n",

bio->bi_status);

How is error handling forthis going to work?

Quoted 2 lines

+ bio_set_op_attrs(bio, REQ_OP_READ, 0);

Please assign to bi_opf directly instead of using bio_set_op_attrs.

This is my latest version of this patchset based on inputs from Andreas and Steve.
We readahead the journal sequentially in large chunks using bios. Pagecache pages for the journal inode's mapping are used for the I/O.

There's also some cleanup of the bio functions with this patchset.

xfstests ran to completion with this.

Abhi Das (4):
gfs2: add more timing info to journal recovery process
gfs2: changes to gfs2_log_XXX_bio
gfs2: add a helper function to get_log_header that can be used
elsewhere
gfs2: read journal in large chunks to locate the head

  fs/gfs2/bmap.c       |   8 +-
  fs/gfs2/glops.c      |   1 +
  fs/gfs2/log.c        |   4 +-
  fs/gfs2/lops.c       | 240 +++++++++++++++++++++++++++++++++++++++++++--------
  fs/gfs2/lops.h       |   4 +-
  fs/gfs2/ops_fstype.c |   1 +
  fs/gfs2/recovery.c   | 178 ++++++++------------------------------
  fs/gfs2/recovery.h   |   4 +-
  fs/gfs2/super.c      |   1 +
  9 files changed, 255 insertions(+), 186 deletions(-)

This is my latest version of this patchset based on inputs from Andreas and Steve.
We readahead the journal sequentially in large chunks using bios. Pagecache pages for the journal inode's mapping are used for the I/O.

There's also some cleanup of the bio functions with this patchset.

xfstests ran to completion with this.

Abhi Das (4):
gfs2: add more timing info to journal recovery process
gfs2: changes to gfs2_log_XXX_bio
gfs2: add a helper function to get_log_header that can be used
elsewhere
gfs2: read journal in large chunks to locate the head