} while (page_bh != head);
}
+struct mpage_readpage_args {
+ struct bio *bio;
+ struct page *page;
+ unsigned int nr_pages;
+ bool is_readahead;
+ sector_t last_block_in_bio;
+ struct buffer_head map_bh;
+ unsigned long first_logical_block;
+ get_block_t *get_block;
+};
+
/*
* This is the worker routine which does all the work of mapping the disk
* blocks and constructs largest possible bios, submits them for IO if the
* represent the validity of its disk mapping and to decide when to do the next
* get_block() call.
*/
-static struct bio *
-do_mpage_readpage(struct bio *bio, struct page *page, unsigned nr_pages,
- sector_t *last_block_in_bio, struct buffer_head *map_bh,
- unsigned long *first_logical_block, get_block_t get_block,
- gfp_t gfp)
+static struct bio *do_mpage_readpage(struct mpage_readpage_args *args)
{
+ struct page *page = args->page;
struct inode *inode = page->mapping->host;
const unsigned blkbits = inode->i_blkbits;
const unsigned blocks_per_page = PAGE_SIZE >> blkbits;
const unsigned blocksize = 1 << blkbits;
+ struct buffer_head *map_bh = &args->map_bh;
sector_t block_in_file;
sector_t last_block;
sector_t last_block_in_file;
struct block_device *bdev = NULL;
int length;
int fully_mapped = 1;
+ int op_flags;
unsigned nblocks;
unsigned relative_block;
+ gfp_t gfp;
+
+ if (args->is_readahead) {
+ op_flags = REQ_RAHEAD;
+ gfp = readahead_gfp_mask(page->mapping);
+ } else {
+ op_flags = 0;
+ gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL);
+ }
if (page_has_buffers(page))
goto confused;
block_in_file = (sector_t)page->index << (PAGE_SHIFT - blkbits);
- last_block = block_in_file + nr_pages * blocks_per_page;
+ last_block = block_in_file + args->nr_pages * blocks_per_page;
last_block_in_file = (i_size_read(inode) + blocksize - 1) >> blkbits;
if (last_block > last_block_in_file)
last_block = last_block_in_file;
* Map blocks using the result from the previous get_blocks call first.
*/
nblocks = map_bh->b_size >> blkbits;
- if (buffer_mapped(map_bh) && block_in_file > *first_logical_block &&
- block_in_file < (*first_logical_block + nblocks)) {
- unsigned map_offset = block_in_file - *first_logical_block;
+ if (buffer_mapped(map_bh) &&
+ block_in_file > args->first_logical_block &&
+ block_in_file < (args->first_logical_block + nblocks)) {
+ unsigned map_offset = block_in_file - args->first_logical_block;
unsigned last = nblocks - map_offset;
for (relative_block = 0; ; relative_block++) {
if (block_in_file < last_block) {
map_bh->b_size = (last_block-block_in_file) << blkbits;
- if (get_block(inode, block_in_file, map_bh, 0))
+ if (args->get_block(inode, block_in_file, map_bh, 0))
goto confused;
- *first_logical_block = block_in_file;
+ args->first_logical_block = block_in_file;
}
if (!buffer_mapped(map_bh)) {
/*
* This page will go to BIO. Do we need to send this BIO off first?
