[PATCH 10/11] ext3: Implement delayed allocation on page_mkwrite time

From: Jan Kara
Date: Mon Jun 15 2009 - 14:03:29 EST

We don't want to really allocate blocks on page_mkwrite() time because for
random writes via mmap it results is much more fragmented files. So just
reserve enough free blocks in page_mkwrite() and do the real allocation from
writepage().

Signed-off-by: Jan Kara <jack@xxxxxxx>
---
fs/ext3/balloc.c | 96 ++++++++++++++--------
fs/ext3/ialloc.c | 2 +-
fs/ext3/inode.c | 196 +++++++++++++++++++++++++++-----------------
fs/ext3/resize.c | 2 +-
fs/ext3/super.c | 42 ++++++----
include/linux/ext3_fs.h | 9 ++-
include/linux/ext3_fs_i.h | 1 +
include/linux/ext3_fs_sb.h | 3 +-
8 files changed, 219 insertions(+), 132 deletions(-)

diff --git a/fs/ext3/balloc.c b/fs/ext3/balloc.c
index 27967f9..0e294a1 100644
--- a/fs/ext3/balloc.c
+++ b/fs/ext3/balloc.c
@@ -19,6 +19,8 @@
#include <linux/ext3_jbd.h>
#include <linux/quotaops.h>
#include <linux/buffer_head.h>
+#include <linux/delalloc_counter.h>
+#include <linux/writeback.h>

/*
* balloc.c contains the blocks allocation and deallocation routines
@@ -632,7 +634,7 @@ do_more:
spin_lock(sb_bgl_lock(sbi, block_group));
le16_add_cpu(&desc->bg_free_blocks_count, group_freed);
spin_unlock(sb_bgl_lock(sbi, block_group));
- percpu_counter_add(&sbi->s_freeblocks_counter, count);
+ dac_free(&sbi->s_alloc_counter, count);

/* We dirtied the bitmap block */
BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
@@ -1410,23 +1412,19 @@ out:
}

/**
- * ext3_has_free_blocks()
- * @sbi: in-core super block structure.
+ * ext3_free_blocks_limit()
+ * @sb: super block
*
* Check if filesystem has at least 1 free block available for allocation.
*/
-static int ext3_has_free_blocks(struct ext3_sb_info *sbi)
+ext3_fsblk_t ext3_free_blocks_limit(struct super_block *sb)
{
- ext3_fsblk_t free_blocks, root_blocks;
+ struct ext3_sb_info *sbi = EXT3_SB(sb);

- free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
- root_blocks = le32_to_cpu(sbi->s_es->s_r_blocks_count);
- if (free_blocks < root_blocks + 1 && !capable(CAP_SYS_RESOURCE) &&
- sbi->s_resuid != current_fsuid() &&
- (sbi->s_resgid == 0 || !in_group_p (sbi->s_resgid))) {
- return 0;
- }
- return 1;
+ if (!capable(CAP_SYS_RESOURCE) && sbi->s_resuid != current_fsuid() &&
+ (sbi->s_resgid == 0 || !in_group_p(sbi->s_resgid)))
+ return le32_to_cpu(sbi->s_es->s_r_blocks_count) + 1;
+ return 0;
}

/**
@@ -1443,12 +1441,23 @@ static int ext3_has_free_blocks(struct ext3_sb_info *sbi)
*/
int ext3_should_retry_alloc(struct super_block *sb, int *retries)
{
- if (!ext3_has_free_blocks(EXT3_SB(sb)) || (*retries)++ > 3)
+ struct ext3_sb_info *sbi = EXT3_SB(sb);
+ ext3_fsblk_t free_blocks, limit, reserved_blocks;
+
+ free_blocks = dac_get_avail(&sbi->s_alloc_counter);
+ limit = ext3_free_blocks_limit(sb);
+ reserved_blocks = dac_get_reserved(&sbi->s_alloc_counter);
+ if (!free_blocks + reserved_blocks < limit || (*retries)++ > 3)
return 0;

jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb->s_id);
-
- return journal_force_commit_nested(EXT3_SB(sb)->s_journal);
+ /*
+ * There's a chance commit will free some blocks and writeback can
+ * write delayed blocks so that excessive reservation gets released.
+ */
+ if (reserved_blocks)
+ wakeup_pdflush(0);
+ return journal_force_commit_nested(sbi->s_journal);
}

