Re: [PATCH 1/2] f2fs: swap: remove dead codes
From: Chao Yu
Date: Wed May 26 2021 - 22:12:31 EST
On 2021/5/27 9:40, Jaegeuk Kim wrote:
On 05/26, Chao Yu wrote:
On 2021/5/26 21:30, Jaegeuk Kim wrote:
On 05/26, Chao Yu wrote:
After commit af4b6b8edf6a ("f2fs: introduce check_swap_activate_fast()"),
we will never run into original logic of check_swap_activate() before
f2fs supports non 4k-sized page, so let's delete those dead codes.
Why not keeping this for large page support in future maybe?
Well, if so, at that time, it would be better to refactor
check_swap_activate_fast() implementation based on f2fs_map_block() rather
than refactoring check_swap_activate() implementation based on low efficient
bmap()?
Let's first check whether we support large page. Have you quickly tested it?
If we support it now and current flow is just inefficient, I'd say keeping but
refactoring it later.
Let me check this, but I guess it missed to handle large page in lots of flows,
not sure where we may panic at... :(
Thanks,
Thanks,
Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
---
fs/f2fs/data.c | 171 +------------------------------------------------
1 file changed, 3 insertions(+), 168 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 3058c7e28b11..9c23fde93b76 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -3830,67 +3830,7 @@ int f2fs_migrate_page(struct address_space *mapping,
#endif
#ifdef CONFIG_SWAP
-static int f2fs_is_file_aligned(struct inode *inode)
-{
- struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
- block_t main_blkaddr = SM_I(sbi)->main_blkaddr;
- block_t cur_lblock;
- block_t last_lblock;
- block_t pblock;
- unsigned long nr_pblocks;
- unsigned int blocks_per_sec = BLKS_PER_SEC(sbi);
- unsigned int not_aligned = 0;
- int ret = 0;
-
- cur_lblock = 0;
- last_lblock = bytes_to_blks(inode, i_size_read(inode));
-
- while (cur_lblock < last_lblock) {
- struct f2fs_map_blocks map;
-
- memset(&map, 0, sizeof(map));
- map.m_lblk = cur_lblock;
- map.m_len = last_lblock - cur_lblock;
- map.m_next_pgofs = NULL;
- map.m_next_extent = NULL;
- map.m_seg_type = NO_CHECK_TYPE;
- map.m_may_create = false;
-
- ret = f2fs_map_blocks(inode, &map, 0, F2FS_GET_BLOCK_FIEMAP);
- if (ret)
- goto out;
-
- /* hole */
- if (!(map.m_flags & F2FS_MAP_FLAGS)) {
- f2fs_err(sbi, "Swapfile has holes\n");
- ret = -ENOENT;
- goto out;
- }
-
- pblock = map.m_pblk;
- nr_pblocks = map.m_len;
-
- if ((pblock - main_blkaddr) & (blocks_per_sec - 1) ||
- nr_pblocks & (blocks_per_sec - 1)) {
- if (f2fs_is_pinned_file(inode)) {
- f2fs_err(sbi, "Swapfile does not align to section");
- ret = -EINVAL;
- goto out;
- }
- not_aligned++;
- }
-
- cur_lblock += nr_pblocks;
- }
- if (not_aligned)
- f2fs_warn(sbi, "Swapfile (%u) is not align to section: \n"
- "\t1) creat(), 2) ioctl(F2FS_IOC_SET_PIN_FILE), 3) fallocate()",
- not_aligned);
-out:
- return ret;
-}
-
-static int check_swap_activate_fast(struct swap_info_struct *sis,
+static int check_swap_activate(struct swap_info_struct *sis,
struct file *swap_file, sector_t *span)
{
struct address_space *mapping = swap_file->f_mapping;
@@ -3907,6 +3847,8 @@ static int check_swap_activate_fast(struct swap_info_struct *sis,
unsigned int not_aligned = 0;
int ret = 0;
+ f2fs_bug_on(sbi, PAGE_SIZE != F2FS_BLKSIZE);
+
/*
* Map all the blocks into the extent list. This code doesn't try
* to be very smart.
@@ -3986,113 +3928,6 @@ static int check_swap_activate_fast(struct swap_info_struct *sis,
return ret;
}
-/* Copied from generic_swapfile_activate() to check any holes */
-static int check_swap_activate(struct swap_info_struct *sis,
- struct file *swap_file, sector_t *span)
-{
- struct address_space *mapping = swap_file->f_mapping;
- struct inode *inode = mapping->host;
- struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
- unsigned blocks_per_page;
- unsigned long page_no;
- sector_t probe_block;
- sector_t last_block;
- sector_t lowest_block = -1;
- sector_t highest_block = 0;
- int nr_extents = 0;
- int ret = 0;
-
- if (PAGE_SIZE == F2FS_BLKSIZE)
- return check_swap_activate_fast(sis, swap_file, span);
-
- ret = f2fs_is_file_aligned(inode);
- if (ret)
- goto out;
-
- blocks_per_page = bytes_to_blks(inode, PAGE_SIZE);
-
- /*
- * Map all the blocks into the extent list. This code doesn't try
- * to be very smart.
- */
- probe_block = 0;
- page_no = 0;
- last_block = bytes_to_blks(inode, i_size_read(inode));
- while ((probe_block + blocks_per_page) <= last_block &&
- page_no < sis->max) {
- unsigned block_in_page;
- sector_t first_block;
- sector_t block = 0;
-
- cond_resched();
-
- block = probe_block;
- ret = bmap(inode, &block);
- if (ret)
- goto out;
- if (!block)
- goto bad_bmap;
- first_block = block;
-
- /*
- * It must be PAGE_SIZE aligned on-disk
- */
- if (first_block & (blocks_per_page - 1)) {
- probe_block++;
- goto reprobe;
- }
-
- for (block_in_page = 1; block_in_page < blocks_per_page;
- block_in_page++) {
-
- block = probe_block + block_in_page;
- ret = bmap(inode, &block);
- if (ret)
- goto out;
- if (!block)
- goto bad_bmap;
-
- if (block != first_block + block_in_page) {
- /* Discontiguity */
- probe_block++;
- goto reprobe;
- }
- }
-
- first_block >>= (PAGE_SHIFT - inode->i_blkbits);
- if (page_no) { /* exclude the header page */
- if (first_block < lowest_block)
- lowest_block = first_block;
- if (first_block > highest_block)
- highest_block = first_block;
- }
-
- /*
- * We found a PAGE_SIZE-length, PAGE_SIZE-aligned run of blocks
- */
- ret = add_swap_extent(sis, page_no, 1, first_block);
- if (ret < 0)
- goto out;
- nr_extents += ret;
- page_no++;
- probe_block += blocks_per_page;
-reprobe:
- continue;
- }
- ret = nr_extents;
- *span = 1 + highest_block - lowest_block;
- if (page_no == 0)
- page_no = 1; /* force Empty message */
- sis->max = page_no;
- sis->pages = page_no - 1;
- sis->highest_bit = page_no - 1;
-out:
- return ret;
-bad_bmap:
- f2fs_err(sbi, "Swapfile has holes\n");
- return -EINVAL;
-}
-
static int f2fs_swap_activate(struct swap_info_struct *sis, struct file *file,
sector_t *span)
{
--
2.29.2
.