ext4: Add blocks added during resize to bitmap
authorAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Tue, 6 Jan 2009 02:36:02 +0000 (21:36 -0500)
committerTheodore Ts'o <tytso@mit.edu>
Tue, 6 Jan 2009 02:36:02 +0000 (21:36 -0500)
With this change new blocks added during resize
are marked as free in the block bitmap and the
group is flagged with EXT4_GROUP_INFO_NEED_INIT_BIT
flag.  This makes sure when mballoc tries to allocate
blocks from the new group we would reload the
buddy information using the bitmap present in the disk.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
fs/ext4/balloc.c
fs/ext4/ext4.h
fs/ext4/resize.c

index a0c23b0..c54192e 100644 (file)
@@ -20,6 +20,7 @@
 #include "ext4.h"
 #include "ext4_jbd2.h"
 #include "group.h"
+#include "mballoc.h"
 
 /*
  * balloc.c contains the blocks allocation and deallocation routines
@@ -350,62 +351,43 @@ ext4_read_block_bitmap(struct super_block *sb, ext4_group_t block_group)
 }
 
 /**
- * ext4_free_blocks_sb() -- Free given blocks and update quota
+ * ext4_add_groupblocks() -- Add given blocks to an existing group
  * @handle:                    handle to this transaction
  * @sb:                                super block
- * @block:                     start physcial block to free
+ * @block:                     start physcial block to add to the block group
  * @count:                     number of blocks to free
- * @pdquot_freed_blocks:       pointer to quota
  *
- * XXX This function is only used by the on-line resizing code, which
- * should probably be fixed up to call the mballoc variant.  There
- * this needs to be cleaned up later; in fact, I'm not convinced this
- * is 100% correct in the face of the mballoc code.  The online resizing
- * code needs to be fixed up to more tightly (and correctly) interlock
- * with the mballoc code.
+ * This marks the blocks as free in the bitmap. We ask the
+ * mballoc to reload the buddy after this by setting group
+ * EXT4_GROUP_INFO_NEED_INIT_BIT flag
  */
-void ext4_free_blocks_sb(handle_t *handle, struct super_block *sb,
-                        ext4_fsblk_t block, unsigned long count,
-                        unsigned long *pdquot_freed_blocks)
+void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
+                        ext4_fsblk_t block, unsigned long count)
 {
        struct buffer_head *bitmap_bh = NULL;
        struct buffer_head *gd_bh;
        ext4_group_t block_group;
        ext4_grpblk_t bit;
        unsigned int i;
-       unsigned int overflow;
        struct ext4_group_desc *desc;
        struct ext4_super_block *es;
        struct ext4_sb_info *sbi;
        int err = 0, ret;
-       ext4_grpblk_t group_freed;
+       ext4_grpblk_t blocks_freed;
+       struct ext4_group_info *grp;
 
-       *pdquot_freed_blocks = 0;
        sbi = EXT4_SB(sb);
        es = sbi->s_es;
-       if (block < le32_to_cpu(es->s_first_data_block) ||
-           block + count < block ||
-           block + count > ext4_blocks_count(es)) {
-               ext4_error(sb, "ext4_free_blocks",
-                          "Freeing blocks not in datazone - "
-                          "block = %llu, count = %lu", block, count);
-               goto error_return;
-       }
-
-       ext4_debug("freeing block(s) %llu-%llu\n", block, block + count - 1);
+       ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1);
 
-do_more:
-       overflow = 0;
        ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
        /*
         * Check to see if we are freeing blocks across a group
         * boundary.
         */
        if (bit + count > EXT4_BLOCKS_PER_GROUP(sb)) {
-               overflow = bit + count - EXT4_BLOCKS_PER_GROUP(sb);
-               count -= overflow;
+               goto error_return;
        }
-       brelse(bitmap_bh);
        bitmap_bh = ext4_read_block_bitmap(sb, block_group);
        if (!bitmap_bh)
                goto error_return;
@@ -418,18 +400,17 @@ do_more:
            in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) ||
            in_range(block + count - 1, ext4_inode_table(sb, desc),
                     sbi->s_itb_per_group)) {
-               ext4_error(sb, "ext4_free_blocks",
-                          "Freeing blocks in system zones - "
+               ext4_error(sb, __func__,
+                          "Adding blocks in system zones - "
                           "Block = %llu, count = %lu",
                           block, count);
                goto error_return;
        }
 
        /*
-        * We are about to start releasing blocks in the bitmap,
+        * We are about to add blocks to the bitmap,
         * so we need undo access.
         */
-       /* @@@ check errors */
        BUFFER_TRACE(bitmap_bh, "getting undo access");
        err = ext4_journal_get_undo_access(handle, bitmap_bh);
        if (err)
@@ -445,87 +426,28 @@ do_more:
        if (err)
                goto error_return;
 
