Btrfs: Back port to 2.6.18-el kernels

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 160 insertions, 8 deletions

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 8326a18413ff..0d1e59a86e49 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)) {