f2fs: reduce unncessary locking pages during read
This patch reduces redundant locking and unlocking pages during read operations. In f2fs_readpage, let's use wait_on_page_locked() instead of lock_page. And then, when we need to modify any data finally, let's lock the page so that we can avoid lock contention. [readpage rule] - The f2fs_readpage returns unlocked page, or released page too in error cases. - Its caller should handle read error, -EIO, after locking the page, which indicates read completion. - Its caller should check PageUptodate after grab_cache_page. Signed-off-by: Changman Lee <cm224.lee@samsung.com> Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This commit is contained in:
Jaegeuk Kim
parent
25c0a6e529
commit
393ff91f57
|
|
@ -57,13 +57,15 @@ repeat:
|
|||
cond_resched();
|
||||
goto repeat;
|
||||
}
|
||||
if (f2fs_readpage(sbi, page, index, READ_SYNC)) {
|
||||
f2fs_put_page(page, 1);
|
||||
goto repeat;
|
||||
}
|
||||
mark_page_accessed(page);
|
||||
if (PageUptodate(page))
|
||||
goto out;
|
||||
|
||||
/* We do not allow returning an errorneous page */
|
||||
if (f2fs_readpage(sbi, page, index, READ_SYNC))
|
||||
goto repeat;
|
||||
|
||||
lock_page(page);
|
||||
out:
|
||||
mark_page_accessed(page);
|
||||
return page;
|
||||
}
|
||||
|
||||
|
|
|
|||
|
|
@ -199,12 +199,17 @@ struct page *find_data_page(struct inode *inode, pgoff_t index)
|
|||
if (!page)
|
||||
return ERR_PTR(-ENOMEM);
|
||||
|
||||
err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
|
||||
if (err) {
|
||||
f2fs_put_page(page, 1);
|
||||
return ERR_PTR(err);
|
||||
if (PageUptodate(page)) {
|
||||
unlock_page(page);
|
||||
return page;
|
||||
}
|
||||
|
||||
err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
|
||||
wait_on_page_locked(page);
|
||||
if (!PageUptodate(page)) {
|
||||
f2fs_put_page(page, 0);
|
||||
return ERR_PTR(-EIO);
|
||||
}
|
||||
unlock_page(page);
|
||||
return page;
|
||||
}
|
||||
|
||||
|
|
@ -241,9 +246,13 @@ struct page *get_lock_data_page(struct inode *inode, pgoff_t index)
|
|||
BUG_ON(dn.data_blkaddr == NULL_ADDR);
|
||||
|
||||
err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
|
||||
if (err) {
|
||||
f2fs_put_page(page, 1);
|
||||
if (err)
|
||||
return ERR_PTR(err);
|
||||
|
||||
lock_page(page);
|
||||
if (!PageUptodate(page)) {
|
||||
f2fs_put_page(page, 1);
|
||||
return ERR_PTR(-EIO);
|
||||
}
|
||||
return page;
|
||||
}
|
||||
|
|
@ -283,14 +292,17 @@ struct page *get_new_data_page(struct inode *inode, pgoff_t index,
|
|||
|
||||
if (dn.data_blkaddr == NEW_ADDR) {
|
||||
zero_user_segment(page, 0, PAGE_CACHE_SIZE);
|
||||
SetPageUptodate(page);
|
||||
} else {
|
||||
err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
|
||||
if (err) {
|
||||
f2fs_put_page(page, 1);
|
||||
if (err)
|
||||
return ERR_PTR(err);
|
||||
lock_page(page);
|
||||
if (!PageUptodate(page)) {
|
||||
f2fs_put_page(page, 1);
|
||||
return ERR_PTR(-EIO);
|
||||
}
|
||||
}
|
||||
SetPageUptodate(page);
|
||||
|
||||
if (new_i_size &&
|
||||
i_size_read(inode) < ((index + 1) << PAGE_CACHE_SHIFT)) {
|
||||
|
|
@ -325,22 +337,14 @@ static void read_end_io(struct bio *bio, int err)
|
|||
|
||||
/*
|
||||
* Fill the locked page with data located in the block address.
|
||||
* Read operation is synchronous, and caller must unlock the page.
|
||||
* Return unlocked page.
