btrfs: introduce btrfs_subpage for data inodes
To support subpage sector size, data also need extra info to make sure
which sectors in a page are uptodate/dirty/...
This patch will make pages for data inodes get btrfs_subpage structure
attached, and detached when the page is freed.
This patch also slightly changes the timing when
set_page_extent_mapped() is called to make sure:
- We have page->mapping set
page->mapping->host is used to grab btrfs_fs_info, thus we can only
call this function after page is mapped to an inode.
One call site attaches pages to inode manually, thus we have to modify
the timing of set_page_extent_mapped() a bit.
- As soon as possible, before other operations
Since memory allocation can fail, we have to do extra error handling.
Calling set_page_extent_mapped() as soon as possible can simply the
error handling for several call sites.
The idea is pretty much the same as iomap_page, but with more bitmaps
for btrfs specific cases.
Currently the plan is to switch iomap if iomap can provide sector
aligned write back (only write back dirty sectors, but not the full
page, data balance require this feature).
So we will stick to btrfs specific bitmap for now.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 5ae3fa0..6d203ac 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -542,13 +542,19 @@ static noinline int add_ra_bio_pages(struct inode *inode,
goto next;
}
- end = last_offset + PAGE_SIZE - 1;
/*
* at this point, we have a locked page in the page cache
* for these bytes in the file. But, we have to make
* sure they map to this compressed extent on disk.
*/
- set_page_extent_mapped(page);
+ ret = set_page_extent_mapped(page);
+ if (ret < 0) {
+ unlock_page(page);
+ put_page(page);
+ break;
+ }
+
+ end = last_offset + PAGE_SIZE - 1;
lock_extent(tree, last_offset, end);
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, last_offset,
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 491fc01..5ff85ec 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3191,10 +3191,38 @@ static int attach_extent_buffer_page(struct extent_buffer *eb,
return ret;
}
-void set_page_extent_mapped(struct page *page)
+int set_page_extent_mapped(struct page *page)
{
+ struct btrfs_fs_info *fs_info;
+
+ ASSERT(page->mapping);
+
+ if (PagePrivate(page))
+ return 0;
+
+ fs_info = btrfs_sb(page->mapping->host->i_sb);
+
+ if (fs_info->sectorsize < PAGE_SIZE)
+ return btrfs_attach_subpage(fs_info, page, BTRFS_SUBPAGE_DATA);
+
+ attach_page_private(page, (void *)EXTENT_PAGE_PRIVATE);
+ return 0;
+}
+
+void clear_page_extent_mapped(struct page *page)
+{
+ struct btrfs_fs_info *fs_info;
+
+ ASSERT(page->mapping);
+
if (!PagePrivate(page))
- attach_page_private(page, (void *)EXTENT_PAGE_PRIVATE);
+ return;
+
+ fs_info = btrfs_sb(page->mapping->host->i_sb);
+ if (fs_info->sectorsize < PAGE_SIZE)
+ return btrfs_detach_subpage(fs_info, page);
+
+ detach_page_private(page);
}
static struct extent_map *
@@ -3251,7 +3279,12 @@ int btrfs_do_readpage(struct page *page, struct extent_map **em_cached,
unsigned long this_bio_flag = 0;
struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
- set_page_extent_mapped(page);
+ ret = set_page_extent_mapped(page);
+ if (ret < 0) {
+ unlock_extent(tree, start, end);
+ SetPageError(page);
+ goto out;
+ }
if (!PageUptodate(page)) {
if (cleancache_get_page(page) == 0) {
@@ -3691,7 +3724,11 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
flush_dcache_page(page);
}
- set_page_extent_mapped(page);
+ ret = set_page_extent_mapped(page);
+ if (ret < 0) {
+ SetPageError(page);
+ goto done;
+ }
if (!epd->extent_locked) {
ret = writepage_delalloc(BTRFS_I(inode), page, wbc, start,
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 2d8187c..047b3e6 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -178,7 +178,8 @@ int btree_write_cache_pages(struct address_space *mapping,
void extent_readahead(struct readahead_control *rac);
int extent_fiemap(struct btrfs_inode *inode, struct fiemap_extent_info *fieinfo,
u64 start, u64 len);
-void set_page_extent_mapped(struct page *page);
+int set_page_extent_mapped(struct page *page);
+void clear_page_extent_mapped(struct page *page);
struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
u64 start, u64 owner_root, int level);
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index be5350f..bf52d7e 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1369,6 +1369,12 @@ static noinline int prepare_pages(struct inode *inode, struct page **pages,
goto fail;
}
+ err = set_page_extent_mapped(pages[i]);
+ if (err < 0) {
+ faili = i;
+ goto fail;
+ }
+
if (i == 0)
err = prepare_uptodate_page(inode, pages[i], pos,
force_uptodate);
@@ -1453,23 +1459,11 @@ lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct page **pages,
}
/*
- * It's possible the pages are dirty right now, but we don't want
- * to clean them yet because copy_from_user may catch a page fault
- * and we might have to fall back to one page at a time. If that
- * happens, we'll unlock these pages and we'd have a window where
- * reclaim could sneak in and drop the once-dirty page on the floor
- * without writing it.
- *
- * We have the pages locked and the extent range locked, so there's
- * no way someone can start IO on any dirty pages in this range.
- *
- * We'll call btrfs_dirty_pages() later on, and that will flip around
- * delalloc bits and dirty the pages as required.
