Merge tag 'docs-4.9' of git://git.lwn.net/linux
[cascardo/linux.git] / fs / btrfs / extent_io.c
index aaee3ef..44fe66b 100644 (file)
@@ -163,13 +163,13 @@ int __init extent_io_init(void)
 {
        extent_state_cache = kmem_cache_create("btrfs_extent_state",
                        sizeof(struct extent_state), 0,
-                       SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
+                       SLAB_MEM_SPREAD, NULL);
        if (!extent_state_cache)
                return -ENOMEM;
 
        extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
                        sizeof(struct extent_buffer), 0,
-                       SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
+                       SLAB_MEM_SPREAD, NULL);
        if (!extent_buffer_cache)
                goto free_state_cache;
 
@@ -2049,9 +2049,10 @@ int repair_io_failure(struct inode *inode, u64 start, u64 length, u64 logical,
                return -EIO;
        }
        bio->bi_bdev = dev->bdev;
+       bio_set_op_attrs(bio, REQ_OP_WRITE, WRITE_SYNC);
        bio_add_page(bio, page, length, pg_offset);
 
-       if (btrfsic_submit_bio_wait(WRITE_SYNC, bio)) {
+       if (btrfsic_submit_bio_wait(bio)) {
                /* try to remap that extent elsewhere? */
                btrfs_bio_counter_dec(fs_info);
                bio_put(bio);
@@ -2386,7 +2387,7 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
        int read_mode;
        int ret;
 
-       BUG_ON(failed_bio->bi_rw & REQ_WRITE);
+       BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
 
        ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
        if (ret)
@@ -2412,12 +2413,12 @@ static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
                free_io_failure(inode, failrec);
                return -EIO;
        }
+       bio_set_op_attrs(bio, REQ_OP_READ, read_mode);
 
        pr_debug("Repair Read Error: submitting new read[%#x] to this_mirror=%d, in_validation=%d\n",
                 read_mode, failrec->this_mirror, failrec->in_validation);
 
-       ret = tree->ops->submit_bio_hook(inode, read_mode, bio,
-                                        failrec->this_mirror,
+       ret = tree->ops->submit_bio_hook(inode, bio, failrec->this_mirror,
                                         failrec->bio_flags, 0);
        if (ret) {
                free_io_failure(inode, failrec);
@@ -2696,12 +2697,6 @@ struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask)
                btrfs_bio->csum = NULL;
                btrfs_bio->csum_allocated = NULL;
                btrfs_bio->end_io = NULL;
-
-#ifdef CONFIG_BLK_CGROUP
-               /* FIXME, put this into bio_clone_bioset */
-               if (bio->bi_css)
-                       bio_associate_blkcg(new, bio->bi_css);
-#endif
        }
        return new;
 }
@@ -2723,8 +2718,8 @@ struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
 }
 
 
-static int __must_check submit_one_bio(int rw, struct bio *bio,
-                                      int mirror_num, unsigned long bio_flags)
+static int __must_check submit_one_bio(struct bio *bio, int mirror_num,
+                                      unsigned long bio_flags)
 {
        int ret = 0;
        struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
@@ -2735,33 +2730,31 @@ static int __must_check submit_one_bio(int rw, struct bio *bio,
        start = page_offset(page) + bvec->bv_offset;
 
        bio->bi_private = NULL;
-
        bio_get(bio);
 
        if (tree->ops && tree->ops->submit_bio_hook)
-               ret = tree->ops->submit_bio_hook(page->mapping->host, rw, bio,
+               ret = tree->ops->submit_bio_hook(page->mapping->host, bio,
                                           mirror_num, bio_flags, start);
        else
-               btrfsic_submit_bio(rw, bio);
+               btrfsic_submit_bio(bio);
 
        bio_put(bio);
        return ret;
 }
 
-static int merge_bio(int rw, struct extent_io_tree *tree, struct page *page,
+static int merge_bio(struct extent_io_tree *tree, struct page *page,
                     unsigned long offset, size_t size, struct bio *bio,
                     unsigned long bio_flags)
 {
        int ret = 0;
        if (tree->ops && tree->ops->merge_bio_hook)
-               ret = tree->ops->merge_bio_hook(rw, page, offset, size, bio,
+               ret = tree->ops->merge_bio_hook(page, offset, size, bio,
                                                bio_flags);
-       BUG_ON(ret < 0);
        return ret;
 
