}
/*
- * the writepage semantics are similar to regular writepage. extent
- * records are inserted to lock ranges in the tree, and as dirty areas
- * are found, they are marked writeback. Then the lock bits are removed
- * and the end_io handler clears the writeback ranges
+ * helper for __extent_writepage, doing all of the delayed allocation setup.
+ *
+ * This returns 1 if our fill_delalloc function did all the work required
+ * to write the page (copy into inline extent). In this case the IO has
+ * been started and the page is already unlocked.
+ *
+ * This returns 0 if all went well (page still locked)
+ * This returns < 0 if there were errors (page still locked)
*/
-static int __extent_writepage(struct page *page, struct writeback_control *wbc,
- void *data)
+static noinline_for_stack int writepage_delalloc(struct inode *inode,
+ struct page *page, struct writeback_control *wbc,
+ struct extent_page_data *epd,
+ u64 delalloc_start,
+ unsigned long *nr_written)
+{
+ struct extent_io_tree *tree = epd->tree;
+ u64 page_end = delalloc_start + PAGE_CACHE_SIZE - 1;
+ u64 nr_delalloc;
+ u64 delalloc_to_write = 0;
+ u64 delalloc_end = 0;
+ int ret;
+ int page_started = 0;
+
+ if (epd->extent_locked || !tree->ops || !tree->ops->fill_delalloc)
+ return 0;
+
+ while (delalloc_end < page_end) {
+ nr_delalloc = find_lock_delalloc_range(inode, tree,
+ page,
+ &delalloc_start,
+ &delalloc_end,
+ 128 * 1024 * 1024);
+ if (nr_delalloc == 0) {
+ delalloc_start = delalloc_end + 1;
+ continue;
+ }
+ ret = tree->ops->fill_delalloc(inode, page,
+ delalloc_start,
+ delalloc_end,
+ &page_started,
+ nr_written);
+ /* File system has been set read-only */
+ if (ret) {
+ SetPageError(page);
+ /* fill_delalloc should be return < 0 for error
+ * but just in case, we use > 0 here meaning the
+ * IO is started, so we don't want to return > 0
+ * unless things are going well.
+ */
+ ret = ret < 0 ? ret : -EIO;
+ goto done;
+ }
+ /*
+ * delalloc_end is already one less than the total
+ * length, so we don't subtract one from
+ * PAGE_CACHE_SIZE
+ */
+ delalloc_to_write += (delalloc_end - delalloc_start +
+ PAGE_CACHE_SIZE) >>
+ PAGE_CACHE_SHIFT;
+ delalloc_start = delalloc_end + 1;
+ }
+ if (wbc->nr_to_write < delalloc_to_write) {
+ int thresh = 8192;
+
+ if (delalloc_to_write < thresh * 2)
+ thresh = delalloc_to_write;
+ wbc->nr_to_write = min_t(u64, delalloc_to_write,
+ thresh);
+ }
+
+ /* did the fill delalloc function already unlock and start
+ * the IO?
+ */
+ if (page_started) {
+ /*
+ * we've unlocked the page, so we can't update
+ * the mapping's writeback index, just update
+ * nr_to_write.
+ */
+ wbc->nr_to_write -= *nr_written;
+ return 1;
+ }
+
+ ret = 0;
+
+done:
+ return ret;
+}
+
+/*
+ * helper for __extent_writepage. This calls the writepage start hooks,
+ * and does the loop to map the page into extents and bios.
