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Date: Wed, 27 Aug 2008 20:58:31 +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: [PATCH -V3 06/11] ext4: Update meta-data reservation with delalloc.
This makes the meta-data reservation simpler. The logic
followed is simpler. After each block allocation request
if we have allocated some meta-data blocks subtract the
same from the reserved meta-data blocks. If the total
reserved data blocks after allocation is zero, free the
remaining meta-data blocks reserved. During reservation
if the total reserved blocks need more meta-data blocks
add the extra meta-data blocks needed to the reserve_meta_blocks
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@...ux.vnet.ibm.com>
---
fs/ext4/inode.c | 75 +++++++++++++++++++++++++++----------------------------
1 files changed, 37 insertions(+), 38 deletions(-)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index a45121f..3ef0822 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1019,31 +1019,34 @@ static int ext4_calc_metadata_amount(struct inode *inode, int blocks)
static void ext4_da_update_reserve_space(struct inode *inode, int used)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
- int total, mdb, mdb_free;
spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
- /* recalculate the number of metablocks still need to be reserved */
- total = EXT4_I(inode)->i_reserved_data_blocks - used;
- mdb = ext4_calc_metadata_amount(inode, total);
-
- /* figure out how many metablocks to release */
- BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
- mdb_free = EXT4_I(inode)->i_reserved_meta_blocks - mdb;
-
- if (mdb_free) {
- /* Account for allocated meta_blocks */
- mdb_free -= EXT4_I(inode)->i_allocated_meta_blocks;
-
- /* update fs dirty blocks counter */
- percpu_counter_sub(&sbi->s_dirtyblocks_counter, mdb_free);
+ if (EXT4_I(inode)->i_allocated_meta_blocks) {
+ /* update the reseved meta- blocks */
+ BUG_ON(EXT4_I(inode)->i_allocated_meta_blocks >
+ EXT4_I(inode)->i_reserved_meta_blocks);
+ EXT4_I(inode)->i_reserved_meta_blocks -=
+ EXT4_I(inode)->i_allocated_meta_blocks;
EXT4_I(inode)->i_allocated_meta_blocks = 0;
- EXT4_I(inode)->i_reserved_meta_blocks = mdb;
+ /*
+ * We already updated the percpu dirty
+ * block counter in the block allocation path.
+ */
}
-
/* update per-inode reservations */
BUG_ON(used > EXT4_I(inode)->i_reserved_data_blocks);
EXT4_I(inode)->i_reserved_data_blocks -= used;
+ if (!EXT4_I(inode)->i_reserved_data_blocks) {
+ /*
+ * If we don't have any reserved data blocks
+ * release all the resered meta data blocks
+ * update percpu dirty block counter also.
+ */
+ percpu_counter_sub(&sbi->s_dirtyblocks_counter,
+ EXT4_I(inode)->i_reserved_meta_blocks);
+ EXT4_I(inode)->i_reserved_meta_blocks = 0;
+ }
spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
}
@@ -1524,7 +1527,7 @@ static int ext4_da_reserve_space(struct inode *inode, int nrblocks)
{
int retries = 0;
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
- unsigned long md_needed, mdblocks, total = 0;
+ unsigned long md_needed = 0, mdblocks, total = 0;
/*
* recalculate the amount of metadata blocks to reserve
@@ -1535,9 +1538,9 @@ static int ext4_da_reserve_space(struct inode *inode, int nrblocks)
spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
total = EXT4_I(inode)->i_reserved_data_blocks + nrblocks;
mdblocks = ext4_calc_metadata_amount(inode, total);
- BUG_ON(mdblocks < EXT4_I(inode)->i_reserved_meta_blocks);
+ if (mdblocks > EXT4_I(inode)->i_reserved_meta_blocks)
+ md_needed = mdblocks - EXT4_I(inode)->i_reserved_meta_blocks;
- md_needed = mdblocks - EXT4_I(inode)->i_reserved_meta_blocks;
total = md_needed + nrblocks;
if (ext4_claim_free_blocks(sbi, total)) {
@@ -1549,7 +1552,7 @@ static int ext4_da_reserve_space(struct inode *inode, int nrblocks)
return -ENOSPC;
}
EXT4_I(inode)->i_reserved_data_blocks += nrblocks;
- EXT4_I(inode)->i_reserved_meta_blocks = mdblocks;
+ EXT4_I(inode)->i_reserved_meta_blocks += md_needed;
spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
return 0; /* success */
@@ -1558,13 +1561,12 @@ static int ext4_da_reserve_space(struct inode *inode, int nrblocks)
static void ext4_da_release_space(struct inode *inode, int to_free)
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
- int total, mdb, mdb_free, release;
+ int release, mdb_free = 0;
if (!to_free)
return; /* Nothing to release, exit */
spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
-
if (!EXT4_I(inode)->i_reserved_data_blocks) {
/*
* if there is no reserved blocks, but we try to free some
@@ -1578,26 +1580,23 @@ static void ext4_da_release_space(struct inode *inode, int to_free)
spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
return;
}
+ /* update per-inode reservations */
+ BUG_ON(to_free > EXT4_I(inode)->i_reserved_data_blocks);
+ EXT4_I(inode)->i_reserved_data_blocks -= to_free;
+ if (!EXT4_I(inode)->i_reserved_data_blocks) {
+ /*
+ * If we don't have any reserved data blocks
+ * release all the resered meta data blocks
+ * update percpu dirty block counter also.
+ */
+ mdb_free = EXT4_I(inode)->i_reserved_meta_blocks;
+ EXT4_I(inode)->i_reserved_meta_blocks = 0;
- /* recalculate the number of metablocks still need to be reserved */
- total = EXT4_I(inode)->i_reserved_data_blocks - to_free;
- mdb = ext4_calc_metadata_amount(inode, total);
-
- /* figure out how many metablocks to release */
- BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
- mdb_free = EXT4_I(inode)->i_reserved_meta_blocks - mdb;
-
+ }
release = to_free + mdb_free;
/* update fs dirty blocks counter for truncate case */
percpu_counter_sub(&sbi->s_dirtyblocks_counter, release);
-
- /* update per-inode reservations */
- BUG_ON(to_free > EXT4_I(inode)->i_reserved_data_blocks);
- EXT4_I(inode)->i_reserved_data_blocks -= to_free;
-
- BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
- EXT4_I(inode)->i_reserved_meta_blocks = mdb;
spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
}
--
1.6.0.1.90.g27a6e
--
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