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Date: Fri, 24 Oct 2008 12:04:25 +0530
From: "Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
To: cmm@...ibm.com, tytso@....edu, frederic.bohe@...l.net
Cc: linux-ext4@...r.kernel.org,
"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
Subject: [RFC PATCH 1/3] 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 | 52 +++++++++++++++-------------------------------------
fs/ext4/ext4.h | 2 +-
fs/ext4/resize.c | 10 ++--------
3 files changed, 18 insertions(+), 46 deletions(-)
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index b9821be..b67f1ff 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
@@ -350,21 +351,18 @@ 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 and update quota
* @handle: handle to this transaction
* @sb: super block
* @block: start physcial block to free
* @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,
+void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
ext4_fsblk_t block, unsigned long count,
unsigned long *pdquot_freed_blocks)
{
@@ -379,6 +377,7 @@ void ext4_free_blocks_sb(handle_t *handle, struct super_block *sb,
struct ext4_sb_info *sbi;
int err = 0, ret;
ext4_grpblk_t group_freed;
+ struct ext4_group_info *grp;
*pdquot_freed_blocks = 0;
sbi = EXT4_SB(sb);
@@ -419,7 +418,7 @@ void ext4_free_blocks_sb(handle_t *handle, struct super_block *sb,
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 - "
+ "Adding blocks in system zones - "
"Block = %llu, count = %lu",
block, count);
goto error_return;
@@ -472,35 +471,7 @@ void ext4_free_blocks_sb(handle_t *handle, struct super_block *sb,
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.
- */
BUFFER_TRACE(bitmap_bh, "clear bit");
if (!ext4_clear_bit_atomic(sb_bgl_lock(sbi, block_group),
bit + i, bitmap_bh->b_data)) {
@@ -545,6 +516,13 @@ void ext4_free_blocks_sb(handle_t *handle, struct super_block *sb,
goto do_more;
}
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, count);
error_return:
brelse(bitmap_bh);
ext4_std_error(sb, err);
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 3882a6c..ca915d5 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1024,7 +1024,7 @@ extern ext4_fsblk_t 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,
+extern void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
ext4_fsblk_t block, unsigned long count,
unsigned long *pdquot_freed_blocks);
extern ext4_fsblk_t ext4_count_free_blocks(struct super_block *);
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index b6ec184..a8403a8 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -977,7 +977,6 @@ int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
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 +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, &freed_blocks);
ext4_debug("freed blocks %llu through %llu\n", o_blocks_count,
o_blocks_count + add);
if ((err = ext4_journal_stop(handle)))
@@ -1119,12 +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))
--
1.6.0.3.514.g2f91b
--
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