/**
@@ -1466,7 +1475,8 @@ int ext3_should_retry_alloc(struct super_block *sb, int *retries)
*
*/
ext3_fsblk_t ext3_new_blocks(handle_t *handle, struct inode *inode,
- ext3_fsblk_t goal, unsigned long *count, int *errp)
+ ext3_fsblk_t goal, unsigned long *count,
+ unsigned int *reserved, int *errp)
{
struct buffer_head *bitmap_bh = NULL;
struct buffer_head *gdp_bh;
@@ -1477,7 +1487,7 @@ ext3_fsblk_t ext3_new_blocks(handle_t *handle, struct inode *inode,
ext3_fsblk_t ret_block; /* filesyetem-wide allocated block */
int bgi; /* blockgroup iteration index */
int fatal = 0, err;
- int performed_allocation = 0;
+ int got_quota = 0, got_space = 0;
ext3_grpblk_t free_blocks; /* number of free blocks in a group */
struct super_block *sb;
struct ext3_group_desc *gdp;
@@ -1498,16 +1508,27 @@ ext3_fsblk_t ext3_new_blocks(handle_t *handle, struct inode *inode,
printk("ext3_new_block: nonexistent device");
return 0;
}
+ sbi = EXT3_SB(sb);

- /*
- * Check quota for allocation of this block.
- */
- if (vfs_dq_alloc_block(inode, num)) {
- *errp = -EDQUOT;
- return 0;
+ if (!*reserved) {
+ /*
+ * Check quota for allocation of this block.
+ */
+ if (vfs_dq_alloc_block(inode, num)) {
+ *errp = -EDQUOT;
+ goto out;
+ }
+ got_quota = 1;
+ if (dac_alloc(&sbi->s_alloc_counter, num,
+ ext3_free_blocks_limit(sb)) < 0) {
+ *errp = -ENOSPC;
+ goto out;
+ }
+ got_space = 1;
+ } else {
+ WARN_ON(*reserved < num);
}

- sbi = EXT3_SB(sb);
es = EXT3_SB(sb)->s_es;
ext3_debug("goal=%lu.\n", goal);
/*
@@ -1522,11 +1543,6 @@ ext3_fsblk_t ext3_new_blocks(handle_t *handle, struct inode *inode,
if (block_i && ((windowsz = block_i->rsv_window_node.rsv_goal_size) > 0))
my_rsv = &block_i->rsv_window_node;

- if (!ext3_has_free_blocks(sbi)) {
- *errp = -ENOSPC;
- goto out;
- }
-
/*
* First, test whether the goal block is free.
*/
@@ -1650,8 +1666,6 @@ allocated:
goto retry_alloc;
}

- performed_allocation = 1;
-
#ifdef CONFIG_JBD_DEBUG
{
struct buffer_head *debug_bh;
@@ -1701,7 +1715,6 @@ allocated:
spin_lock(sb_bgl_lock(sbi, group_no));
le16_add_cpu(&gdp->bg_free_blocks_count, -num);
spin_unlock(sb_bgl_lock(sbi, group_no));
- percpu_counter_sub(&sbi->s_freeblocks_counter, num);

BUFFER_TRACE(gdp_bh, "journal_dirty_metadata for group descriptor");
err = ext3_journal_dirty_metadata(handle, gdp_bh);
@@ -1713,7 +1726,15 @@ allocated:

*errp = 0;
brelse(bitmap_bh);
- vfs_dq_free_block(inode, *count-num);
+ if (*reserved) {
+ dac_alloc_reserved(&sbi->s_alloc_counter, num);
+ vfs_dq_claim_block(inode, num);
+ atomic_sub(num, &EXT3_I(inode)->i_reserved_blocks);
+ *reserved -= num;
+ } else {
+ dac_free(&sbi->s_alloc_counter, *count - num);
+ vfs_dq_free_block(inode, *count - num);
+ }
*count = num;
return ret_block;

@@ -1727,8 +1748,10 @@ out:
/*
* Undo the block allocation
*/
- if (!performed_allocation)
+ if (got_quota)
vfs_dq_free_block(inode, *count);
+ if (got_space)
+ dac_free(&sbi->s_alloc_counter, *count);
brelse(bitmap_bh);
return 0;
}
@@ -1737,8 +1760,9 @@ ext3_fsblk_t ext3_new_block(handle_t *handle, struct inode *inode,
ext3_fsblk_t goal, int *errp)
{
unsigned long count = 1;
+ unsigned int reserved = 0;

