From 6da6abae027e2dbc59bca5f4168b0760f25068c7 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Tue, 18 Dec 2007 16:15:09 -0500 Subject: Btrfs: Back port to 2.6.18-el kernels Signed-off-by: Chris Mason --- fs/btrfs/extent_map.c | 168 +++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 160 insertions(+), 8 deletions(-) (limited to 'fs/btrfs/extent_map.c') diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c index 8326a18413f..0d1e59a86e4 100644 --- a/fs/btrfs/extent_map.c +++ b/fs/btrfs/extent_map.c @@ -1585,8 +1585,18 @@ extent_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs, static int submit_one_bio(int rw, struct bio *bio) { + u64 maxsector; int ret = 0; + bio_get(bio); + + maxsector = bio->bi_bdev->bd_inode->i_size >> 9; + if (maxsector < bio->bi_sector) { + printk("sector too large max %Lu got %llu\n", maxsector, + (unsigned long long)bio->bi_sector); + WARN_ON(1); + } + submit_bio(rw, bio); if (bio_flagged(bio, BIO_EOPNOTSUPP)) ret = -EOPNOTSUPP; @@ -1678,8 +1688,12 @@ static int __extent_read_full_page(struct extent_map_tree *tree, while (cur <= end) { if (cur >= last_byte) { + char *userpage; iosize = PAGE_CACHE_SIZE - page_offset; - zero_user_page(page, page_offset, iosize, KM_USER0); + userpage = kmap_atomic(page, KM_USER0); + memset(userpage + page_offset, 0, iosize); + flush_dcache_page(page); + kunmap_atomic(userpage, KM_USER0); set_extent_uptodate(tree, cur, cur + iosize - 1, GFP_NOFS); unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); @@ -1707,7 +1721,12 @@ static int __extent_read_full_page(struct extent_map_tree *tree, /* we've found a hole, just zero and go on */ if (block_start == EXTENT_MAP_HOLE) { - zero_user_page(page, page_offset, iosize, KM_USER0); + char *userpage; + userpage = kmap_atomic(page, KM_USER0); + memset(userpage + page_offset, 0, iosize); + flush_dcache_page(page); + kunmap_atomic(userpage, KM_USER0); + set_extent_uptodate(tree, cur, cur + iosize - 1, GFP_NOFS); unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); @@ -1804,9 +1823,14 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc, } if (page->index == end_index) { + char *userpage; + size_t offset = i_size & (PAGE_CACHE_SIZE - 1); - zero_user_page(page, offset, - PAGE_CACHE_SIZE - offset, KM_USER0); + + userpage = kmap_atomic(page, KM_USER0); + memset(userpage + offset, 0, PAGE_CACHE_SIZE - offset); + flush_dcache_page(page); + kunmap_atomic(userpage, KM_USER0); } set_page_extent_mapped(page); @@ -1921,6 +1945,129 @@ done: return 0; } +#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18) + +/* Taken directly from 2.6.23 for 2.6.18 back port */ +typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc, + void *data); + +/** + * write_cache_pages - walk the list of dirty pages of the given address space + * and write all of them. + * @mapping: address space structure to write + * @wbc: subtract the number of written pages from *@wbc->nr_to_write + * @writepage: function called for each page + * @data: data passed to writepage function + * + * If a page is already under I/O, write_cache_pages() skips it, even + * if it's dirty. This is desirable behaviour for memory-cleaning writeback, + * but it is INCORRECT for data-integrity system calls such as fsync(). fsync() + * and msync() need to guarantee that all the data which was dirty at the time + * the call was made get new I/O started against them. If wbc->sync_mode is + * WB_SYNC_ALL then we were called for data integrity and we must wait for + * existing IO to complete. + */ +static int write_cache_pages(struct address_space *mapping, + struct writeback_control *wbc, writepage_t