 }
 
-static int submit_extent_page(int rw, struct extent_io_tree *tree,
+static int submit_extent_page(int op, int op_flags, struct extent_io_tree *tree,
                              struct writeback_control *wbc,
                              struct page *page, sector_t sector,
                              size_t size, unsigned long offset,
@@ -2789,10 +2782,9 @@ static int submit_extent_page(int rw, struct extent_io_tree *tree,
 
                if (prev_bio_flags != bio_flags || !contig ||
                    force_bio_submit ||
-                   merge_bio(rw, tree, page, offset, page_size, bio, bio_flags) ||
+                   merge_bio(tree, page, offset, page_size, bio, bio_flags) ||
                    bio_add_page(bio, page, page_size, offset) < page_size) {
-                       ret = submit_one_bio(rw, bio, mirror_num,
-                                            prev_bio_flags);
+                       ret = submit_one_bio(bio, mirror_num, prev_bio_flags);
                        if (ret < 0) {
                                *bio_ret = NULL;
                                return ret;
@@ -2813,6 +2805,7 @@ static int submit_extent_page(int rw, struct extent_io_tree *tree,
        bio_add_page(bio, page, page_size, offset);
        bio->bi_end_io = end_io_func;
        bio->bi_private = tree;
+       bio_set_op_attrs(bio, op, op_flags);
        if (wbc) {
                wbc_init_bio(wbc, bio);
                wbc_account_io(wbc, page, page_size);
@@ -2821,7 +2814,7 @@ static int submit_extent_page(int rw, struct extent_io_tree *tree,
        if (bio_ret)
                *bio_ret = bio;
        else
-               ret = submit_one_bio(rw, bio, mirror_num, bio_flags);
+               ret = submit_one_bio(bio, mirror_num, bio_flags);
 
        return ret;
 }
@@ -2879,13 +2872,14 @@ __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
  * into the tree that are removed when the IO is done (by the end_io
  * handlers)
  * XXX JDM: This needs looking at to ensure proper page locking
+ * return 0 on success, otherwise return error
  */
 static int __do_readpage(struct extent_io_tree *tree,
                         struct page *page,
                         get_extent_t *get_extent,
                         struct extent_map **em_cached,
                         struct bio **bio, int mirror_num,
-                        unsigned long *bio_flags, int rw,
+                        unsigned long *bio_flags, int read_flags,
                         u64 *prev_em_start)
 {
        struct inode *inode = page->mapping->host;
@@ -2900,7 +2894,7 @@ static int __do_readpage(struct extent_io_tree *tree,
        sector_t sector;
        struct extent_map *em;
        struct block_device *bdev;
-       int ret;
+       int ret = 0;
        int nr = 0;
        size_t pg_offset = 0;
        size_t iosize;
@@ -3068,8 +3062,8 @@ static int __do_readpage(struct extent_io_tree *tree,
                }
 
                pnr -= page->index;
-               ret = submit_extent_page(rw, tree, NULL, page,
-                                        sector, disk_io_size, pg_offset,
+               ret = submit_extent_page(REQ_OP_READ, read_flags, tree, NULL,
+                                        page, sector, disk_io_size, pg_offset,
                                         bdev, bio, pnr,
                                         end_bio_extent_readpage, mirror_num,
                                         *bio_flags,
@@ -3081,6 +3075,7 @@ static int __do_readpage(struct extent_io_tree *tree,
                } else {
                        SetPageError(page);
                        unlock_extent(tree, cur, cur + iosize - 1);
+                       goto out;
                }
                cur = cur + iosize;
                pg_offset += iosize;
@@ -3091,7 +3086,7 @@ out:
                        SetPageUptodate(page);
                unlock_page(page);
        }
-       return 0;
+       return ret;
 }
 
 static inline void __do_contiguous_readpages(struct extent_io_tree *tree,
@@ -3100,7 +3095,7 @@ static inline void __do_contiguous_readpages(struct extent_io_tree *tree,
                                             get_extent_t *get_extent,
                                             struct extent_map **em_cached,
                                             struct bio **bio, int mirror_num,
-                                            unsigned long *bio_flags, int rw,
+                                            unsigned long *bio_flags,
                                             u64 *prev_em_start)
 {
        struct inode *inode;
@@ -3121,7 +3116,7 @@ static inline void __do_contiguous_readpages(struct extent_io_tree *tree,
 