|
||||
*/
|
||||
int f2fs_readpage(struct f2fs_sb_info *sbi, struct page *page,
|
||||
block_t blk_addr, int type)
|
||||
{
|
||||
struct block_device *bdev = sbi->sb->s_bdev;
|
||||
bool sync = (type == READ_SYNC);
|
||||
struct bio *bio;
|
||||
|
||||
/* This page can be already read by other threads */
|
||||
if (PageUptodate(page)) {
|
||||
if (!sync)
|
||||
unlock_page(page);
|
||||
return 0;
|
||||
}
|
||||
|
||||
down_read(&sbi->bio_sem);
|
||||
|
||||
/* Allocate a new bio */
|
||||
|
|
@ -354,18 +358,12 @@ int f2fs_readpage(struct f2fs_sb_info *sbi, struct page *page,
|
|||
kfree(bio->bi_private);
|
||||
bio_put(bio);
|
||||
up_read(&sbi->bio_sem);
|
||||
f2fs_put_page(page, 1);
|
||||
return -EFAULT;
|
||||
}
|
||||
|
||||
submit_bio(type, bio);
|
||||
up_read(&sbi->bio_sem);
|
||||
|
||||
/* wait for read completion if sync */
|
||||
if (sync) {
|
||||
lock_page(page);
|
||||
if (PageError(page))
|
||||
return -EIO;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
|
@ -636,18 +634,22 @@ static int f2fs_write_begin(struct file *file, struct address_space *mapping,
|
|||
|
||||
/* Reading beyond i_size is simple: memset to zero */
|
||||
zero_user_segments(page, 0, start, end, PAGE_CACHE_SIZE);
|
||||
return 0;
|
||||
goto out;
|
||||
}
|
||||
|
||||
if (dn.data_blkaddr == NEW_ADDR) {
|
||||
zero_user_segment(page, 0, PAGE_CACHE_SIZE);
|
||||
} else {
|
||||
err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
|
||||
if (err) {
|
||||
f2fs_put_page(page, 1);
|
||||
if (err)
|
||||
return err;
|
||||
lock_page(page);
|
||||
if (!PageUptodate(page)) {
|
||||
f2fs_put_page(page, 1);
|
||||
return -EIO;
|
||||
}
|
||||
}
|
||||
out:
|
||||
SetPageUptodate(page);
|
||||
clear_cold_data(page);
|
||||
return 0;
|
||||
|
|
|
|||
|
|
@ -100,10 +100,13 @@ static void ra_nat_pages(struct f2fs_sb_info *sbi, int nid)
|
|||
page = grab_cache_page(mapping, index);
|
||||
if (!page)
|
||||
continue;
|
||||
if (f2fs_readpage(sbi, page, index, READ)) {
|
||||
if (PageUptodate(page)) {
|
||||
f2fs_put_page(page, 1);
|
||||
continue;
|
||||
}
|
||||
if (f2fs_readpage(sbi, page, index, READ))
|
||||
continue;
|
||||
|
||||
f2fs_put_page(page, 0);
|
||||
}
|
||||
}
|
||||
|
|
@ -851,8 +854,16 @@ static int read_node_page(struct page *page, int type)
|
|||
|
||||
get_node_info(sbi, page->index, &ni);
|
||||
|
||||
if (ni.blk_addr == NULL_ADDR)
|
||||
if (ni.blk_addr == NULL_ADDR) {
|
||||
f2fs_put_page(page, 1);
|
||||
return -ENOENT;
|
||||
}
|
||||
|
||||
if (PageUptodate(page)) {
|
||||
unlock_page(page);
|
||||
return 0;
|
||||
}
|
||||
|
||||
return f2fs_readpage(sbi, page, ni.blk_addr, type);
|
||||
}
|
||||
|
||||
|
|
@ -865,19 +876,18 @@ void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid)
|
|||
struct page *apage;
|
||||
|
||||
apage = find_get_page(mapping, nid);
|
||||
if (apage && PageUptodate(apage))
|
||||
goto release_out;
|
||||
if (apage && PageUptodate(apage)) {
|
||||
f2fs_put_page(apage, 0);
|
||||
return;
|
||||
}
|
||||
f2fs_put_page(apage, 0);
|
||||
|
||||
apage = grab_cache_page(mapping, nid);
|
||||
if (!apage)
|
||||
return;
|
||||
|
||||
if (read_node_page(apage, READA))
|
||||
unlock_page(apage);
|
||||
|
||||
release_out:
|
||||
f2fs_put_page(apage, 0);
|
||||
if (read_node_page(apage, READA) == 0)
|
||||
f2fs_put_page(apage, 0);
|
||||
return;
|
||||
}
|
||||
|
||||
|
|
@ -892,11 +902,14 @@ struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)
|
|||
return ERR_PTR(-ENOMEM);
|
||||
|
||||
err = read_node_page(page, READ_SYNC);
|
||||
if (err) {
|
||||
f2fs_put_page(page, 1);
|
||||
if (err)
|
||||
return ERR_PTR(err);
|
||||
}
|
||||
|
||||
lock_page(page);
|
||||
if (!PageUptodate(page)) {
|
||||
f2fs_put_page(page, 1);
|
||||
return ERR_PTR(-EIO);
|
||||
}
|
||||
BUG_ON(nid != nid_of_node(page));
|
||||
mark_page_accessed(page);
|
||||
return page;
|
||||
|
|
@ -928,11 +941,8 @@ repeat:
|
|||
goto page_hit;
|
||||
|
||||
err = read_node_page(page, READ_SYNC);
|
||||
unlock_page(page);
|
||||
if (err) {
|
||||
f2fs_put_page(page, 0);
|
||||
if (err)
|
||||
return ERR_PTR(err);
|
||||
}
|
||||
|
||||
/* Then, try readahead for siblings of the desired node */
|
||||
end = start + MAX_RA_NODE;
|
||||
|
|
@ -957,6 +967,7 @@ page_hit:
|
|||
f2fs_put_page(page, 1);
|
||||
goto repeat;
|
||||
}
|
||||
mark_page_accessed(page);
|
||||
return page;
|
||||
}
|
||||
|
||||
|
|
@ -1473,23 +1484,24 @@ int restore_node_summary(struct f2fs_sb_info *sbi,
|
|||
sum_entry = &sum->entries[0];
|
||||
|
||||
for (i = 0; i < last_offset; i++, sum_entry++) {
|
||||
if (f2fs_readpage(sbi, page, addr, READ_SYNC))
|
||||
goto out;
|
||||
|
||||
rn = (struct f2fs_node *)page_address(page);
|
||||
sum_entry->nid = rn->footer.nid;
|
||||
sum_entry->version = 0;
|
||||
sum_entry->ofs_in_node = 0;
|
||||
addr++;
|
||||
|
||||
/*
|
||||
* In order to read next node page,
|
||||
* we must clear PageUptodate flag.