+ *
+ * We return 1 if the IO is started and the page is unlocked,
+ * 0 if all went well (page still locked)
+ * < 0 if there were errors (page still locked)
+ */
+static noinline_for_stack int __extent_writepage_io(struct inode *inode,
+ struct page *page,
+ struct writeback_control *wbc,
+ struct extent_page_data *epd,
+ loff_t i_size,
+ unsigned long nr_written,
+ int write_flags, int *nr_ret)
{
- struct inode *inode = page->mapping->host;
- struct extent_page_data *epd = data;
struct extent_io_tree *tree = epd->tree;
u64 start = page_offset(page);
- u64 delalloc_start;
u64 page_end = start + PAGE_CACHE_SIZE - 1;
u64 end;
u64 cur = start;
u64 extent_offset;
- u64 last_byte = i_size_read(inode);
u64 block_start;
u64 iosize;
sector_t sector;
struct extent_state *cached_state = NULL;
struct extent_map *em;
struct block_device *bdev;
- int ret;
- int nr = 0;
size_t pg_offset = 0;
size_t blocksize;
- loff_t i_size = i_size_read(inode);
- unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
- u64 nr_delalloc;
- u64 delalloc_end;
- int page_started;
- int compressed;
- int write_flags;
- unsigned long nr_written = 0;
- bool fill_delalloc = true;
-
- if (wbc->sync_mode == WB_SYNC_ALL)
- write_flags = WRITE_SYNC;
- else
- write_flags = WRITE;
-
- trace___extent_writepage(page, inode, wbc);
-
- WARN_ON(!PageLocked(page));
-
- ClearPageError(page);
-
- pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
- if (page->index > end_index ||
- (page->index == end_index && !pg_offset)) {
- page->mapping->a_ops->invalidatepage(page, 0, PAGE_CACHE_SIZE);
- unlock_page(page);
- return 0;
- }
-
- if (page->index == end_index) {
- char *userpage;
-
- userpage = kmap_atomic(page);
- memset(userpage + pg_offset, 0,
- PAGE_CACHE_SIZE - pg_offset);
- kunmap_atomic(userpage);
- flush_dcache_page(page);
- }
- pg_offset = 0;
-
- set_page_extent_mapped(page);
-
- if (!tree->ops || !tree->ops->fill_delalloc)
- fill_delalloc = false;
-
- delalloc_start = start;
- delalloc_end = 0;
- page_started = 0;
- if (!epd->extent_locked && fill_delalloc) {
- u64 delalloc_to_write = 0;
- /*
- * make sure the wbc mapping index is at least updated
- * to this page.
- */
- update_nr_written(page, wbc, 0);
-
- while (delalloc_end < page_end) {
- nr_delalloc = find_lock_delalloc_range(inode, tree,
- page,
- &delalloc_start,
- &delalloc_end,
- 128 * 1024 * 1024);
- if (nr_delalloc == 0) {
- delalloc_start = delalloc_end + 1;
- continue;
- }
- ret = tree->ops->fill_delalloc(inode, page,
- delalloc_start,
- delalloc_end,
- &page_started,
- &nr_written);
- /* File system has been set read-only */
- if (ret) {
- SetPageError(page);
- goto done;
- }
- /*
- * delalloc_end is already one less than the total
- * length, so we don't subtract one from
- * PAGE_CACHE_SIZE
- */
- delalloc_to_write += (delalloc_end - delalloc_start +
- PAGE_CACHE_SIZE) >>
- PAGE_CACHE_SHIFT;
- delalloc_start = delalloc_end + 1;
- }
- if (wbc->nr_to_write < delalloc_to_write) {
- int thresh = 8192;
-
- if (delalloc_to_write < thresh * 2)
- thresh = delalloc_to_write;
- wbc->nr_to_write = min_t(u64, delalloc_to_write,
- thresh);
- }
+ int ret = 0;
+ int nr = 0;
+ bool compressed;
- /* did the fill delalloc function already unlock and start
- * the IO?
- */
- if (page_started) {
- ret = 0;
- /*
- * we've unlocked the page, so we can't update
- * the mapping's writeback index, just update
- * nr_to_write.
