[PATCH v6 13/16] f2fs: Convert from readpages to readahead

Matthew Wilcox
2020-02-17T18:46:59Z

From: "Matthew Wilcox (Oracle)" <willy@infradead.org>

Use the new readahead operation in f2fs

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
fs/f2fs/data.c | 50 +++++++++++++++----------------------
fs/f2fs/f2fs.h | 5 ++--
include/trace/events/f2fs.h | 6 ++---
3 files changed, 25 insertions(+), 36 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index b27b72107911..87964e4cb6b8 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2159,13 +2159,11 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret,
* use ->readpage() or do the necessary surgery to decouple ->readpages()
* from read-ahead.
*/
-int f2fs_mpage_readpages(struct address_space *mapping,
- struct list_head *pages, struct page *page,
- unsigned nr_pages, bool is_readahead)
+int f2fs_mpage_readpages(struct inode *inode, struct readahead_control *rac,
+ struct page *page)
{
struct bio *bio = NULL;
sector_t last_block_in_bio = 0;
- struct inode *inode = mapping->host;
struct f2fs_map_blocks map;
#ifdef CONFIG_F2FS_FS_COMPRESSION
struct compress_ctx cc = {
@@ -2179,6 +2177,7 @@ int f2fs_mpage_readpages(struct address_space *mapping,
.nr_cpages = 0,
};
#endif
+ unsigned nr_pages = rac ? readahead_count(rac) : 1;
unsigned max_nr_pages = nr_pages;
int ret = 0;

@@ -2192,15 +2191,9 @@ int f2fs_mpage_readpages(struct address_space *mapping,
map.m_may_create = false;

for (; nr_pages; nr_pages--) {
- if (pages) {
- page = list_last_entry(pages, struct page, lru);
-
+ if (rac) {
+ page = readahead_page(rac);
prefetchw(&page->flags);
- list_del(&page->lru);
- if (add_to_page_cache_lru(page, mapping,
- page_index(page),
- readahead_gfp_mask(mapping)))
- goto next_page;
}

#ifdef CONFIG_F2FS_FS_COMPRESSION
@@ -2210,7 +2203,7 @@ int f2fs_mpage_readpages(struct address_space *mapping,
ret = f2fs_read_multi_pages(&cc, &bio,
max_nr_pages,
&last_block_in_bio,
- is_readahead);
+ rac);
f2fs_destroy_compress_ctx(&cc);
if (ret)
goto set_error_page;
@@ -2233,7 +2226,7 @@ int f2fs_mpage_readpages(struct address_space *mapping,
#endif

ret = f2fs_read_single_page(inode, page, max_nr_pages, &map,
- &bio, &last_block_in_bio, is_readahead);
+ &bio, &last_block_in_bio, rac);
if (ret) {
#ifdef CONFIG_F2FS_FS_COMPRESSION
set_error_page:
@@ -2242,8 +2235,10 @@ int f2fs_mpage_readpages(struct address_space *mapping,
zero_user_segment(page, 0, PAGE_SIZE);
unlock_page(page);
}
+#ifdef CONFIG_F2FS_FS_COMPRESSION
next_page:
- if (pages)
+#endif
+ if (rac)
put_page(page);

#ifdef CONFIG_F2FS_FS_COMPRESSION
@@ -2253,16 +2248,15 @@ int f2fs_mpage_readpages(struct address_space *mapping,
ret = f2fs_read_multi_pages(&cc, &bio,
max_nr_pages,
&last_block_in_bio,
- is_readahead);
+ rac);
f2fs_destroy_compress_ctx(&cc);
}
}
#endif
}
- BUG_ON(pages && !list_empty(pages));
if (bio)
__submit_bio(F2FS_I_SB(inode), bio, DATA);
- return pages ? 0 : ret;
+ return ret;
}

static int f2fs_read_data_page(struct file *file, struct page *page)
@@ -2281,28 +2275,24 @@ 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_file_mapping(page),
- NULL, page, 1, false);
+ ret = f2fs_mpage_readpages(inode, NULL, page);
return ret;
}

-static int f2fs_read_data_pages(struct file *file,
- struct address_space *mapping,
- struct list_head *pages, unsigned nr_pages)
+static void f2fs_readahead(struct readahead_control *rac)
{
- struct inode *inode = mapping->host;
- struct page *page = list_last_entry(pages, struct page, lru);
+ struct inode *inode = rac->mapping->host;

- trace_f2fs_readpages(inode, page, nr_pages);
+ trace_f2fs_readpages(inode, readahead_index(rac), readahead_count(rac));

if (!f2fs_is_compress_backend_ready(inode))
- return 0;
+ return;

/* If the file has inline data, skip readpages */
if (f2fs_has_inline_data(inode))
- return 0;
+ return;

- return f2fs_mpage_readpages(mapping, pages, NULL, nr_pages, true);
+ f2fs_mpage_readpages(inode, rac, NULL);
}

int f2fs_encrypt_one_page(struct f2fs_io_info *fio)
@@ -3784,7 +3774,7 @@ static void f2fs_swap_deactivate(struct file *file)

const struct address_space_operations f2fs_dblock_aops = {
.readpage = f2fs_read_data_page,
- .readpages = f2fs_read_data_pages,
+ .readahead = f2fs_readahead,
.writepage = f2fs_write_data_page,
.writepages = f2fs_write_data_pages,
.write_begin = f2fs_write_begin,
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 5355be6b6755..b5e72dee8826 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -3344,9 +3344,8 @@ int f2fs_reserve_new_block(struct dnode_of_data *dn);
int f2fs_get_block(struct dnode_of_data *dn, pgoff_t index);
int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from);
int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index);
-int f2fs_mpage_readpages(struct address_space *mapping,
- struct list_head *pages, struct page *page,
- unsigned nr_pages, bool is_readahead);
+int f2fs_mpage_readpages(struct inode *inode, struct readahead_control *rac,
+ struct page *page);
struct page *f2fs_get_read_data_page(struct inode *inode, pgoff_t index,
int op_flags, bool for_write);
struct page *f2fs_find_data_page(struct inode *inode, pgoff_t index);
diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
index 67a97838c2a0..d72da4a33883 100644
--- a/include/trace/events/f2fs.h
+++ b/include/trace/events/f2fs.h
@@ -1375,9 +1375,9 @@ TRACE_EVENT(f2fs_writepages,

TRACE_EVENT(f2fs_readpages,

- TP_PROTO(struct inode *inode, struct page *page, unsigned int nrpage),
+ TP_PROTO(struct inode *inode, pgoff_t start, unsigned int nrpage),

- TP_ARGS(inode, page, nrpage),
+ TP_ARGS(inode, start, nrpage),

TP_STRUCT__entry(
__field(dev_t, dev)
@@ -1389,7 +1389,7 @@ TRACE_EVENT(f2fs_readpages,
TP_fast_assign(
__entry->dev = inode->i_sb->s_dev;
__entry->ino = inode->i_ino;
- __entry->start = page->index;
+ __entry->start = start;
__entry->nrpage = nrpage;
),

--
2.25.0