writepage, + void *data) +{ + struct backing_dev_info *bdi = mapping->backing_dev_info; + int ret = 0; + int done = 0; + struct pagevec pvec; + int nr_pages; + pgoff_t index; + pgoff_t end; /* Inclusive */ + int scanned = 0; + int range_whole = 0; + + if (wbc->nonblocking && bdi_write_congested(bdi)) { + wbc->encountered_congestion = 1; + return 0; + } + + pagevec_init(&pvec, 0); + if (wbc->range_cyclic) { + index = mapping->writeback_index; /* Start from prev offset */ + end = -1; + } else { + index = wbc->range_start >> PAGE_CACHE_SHIFT; + end = wbc->range_end >> PAGE_CACHE_SHIFT; + if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) + range_whole = 1; + scanned = 1; + } +retry: + while (!done && (index <= end) && + (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, + PAGECACHE_TAG_DIRTY, + min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) { + unsigned i; + + scanned = 1; + for (i = 0; i < nr_pages; i++) { + struct page *page = pvec.pages[i]; + + /* + * At this point we hold neither mapping->tree_lock nor + * lock on the page itself: the page may be truncated or + * invalidated (changing page->mapping to NULL), or even + * swizzled back from swapper_space to tmpfs file + * mapping + */ + lock_page(page); + + if (unlikely(page->mapping != mapping)) { + unlock_page(page); + continue; + } + + if (!wbc->range_cyclic && page->index > end) { + done = 1; + unlock_page(page); + continue; + } + + if (wbc->sync_mode != WB_SYNC_NONE) + wait_on_page_writeback(page); + + if (PageWriteback(page) || + !clear_page_dirty_for_io(page)) { + unlock_page(page); + continue; + } + + ret = (*writepage)(page, wbc, data); + + if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) { + unlock_page(page); + ret = 0; + } + if (ret || (--(wbc->nr_to_write) <= 0)) + done = 1; + if (wbc->nonblocking && bdi_write_congested(bdi)) { + wbc->encountered_congestion = 1; + done = 1; + } + } + pagevec_release(&pvec); + cond_resched(); + } + if (!scanned && !done) { + /* + * We hit the last page and there is more work to be done: wrap + * back to the start of the file + */ + scanned = 1; + index = 0; + goto retry; + } + if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) + mapping->writeback_index = index; + return ret; +} +#endif + int extent_write_full_page(struct extent_map_tree *tree, struct page *page, get_extent_t *get_extent, struct writeback_control *wbc) @@ -1945,18 +2092,20 @@ int extent_write_full_page(struct extent_map_tree *tree, struct page *page, ret = __extent_writepage(page, wbc, &epd); write_cache_pages(mapping, &wbc_writepages, __extent_writepage, &epd); - if (epd.bio) + if (epd.bio) { submit_one_bio(WRITE, epd.bio); + } return ret; } EXPORT_SYMBOL(extent_write_full_page); + int extent_writepages(struct extent_map_tree *tree, struct address_space *mapping, get_extent_t *get_extent, struct writeback_control *wbc) { - int ret; + int ret = 0; struct extent_page_data epd = { .bio = NULL, .tree = tree, @@ -1964,8 +2113,9 @@ int extent_writepages(struct extent_map_tree *tree, }; ret = write_cache_pages(mapping, wbc, __extent_writepage, &epd); - if (epd.bio) + if (epd.bio) { submit_one_bio(WRITE, epd.bio); + } return ret; } EXPORT_SYMBOL(extent_writepages); @@ -2106,7 +2256,9 @@ int extent_prepare_write(struct extent_map_tree *tree, flush_dcache_page(page); kunmap_atomic(kaddr, KM_USER0); } - if (!isnew && !PageUptodate(page) && + if ((em->block_start != EXTENT_MAP_HOLE && + em->block_start != EXTENT_MAP_INLINE) && + !isnew && !PageUptodate(page) && (block_off_end > to || block_off_start < from) && !test_range_bit(tree, block_start, cur_end, EXTENT_UPTODATE, 1)) { -- cgit v1.2.3