- */
- wbc->nr_to_write -= nr_written;
- goto done_unlocked;
- }
- }
if (tree->ops && tree->ops->writepage_start_hook) {
ret = tree->ops->writepage_start_hook(page, start,
page_end);
wbc->pages_skipped++;
else
redirty_page_for_writepage(wbc, page);
+
update_nr_written(page, wbc, nr_written);
unlock_page(page);
- ret = 0;
+ ret = 1;
goto done_unlocked;
}
}
update_nr_written(page, wbc, nr_written + 1);
end = page_end;
- if (last_byte <= start) {
+ if (i_size <= start) {
if (tree->ops && tree->ops->writepage_end_io_hook)
tree->ops->writepage_end_io_hook(page, start,
page_end, NULL, 1);
blocksize = inode->i_sb->s_blocksize;
while (cur <= end) {
- if (cur >= last_byte) {
+ u64 em_end;
+ if (cur >= i_size) {
if (tree->ops && tree->ops->writepage_end_io_hook)
tree->ops->writepage_end_io_hook(page, cur,
page_end, NULL, 1);
}
extent_offset = cur - em->start;
- BUG_ON(extent_map_end(em) <= cur);
+ em_end = extent_map_end(em);
+ BUG_ON(em_end <= cur);
BUG_ON(end < cur);
- iosize = min(extent_map_end(em) - cur, end - cur + 1);
+ iosize = min(em_end - cur, end - cur + 1);
iosize = ALIGN(iosize, blocksize);
sector = (em->block_start + extent_offset) >> 9;
bdev = em->bdev;
pg_offset += iosize;
continue;
}
- /* leave this out until we have a page_mkwrite call */
- if (0 && !test_range_bit(tree, cur, cur + iosize - 1,
- EXTENT_DIRTY, 0, NULL)) {
- cur = cur + iosize;
- pg_offset += iosize;
- continue;
- }
if (tree->ops && tree->ops->writepage_io_hook) {
ret = tree->ops->writepage_io_hook(page, cur,
if (ret) {
SetPageError(page);
} else {
- unsigned long max_nr = end_index + 1;
+ unsigned long max_nr = (i_size >> PAGE_CACHE_SHIFT) + 1;
set_range_writeback(tree, cur, cur + iosize - 1);
if (!PageWriteback(page)) {
pg_offset += iosize;
nr++;
}
+done:
+ *nr_ret = nr;
+
+done_unlocked:
+
+ /* drop our reference on any cached states */
+ free_extent_state(cached_state);
+ return ret;
+}
+
+/*
+ * the writepage semantics are similar to regular writepage. extent
+ * records are inserted to lock ranges in the tree, and as dirty areas
+ * are found, they are marked writeback. Then the lock bits are removed
+ * and the end_io handler clears the writeback ranges
+ */
+static int __extent_writepage(struct page *page, struct writeback_control *wbc,
+ void *data)
+{
+ struct inode *inode = page->mapping->host;
+ struct extent_page_data *epd = data;
+ u64 start = page_offset(page);
+ u64 page_end = start + PAGE_CACHE_SIZE - 1;
+ int ret;
+ int nr = 0;
+ size_t pg_offset = 0;
+ loff_t i_size = i_size_read(inode);
+ unsigned long end_index = i_size >> PAGE_CACHE_SHIFT;
+ int write_flags;
+ 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);
+
+ WARN_ON(!PageLocked(page));
+
+ ClearPageError(page);
+
+ pg_offset = i_size & (PAGE_CACHE_SIZE - 1);
+ if (page->index > end_index ||
+ (page->index == end_index && !pg_offset)) {
+ page->mapping->a_ops->invalidatepage(page, 0, PAGE_CACHE_SIZE);
+ unlock_page(page);
+ return 0;
+ }
+
+ if (page->index == end_index) {
+ char *userpage;
+
+ userpage = kmap_atomic(page);
+ memset(userpage + pg_offset, 0,
+ PAGE_CACHE_SIZE - pg_offset);
+ kunmap_atomic(userpage);
+ flush_dcache_page(page);
+ }
+
+ pg_offset = 0;
+
+ set_page_extent_mapped(page);
+
+ ret = writepage_delalloc(inode, page, wbc, epd, start, &nr_written);
+ if (ret == 1)
+ goto done_unlocked;
+ if (ret)
+ goto done;
+
+ ret = __extent_writepage_io(inode, page, wbc, epd,
+ i_size, nr_written, write_flags, &nr);
+ if (ret == 1)
+ goto done_unlocked;
+
done:
if (nr == 0) {
/* make sure the mapping tag for page dirty gets cleared */
end_extent_writepage(page, ret, start, page_end);
}
unlock_page(page);
+ return ret;
done_unlocked:
-
- /* drop our reference on any cached states */
- free_extent_state(cached_state);
- return ret;
+ return 0;
}
static int eb_wait(void *word)
projects / mirror_ubuntu-disco-kernel.git / commitdiff