[PATCHv3 37/41] ext4: make EXT4_IOC_MOVE_EXT work with huge pages

Kirill A. Shutemov
2016-09-15T11:55:19Z

Adjust how we find relevant block within page and how we clear the
required part of the page.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
fs/ext4/move_extent.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index a920c5d29fac..f3efdd0e0eaf 100644
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -210,7 +210,9 @@ mext_page_mkuptodate(struct page *page, unsigned from, unsigned to)
return err;
}
if (!buffer_mapped(bh)) {
- zero_user(page, block_start, blocksize);
+ zero_user(page + block_start / PAGE_SIZE,
+ block_start % PAGE_SIZE,
+ blocksize);
set_buffer_uptodate(bh);
continue;
}
@@ -267,10 +269,11 @@ move_extent_per_page(struct file *o_filp, struct inode *donor_inode,
unsigned int tmp_data_size, data_size, replaced_size;
int i, err2, jblocks, retries = 0;
int replaced_count = 0;
- int from = data_offset_in_page << orig_inode->i_blkbits;
+ int from;
int blocks_per_page = PAGE_SIZE >> orig_inode->i_blkbits;
struct super_block *sb = orig_inode->i_sb;
struct buffer_head *bh = NULL;
+ int diff;

/*
* It needs twice the amount of ordinary journal buffers because
@@ -355,6 +358,9 @@ again:
goto unlock_pages;
}
data_copy:
+ diff = (pagep[0] - compound_head(pagep[0])) * blocks_per_page;
+ from = (data_offset_in_page + diff) << orig_inode->i_blkbits;
+ pagep[0] = compound_head(pagep[0]);
*err = mext_page_mkuptodate(pagep[0], from, from + replaced_size);
if (*err)
goto unlock_pages;
@@ -384,7 +390,7 @@ data_copy:
if (!page_has_buffers(pagep[0]))
create_empty_buffers(pagep[0], 1 << orig_inode->i_blkbits, 0);
bh = page_buffers(pagep[0]);
- for (i = 0; i < data_offset_in_page; i++)
+ for (i = 0; i < data_offset_in_page + diff; i++)
bh = bh->b_this_page;
for (i = 0; i < block_len_in_page; i++) {
*err = ext4_get_block(orig_inode, orig_blk_offset + i, bh, 0);