- return ext3_new_blocks(handle, inode, goal, &count, errp);
+ return ext3_new_blocks(handle, inode, goal, &count, &reserved, errp);
}

/**
diff --git a/fs/ext3/ialloc.c b/fs/ext3/ialloc.c
index b399912..347e24c 100644
--- a/fs/ext3/ialloc.c
+++ b/fs/ext3/ialloc.c
@@ -269,7 +269,7 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent)

freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
avefreei = freei / ngroups;
- freeb = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
+ freeb = dac_get_avail(&sbi->s_alloc_counter);
avefreeb = freeb / ngroups;
ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);

diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index ec112b4..cfec38b 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -38,6 +38,7 @@
#include <linux/bio.h>
#include <linux/fiemap.h>
#include <linux/namei.h>
+#include <linux/mount.h>
#include "xattr.h"
#include "acl.h"

@@ -516,7 +517,8 @@ static int ext3_blks_to_allocate(Indirect *branch, int k, unsigned long blks,
*/
static int ext3_alloc_blocks(handle_t *handle, struct inode *inode,
ext3_fsblk_t goal, int indirect_blks, int blks,
- ext3_fsblk_t new_blocks[4], int *err)
+ unsigned int *reserved, ext3_fsblk_t new_blocks[4],
+ int *err)
{
int target, i;
unsigned long count = 0;
@@ -537,7 +539,8 @@ static int ext3_alloc_blocks(handle_t *handle, struct inode *inode,
while (1) {
count = target;
/* allocating blocks for indirect blocks and direct blocks */
- current_block = ext3_new_blocks(handle,inode,goal,&count,err);
+ current_block = ext3_new_blocks(handle, inode, goal, &count,
+ reserved, err);
if (*err)
goto failed_out;

@@ -591,8 +594,8 @@ failed_out:
* as described above and return 0.
*/
static int ext3_alloc_branch(handle_t *handle, struct inode *inode,
- int indirect_blks, int *blks, ext3_fsblk_t goal,
- int *offsets, Indirect *branch)
+ int indirect_blks, int *blks, unsigned int *reserved,
+ ext3_fsblk_t goal, int *offsets, Indirect *branch)
{
int blocksize = inode->i_sb->s_blocksize;
int i, n = 0;
@@ -603,7 +606,7 @@ static int ext3_alloc_branch(handle_t *handle, struct inode *inode,
ext3_fsblk_t current_block;

num = ext3_alloc_blocks(handle, inode, goal, indirect_blks,
- *blks, new_blocks, &err);
+ *blks, reserved, new_blocks, &err);
if (err)
return err;

@@ -800,6 +803,7 @@ int ext3_get_blocks_handle(handle_t *handle, struct inode *inode,
int depth;
struct ext3_inode_info *ei = EXT3_I(inode);
int count = 0;
+ unsigned int reserved = 0;
ext3_fsblk_t first_block = 0;


@@ -898,8 +902,24 @@ int ext3_get_blocks_handle(handle_t *handle, struct inode *inode,
/*
* Block out ext3_truncate while we alter the tree
*/
- err = ext3_alloc_branch(handle, inode, indirect_blks, &count, goal,
- offsets + (partial - chain), partial);
+ if (buffer_delay(bh_result)) {
+ WARN_ON(maxblocks != 1);
+ WARN_ON(!bh_result->b_page || !PageLocked(bh_result->b_page));
+ reserved = EXT3_DA_BLOCK_RESERVE;
+ }
+ err = ext3_alloc_branch(handle, inode, indirect_blks, &count,
+ &reserved, goal, offsets + (partial - chain),
+ partial);
+ /* Release additional reservation we had for this block */
+ if (!err && buffer_delay(bh_result)) {
+ dac_cancel_reserved(&EXT3_SB(inode->i_sb)->s_alloc_counter,
+ reserved);
+ vfs_dq_release_reservation_block(inode, reserved);
+ atomic_sub(reserved, &ei->i_reserved_blocks);
+ clear_buffer_delay(bh_result);
+ } else if (!err) {
+ set_buffer_new(bh_result);
+ }