*/
- if (bio && (*last_block_in_bio != blocks[0] - 1))
- bio = mpage_bio_submit(REQ_OP_READ, 0, bio);
+ if (args->bio && (args->last_block_in_bio != blocks[0] - 1))
+ args->bio = mpage_bio_submit(REQ_OP_READ, op_flags, args->bio);
alloc_new:
- if (bio == NULL) {
+ if (args->bio == NULL) {
if (first_hole == blocks_per_page) {
if (!bdev_read_page(bdev, blocks[0] << (blkbits - 9),
page))
goto out;
}
- bio = mpage_alloc(bdev, blocks[0] << (blkbits - 9),
- min_t(int, nr_pages, BIO_MAX_PAGES), gfp);
- if (bio == NULL)
+ args->bio = mpage_alloc(bdev, blocks[0] << (blkbits - 9),
+ min_t(int, args->nr_pages,
+ BIO_MAX_PAGES),
+ gfp);
+ if (args->bio == NULL)
goto confused;
}
length = first_hole << blkbits;
- if (bio_add_page(bio, page, length, 0) < length) {
- bio = mpage_bio_submit(REQ_OP_READ, 0, bio);
+ if (bio_add_page(args->bio, page, length, 0) < length) {
+ args->bio = mpage_bio_submit(REQ_OP_READ, op_flags, args->bio);
goto alloc_new;
}
- relative_block = block_in_file - *first_logical_block;
+ relative_block = block_in_file - args->first_logical_block;
nblocks = map_bh->b_size >> blkbits;
if ((buffer_boundary(map_bh) && relative_block == nblocks) ||
(first_hole != blocks_per_page))
- bio = mpage_bio_submit(REQ_OP_READ, 0, bio);
+ args->bio = mpage_bio_submit(REQ_OP_READ, op_flags, args->bio);
else
- *last_block_in_bio = blocks[blocks_per_page - 1];
+ args->last_block_in_bio = blocks[blocks_per_page - 1];
out:
- return bio;
+ return args->bio;
confused:
- if (bio)
- bio = mpage_bio_submit(REQ_OP_READ, 0, bio);
+ if (args->bio)
+ args->bio = mpage_bio_submit(REQ_OP_READ, op_flags, args->bio);
if (!PageUptodate(page))
- block_read_full_page(page, get_block);
+ block_read_full_page(page, args->get_block);
else
unlock_page(page);
goto out;
mpage_readpages(struct address_space *mapping, struct list_head *pages,
unsigned nr_pages, get_block_t get_block)
{
- struct bio *bio = NULL;
+ struct mpage_readpage_args args = {
+ .get_block = get_block,
+ .is_readahead = true,
+ };
unsigned page_idx;
- sector_t last_block_in_bio = 0;
- struct buffer_head map_bh;
- unsigned long first_logical_block = 0;
- gfp_t gfp = readahead_gfp_mask(mapping);
- map_bh.b_state = 0;
- map_bh.b_size = 0;
for (page_idx = 0; page_idx < nr_pages; page_idx++) {
struct page *page = lru_to_page(pages);
list_del(&page->lru);
if (!add_to_page_cache_lru(page, mapping,
page->index,
- gfp)) {
- bio = do_mpage_readpage(bio, page,
- nr_pages - page_idx,
- &last_block_in_bio, &map_bh,
- &first_logical_block,
- get_block, gfp);
+ readahead_gfp_mask(mapping))) {
+ args.page = page;
+ args.nr_pages = nr_pages - page_idx;
+ args.bio = do_mpage_readpage(&args);
}
put_page(page);
}
BUG_ON(!list_empty(pages));
- if (bio)
- mpage_bio_submit(REQ_OP_READ, 0, bio);
+ if (args.bio)
+ mpage_bio_submit(REQ_OP_READ, REQ_RAHEAD, args.bio);
return 0;
}
EXPORT_SYMBOL(mpage_readpages);
*/
int mpage_readpage(struct page *page, get_block_t get_block)
{
- struct bio *bio = NULL;
- sector_t last_block_in_bio = 0;
- struct buffer_head map_bh;
- unsigned long first_logical_block = 0;
- gfp_t gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL);
+ struct mpage_readpage_args args = {
+ .page = page,
+ .nr_pages = 1,
+ .get_block = get_block,
+ };
- map_bh.b_state = 0;
- map_bh.b_size = 0;
- bio = do_mpage_readpage(bio, page, 1, &last_block_in_bio,
- &map_bh, &first_logical_block, get_block, gfp);
- if (bio)
- mpage_bio_submit(REQ_OP_READ, 0, bio);
+ args.bio = do_mpage_readpage(&args);
+ if (args.bio)
+ mpage_bio_submit(REQ_OP_READ, 0, args.bio);
return 0;
}
EXPORT_SYMBOL(mpage_readpage);
git.samba.org / sfrench / cifs-2.6.git / blobdiff