        for (index = 0; index < nr_pages; index++) {
                __do_readpage(tree, pages[index], get_extent, em_cached, bio,
-                             mirror_num, bio_flags, rw, prev_em_start);
+                             mirror_num, bio_flags, 0, prev_em_start);
                put_page(pages[index]);
        }
 }
@@ -3131,7 +3126,7 @@ static void __extent_readpages(struct extent_io_tree *tree,
                               int nr_pages, get_extent_t *get_extent,
                               struct extent_map **em_cached,
                               struct bio **bio, int mirror_num,
-                              unsigned long *bio_flags, int rw,
+                              unsigned long *bio_flags,
                               u64 *prev_em_start)
 {
        u64 start = 0;
@@ -3153,7 +3148,7 @@ static void __extent_readpages(struct extent_io_tree *tree,
                                                  index - first_index, start,
                                                  end, get_extent, em_cached,
                                                  bio, mirror_num, bio_flags,
-                                                 rw, prev_em_start);
+                                                 prev_em_start);
                        start = page_start;
                        end = start + PAGE_SIZE - 1;
                        first_index = index;
@@ -3164,7 +3159,7 @@ static void __extent_readpages(struct extent_io_tree *tree,
                __do_contiguous_readpages(tree, &pages[first_index],
                                          index - first_index, start,
                                          end, get_extent, em_cached, bio,
-                                         mirror_num, bio_flags, rw,
+                                         mirror_num, bio_flags,
                                          prev_em_start);
 }
 
@@ -3172,7 +3167,7 @@ static int __extent_read_full_page(struct extent_io_tree *tree,
                                   struct page *page,
                                   get_extent_t *get_extent,
                                   struct bio **bio, int mirror_num,
-                                  unsigned long *bio_flags, int rw)
+                                  unsigned long *bio_flags, int read_flags)
 {
        struct inode *inode = page->mapping->host;
        struct btrfs_ordered_extent *ordered;
@@ -3192,7 +3187,7 @@ static int __extent_read_full_page(struct extent_io_tree *tree,
        }
 
        ret = __do_readpage(tree, page, get_extent, NULL, bio, mirror_num,
-                           bio_flags, rw, NULL);
+                           bio_flags, read_flags, NULL);
        return ret;
 }
 
@@ -3204,9 +3199,9 @@ int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
        int ret;
 
        ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num,
-                                     &bio_flags, READ);
+                                     &bio_flags, 0);
        if (bio)
-               ret = submit_one_bio(READ, bio, mirror_num, bio_flags);
+               ret = submit_one_bio(bio, mirror_num, bio_flags);
        return ret;
 }
 
@@ -3440,8 +3435,8 @@ static noinline_for_stack int __extent_writepage_io(struct inode *inode,
                               page->index, cur, end);
                }
 
-               ret = submit_extent_page(write_flags, tree, wbc, page,
-                                        sector, iosize, pg_offset,
+               ret = submit_extent_page(REQ_OP_WRITE, write_flags, tree, wbc,
+                                        page, sector, iosize, pg_offset,
                                         bdev, &epd->bio, max_nr,
                                         end_bio_extent_writepage,
                                         0, 0, 0, false);
@@ -3480,13 +3475,11 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
        size_t pg_offset = 0;
        loff_t i_size = i_size_read(inode);
        unsigned long end_index = i_size >> PAGE_SHIFT;
-       int write_flags;
+       int write_flags = 0;
        unsigned long nr_written = 0;
 
        if (wbc->sync_mode == WB_SYNC_ALL)
                write_flags = WRITE_SYNC;
-       else
-               write_flags = WRITE;
 
        trace___extent_writepage(page, inode, wbc);
 
@@ -3730,7 +3723,7 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
        u64 offset = eb->start;
        unsigned long i, num_pages;
        unsigned long bio_flags = 0;
-       int rw = (epd->sync_io ? WRITE_SYNC : WRITE) | REQ_META;
+       int write_flags = (epd->sync_io ? WRITE_SYNC : 0) | REQ_META;
        int ret = 0;
 
        clear_bit(EXTENT_BUFFER_WRITE_ERR, &eb->bflags);
@@ -3744,9 +3737,10 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb,
 
                clear_page_dirty_for_io(p);
                set_page_writeback(p);
-               ret = submit_extent_page(rw, tree, wbc, p, offset >> 9,
-                                        PAGE_SIZE, 0, bdev, &epd->bio,
-                                        -1, end_bio_extent_buffer_writepage,
+               ret = submit_extent_page(REQ_OP_WRITE, write_flags, tree, wbc,
+                                        p, offset >> 9, PAGE_SIZE, 0, bdev,
+                                        &epd->bio, -1,
+                                        end_bio_extent_buffer_writepage,
                                         0, epd->bio_flags, bio_flags, false);
                epd->bio_flags = bio_flags;
                if (ret) {
@@ -4056,13 +4050,12 @@ retry:
 static void flush_epd_write_bio(struct extent_page_data *epd)
 {
        if (epd->bio) {
-               int rw = WRITE;
                int ret;
 
