For the subpagesize-blocksize scenario, a page can contain multiple blocks. In such cases, this patch handles reading data from files.
To track the status of individual blocks of a page, this patch makes use of a bitmap pointed to by page->private. Signed-off-by: Chandan Rajendra <[email protected]> --- fs/btrfs/extent_io.c | 301 +++++++++++++++++++++++++++++++++------------------ fs/btrfs/extent_io.h | 28 ++++- fs/btrfs/inode.c | 13 +-- 3 files changed, 224 insertions(+), 118 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 782f3bc..d37badb 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -1325,6 +1325,88 @@ int clear_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end, cached_state, mask); } +static int modify_page_blks_state(struct page *page, + unsigned long blk_states, + u64 start, u64 end, int set) +{ + struct inode *inode = page->mapping->host; + unsigned long *bitmap; + unsigned long state; + u64 nr_blks; + u64 blk; + + BUG_ON(!PagePrivate(page)); + + bitmap = ((struct btrfs_page_private *)page->private)->bstate; + + blk = (start & (PAGE_CACHE_SIZE - 1)) >> inode->i_blkbits; + nr_blks = (end - start + 1) >> inode->i_blkbits; + + while (nr_blks--) { + state = find_next_bit(&blk_states, BLK_NR_STATE, 0); + + while (state < BLK_NR_STATE) { + if (set) + set_bit((blk * BLK_NR_STATE) + state, bitmap); + else + clear_bit((blk * BLK_NR_STATE) + state, bitmap); + + state = find_next_bit(&blk_states, BLK_NR_STATE, + state + 1); + } + + ++blk; + } + + return 0; +} + +int set_page_blks_state(struct page *page, unsigned long blk_states, + u64 start, u64 end) +{ + return modify_page_blks_state(page, blk_states, start, end, 1); +} + +int clear_page_blks_state(struct page *page, unsigned long blk_states, + u64 start, u64 end) +{ + return modify_page_blks_state(page, blk_states, start, end, 0); +} + +int test_page_blks_state(struct page *page, enum blk_state blk_state, + u64 start, u64 end, int check_all) +{ + struct inode *inode = page->mapping->host; + unsigned long *bitmap; + unsigned long blk; + u64 nr_blks; + int found = 0; + + BUG_ON(!PagePrivate(page)); + + bitmap = ((struct btrfs_page_private *)page->private)->bstate; + + blk = (start & (PAGE_CACHE_SIZE - 1)) >> inode->i_blkbits; + nr_blks = (end - start + 1) >> inode->i_blkbits; + + while (nr_blks--) { + if (test_bit((blk * BLK_NR_STATE) + blk_state, bitmap)) { + if (!check_all) + return 1; + found = 1; + } else if (check_all) { + return 0; + } + + ++blk; + } + + if (!check_all && !found) + return 0; + + return 1; +} + /* * either insert or lock state struct between start and end use mask to tell * us if waiting is desired. @@ -1982,14 +2064,22 @@ int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end, * helper function to set a given page up to date if all the * extents in the tree for that page are up to date */ -static void check_page_uptodate(struct extent_io_tree *tree, struct page *page) +static void check_page_uptodate(struct page *page) { u64 start = page_offset(page); u64 end = start + PAGE_CACHE_SIZE - 1; - if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL)) + if (test_page_blks_state(page, BLK_STATE_UPTODATE, start, end, 1)) SetPageUptodate(page); } +static int page_read_complete(struct page *page) +{ + u64 start = page_offset(page); + u64 end = start + PAGE_CACHE_SIZE - 1; + + return !test_page_blks_state(page, BLK_STATE_IO, start, end, 0); +} + int free_io_failure(struct inode *inode, struct io_failure_record *rec) { int ret; @@ -2311,7 +2401,9 @@ int btrfs_check_repairable(struct inode *inode, struct bio *failed_bio, * a) deliver good data to the caller * b) correct the bad sectors on disk */ - if (failed_bio->bi_vcnt > 1) { + if ((failed_bio->bi_vcnt > 1) + || (failed_bio->bi_io_vec->bv_len + > BTRFS_I(inode)->root->sectorsize)) { /* * to fulfill b), we need to know the exact failing sectors, as * we don't want to rewrite