|
||||
*/
|
||||
ClearPageUptodate(page);
|
||||
|
||||
if (f2fs_readpage(sbi, page, addr, READ_SYNC))
|
||||
goto out;
|
||||
|
||||
lock_page(page);
|
||||
rn = (struct f2fs_node *)page_address(page);
|
||||
sum_entry->nid = rn->footer.nid;
|
||||
sum_entry->version = 0;
|
||||
sum_entry->ofs_in_node = 0;
|
||||
addr++;
|
||||
}
|
||||
out:
|
||||
unlock_page(page);
|
||||
out:
|
||||
__free_pages(page, 0);
|
||||
return 0;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -112,11 +112,16 @@ static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head)
|
|||
while (1) {
|
||||
struct fsync_inode_entry *entry;
|
||||
|
||||
if (f2fs_readpage(sbi, page, blkaddr, READ_SYNC))
|
||||
err = f2fs_readpage(sbi, page, blkaddr, READ_SYNC);
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
if (cp_ver != cpver_of_node(page))
|
||||
goto out;
|
||||
lock_page(page);
|
||||
|
||||
if (cp_ver != cpver_of_node(page)) {
|
||||
err = -EINVAL;
|
||||
goto unlock_out;
|
||||
}
|
||||
|
||||
if (!is_fsync_dnode(page))
|
||||
goto next;
|
||||
|
|
@ -131,7 +136,7 @@ static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head)
|
|||
if (IS_INODE(page) && is_dent_dnode(page)) {
|
||||
if (recover_inode_page(sbi, page)) {
|
||||
err = -ENOMEM;
|
||||
goto out;
|
||||
goto unlock_out;
|
||||
}
|
||||
}
|
||||
|
||||
|
|
@ -139,14 +144,14 @@ static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head)
|
|||
entry = kmem_cache_alloc(fsync_entry_slab, GFP_NOFS);
|
||||
if (!entry) {
|
||||
err = -ENOMEM;
|
||||
goto out;
|
||||
goto unlock_out;
|
||||
}
|
||||
|
||||
entry->inode = f2fs_iget(sbi->sb, ino_of_node(page));
|
||||
if (IS_ERR(entry->inode)) {
|
||||
err = PTR_ERR(entry->inode);
|
||||
kmem_cache_free(fsync_entry_slab, entry);
|
||||
goto out;
|
||||
goto unlock_out;
|
||||
}
|
||||
|
||||
list_add_tail(&entry->list, head);
|
||||
|
|
@ -155,15 +160,15 @@ static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head)
|
|||
if (IS_INODE(page)) {
|
||||
err = recover_inode(entry->inode, page);
|
||||
if (err)
|
||||
goto out;
|
||||
goto unlock_out;
|
||||
}
|
||||
next:
|
||||
/* check next segment */
|
||||
blkaddr = next_blkaddr_of_node(page);
|
||||
ClearPageUptodate(page);
|
||||
}
|
||||
out:
|
||||
unlock_out:
|
||||
unlock_page(page);
|
||||
out:
|
||||
__free_pages(page, 0);
|
||||
return err;
|
||||
}
|
||||
|
|
@ -319,8 +324,10 @@ static void recover_data(struct f2fs_sb_info *sbi,
|
|||
if (f2fs_readpage(sbi, page, blkaddr, READ_SYNC))
|
||||
goto out;
|
||||
|
||||
lock_page(page);
|
||||
|
||||
if (cp_ver != cpver_of_node(page))
|
||||
goto out;
|
||||
goto unlock_out;
|
||||
|
||||
entry = get_fsync_inode(head, ino_of_node(page));
|
||||
if (!entry)
|
||||
|
|
@ -336,10 +343,10 @@ static void recover_data(struct f2fs_sb_info *sbi,
|
|||
next:
|
||||
/* check next segment */
|
||||
blkaddr = next_blkaddr_of_node(page);
|
||||
ClearPageUptodate(page);
|
||||
}
|
||||
out:
|
||||
unlock_out:
|
||||
unlock_page(page);
|
||||
out:
|
||||
__free_pages(page, 0);
|
||||
|
||||
allocate_new_segments(sbi);
|
||||
|
|
|
|||
Loading…
Reference in New Issue