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       | 14 ++++++++++----
  18  fs/ext4/move_extent.c |  3 ++-
  19  fs/ext4/namei.c       |  8 +++++---
  20  fs/ext4/resize.c      |  4 +++-
  21  7 files changed, 28 insertions(+), 12 deletions(-)
  22
  23 diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
  24 index 2a97dff87b96..342e4f0c23db 100644
  25 --- a/fs/ext4/extents.c
  26 +++ b/fs/ext4/extents.c
  27 @@ -517,6 +517,7 @@ __read_extent_tree_block(const char *function, unsigned int line,
  28  {
  29         struct buffer_head              *bh;
  30         int                             err;
  31 +       journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
  32
  33         bh = sb_getblk_gfp(inode->i_sb, pblk, __GFP_MOVABLE | GFP_NOFS);
  34         if (unlikely(!bh))
  35 @@ -524,7 +525,7 @@ __read_extent_tree_block(const char *function, unsigned int line,
  36
  37         if (!bh_uptodate_or_lock(bh)) {
  38                 trace_ext4_ext_load_extent(inode, pblk, _RET_IP_);
  39 -               err = bh_submit_read(bh);
  40 +               err = jbd2_bh_submit_read(journal, bh, __func__);
  41                 if (err < 0)
  42                         goto errout;
  43         }
  44 diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
  45 index b14bae2598bc..a095b8c1465a 100644
  46 --- a/fs/ext4/ialloc.c
  47 +++ b/fs/ext4/ialloc.c
  48 @@ -14,6 +14,7 @@
  49
  50  #include <linux/time.h>
  51  #include <linux/fs.h>
  52 +#include <linux/jbd2.h>
  53  #include <linux/stat.h>
  54  #include <linux/string.h>
  55  #include <linux/quotaops.h>
  56 @@ -160,6 +161,7 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
  57         struct buffer_head *bh = NULL;
  58         ext4_fsblk_t bitmap_blk;
  59         int err;
  60 +       journal_t *journal = EXT4_SB(sb)->s_journal;
  61
  62         desc = ext4_get_group_desc(sb, block_group, NULL);
  63         if (!desc)
  64 @@ -214,7 +216,8 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
  65         trace_ext4_load_inode_bitmap(sb, block_group);
  66         bh->b_end_io = ext4_end_bitmap_read;
  67         get_bh(bh);
  68 -       submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
  69 +       jbd2_submit_bh(journal, REQ_OP_READ, REQ_META | REQ_PRIO, bh, __func__);
  70 +
  71         wait_on_buffer(bh);
  72         if (!buffer_uptodate(bh)) {
  73                 put_bh(bh);
  74 diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c
  75 index bc15c2c17633..21531ef4a182 100644
  76 --- a/fs/ext4/indirect.c
  77 +++ b/fs/ext4/indirect.c
  78 @@ -145,6 +145,7 @@ static Indirect *ext4_get_branch(struct inode *inode, int depth,
  79                                  Indirect chain[4], int *err)
  80  {
  81         struct super_block *sb = inode->i_sb;
  82 +       journal_t *journal = EXT4_SB(sb)->s_journal;
  83         Indirect *p = chain;
  84         struct buffer_head *bh;
  85         int ret = -EIO;
  86 @@ -162,7 +163,7 @@ static Indirect *ext4_get_branch(struct inode *inode, int depth,
  87                 }
  88
  89                 if (!bh_uptodate_or_lock(bh)) {
  90 -                       if (bh_submit_read(bh) < 0) {
  91 +                       if (jbd2_bh_submit_read(journal, bh, __func__) < 0) {
  92                                 put_bh(bh);
  93                                 goto failure;
  94                         }
  95 diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
  96 index 1908ac336ee5..374a9767a0ed 100644
  97 --- a/fs/ext4/inode.c
  98 +++ b/fs/ext4/inode.c
  99 @@ -995,13 +995,15 @@ struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
 100                                ext4_lblk_t block, int map_flags)
 101  {
 102         struct buffer_head *bh;
 103 +       journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
 104
 105         bh = ext4_getblk(handle, inode, block, map_flags);
 106         if (IS_ERR(bh))
 107                 return bh;
 108         if (!bh || buffer_uptodate(bh))
 109                 return bh;
 110 -       ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &bh);
 111 +       jbd2_ll_rw_block(journal, REQ_OP_READ, REQ_META | REQ_PRIO, 1, &bh,
 112 +                        __func__);
 113         wait_on_buffer(bh);
 114         if (buffer_uptodate(bh))
 115                 return bh;
 116 @@ -4343,6 +4345,7 @@ static int __ext4_get_inode_loc(struct inode *inode,
 117         struct super_block      *sb = inode->i_sb;
 118         ext4_fsblk_t            block;
 119         int                     inodes_per_block, inode_offset;
 120 +       journal_t               *journal = EXT4_SB(sb)->s_journal;
 121
 122         iloc->bh = NULL;
 123         if (!ext4_valid_inum(sb, inode->i_ino))