any more than the failed ones. thus, @@ -2520,18 +2612,6 @@ static void end_bio_extent_writepage(struct bio *bio, int err) bio_put(bio); } -static void -endio_readpage_release_extent(struct extent_io_tree *tree, u64 start, u64 len, - int uptodate) -{ - struct extent_state *cached = NULL; - u64 end = start + len - 1; - - if (uptodate && tree->track_uptodate) - set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC); - unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC); -} - /* * after a readpage IO is done, we need to: * clear the uptodate bits on error @@ -2548,14 +2628,16 @@ static void end_bio_extent_readpage(struct bio *bio, int err) struct bio_vec *bvec; int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); struct btrfs_io_bio *io_bio = btrfs_io_bio(bio); + struct extent_state *cached = NULL; + struct btrfs_page_private *pg_private; struct extent_io_tree *tree; + unsigned long flags; u64 offset = 0; u64 start; u64 end; - u64 len; - u64 extent_start = 0; - u64 extent_len = 0; + int nr_sectors; int mirror; + int unlock; int ret; int i; @@ -2565,54 +2647,31 @@ static void end_bio_extent_readpage(struct bio *bio, int err) bio_for_each_segment_all(bvec, bio, i) { struct page *page = bvec->bv_page; struct inode *inode = page->mapping->host; + struct btrfs_root *root = BTRFS_I(inode)->root; pr_debug("end_bio_extent_readpage: bi_sector=%llu, err=%d, " "mirror=%u\n", (u64)bio->bi_iter.bi_sector, err, io_bio->mirror_num); tree = &BTRFS_I(inode)->io_tree; - /* We always issue full-page reads, but if some block - * in a page fails to read, blk_update_request() will - * advance bv_offset and adjust bv_len to compensate. - * Print a warning for nonzero offsets, and an error - * if they don't add up to a full page. */ - if (bvec->bv_offset || bvec->bv_len != PAGE_CACHE_SIZE) { - if (bvec->bv_offset + bvec->bv_len != PAGE_CACHE_SIZE) - btrfs_err(BTRFS_I(page->mapping->host)->root->fs_info, - "partial page read in btrfs with offset %u and length %u", - bvec->bv_offset, bvec->bv_len); - else - btrfs_info(BTRFS_I(page->mapping->host)->root->fs_info, - "incomplete page read in btrfs with offset %u and " - "length %u", - bvec->bv_offset, bvec->bv_len); - } - - start = page_offset(page); - end = start + bvec->bv_offset + bvec->bv_len - 1; - len = bvec->bv_len; - + start = page_offset(page) + bvec->bv_offset; + end = start + bvec->bv_len - 1; + nr_sectors = bvec->bv_len >> inode->i_sb->s_blocksize_bits; mirror = io_bio->mirror_num; - if (likely(uptodate && tree->ops && - tree->ops->readpage_end_io_hook)) { + +next_block: + if (likely(uptodate)) { ret = tree->ops->readpage_end_io_hook(io_bio, offset, - page, start, end, - mirror); + page, start, + start + root->sectorsize - 1, + mirror); if (ret) uptodate = 0; else clean_io_failure(inode, start, page, 0); } - if (likely(uptodate)) - goto readpage_ok; - - if (tree->ops && tree->ops->readpage_io_failed_hook) { - ret = tree->ops->readpage_io_failed_hook(page, mirror); - if (!ret && !err && - test_bit(BIO_UPTODATE, &bio->bi_flags)) - uptodate = 1; - } else { + if (!uptodate) { /* * The generic bio_readpage_error handles errors the * following way: If possible, new read requests are @@ -2623,61 +2682,63 @@ static void end_bio_extent_readpage(struct bio *bio, int err) * can't handle the error it will return -EIO and we * remain responsible for that page. */ - ret = bio_readpage_error(bio, offset, page, start, end, - mirror); + ret = bio_readpage_error(bio, offset, page, + start, start + root->sectorsize - 1, + mirror); if (ret == 0) { - uptodate = - test_bit(BIO_UPTODATE, &bio->bi_flags); + uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); if (err) uptodate = 0; - offset += len; - continue; + offset += root->sectorsize; + if (--nr_sectors) { + start += root->sectorsize; + goto next_block; + } else { + continue; + } } } -readpage_ok: - if (likely(uptodate)) { - loff_t