/*
* The ext3_splice_branch call will free and forget any buffers
@@ -914,8 +934,6 @@ int ext3_get_blocks_handle(handle_t *handle, struct inode *inode,
mutex_unlock(&ei->truncate_mutex);
if (err)
goto cleanup;
-
- set_buffer_new(bh_result);
got_it:
map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
if (count > blocks_to_boundary)
@@ -1432,9 +1450,9 @@ static sector_t ext3_bmap(struct address_space *mapping, sector_t block)
return generic_block_bmap(mapping,block,ext3_get_block);
}

-static int buffer_unmapped(handle_t *handle, struct buffer_head *bh)
+static int ext3_bh_delay(handle_t *handle, struct buffer_head *bh)
{
- return !buffer_mapped(bh);
+ return buffer_delay(bh);
}

/*
@@ -1496,12 +1514,31 @@ static int ext3_common_writepage(struct page *page,
struct writeback_control *wbc)
{
struct inode *inode = page->mapping->host;
- int ret = 0;
+ int ret = 0, delay = 1, err;
+ handle_t *handle = NULL;

+ /* Start a transaction only if the page has delayed buffers */
+ if (page_has_buffers(page))
+ delay = walk_page_buffers(NULL, page_buffers(page), 0,
+ PAGE_CACHE_SIZE, NULL, ext3_bh_delay);
+ if (delay) {
+ handle = ext3_journal_start(inode,
+ ext3_writepage_trans_blocks(inode));
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ goto out;
+ }
+ }
if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode))
ret = nobh_writepage(page, ext3_get_block, wbc);
else
ret = block_write_full_page(page, ext3_get_block, wbc);
+ if (delay) {
+ err = ext3_journal_stop(handle);
+ if (!ret)
+ ret = err;
+ }
+out:
return ret;
}

@@ -1576,15 +1613,37 @@ ext3_readpages(struct file *file, struct address_space *mapping,
return mpage_readpages(mapping, pages, nr_pages, ext3_get_block);
}

+
+static int truncate_delayed_bh(handle_t *handle, struct buffer_head *bh)
+{
+ if (buffer_delay(bh)) {
+ struct inode *inode = bh->b_page->mapping->host;
+ struct ext3_inode_info *ei = EXT3_I(inode);
+
+ atomic_sub(EXT3_DA_BLOCK_RESERVE, &ei->i_reserved_blocks);
+ vfs_dq_release_reservation_block(inode, EXT3_DA_BLOCK_RESERVE);
+ dac_cancel_reserved(&EXT3_SB(inode->i_sb)->s_alloc_counter,
+ EXT3_DA_BLOCK_RESERVE);
+ clear_buffer_delay(bh);
+ }
+ return 0;
+}
+
static void ext3_invalidatepage(struct page *page, unsigned long offset)
{
- journal_t *journal = EXT3_JOURNAL(page->mapping->host);
+ struct inode *inode = page->mapping->host;
+ journal_t *journal = EXT3_JOURNAL(inode);
+ int bsize = 1 << inode->i_blkbits;

/*
* If it's a full truncate we just forget about the pending dirtying
*/
if (offset == 0)
ClearPageChecked(page);
+ if (page_has_buffers(page)) {
+ walk_page_buffers(NULL, page_buffers(page), offset + bsize - 1,
+ PAGE_CACHE_SIZE, NULL, truncate_delayed_bh);
+ }

journal_invalidatepage(journal, page, offset);
}
@@ -1685,75 +1744,58 @@ out:
return ret;
}

-int ext3_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
+/*
+ * Reserve block writes instead of allocation. Called only on buffer heads
+ * attached to a page (and thus for 1 block).
+ */
+static int ext3_da_get_block(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh, int create)
{
- struct page *page = vmf->page;
- struct file *file = vma->vm_file;
- struct address_space *mapping = file->f_mapping;
- struct inode *inode = file->f_path.dentry->d_inode;
- int ret = VM_FAULT_NOPAGE;
- loff_t size;
- int len;
- void *fsdata;
-
- block_wait_on_hole_extend(inode, page_offset(page));
- /*
- * Get i_alloc_sem to stop truncates messing with the inode. We cannot
- * get i_mutex because we are already holding mmap_sem.
- */
- down_read(&inode->i_alloc_sem);
- size = i_size_read(inode);
- if ((page->mapping != inode->i_mapping) ||
- (page_offset(page) > size)) {
- /* page got truncated out from underneath us */
- goto out_unlock;
- }
-
- /* page is wholly or partially inside EOF */
- if (((page->index + 1) << PAGE_CACHE_SHIFT) > size)
- len = size & ~PAGE_CACHE_MASK;
- else
- len = PAGE_CACHE_SIZE;
+ int ret, rsv;
+ struct ext3_sb_info *sbi;