-               if (epd->sync_io)
-                       rw = WRITE_SYNC;
+               bio_set_op_attrs(epd->bio, REQ_OP_WRITE,
+                                epd->sync_io ? WRITE_SYNC : 0);
 
-               ret = submit_one_bio(rw, epd->bio, 0, epd->bio_flags);
+               ret = submit_one_bio(epd->bio, 0, epd->bio_flags);
                BUG_ON(ret < 0); /* -ENOMEM */
                epd->bio = NULL;
        }
@@ -4180,7 +4173,8 @@ int extent_readpages(struct extent_io_tree *tree,
                prefetchw(&page->flags);
                list_del(&page->lru);
                if (add_to_page_cache_lru(page, mapping,
-                                       page->index, GFP_NOFS)) {
+                                       page->index,
+                                       readahead_gfp_mask(mapping))) {
                        put_page(page);
                        continue;
                }
@@ -4189,19 +4183,19 @@ int extent_readpages(struct extent_io_tree *tree,
                if (nr < ARRAY_SIZE(pagepool))
                        continue;
                __extent_readpages(tree, pagepool, nr, get_extent, &em_cached,
-                                  &bio, 0, &bio_flags, READ, &prev_em_start);
+                                  &bio, 0, &bio_flags, &prev_em_start);
                nr = 0;
        }
        if (nr)
                __extent_readpages(tree, pagepool, nr, get_extent, &em_cached,
-                                  &bio, 0, &bio_flags, READ, &prev_em_start);
+                                  &bio, 0, &bio_flags, &prev_em_start);
 
        if (em_cached)
                free_extent_map(em_cached);
 
        BUG_ON(!list_empty(pages));
        if (bio)
-               return submit_one_bio(READ, bio, 0, bio_flags);
+               return submit_one_bio(bio, 0, bio_flags);
        return 0;
 }
 
@@ -5231,22 +5225,38 @@ int read_extent_buffer_pages(struct extent_io_tree *tree,
        atomic_set(&eb->io_pages, num_reads);
        for (i = start_i; i < num_pages; i++) {
                page = eb->pages[i];
+
                if (!PageUptodate(page)) {
+                       if (ret) {
+                               atomic_dec(&eb->io_pages);
+                               unlock_page(page);
+                               continue;
+                       }
+
                        ClearPageError(page);
                        err = __extent_read_full_page(tree, page,
                                                      get_extent, &bio,
                                                      mirror_num, &bio_flags,
-                                                     READ | REQ_META);
-                       if (err)
+                                                     REQ_META);
+                       if (err) {
                                ret = err;
+                               /*
+                                * We use &bio in above __extent_read_full_page,
+                                * so we ensure that if it returns error, the
+                                * current page fails to add itself to bio and
+                                * it's been unlocked.
+                                *
+                                * We must dec io_pages by ourselves.
+                                */
+                               atomic_dec(&eb->io_pages);
+                       }
                } else {
                        unlock_page(page);
                }
        }
 
        if (bio) {
-               err = submit_one_bio(READ | REQ_META, bio, mirror_num,
-                                    bio_flags);
+               err = submit_one_bio(bio, mirror_num, bio_flags);
                if (err)
                        return err;
        }
@@ -5342,6 +5352,11 @@ int read_extent_buffer_to_user(struct extent_buffer *eb, void __user *dstv,
        return ret;
 }
 
+/*
+ * return 0 if the item is found within a page.
+ * return 1 if the item spans two pages.
+ * return -EINVAL otherwise.
+ */
 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
                               unsigned long min_len, char **map,
                               unsigned long *map_start,
@@ -5356,7 +5371,7 @@ int map_private_extent_buffer(struct extent_buffer *eb, unsigned long start,
                PAGE_SHIFT;
 
        if (i != end_i)
-               return -EINVAL;
+               return 1;
 
        if (i == 0) {
                offset = start_offset;