[PATCH] f2fs: support swap file w/ DIO

From: Jaegeuk Kim
Date: Wed Jul 03 2019 - 11:53:29 EST


Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
fs/f2fs/data.c | 142 ++++++++++++++++++++++++++++++++++--
fs/f2fs/f2fs.h | 5 +-
include/trace/events/f2fs.h | 11 +--
3 files changed, 143 insertions(+), 15 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 1e2d924e2ea7..6a8db4abdf5f 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -14,6 +14,7 @@
#include <linux/pagevec.h>
#include <linux/blkdev.h>
#include <linux/bio.h>
+#include <linux/swap.h>
#include <linux/prefetch.h>
#include <linux/uio.h>
#include <linux/cleancache.h>
@@ -54,7 +55,7 @@ static bool __is_cp_guaranteed(struct page *page)

static enum count_type __read_io_type(struct page *page)
{
- struct address_space *mapping = page->mapping;
+ struct address_space *mapping = page_file_mapping(page);

if (mapping) {
struct inode *inode = mapping->host;
@@ -1585,7 +1586,7 @@ static int f2fs_read_single_page(struct inode *inode, struct page *page,
sector_t block_nr;
int ret = 0;

- block_in_file = (sector_t)page->index;
+ block_in_file = (sector_t)page_index(page);
last_block = block_in_file + nr_pages;
last_block_in_file = (i_size_read(inode) + blocksize - 1) >>
blkbits;
@@ -1618,7 +1619,8 @@ static int f2fs_read_single_page(struct inode *inode, struct page *page,
block_nr = map->m_pblk + block_in_file - map->m_lblk;
SetPageMappedToDisk(page);

- if (!PageUptodate(page) && !cleancache_get_page(page)) {
+ if (!PageUptodate(page) && (!PageSwapCache(page) &&
+ !cleancache_get_page(page))) {
SetPageUptodate(page);
goto confused;
}
@@ -1716,7 +1718,7 @@ static int f2fs_mpage_readpages(struct address_space *mapping,
prefetchw(&page->flags);
list_del(&page->lru);
if (add_to_page_cache_lru(page, mapping,
- page->index,
+ page_index(page),
readahead_gfp_mask(mapping)))
goto next_page;
}
@@ -1740,7 +1742,7 @@ static int f2fs_mpage_readpages(struct address_space *mapping,

static int f2fs_read_data_page(struct file *file, struct page *page)
{
- struct inode *inode = page->mapping->host;
+ struct inode *inode = page_file_mapping(page)->host;
int ret = -EAGAIN;

trace_f2fs_readpage(page, DATA);
@@ -1749,7 +1751,8 @@ static int f2fs_read_data_page(struct file *file, struct page *page)
if (f2fs_has_inline_data(inode))
ret = f2fs_read_inline_data(inode, page);
if (ret == -EAGAIN)
- ret = f2fs_mpage_readpages(page->mapping, NULL, page, 1, false);
+ ret = f2fs_mpage_readpages(page_file_mapping(page),
+ NULL, page, 1, false);
return ret;
}

@@ -2851,13 +2854,14 @@ int f2fs_release_page(struct page *page, gfp_t wait)

static int f2fs_set_data_page_dirty(struct page *page)
{
- struct address_space *mapping = page->mapping;
- struct inode *inode = mapping->host;
+ struct inode *inode = page_file_mapping(page)->host;

trace_f2fs_set_page_dirty(page, DATA);

if (!PageUptodate(page))
SetPageUptodate(page);
+ if (PageSwapCache(page))
+ return __set_page_dirty_nobuffers(page);

if (f2fs_is_atomic_file(inode) && !f2fs_is_commit_atomic_write(inode)) {
if (!IS_ATOMIC_WRITTEN_PAGE(page)) {
@@ -2949,6 +2953,126 @@ int f2fs_migrate_page(struct address_space *mapping,
}
#endif

