add-indirection-to-metadata-block-read-paths

   1 Add indirection to metadata read paths
   2
   3 From: Abutalib Aghayev <agayev@cs.cmu.edu>
   4
   5 Change all metadata block reads to use jmap-aware function that first looks
   6 up the metadata block in the jmap.  If lookup is successful, the function
   7 reads the corresponding log block from the journal and copies it to the
   8 metadata block buffer head.  Otherwise, it reads the metadata block from
   9 the file system, just like standard jmap-unaware function.
  10
  11 Signed-off-by: Abutalib Aghayev <agayev@cs.cmu.edu>
  12 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
  13 ---
  14  fs/ext4/extents.c     |  3 ++-
  15  fs/ext4/ialloc.c      |  5 ++++-
  16  fs/ext4/indirect.c    |  3 ++-
  17  fs/ext4/inode.c       | 20 ++++++++++++++------
  18  fs/ext4/move_extent.c |  3 ++-
  19  fs/ext4/resize.c      |  4 +++-
  20  6 files changed, 27 insertions(+), 11 deletions(-)
  21
  22 diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
  23 index 97f0fd06728d..47914c6a2556 100644
  24 --- a/fs/ext4/extents.c
  25 +++ b/fs/ext4/extents.c
  26 @@ -517,6 +517,7 @@ __read_extent_tree_block(const char *function, unsigned int line,
  27  {
  28         struct buffer_head              *bh;
  29         int                             err;
  30 +       journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
  31
  32         bh = sb_getblk_gfp(inode->i_sb, pblk, __GFP_MOVABLE | GFP_NOFS);
  33         if (unlikely(!bh))
  34 @@ -524,7 +525,7 @@ __read_extent_tree_block(const char *function, unsigned int line,
  35
  36         if (!bh_uptodate_or_lock(bh)) {
  37                 trace_ext4_ext_load_extent(inode, pblk, _RET_IP_);
  38 -               err = bh_submit_read(bh);
  39 +               err = jbd2_bh_submit_read(journal, bh, __func__);
  40                 if (err < 0)
  41                         goto errout;
  42         }
  43 diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
  44 index 507bfb3344d4..1c3447629e76 100644
  45 --- a/fs/ext4/ialloc.c
  46 +++ b/fs/ext4/ialloc.c
  47 @@ -14,6 +14,7 @@
  48
  49  #include <linux/time.h>
  50  #include <linux/fs.h>
  51 +#include <linux/jbd2.h>
  52  #include <linux/stat.h>
  53  #include <linux/string.h>
  54  #include <linux/quotaops.h>
  55 @@ -162,6 +163,7 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
  56         struct buffer_head *bh = NULL;
  57         ext4_fsblk_t bitmap_blk;
  58         int err;
  59 +       journal_t *journal = EXT4_SB(sb)->s_journal;
  60
  61         desc = ext4_get_group_desc(sb, block_group, NULL);
  62         if (!desc)
  63 @@ -216,7 +218,8 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
  64         trace_ext4_load_inode_bitmap(sb, block_group);
  65         bh->b_end_io = ext4_end_bitmap_read;
  66         get_bh(bh);
  67 -       submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
  68 +       jbd2_submit_bh(journal, REQ_OP_READ, REQ_META | REQ_PRIO, bh, __func__);
  69 +
  70         wait_on_buffer(bh);
  71         if (!buffer_uptodate(bh)) {
  72                 put_bh(bh);
  73 diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c
  74 index 7ffa290cbb8e..06a79f5e563e 100644
  75 --- a/fs/ext4/indirect.c
  76 +++ b/fs/ext4/indirect.c
  77 @@ -145,6 +145,7 @@ static Indirect *ext4_get_branch(struct inode *inode, int depth,
  78                                  Indirect chain[4], int *err)
  79  {
  80         struct super_block *sb = inode->i_sb;
  81 +       journal_t *journal = EXT4_SB(sb)->s_journal;
  82         Indirect *p = chain;
  83         struct buffer_head *bh;
  84         int ret = -EIO;
  85 @@ -162,7 +163,7 @@ static Indirect *ext4_get_branch(struct inode *inode, int depth,
  86                 }
  87
  88                 if (!bh_uptodate_or_lock(bh)) {
  89 -                       if (bh_submit_read(bh) < 0) {
  90 +                       if (jbd2_bh_submit_read(journal, bh, __func__) < 0) {
  91                                 put_bh(bh);
  92                                 goto failure;
  93                         }
  94 diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
  95 index c774bdc22759..a56e717b39be 100644
  96 --- a/fs/ext4/inode.c
  97 +++ b/fs/ext4/inode.c
  98 @@ -1001,13 +1001,15 @@ struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
  99                                ext4_lblk_t block, int map_flags)
 100  {
 101         struct buffer_head *bh;
 102 +       journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
 103
 104         bh = ext4_getblk(handle, inode, block, map_flags);
 105         if (IS_ERR(bh))
 106                 return bh;
 107         if (!bh || buffer_uptodate(bh))
 108                 return bh;
 109 -       ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &bh);
