[PATCHv2 33/41] ext4: make ext4_block_write_begin() aware about huge pages
From: Kirill A. Shutemov <hidden>
Date: 2016-08-12 18:38:16
Also in:
linux-ext4, linux-fsdevel, linux-mm, lkml
Subsystem:
ext4 file system, filesystems (vfs and infrastructure), the rest · Maintainers:
"Theodore Ts'o", Alexander Viro, Christian Brauner, Linus Torvalds
It simply matches changes to __block_write_begin_int(). Signed-off-by: Kirill A. Shutemov <redacted> --- fs/ext4/inode.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index bee21fffbfb9..1c325f62e766 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c@@ -1079,9 +1079,8 @@ int do_journal_get_write_access(handle_t *handle, static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len, get_block_t *get_block) { - unsigned from = pos & (PAGE_SIZE - 1); - unsigned to = from + len; - struct inode *inode = page->mapping->host; + unsigned from, to; + struct inode *inode = page_mapping(page)->host; unsigned block_start, block_end; sector_t block; int err = 0;
@@ -1090,9 +1089,12 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len, struct buffer_head *bh, *head, *wait[2], **wait_bh = wait; bool decrypt = false; + page = compound_head(page); + from = pos & ~hpage_mask(page); + to = from + len; BUG_ON(!PageLocked(page)); - BUG_ON(from > PAGE_SIZE); - BUG_ON(to > PAGE_SIZE); + BUG_ON(from > hpage_size(page)); + BUG_ON(to > hpage_size(page)); BUG_ON(from > to); if (!page_has_buffers(page))
@@ -1127,9 +1129,15 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len, mark_buffer_dirty(bh); continue; } - if (block_end > to || block_start < from) - zero_user_segments(page, to, block_end, - block_start, from); + if (block_end > to || block_start < from) { + BUG_ON(to - from > PAGE_SIZE); + zero_user_segments(page + + block_start / PAGE_SIZE, + to % PAGE_SIZE, + (block_start % PAGE_SIZE) + blocksize, + block_start % PAGE_SIZE, + from % PAGE_SIZE); + } continue; } }
--
2.8.1