Re: [f2fs-dev 3/5] f2fs: Add a new function: f2fs_reserve_block()

From: Jaegeuk Kim
Date: Mon Oct 28 2013 - 20:57:03 EST


Hi Huajun,

2013-10-29 (í), 00:53 +0800, Huajun Li:
> Hi Jaegeuk,
>
> Thanks for your kindly review and comments.
>
> On Mon, Oct 28, 2013 at 8:28 PM, Jaegeuk Kim <jaegeuk.kim@xxxxxxxxxxx> wrote:
> > 2013-10-28 (ì), 21:16 +0900, Jaegeuk Kim:
> > Hi,
> >
> >>
> >> 2013-10-26 (í), 00:01 +0800, Huajun Li:
> >> > From: Huajun Li <huajun.li@xxxxxxxxx>
> >> >
> >> > Add the function f2fs_reserve_block() to easily reserve new blocks.
> >> >
> >> > Signed-off-by: Huajun Li <huajun.li@xxxxxxxxx>
> >> > Signed-off-by: Haicheng Li <haicheng.li@xxxxxxxxxxxxxxx>
> >> > Signed-off-by: Weihong Xu <weihong.xu@xxxxxxxxx>
> >> > ---
> >> > fs/f2fs/data.c | 29 ++++++++++++++++++-----------
> >> > fs/f2fs/f2fs.h | 1 +
> >> > 2 files changed, 19 insertions(+), 11 deletions(-)
> >> >
> >> > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> >> > index c8887d8..7b31911 100644
> >> > --- a/fs/f2fs/data.c
> >> > +++ b/fs/f2fs/data.c
> >> > @@ -64,6 +64,23 @@ int reserve_new_block(struct dnode_of_data *dn)
> >> > return 0;
> >> > }
> >> >
> >> > +int f2fs_reserve_block(struct inode *inode,
> >> > + struct dnode_of_data *dn, pgoff_t index)
> >>
> >
> > We don't need to get dnode_of_data from parameters, since it is
> > used by this function only.
>
> After calling f2fs_reserve_block(), we need dn.data_blkaddr to check
> whether it is NEW_ADDR. So IMO, it's nice to keep this parameter.
>

Ah, got it.
BTW, I found another flows we can clean up wrt this issue.
How about this?

---
fs/f2fs/data.c | 51 +++++++++++++++++++++++----------------------------
fs/f2fs/f2fs.h | 1 +
fs/f2fs/file.c | 39 ++++++---------------------------------
3 files changed, 30 insertions(+), 61 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index c8887d8..b8c4f76d 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -64,6 +64,22 @@ int reserve_new_block(struct dnode_of_data *dn)
return 0;
}

+int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index)
+{
+ bool need_put = dn->inode_page ? false : true;
+ int err;
+
+ err = get_dnode_of_data(dn, index, ALLOC_NODE);
+ if (err)
+ return err;
+ if (dn->data_blkaddr == NULL_ADDR)
+ err = reserve_new_block(dn);
+
+ if (need_put)
+ f2fs_put_dnode(dn);
+ return err;
+}
+
static int check_extent_cache(struct inode *inode, pgoff_t pgofs,
struct buffer_head *bh_result)
{
@@ -300,19 +316,9 @@ struct page *get_new_data_page(struct inode *inode,
int err;

set_new_dnode(&dn, inode, npage, npage, 0);
- err = get_dnode_of_data(&dn, index, ALLOC_NODE);
+ err = f2fs_reserve_block(&dn, index);
if (err)
return ERR_PTR(err);
-
- if (dn.data_blkaddr == NULL_ADDR) {
- if (reserve_new_block(&dn)) {
- if (!npage)
- f2fs_put_dnode(&dn);
- return ERR_PTR(-ENOSPC);
- }
- }
- if (!npage)
- f2fs_put_dnode(&dn);
repeat:
page = grab_cache_page(mapping, index);
if (!page)
@@ -644,21 +650,15 @@ repeat:
*pagep = page;

f2fs_lock_op(sbi);
-
set_new_dnode(&dn, inode, NULL, NULL, 0);
- err = get_dnode_of_data(&dn, index, ALLOC_NODE);
- if (err)
- goto err;
-
- if (dn.data_blkaddr == NULL_ADDR)
- err = reserve_new_block(&dn);
-
- f2fs_put_dnode(&dn);
- if (err)
- goto err;
-
+ err = f2fs_reserve_block(&dn, index);
f2fs_unlock_op(sbi);

+ if (err) {
+ f2fs_put_page(page, 1);
+ return err;
+ }
+
if ((len == PAGE_CACHE_SIZE) || PageUptodate(page))
return 0;

@@ -691,11 +691,6 @@ out:
SetPageUptodate(page);
clear_cold_data(page);
return 0;
-
-err:
- f2fs_unlock_op(sbi);
- f2fs_put_page(page, 1);
- return err;
}

static int f2fs_write_end(struct file *file,
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index c9d394c..e77ca20 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1112,6 +1112,7 @@ void destroy_checkpoint_caches(void);
* data.c
*/
int reserve_new_block(struct dnode_of_data *);
+int f2fs_reserve_block(struct dnode_of_data *, pgoff_t);
void update_extent_cache(block_t, struct dnode_of_data *);
struct page *find_data_page(struct inode *, pgoff_t, bool);
struct page *get_lock_data_page(struct inode *, pgoff_t);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 2d4190a..21ef0d1 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -33,7 +33,6 @@ static int f2fs_vm_page_mkwrite(struct vm_area_struct
*vma,
struct page *page = vmf->page;
struct inode *inode = file_inode(vma->vm_file);
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
- block_t old_blk_addr;
struct dnode_of_data dn;
int err;

@@ -44,24 +43,10 @@ static int f2fs_vm_page_mkwrite(struct
vm_area_struct *vma,
/* block allocation */
f2fs_lock_op(sbi);
set_new_dnode(&dn, inode, NULL, NULL, 0);
- err = get_dnode_of_data(&dn, page->index, ALLOC_NODE);
- if (err) {
- f2fs_unlock_op(sbi);
- goto out;
- }
-
- old_blk_addr = dn.data_blkaddr;
-
- if (old_blk_addr == NULL_ADDR) {
- err = reserve_new_block(&dn);
- if (err) {
- f2fs_put_dnode(&dn);
- f2fs_unlock_op(sbi);
- goto out;
- }
- }
- f2fs_put_dnode(&dn);
+ err = f2fs_reserve_block(&dn, page->index);
f2fs_unlock_op(sbi);
+ if (err)
+ goto out;

file_update_time(vma->vm_file);
lock_page(page);
@@ -531,22 +516,10 @@ static int expand_inode_data(struct inode *inode,
loff_t offset,

f2fs_lock_op(sbi);
set_new_dnode(&dn, inode, NULL, NULL, 0);
- ret = get_dnode_of_data(&dn, index, ALLOC_NODE);
- if (ret) {
- f2fs_unlock_op(sbi);
- break;
- }
-
- if (dn.data_blkaddr == NULL_ADDR) {
- ret = reserve_new_block(&dn);
- if (ret) {
- f2fs_put_dnode(&dn);
- f2fs_unlock_op(sbi);
- break;
- }
- }
- f2fs_put_dnode(&dn);
+ ret = f2fs_reserve_block(&dn, index);
f2fs_unlock_op(sbi);
+ if (ret)
+ break;

if (pg_start == pg_end)
new_size = offset + len;
--
1.8.4.474.g128a96c

--
Jaegeuk Kim
Samsung

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