- /*
- * Check for the common case that everything is already mapped. We
- * have to get the page lock so that buffers cannot be released
- * under us.
- */
- lock_page(page);
- if (page_has_buffers(page)) {
- if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
- buffer_unmapped)) {
- unlock_page(page);
- ret = 0;
- goto out_unlock;
- }
- }
- unlock_page(page);
+ /* Buffer has already blocks reserved? */
+ if (buffer_delay(bh))
+ return 0;

- /*
- * OK, we may need to fill the hole... Do write_begin write_end to do
- * block allocation/reservation. We are not holding inode.i_mutex
- * here. That allows parallel write_begin, write_end call. lock_page
- * prevent this from happening on the same page though.
- */
- ret = mapping->a_ops->write_begin(file, mapping, page_offset(page),
- len, AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata);
+ ret = ext3_get_blocks_handle(NULL, inode, iblock, 1, bh, 0);
if (ret < 0)
- goto out_unlock;
- ret = mapping->a_ops->write_end(file, mapping, page_offset(page),
- len, len, page, fsdata);
- if (ret < 0)
- goto out_unlock;
- ret = 0;
-out_unlock:
- if (unlikely(ret)) {
- if (ret == -ENOMEM)
- ret = VM_FAULT_OOM;
- else /* -ENOSPC, -EIO, etc */
- ret = VM_FAULT_SIGBUS;
+ goto out;
+ if (ret > 0 || !create) {
+ ret = 0;
+ goto out;
+ }
+ /* Upperbound on number of needed blocks */
+ rsv = EXT3_DA_BLOCK_RESERVE;
+ /* Delayed allocation needed */
+ if (vfs_dq_reserve_block(inode, rsv)) {
+ ret = -EDQUOT;
+ goto out;
+ }
+ sbi = EXT3_SB(inode->i_sb);
+ ret = dac_reserve(&sbi->s_alloc_counter, rsv,
+ ext3_free_blocks_limit(inode->i_sb));
+ if (ret < 0) {
+ vfs_dq_release_reservation_block(inode, rsv);
+ goto out;
}
- up_read(&inode->i_alloc_sem);
+ set_buffer_delay(bh);
+ set_buffer_new(bh);
+ atomic_add(rsv, &EXT3_I(inode)->i_reserved_blocks);
+out:
+ return ret;
+}
+
+int ext3_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ int retry = 0;
+ int ret;
+ struct super_block *sb = vma->vm_file->f_path.mnt->mnt_sb;
+
+ do {
+ ret = block_page_mkwrite(vma, vmf, ext3_da_get_block);
+ } while (ret == VM_FAULT_SIGBUS &&
+ ext3_should_retry_alloc(sb, &retry));
return ret;
}

diff --git a/fs/ext3/resize.c b/fs/ext3/resize.c
index 8a0b263..2f6688a 100644
--- a/fs/ext3/resize.c
+++ b/fs/ext3/resize.c
@@ -928,7 +928,7 @@ int ext3_group_add(struct super_block *sb, struct ext3_new_group_data *input)
le32_add_cpu(&es->s_r_blocks_count, input->reserved_blocks);