+#ifdef CONFIG_SWAP
+/* Copied from generic_swapfile_activate() to check any holes */
+static int check_swap_activate(struct file *swap_file, unsigned int max)
+{
+ struct address_space *mapping = swap_file->f_mapping;
+ struct inode *inode = mapping->host;
+ unsigned blocks_per_page;
+ unsigned long page_no;
+ unsigned blkbits;
+ sector_t probe_block;
+ sector_t last_block;
+ sector_t lowest_block = -1;
+ sector_t highest_block = 0;
+
+ blkbits = inode->i_blkbits;
+ blocks_per_page = PAGE_SIZE >> blkbits;
+
+ /*
+ * 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 = i_size_read(inode) >> blkbits;
+ while ((probe_block + blocks_per_page) <= last_block && page_no < max) {
+ unsigned block_in_page;
+ sector_t first_block;
+
+ cond_resched();
+
+ first_block = bmap(inode, probe_block);
+ if (first_block == 0)
+ goto bad_bmap;
+
+ /*
+ * 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++) {
+ sector_t block;
+
+ block = bmap(inode, probe_block + block_in_page);
+ if (block == 0)
+ goto bad_bmap;
+ if (block != first_block + block_in_page) {
+ /* Discontiguity */
+ probe_block++;
+ goto reprobe;
+ }
+ }
+
+ first_block >>= (PAGE_SHIFT - 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;
+ }
+
+ page_no++;
+ probe_block += blocks_per_page;
+reprobe:
+ continue;
+ }
+ return 0;
+
+bad_bmap:
+ pr_err("swapon: swapfile has holes\n");
+ return -EINVAL;
+}
+
+static int f2fs_swap_activate(struct swap_info_struct *sis, struct file *file,
+ sector_t *span)
+{
+ struct inode *inode = file_inode(file);
+ int ret;
+
+ if (!S_ISREG(inode->i_mode))
+ return -EINVAL;
+
+ if (f2fs_readonly(F2FS_I_SB(inode)->sb))
+ return -EROFS;
+
+ ret = f2fs_convert_inline_inode(inode);
+ if (ret)
+ return ret;
+
+ ret = check_swap_activate(file, sis->max);
+ if (ret)
+ return ret;
+
+ set_inode_flag(inode, FI_PIN_FILE);
+ f2fs_precache_extents(inode);
+ f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
+ return 0;
+}
+
+static void f2fs_swap_deactivate(struct file *file)
+{
+ struct inode *inode = file_inode(file);
+
+ clear_inode_flag(inode, FI_PIN_FILE);
+}
+#else
+static int f2fs_swap_activate(struct swap_info_struct *sis, struct file *file,
+ sector_t *span)
+{
+ return -EOPNOTSUPP;
+}
+
+static void f2fs_swap_deactivate(struct file *file)
+{
+}
+#endif
+
const struct address_space_operations f2fs_dblock_aops = {
.readpage = f2fs_read_data_page,
.readpages = f2fs_read_data_pages,
@@ -2961,6 +3085,8 @@ const struct address_space_operations f2fs_dblock_aops = {
.releasepage = f2fs_release_page,
.direct_IO = f2fs_direct_IO,
.bmap = f2fs_bmap,
+ .swap_activate = f2fs_swap_activate,
+ .swap_deactivate = f2fs_swap_deactivate,
#ifdef CONFIG_MIGRATION
.migratepage = f2fs_migrate_page,
#endif
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 761c5a59ef77..17382da7f0bd 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1498,7 +1498,7 @@ static inline struct f2fs_sb_info *F2FS_M_SB(struct address_space *mapping)

static inline struct f2fs_sb_info *F2FS_P_SB(struct page *page)
{
- return F2FS_M_SB(page->mapping);
+ return F2FS_M_SB(page_file_mapping(page));
}

static inline struct f2fs_super_block *F2FS_RAW_SUPER(struct f2fs_sb_info *sbi)
@@ -3683,7 +3683,8 @@ static inline bool f2fs_force_buffered_io(struct inode *inode,
if (test_opt(sbi, LFS) && (rw == WRITE) &&
block_unaligned_IO(inode, iocb, iter))
return true;
- if (is_sbi_flag_set(F2FS_I_SB(inode), SBI_CP_DISABLED))
+ if (is_sbi_flag_set(F2FS_I_SB(inode), SBI_CP_DISABLED) &&
+ !(inode->i_flags & S_SWAPFILE))
return true;

return false;
diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
index 53b96f12300c..af79e0c72926 100644
--- a/include/trace/events/f2fs.h
+++ b/include/trace/events/f2fs.h
@@ -1028,8 +1028,8 @@ DECLARE_EVENT_CLASS(f2fs__submit_page_bio,
),

TP_fast_assign(
- __entry->dev = page->mapping->host->i_sb->s_dev;
- __entry->ino = page->mapping->host->i_ino;
+ __entry->dev = page_file_mapping(page)->host->i_sb->s_dev;
+ __entry->ino = page_file_mapping(page)->host->i_ino;
__entry->index = page->index;
__entry->old_blkaddr = fio->old_blkaddr;
__entry->new_blkaddr = fio->new_blkaddr;
@@ -1216,10 +1216,11 @@ DECLARE_EVENT_CLASS(f2fs__page,
),

TP_fast_assign(
- __entry->dev = page->mapping->host->i_sb->s_dev;
- __entry->ino = page->mapping->host->i_ino;
+ __entry->dev = page_file_mapping(page)->host->i_sb->s_dev;
+ __entry->ino = page_file_mapping(page)->host->i_ino;
__entry->type = type;
- __entry->dir = S_ISDIR(page->mapping->host->i_mode);
+ __entry->dir =
+ S_ISDIR(page_file_mapping(page)->host->i_mode);
__entry->index = page->index;
__entry->dirty = PageDirty(page);
__entry->uptodate = PageUptodate(page);
--
2.19.0.605.g01d371f741-goog