 110 +       jbd2_ll_rw_block(journal, REQ_OP_READ, REQ_META | REQ_PRIO, 1, &bh,
 111 +                        __func__);
 112         wait_on_buffer(bh);
 113         if (buffer_uptodate(bh))
 114                 return bh;
 115 @@ -1020,6 +1022,7 @@ int ext4_bread_batch(struct inode *inode, ext4_lblk_t block, int bh_count,
 116                      bool wait, struct buffer_head **bhs)
 117  {
 118         int i, err;
 119 +       journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
 120
 121         for (i = 0; i < bh_count; i++) {
 122                 bhs[i] = ext4_getblk(NULL, inode, block + i, 0 /* map_flags */);
 123 @@ -1033,8 +1036,9 @@ int ext4_bread_batch(struct inode *inode, ext4_lblk_t block, int bh_count,
 124         for (i = 0; i < bh_count; i++)
 125                 /* Note that NULL bhs[i] is valid because of holes. */
 126                 if (bhs[i] && !buffer_uptodate(bhs[i]))
 127 -                       ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1,
 128 -                                   &bhs[i]);
 129 +                       jbd2_ll_rw_block(journal, REQ_OP_READ,
 130 +                                        REQ_META | REQ_PRIO, 1, &bhs[i],
 131 +                                        __func__);
 132
 133         if (!wait)
 134                 return 0;
 135 @@ -4448,6 +4452,7 @@ static int __ext4_get_inode_loc(struct inode *inode,
 136         struct super_block      *sb = inode->i_sb;
 137         ext4_fsblk_t            block;
 138         int                     inodes_per_block, inode_offset;
 139 +       journal_t               *journal = EXT4_SB(sb)->s_journal;
 140
 141         iloc->bh = NULL;
 142         if (!ext4_valid_inum(sb, inode->i_ino))
 143 @@ -4551,8 +4556,10 @@ static int __ext4_get_inode_loc(struct inode *inode,
 144                         table += num / inodes_per_block;
 145                         if (end > table)
 146                                 end = table;
 147 -                       while (b <= end)
 148 -                               sb_breadahead(sb, b++);
 149 +                       if (journal) {
 150 +                               while (b <= end)
 151 +                                       jbd2_sb_breadahead(journal, sb, b++);
 152 +                       }
 153                 }
 154
 155                 /*
 156 @@ -4563,7 +4570,8 @@ static int __ext4_get_inode_loc(struct inode *inode,
 157                 trace_ext4_load_inode(inode);
 158                 get_bh(bh);
 159                 bh->b_end_io = end_buffer_read_sync;
 160 -               submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
 161 +               jbd2_submit_bh(journal, REQ_OP_READ, REQ_META | REQ_PRIO, bh,
 162 +                              __func__);
 163                 wait_on_buffer(bh);
 164                 if (!buffer_uptodate(bh)) {
 165                         EXT4_ERROR_INODE_BLOCK(inode, block,
 166 diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
 167 index 9bb36909ec92..0f6c00d0df17 100644
 168 --- a/fs/ext4/move_extent.c
 169 +++ b/fs/ext4/move_extent.c
 170 @@ -177,6 +177,7 @@ static int
 171  mext_page_mkuptodate(struct page *page, unsigned from, unsigned to)
 172  {
 173         struct inode *inode = page->mapping->host;
 174 +       journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
 175         sector_t block;
 176         struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE];
 177         unsigned int blocksize, block_start, block_end;
 178 @@ -225,7 +226,7 @@ mext_page_mkuptodate(struct page *page, unsigned from, unsigned to)
 179         for (i = 0; i < nr; i++) {
 180                 bh = arr[i];
 181                 if (!bh_uptodate_or_lock(bh)) {
 182 -                       err = bh_submit_read(bh);
 183 +                       err = jbd2_bh_submit_read(journal, bh, __func__);
 184                         if (err)
 185                                 return err;
 186                 }
 187 diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
 188 index 035cd3f4785e..5c817953053b 100644
 189 --- a/fs/ext4/resize.c
 190 +++ b/fs/ext4/resize.c
 191 @@ -1193,10 +1193,12 @@ static int ext4_add_new_descs(handle_t *handle, struct super_block *sb,
 192  static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block)
 193  {
 194         struct buffer_head *bh = sb_getblk(sb, block);
 195 +       journal_t *journal = EXT4_SB(sb)->s_journal;
 196 +
 197         if (unlikely(!bh))
 198                 return NULL;
 199         if (!bh_uptodate_or_lock(bh)) {
 200 -               if (bh_submit_read(bh) < 0) {
 201 +               if (jbd2_bh_submit_read(journal, bh, __func__) < 0) {
 202                         brelse(bh);
 203                         return NULL;
 204                 }