/* Update the free space counts */
- percpu_counter_add(&sbi->s_freeblocks_counter,
+ percpu_counter_add(&sbi->s_alloc_counter.free,
input->free_blocks_count);
percpu_counter_add(&sbi->s_freeinodes_counter,
EXT3_INODES_PER_GROUP(sb));
diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index 26aa64d..036e953 100644
--- a/fs/ext3/super.c
+++ b/fs/ext3/super.c
@@ -417,7 +417,7 @@ static void ext3_put_super (struct super_block * sb)
for (i = 0; i < sbi->s_gdb_count; i++)
brelse(sbi->s_group_desc[i]);
kfree(sbi->s_group_desc);
- percpu_counter_destroy(&sbi->s_freeblocks_counter);
+ dac_destroy(&sbi->s_alloc_counter);
percpu_counter_destroy(&sbi->s_freeinodes_counter);
percpu_counter_destroy(&sbi->s_dirs_counter);
brelse(sbi->s_sbh);
@@ -494,6 +494,7 @@ static void init_once(void *foo)
#ifdef CONFIG_EXT3_FS_XATTR
init_rwsem(&ei->xattr_sem);
#endif
+ atomic_set(&ei->i_reserved_blocks, 0);
mutex_init(&ei->truncate_mutex);
inode_init_once(&ei->vfs_inode);
}
@@ -517,23 +518,26 @@ static void destroy_inodecache(void)

static void ext3_clear_inode(struct inode *inode)
{
- struct ext3_block_alloc_info *rsv = EXT3_I(inode)->i_block_alloc_info;
+ struct ext3_inode_info *ei = EXT3_I(inode);
+ struct ext3_block_alloc_info *rsv = ei->i_block_alloc_info;
#ifdef CONFIG_EXT3_FS_POSIX_ACL
- if (EXT3_I(inode)->i_acl &&
- EXT3_I(inode)->i_acl != EXT3_ACL_NOT_CACHED) {
- posix_acl_release(EXT3_I(inode)->i_acl);
- EXT3_I(inode)->i_acl = EXT3_ACL_NOT_CACHED;
+ if (ei->i_acl && ei->i_acl != EXT3_ACL_NOT_CACHED) {
+ posix_acl_release(ei->i_acl);
+ ei->i_acl = EXT3_ACL_NOT_CACHED;
}
- if (EXT3_I(inode)->i_default_acl &&
- EXT3_I(inode)->i_default_acl != EXT3_ACL_NOT_CACHED) {
- posix_acl_release(EXT3_I(inode)->i_default_acl);
- EXT3_I(inode)->i_default_acl = EXT3_ACL_NOT_CACHED;
+ if (ei->i_default_acl && ei->i_default_acl != EXT3_ACL_NOT_CACHED) {
+ posix_acl_release(ei->i_default_acl);
+ ei->i_default_acl = EXT3_ACL_NOT_CACHED;
}
#endif
ext3_discard_reservation(inode);
- EXT3_I(inode)->i_block_alloc_info = NULL;
+ ei->i_block_alloc_info = NULL;
if (unlikely(rsv))
kfree(rsv);
+ if (atomic_read(&ei->i_reserved_blocks))
+ ext3_warning(inode->i_sb, __func__, "Releasing inode %lu with "
+ "%lu reserved blocks.\n", inode->i_ino,
+ (unsigned long)atomic_read(&ei->i_reserved_blocks));
}

static inline void ext3_show_quota_options(struct seq_file *seq, struct super_block *sb)
@@ -728,10 +732,19 @@ static ssize_t ext3_quota_read(struct super_block *sb, int type, char *data,
static ssize_t ext3_quota_write(struct super_block *sb, int type,
const char *data, size_t len, loff_t off);

+static qsize_t ext3_get_reserved_space(struct inode *inode)
+{
+ return atomic_read(&EXT3_I(inode)->i_reserved_blocks);
+}
+
static struct dquot_operations ext3_quota_operations = {
.initialize = dquot_initialize,
.drop = dquot_drop,
.alloc_space = dquot_alloc_space,
+ .reserve_space = dquot_reserve_space,
+ .claim_space = dquot_claim_space,
+ .release_rsv = dquot_release_reserved_space,
+ .get_reserved_space = ext3_get_reserved_space,
.alloc_inode = dquot_alloc_inode,
.free_space = dquot_free_space,
.free_inode = dquot_free_inode,
@@ -1851,8 +1864,7 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent)
get_random_bytes(&sbi->s_next_generation, sizeof(u32));
spin_lock_init(&sbi->s_next_gen_lock);