-       jbd_lock_bh_state(bitmap_bh);
-
-       for (i = 0, group_freed = 0; i < count; i++) {
-               /*
-                * An HJ special.  This is expensive...
-                */
-#ifdef CONFIG_JBD2_DEBUG
-               jbd_unlock_bh_state(bitmap_bh);
-               {
-                       struct buffer_head *debug_bh;
-                       debug_bh = sb_find_get_block(sb, block + i);
-                       if (debug_bh) {
-                               BUFFER_TRACE(debug_bh, "Deleted!");
-                               if (!bh2jh(bitmap_bh)->b_committed_data)
-                                       BUFFER_TRACE(debug_bh,
-                                               "No commited data in bitmap");
-                               BUFFER_TRACE2(debug_bh, bitmap_bh, "bitmap");
-                               __brelse(debug_bh);
-                       }
-               }
-               jbd_lock_bh_state(bitmap_bh);
-#endif
-               if (need_resched()) {
-                       jbd_unlock_bh_state(bitmap_bh);
-                       cond_resched();
-                       jbd_lock_bh_state(bitmap_bh);
-               }
-               /* @@@ This prevents newly-allocated data from being
-                * freed and then reallocated within the same
-                * transaction.
-                *
-                * Ideally we would want to allow that to happen, but to
-                * do so requires making jbd2_journal_forget() capable of
-                * revoking the queued write of a data block, which
-                * implies blocking on the journal lock.  *forget()
-                * cannot block due to truncate races.
-                *
-                * Eventually we can fix this by making jbd2_journal_forget()
-                * return a status indicating whether or not it was able
-                * to revoke the buffer.  On successful revoke, it is
-                * safe not to set the allocation bit in the committed
-                * bitmap, because we know that there is no outstanding
-                * activity on the buffer any more and so it is safe to
-                * reallocate it.
-                */
-               BUFFER_TRACE(bitmap_bh, "set in b_committed_data");
-               J_ASSERT_BH(bitmap_bh,
-                               bh2jh(bitmap_bh)->b_committed_data != NULL);
-               ext4_set_bit_atomic(sb_bgl_lock(sbi, block_group), bit + i,
-                               bh2jh(bitmap_bh)->b_committed_data);
-
-               /*
-                * We clear the bit in the bitmap after setting the committed
-                * data bit, because this is the reverse order to that which
-                * the allocator uses.
-                */
+       for (i = 0, blocks_freed = 0; i < count; i++) {
                BUFFER_TRACE(bitmap_bh, "clear bit");
                if (!ext4_clear_bit_atomic(sb_bgl_lock(sbi, block_group),
                                                bit + i, bitmap_bh->b_data)) {
-                       jbd_unlock_bh_state(bitmap_bh);
                        ext4_error(sb, __func__,
                                   "bit already cleared for block %llu",
                                   (ext4_fsblk_t)(block + i));
-                       jbd_lock_bh_state(bitmap_bh);
                        BUFFER_TRACE(bitmap_bh, "bit already cleared");
                } else {
-                       group_freed++;
+                       blocks_freed++;
                }
        }
-       jbd_unlock_bh_state(bitmap_bh);
-
        spin_lock(sb_bgl_lock(sbi, block_group));
-       le16_add_cpu(&desc->bg_free_blocks_count, group_freed);
+       le16_add_cpu(&desc->bg_free_blocks_count, blocks_freed);
        desc->bg_checksum = ext4_group_desc_csum(sbi, block_group, desc);
        spin_unlock(sb_bgl_lock(sbi, block_group));
-       percpu_counter_add(&sbi->s_freeblocks_counter, count);
+       percpu_counter_add(&sbi->s_freeblocks_counter, blocks_freed);
 
        if (sbi->s_log_groups_per_flex) {
                ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
                spin_lock(sb_bgl_lock(sbi, flex_group));
-               sbi->s_flex_groups[flex_group].free_blocks += count;
+               sbi->s_flex_groups[flex_group].free_blocks += blocks_freed;
                spin_unlock(sb_bgl_lock(sbi, flex_group));
        }
 
@@ -536,15 +458,17 @@ do_more:
        /* And the group descriptor block */
        BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
        ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);
-       if (!err) err = ret;
-       *pdquot_freed_blocks += group_freed;
-
-       if (overflow && !err) {
-               block += count;
-               count = overflow;
-               goto do_more;
-       }
+       if (!err)
+               err = ret;
        sb->s_dirt = 1;
+       /*
+        * request to reload the buddy with the
+        * new bitmap information
+        */
+       grp = ext4_get_group_info(sb, block_group);
+       set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state));
+       ext4_mb_update_group_info(grp, blocks_freed);
+
 error_return:
        brelse(bitmap_bh);
        ext4_std_error(sb, err);
index 5125c1f..8021bf5 100644 (file)
@@ -1014,9 +1014,8 @@ extern int ext4_claim_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
 extern int ext4_has_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
                        ext4_fsblk_t block, unsigned long count, int metadata);
-extern void ext4_free_blocks_sb(handle_t *handle, struct super_block *sb,
-                               ext4_fsblk_t block, unsigned long count,
-                               unsigned long *pdquot_freed_blocks);
+extern void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
+                               ext4_fsblk_t block, unsigned long count);
 extern ext4_fsblk_t ext4_count_free_blocks(struct super_block *);
 extern void ext4_check_blocks_bitmap(struct super_block *);
 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
index 1865d6a..526db73 100644 (file)
@@ -977,9 +977,7 @@ int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
        struct buffer_head *bh;
        handle_t *handle;
        int err;
-       unsigned long freed_blocks;
        ext4_group_t group;
-       struct ext4_group_info *grp;
 
        /* We don't need to worry about locking wrt other resizers just
         * yet: we're going to revalidate es->s_blocks_count after
@@ -1077,7 +1075,8 @@ int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
        unlock_super(sb);
        ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count,
                   o_blocks_count + add);
-       ext4_free_blocks_sb(handle, sb, o_blocks_count, add, &freed_blocks);
+       /* We add the blocks to the bitmap and set the group need init bit */
+       ext4_add_groupblocks(handle, sb, o_blocks_count, add);
        ext4_debug("freed blocks %llu through %llu\n", o_blocks_count,
                   o_blocks_count + add);
        if ((err = ext4_journal_stop(handle)))
@@ -1120,12 +1119,6 @@ int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
                        ClearPageUptodate(page);
                        page_cache_release(page);
                }
-
-               /* Get the info on the last group */
-               grp = ext4_get_group_info(sb, group);
-
-               /* Update free blocks in group info */
-               ext4_mb_update_group_info(grp, add);
        }
 
        if (test_opt(sb, DEBUG))