i_size = i_size_read(inode); - pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT; - unsigned off; - - /* Zero out the end if this page straddles i_size */ - off = i_size & (PAGE_CACHE_SIZE-1); - if (page->index == end_index && off) - zero_user_segment(page, off, PAGE_CACHE_SIZE); - SetPageUptodate(page); + + if (uptodate) { + set_page_blks_state(page, 1 << BLK_STATE_UPTODATE, start, + start + root->sectorsize - 1); + check_page_uptodate(page); } else { ClearPageUptodate(page); SetPageError(page); } - unlock_page(page); - offset += len; - - if (unlikely(!uptodate)) { - if (extent_len) { - endio_readpage_release_extent(tree, - extent_start, - extent_len, 1); - extent_start = 0; - extent_len = 0; - } - endio_readpage_release_extent(tree, start, - end - start + 1, 0); - } else if (!extent_len) { - extent_start = start; - extent_len = end + 1 - start; - } else if (extent_start + extent_len == start) { - extent_len += end + 1 - start; - } else { - endio_readpage_release_extent(tree, extent_start, - extent_len, uptodate); - extent_start = start; - extent_len = end + 1 - start; + + offset += root->sectorsize; + + if (--nr_sectors) { + clear_page_blks_state(page, 1 << BLK_STATE_IO, + start, start + root->sectorsize - 1); + clear_extent_bit(tree, start, start + root->sectorsize - 1, + EXTENT_LOCKED, 1, 0, &cached, GFP_ATOMIC); + start += root->sectorsize; + goto next_block; } + + WARN_ON(!PagePrivate(page)); + + pg_private = (struct btrfs_page_private *)page->private; + + spin_lock_irqsave(&pg_private->io_lock, flags); + + clear_page_blks_state(page, 1 << BLK_STATE_IO, + start, start + root->sectorsize - 1); + + unlock = page_read_complete(page); + + spin_unlock_irqrestore(&pg_private->io_lock, flags); + + clear_extent_bit(tree, start, start + root->sectorsize - 1, + EXTENT_LOCKED, 1, 0, &cached, GFP_ATOMIC); + + if (unlock) + unlock_page(page); } - if (extent_len) - endio_readpage_release_extent(tree, extent_start, extent_len, - uptodate); if (io_bio->end_io) io_bio->end_io(io_bio, err); bio_put(bio); @@ -2859,13 +2920,36 @@ static void attach_extent_buffer_page(struct extent_buffer *eb, } } -void set_page_extent_mapped(struct page *page) +int set_page_extent_mapped(struct page *page) { + struct btrfs_page_private *pg_private; + if (!PagePrivate(page)) { + pg_private = kzalloc(sizeof(*pg_private), GFP_NOFS); + if (!pg_private) + return -ENOMEM; + + spin_lock_init(&pg_private->io_lock); + SetPagePrivate(page); page_cache_get(page); - set_page_private(page, EXTENT_PAGE_PRIVATE); + + set_page_private(page, (unsigned long)pg_private); + } + + return 0; +} + +int clear_page_extent_mapped(struct page *page) +{ + if (PagePrivate(page)) { + kfree((struct btrfs_page_private *)(page->private)); + ClearPagePrivate(page); + set_page_private(page, 0); + page_cache_release(page); } + + return 0; } static struct extent_map * @@ -2909,6 +2993,7 @@ static int __do_readpage(struct extent_io_tree *tree, unsigned long *bio_flags, int rw) { struct inode *inode = page->mapping->host; + struct extent_state *cached = NULL; u64 start = page_offset(page); u64 page_end = start + PAGE_CACHE_SIZE - 1; u64 end; @@ -2964,8 +3049,8 @@ static int __do_readpage(struct extent_io_tree *tree, memset(userpage + pg_offset, 0, iosize); flush_dcache_page(page); kunmap_atomic(userpage); - set_extent_uptodate(tree, cur, cur + iosize - 1, - &cached, GFP_NOFS); + set_page_blks_state(page, 1 << BLK_STATE_UPTODATE, cur, + cur + iosize - 1); if (!parent_locked) unlock_extent_cached(tree, cur, cur + iosize - 1, @@ -3017,8 +3102,8 @@ static int __do_readpage(struct extent_io_tree *tree, flush_dcache_page(page); kunmap_atomic(userpage); - set_extent_uptodate(tree, cur, cur + iosize - 1, - &cached, GFP_NOFS); + set_page_blks_state(page, 1 << BLK_STATE_UPTODATE, cur, + cur + iosize - 1); unlock_extent_cached(tree, cur, cur + iosize - 1, &cached, GFP_NOFS); cur = cur + iosize; @@ -3026,9 +3111,9 @@ static int __do_readpage(struct extent_io_tree *tree, continue; } /* the get_extent function already copied into the page */ - if (test_range_bit(tree, cur, cur_end, - EXTENT_UPTODATE, 1, NULL)) { - check_page_uptodate(tree, page); + if (test_page_blks_state(page, BLK_STATE_UPTODATE, cur, + cur_end, 1)) { + check_page_uptodate(page); if (!parent_locked) unlock_extent(tree, cur, cur + iosize - 1); cur = cur + iosize; @@ -3048,6 +3133,9 @@ static int __do_readpage(struct extent_io_tree *tree, } pnr -= page->index; + + set_page_blks_state(page, 1 << BLK_STATE_IO, cur, + cur + iosize - 1); ret = submit_extent_page(rw, tree, page, sector, disk_io_size, pg_offset, bdev, bio, pnr, @@ -3059,8 +3147,11 @@ static int __do_readpage(struct extent_io_tree *tree, *bio_flags = this_bio_flag; } else { SetPageError(page); + clear_page_blks_state(page, 1 << BLK_STATE_IO, cur, + cur + iosize - 1); if (!parent_locked) - unlock_extent(tree, cur, cur + iosize - 1); + unlock_extent_cached(tree, cur, cur + iosize - 1, + &cached, GFP_NOFS); } cur = cur + iosize; pg_offset += iosize; diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index c668f36..541b40a 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -51,11 +51,22 @@ #define PAGE_SET_PRIVATE2 (1 << 4) #define PAGE_SET_ERROR (1 << 5) +enum blk_state { + BLK_STATE_UPTODATE, + BLK_STATE_DIRTY, + BLK_STATE_IO, + BLK_NR_STATE, +}; + /* - * page->private values. Every page that is controlled by the extent - * map has page->private set to one. - */ -#define EXTENT_PAGE_PRIVATE 1 + The maximum number of blocks per page (i.e. 32) occurs when using 2k + as the block size and having 64k as the page size. +*/ +#define BLK_STATE_NR_LONGS DIV_ROUND_UP(BLK_NR_STATE * 32, BITS_PER_LONG) +struct btrfs_page_private { + spinlock_t io_lock; + unsigned long bstate[BLK_STATE_NR_LONGS]; +}; struct extent_state; struct btrfs_root; @@ -259,7 +270,14 @@ int extent_readpages(struct extent_io_tree *tree, int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, __u64 start, __u64 len, get_extent_t *get_extent); int get_state_private(struct extent_io_tree *tree, u64 start, u64 *private); -void set_page_extent_mapped(struct page *page); +int set_page_extent_mapped(struct page *page); +int clear_page_extent_mapped(struct page *page); +int set_page_blks_state(struct page *page, unsigned long blk_states, + u64 start, u64 end); +int clear_page_blks_state(struct page *page, unsigned long blk_states, + u64 start, u64 end); +int test_page_blks_state(struct page *page, enum blk_state blk_state, + u64 start, u64 end, int check_all); struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start); diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 0020b56..8262f83 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -6622,7 +6622,6 @@ struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page, struct btrfs_key found_key; struct extent_map *em = NULL; struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; - struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct btrfs_trans_handle *trans = NULL; const bool new_inline = !page || create; @@ -6800,8 +6799,8 @@ next: kunmap(page); btrfs_mark_buffer_dirty(leaf); } - set_extent_uptodate(io_tree, em->start, - extent_map_end(em) - 1, NULL, GFP_NOFS); + set_page_blks_state(page, 1 << BLK_STATE_UPTODATE, em->start, + extent_map_end(em) - 1); goto insert; } not_found: @@ -8392,11 +8391,9 @@ static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags) tree = &BTRFS_I(page->mapping->host)->io_tree; map = &BTRFS_I(page->mapping->host)->extent_tree; ret = try_release_extent_mapping(map, tree, page, gfp_flags); - if (ret == 1) { - ClearPagePrivate(page); - set_page_private(page, 0); - page_cache_release(page); - } + if (ret == 1) + clear_page_extent_mapped(page); + return ret; } -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