+ * We should be called after prepare_pages() which should have locked
+ * all pages in the range.
*/
- for (i = 0; i < num_pages; i++) {
- set_page_extent_mapped(pages[i]);
+ for (i = 0; i < num_pages; i++)
WARN_ON(!PageLocked(pages[i]));
- }
return ret;
}
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 0d6dcb5..6134e10 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -431,11 +431,22 @@ static int io_ctl_prepare_pages(struct btrfs_io_ctl *io_ctl, bool uptodate)
int i;
for (i = 0; i < io_ctl->num_pages; i++) {
+ int ret;
+
page = find_or_create_page(inode->i_mapping, i, mask);
if (!page) {
io_ctl_drop_pages(io_ctl);
return -ENOMEM;
}
+
+ ret = set_page_extent_mapped(page);
+ if (ret < 0) {
+ unlock_page(page);
+ put_page(page);
+ io_ctl_drop_pages(io_ctl);
+ return ret;
+ }
+
io_ctl->pages[i] = page;
if (uptodate && !PageUptodate(page)) {
btrfs_readpage(NULL, page);
@@ -455,10 +466,8 @@ static int io_ctl_prepare_pages(struct btrfs_io_ctl *io_ctl, bool uptodate)
}
}
- for (i = 0; i < io_ctl->num_pages; i++) {
+ for (i = 0; i < io_ctl->num_pages; i++)
clear_page_dirty_for_io(io_ctl->pages[i]);
- set_page_extent_mapped(io_ctl->pages[i]);
- }
return 0;
}
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 3337c8e..5522e9d 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4720,6 +4720,9 @@ int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len,
ret = -ENOMEM;
goto out;
}
+ ret = set_page_extent_mapped(page);
+ if (ret < 0)
+ goto out_unlock;
if (!PageUptodate(page)) {
ret = btrfs_readpage(NULL, page);
@@ -4737,7 +4740,6 @@ int btrfs_truncate_block(struct btrfs_inode *inode, loff_t from, loff_t len,
wait_on_page_writeback(page);
lock_extent_bits(io_tree, block_start, block_end, &cached_state);
- set_page_extent_mapped(page);
ordered = btrfs_lookup_ordered_extent(inode, block_start);
if (ordered) {
@@ -8125,7 +8127,7 @@ static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
{
int ret = try_release_extent_mapping(page, gfp_flags);
if (ret == 1)
- detach_page_private(page);
+ clear_page_extent_mapped(page);
return ret;
}
@@ -8285,7 +8287,7 @@ static void btrfs_invalidatepage(struct page *page, unsigned int offset,
}
ClearPageChecked(page);
- detach_page_private(page);
+ clear_page_extent_mapped(page);
}
/*
@@ -8364,7 +8366,12 @@ vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf)
wait_on_page_writeback(page);
lock_extent_bits(io_tree, page_start, page_end, &cached_state);
- set_page_extent_mapped(page);
+ ret2 = set_page_extent_mapped(page);
+ if (ret2 < 0) {
+ ret = vmf_error(ret2);
+ unlock_extent_cached(io_tree, page_start, page_end, &cached_state);
+ goto out_unlock;
+ }
/*
* we can't set the delalloc bits if there are pending ordered
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 7f2935e..e6a63f6 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1314,6 +1314,13 @@ static int cluster_pages_for_defrag(struct inode *inode,
if (!page)
break;
+ ret = set_page_extent_mapped(page);
+ if (ret < 0) {
+ unlock_page(page);
+ put_page(page);
+ break;
+ }
+
page_start = page_offset(page);
page_end = page_start + PAGE_SIZE - 1;
while (1) {
@@ -1435,7 +1442,6 @@ static int cluster_pages_for_defrag(struct inode *inode,
for (i = 0; i < i_done; i++) {
clear_page_dirty_for_io(pages[i]);
ClearPageChecked(pages[i]);
- set_page_extent_mapped(pages[i]);
set_page_dirty(pages[i]);
unlock_page(pages[i]);
put_page(pages[i]);
diff --git a/fs/btrfs/reflink.c b/fs/btrfs/reflink.c
index b03e789..b24396c 100644
--- a/fs/btrfs/reflink.c
+++ b/fs/btrfs/reflink.c
@@ -81,7 +81,10 @@ static int copy_inline_to_page(struct btrfs_inode *inode,
goto out_unlock;
}
- set_page_extent_mapped(page);
+ ret = set_page_extent_mapped(page);
+ if (ret < 0)
+ goto out_unlock;
+
clear_extent_bit(&inode->io_tree, file_offset, range_end,
EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
0, 0, NULL);
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index d29baf3..473b788 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -2679,6 +2679,15 @@ static int relocate_file_extent_cluster(struct inode *inode,
goto out;
}
}
+ ret = set_page_extent_mapped(page);
+ if (ret < 0) {
+ btrfs_delalloc_release_metadata(BTRFS_I(inode),
+ PAGE_SIZE, true);
+ btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
+ unlock_page(page);
+ put_page(page);
+ goto out;
+ }
if (PageReadahead(page)) {
page_cache_async_readahead(inode->i_mapping,
@@ -2706,8 +2715,6 @@ static int relocate_file_extent_cluster(struct inode *inode,
lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end);
- set_page_extent_mapped(page);
-
if (nr < cluster->nr &&
page_start + offset == cluster->boundary[nr]) {
set_extent_bits(&BTRFS_I(inode)->io_tree,