- err = percpu_counter_init(&sbi->s_freeblocks_counter,
- ext3_count_free_blocks(sb));
+ err = dac_init(&sbi->s_alloc_counter, ext3_count_free_blocks(sb));
if (!err) {
err = percpu_counter_init(&sbi->s_freeinodes_counter,
ext3_count_free_inodes(sb));
@@ -2005,7 +2017,7 @@ cantfind_ext3:
failed_mount4:
journal_destroy(sbi->s_journal);
failed_mount3:
- percpu_counter_destroy(&sbi->s_freeblocks_counter);
+ dac_destroy(&sbi->s_alloc_counter);
percpu_counter_destroy(&sbi->s_freeinodes_counter);
percpu_counter_destroy(&sbi->s_dirs_counter);
failed_mount2:
@@ -2674,7 +2686,7 @@ static int ext3_statfs (struct dentry * dentry, struct kstatfs * buf)
buf->f_type = EXT3_SUPER_MAGIC;
buf->f_bsize = sb->s_blocksize;
buf->f_blocks = le32_to_cpu(es->s_blocks_count) - sbi->s_overhead_last;
- buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter);
+ buf->f_bfree = dac_get_avail_sum(&sbi->s_alloc_counter);
es->s_free_blocks_count = cpu_to_le32(buf->f_bfree);
buf->f_bavail = buf->f_bfree - le32_to_cpu(es->s_r_blocks_count);
if (buf->f_bfree < le32_to_cpu(es->s_r_blocks_count))
diff --git a/include/linux/ext3_fs.h b/include/linux/ext3_fs.h
index 5051874..7f28907 100644
--- a/include/linux/ext3_fs.h
+++ b/include/linux/ext3_fs.h
@@ -809,6 +809,11 @@ ext3_group_first_block_no(struct super_block *sb, unsigned long group_no)
#define ERR_BAD_DX_DIR -75000

/*
+ * Number of blocks we reserve in delayed allocation for one block
+ */
+#define EXT3_DA_BLOCK_RESERVE 4
+
+/*
* Function prototypes
*/

@@ -821,12 +826,14 @@ ext3_group_first_block_no(struct super_block *sb, unsigned long group_no)
# define NORET_AND noreturn,

/* balloc.c */
+extern ext3_fsblk_t ext3_free_blocks_limit(struct super_block *sb);
extern int ext3_bg_has_super(struct super_block *sb, int group);
extern unsigned long ext3_bg_num_gdb(struct super_block *sb, int group);
extern ext3_fsblk_t ext3_new_block (handle_t *handle, struct inode *inode,
ext3_fsblk_t goal, int *errp);
extern ext3_fsblk_t ext3_new_blocks (handle_t *handle, struct inode *inode,
- ext3_fsblk_t goal, unsigned long *count, int *errp);
+ ext3_fsblk_t goal, unsigned long *count,
+ unsigned int *reserved, int *errp);
extern void ext3_free_blocks (handle_t *handle, struct inode *inode,
ext3_fsblk_t block, unsigned long count);
extern void ext3_free_blocks_sb (handle_t *handle, struct super_block *sb,
diff --git a/include/linux/ext3_fs_i.h b/include/linux/ext3_fs_i.h
index 7894dd0..ef288bd 100644
--- a/include/linux/ext3_fs_i.h
+++ b/include/linux/ext3_fs_i.h
@@ -129,6 +129,7 @@ struct ext3_inode_info {

/* on-disk additional length */
__u16 i_extra_isize;
+ atomic_t i_reserved_blocks;

/*
* truncate_mutex is for serialising ext3_truncate() against
diff --git a/include/linux/ext3_fs_sb.h b/include/linux/ext3_fs_sb.h
index f07f34d..f92e162 100644
--- a/include/linux/ext3_fs_sb.h
+++ b/include/linux/ext3_fs_sb.h
@@ -21,6 +21,7 @@
#include <linux/wait.h>
#include <linux/blockgroup_lock.h>
#include <linux/percpu_counter.h>
+#include <linux/delalloc_counter.h>
#endif
#include <linux/rbtree.h>

@@ -58,7 +59,7 @@ struct ext3_sb_info {
u32 s_hash_seed[4];
int s_def_hash_version;
int s_hash_unsigned; /* 3 if hash should be signed, 0 if not */
- struct percpu_counter s_freeblocks_counter;
+ struct delalloc_counter s_alloc_counter;
struct percpu_counter s_freeinodes_counter;
struct percpu_counter s_dirs_counter;
struct blockgroup_lock *s_blockgroup_lock;
--
1.6.0.2

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