Btrfs: use add_to_page_cache_lru, use __page_cache_alloc

Pagecache pages should be allocated with __page_cache_alloc, so they
obey pagecache memory policies.

add_to_page_cache_lru is exported, so it should be used. Benefits over
using a private pagevec: neater code, 128 bytes fewer stack used, percpu
lru ordering is preserved, and finally don't need to flush pagevec
before returning so batching may be shared with other LRU insertions.

Signed-off-by: Nick Piggin <npiggin@suse.de>:
Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 28b92a7218ab4cea7c59db65912c071f13b3697b..1d54c5308df59d361b6efaa41d6870ed32a1394b 100644 (file)
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -31,7 +31,6 @@
 #include <linux/swap.h>
 #include <linux/writeback.h>
 #include <linux/bit_spinlock.h>
-#include <linux/pagevec.h>
 #include "compat.h"
 #include "ctree.h"
 #include "disk-io.h"
@@ -445,7 +444,6 @@ static noinline int add_ra_bio_pages(struct inode *inode,
        unsigned long nr_pages = 0;
        struct extent_map *em;
        struct address_space *mapping = inode->i_mapping;
-       struct pagevec pvec;
        struct extent_map_tree *em_tree;
        struct extent_io_tree *tree;
        u64 end;
@@ -461,7 +459,6 @@ static noinline int add_ra_bio_pages(struct inode *inode,
 
        end_index = (i_size_read(inode) - 1) >> PAGE_CACHE_SHIFT;
 
-       pagevec_init(&pvec, 0);
        while (last_offset < compressed_end) {
                page_index = last_offset >> PAGE_CACHE_SHIFT;
 
@@ -478,26 +475,17 @@ static noinline int add_ra_bio_pages(struct inode *inode,
                        goto next;
                }
 
-               page = alloc_page(mapping_gfp_mask(mapping) & ~__GFP_FS);
+               page = __page_cache_alloc(mapping_gfp_mask(mapping) &
+                                                               ~__GFP_FS);
                if (!page)
                        break;
 
-               page->index = page_index;
-               /*
-                * what we want to do here is call add_to_page_cache_lru,
-                * but that isn't exported, so we reproduce it here
-                */
-               if (add_to_page_cache(page, mapping,
-                                     page->index, GFP_NOFS)) {
+               if (add_to_page_cache_lru(page, mapping, page_index,
+                                                               GFP_NOFS)) {
                        page_cache_release(page);
                        goto next;
                }
 
-               /* open coding of lru_cache_add, also not exported */
-               page_cache_get(page);
-               if (!pagevec_add(&pvec, page))
-                       __pagevec_lru_add_file(&pvec);
-
                end = last_offset + PAGE_CACHE_SIZE - 1;
                /*
                 * at this point, we have a locked page in the page cache
@@ -551,8 +539,6 @@ static noinline int add_ra_bio_pages(struct inode *inode,
 next:
                last_offset += PAGE_CACHE_SIZE;
        }
-       if (pagevec_count(&pvec))
-               __pagevec_lru_add_file(&pvec);
        return 0;
 }
 

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index c99121ac5d6b7f1f9f3b05b2c4b1e47e1ac06cbf..fc742e59815efa4049ad9ee5470cf0701e3106da 100644 (file)
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2679,33 +2679,20 @@ int extent_readpages(struct extent_io_tree *tree,
 {
        struct bio *bio = NULL;
        unsigned page_idx;
-       struct pagevec pvec;
        unsigned long bio_flags = 0;
 
-       pagevec_init(&pvec, 0);
        for (page_idx = 0; page_idx < nr_pages; page_idx++) {
                struct page *page = list_entry(pages->prev, struct page, lru);
 
                prefetchw(&page->flags);
                list_del(&page->lru);
-               /*
-                * what we want to do here is call add_to_page_cache_lru,
-                * but that isn't exported, so we reproduce it here
-                */
-               if (!add_to_page_cache(page, mapping,
+               if (!add_to_page_cache_lru(page, mapping,
                                        page->index, GFP_KERNEL)) {
-
-                       /* open coding of lru_cache_add, also not exported */
-                       page_cache_get(page);
-                       if (!pagevec_add(&pvec, page))
-                               __pagevec_lru_add_file(&pvec);
                        __extent_read_full_page(tree, page, get_extent,
                                                &bio, 0, &bio_flags);
                }
                page_cache_release(page);
        }
-       if (pagevec_count(&pvec))
-               __pagevec_lru_add_file(&pvec);
        BUG_ON(!list_empty(pages));
        if (bio)
                submit_one_bio(READ, bio, 0, bio_flags);