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Message-Id: <1225733769-23734-2-git-send-email-aneesh.kumar@linux.vnet.ibm.com>
Date: Mon, 3 Nov 2008 23:06:02 +0530
From: "Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
To: cmm@...ibm.com, tytso@....edu, sandeen@...hat.com
Cc: linux-ext4@...r.kernel.org,
"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
Subject: [RFC PATCH -v2 2/9] ext4: Add blocks added during resize to bitmap
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 make 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@...ux.vnet.ibm.com>
---
fs/ext4/balloc.c | 136 ++++++++++++------------------------------------------
fs/ext4/ext4.h | 5 +-
fs/ext4/resize.c | 11 +----
3 files changed, 34 insertions(+), 118 deletions(-)
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 4397274..d598fd6 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -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 long i;
- unsigned long 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 @@ void ext4_free_blocks_sb(handle_t *handle, struct super_block *sb,
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 @@ void ext4_free_blocks_sb(handle_t *handle, struct super_block *sb,
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 @@ void ext4_free_blocks_sb(handle_t *handle, struct super_block *sb,
/* And the group descriptor block */
BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
ret = ext4_journal_dirty_metadata(handle, 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);
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index fee616d..004dd25 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1062,9 +1062,8 @@ 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,
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index b6ec184..ecaacbb 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -975,9 +975,7 @@ 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
@@ -1076,7 +1074,8 @@ 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)))
@@ -1119,12 +1118,6 @@ 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))
--
1.6.0.3.514.g2f91b
--
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