 124 @@ -4446,8 +4449,10 @@ static int __ext4_get_inode_loc(struct inode *inode,
 125                         table += num / inodes_per_block;
 126                         if (end > table)
 127                                 end = table;
 128 -                       while (b <= end)
 129 -                               sb_breadahead(sb, b++);
 130 +                       if (journal) {
 131 +                               while (b <= end)
 132 +                                       jbd2_sb_breadahead(journal, sb, b++);
 133 +                       }
 134                 }
 135
 136                 /*
 137 @@ -4458,7 +4463,8 @@ static int __ext4_get_inode_loc(struct inode *inode,
 138                 trace_ext4_load_inode(inode);
 139                 get_bh(bh);
 140                 bh->b_end_io = end_buffer_read_sync;
 141 -               submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
 142 +               jbd2_submit_bh(journal, REQ_OP_READ, REQ_META | REQ_PRIO, bh,
 143 +                              __func__);
 144                 wait_on_buffer(bh);
 145                 if (!buffer_uptodate(bh)) {
 146                         EXT4_ERROR_INODE_BLOCK(inode, block,
 147 diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
 148 index 6fc14def0c70..b6c25638f5f4 100644
 149 --- a/fs/ext4/move_extent.c
 150 +++ b/fs/ext4/move_extent.c
 151 @@ -177,6 +177,7 @@ static int
 152  mext_page_mkuptodate(struct page *page, unsigned from, unsigned to)
 153  {
 154         struct inode *inode = page->mapping->host;
 155 +       journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
 156         sector_t block;
 157         struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE];
 158         unsigned int blocksize, block_start, block_end;
 159 @@ -225,7 +226,7 @@ mext_page_mkuptodate(struct page *page, unsigned from, unsigned to)
 160         for (i = 0; i < nr; i++) {
 161                 bh = arr[i];
 162                 if (!bh_uptodate_or_lock(bh)) {
 163 -                       err = bh_submit_read(bh);
 164 +                       err = jbd2_bh_submit_read(journal, bh, __func__);
 165                         if (err)
 166                                 return err;
 167                 }
 168 diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
 169 index 6ad612c576fc..0812a692db0f 100644
 170 --- a/fs/ext4/namei.c
 171 +++ b/fs/ext4/namei.c
 172 @@ -1361,6 +1361,7 @@ static struct buffer_head * ext4_find_entry (struct inode *dir,
 173         struct buffer_head *bh_use[NAMEI_RA_SIZE];
 174         struct buffer_head *bh, *ret = NULL;
 175         ext4_lblk_t start, block, b;
 176 +       journal_t *journal;
 177         const u8 *name = d_name->name;
 178         int ra_max = 0;         /* Number of bh's in the readahead
 179                                    buffer, bh_use[] */
 180 @@ -1373,6 +1374,7 @@ static struct buffer_head * ext4_find_entry (struct inode *dir,
 181
 182         *res_dir = NULL;
 183         sb = dir->i_sb;
 184 +       journal = EXT4_SB(sb)->s_journal;
 185         namelen = d_name->len;
 186         if (namelen > EXT4_NAME_LEN)
 187                 return NULL;
 188 @@ -1451,9 +1453,9 @@ static struct buffer_head * ext4_find_entry (struct inode *dir,
 189                                 }
 190                                 bh_use[ra_max] = bh;
 191                                 if (bh)
 192 -                                       ll_rw_block(REQ_OP_READ,
 193 -                                                   REQ_META | REQ_PRIO,
 194 -                                                   1, &bh);
 195 +                                       jbd2_ll_rw_block(journal, REQ_OP_READ,
 196 +                                                        REQ_META | REQ_PRIO,
 197 +                                                        1, &bh, __func__);
 198                         }
 199                 }
 200                 if ((bh = bh_use[ra_ptr++]) == NULL)
 201 diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
 202 index c3ed9021b781..8406bca774c8 100644
 203 --- a/fs/ext4/resize.c
 204 +++ b/fs/ext4/resize.c
 205 @@ -1193,10 +1193,12 @@ static int ext4_add_new_descs(handle_t *handle, struct super_block *sb,
 206  static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block)
 207  {
 208         struct buffer_head *bh = sb_getblk(sb, block);
 209 +       journal_t *journal = EXT4_SB(sb)->s_journal;
 210 +
 211         if (unlikely(!bh))
 212                 return NULL;
 213         if (!bh_uptodate_or_lock(bh)) {
 214 -               if (bh_submit_read(bh) < 0) {
 215 +               if (jbd2_bh_submit_read(journal, bh, __func__) < 0) {
 216                         brelse(bh);
 217                         return NULL;
 218                 }