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WSL2-Linux-Kernel
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Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user 

Simplify page cache zeroing of segments of pages through 3 functions

zero_user_segments(page, start1, end1, start2, end2)

        Zeros two segments of the page. It takes the position where to
        start and end the zeroing which avoids length calculations and
	makes code clearer.

zero_user_segment(page, start, end)

        Same for a single segment.

zero_user(page, start, length)

        Length variant for the case where we know the length.

We remove the zero_user_page macro. Issues:

1. Its a macro. Inline functions are preferable.

2. The KM_USER0 macro is only defined for HIGHMEM.

   Having to treat this special case everywhere makes the
   code needlessly complex. The parameter for zeroing is always
   KM_USER0 except in one single case that we open code.

Avoiding KM_USER0 makes a lot of code not having to be dealing
with the special casing for HIGHMEM anymore. Dealing with
kmap is only necessary for HIGHMEM configurations. In those
configurations we use KM_USER0 like we do for a series of other
functions defined in highmem.h.

Since KM_USER0 is depends on HIGHMEM the existing zero_user_page
function could not be a macro. zero_user_* functions introduced
here can be be inline because that constant is not used when these
functions are called.

Also extract the flushing of the caches to be outside of the kmap.

[akpm@linux-foundation.org: fix nfs and ntfs build]
[akpm@linux-foundation.org: fix ntfs build some more]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: David Chinner <dgc@sgi.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Christoph Lameter 2008-02-04 22:28:29 -08:00 коммит произвёл Linus Torvalds
Родитель b98348bdd0
Коммит eebd2aa355
22 изменённых файлов: 103 добавлений и 116 удалений
Показать статистику Скачать Patch файл Скачать Diff файл Показать все файлы Свернуть все файлы

44
fs/buffer.c
Просмотреть файл

@ -1798,7 +1798,7 @@ void page_zero_new_buffers(struct page *page, unsigned from, unsigned to)
start = max(from, block_start);
size = min(to, block_end) - start;
zero_user_page(page, start, size, KM_USER0);
zero_user(page, start, size);
set_buffer_uptodate(bh);
}
@ -1861,19 +1861,10 @@ static int __block_prepare_write(struct inode *inode, struct page *page,
mark_buffer_dirty(bh);
continue;
}
if (block_end > to || block_start < from) {
void *kaddr;
kaddr = kmap_atomic(page, KM_USER0);
if (block_end > to)
memset(kaddr+to, 0,
block_end-to);
if (block_start < from)
memset(kaddr+block_start,
0, from-block_start);
flush_dcache_page(page);
kunmap_atomic(kaddr, KM_USER0);
}
if (block_end > to || block_start < from)
zero_user_segments(page,
to, block_end,
block_start, from);
continue;
}
}
@ -2104,8 +2095,7 @@ int block_read_full_page(struct page *page, get_block_t *get_block)
SetPageError(page);
}
if (!buffer_mapped(bh)) {
zero_user_page(page, i * blocksize, blocksize,
KM_USER0);
zero_user(page, i * blocksize, blocksize);
if (!err)
set_buffer_uptodate(bh);
continue;
@ -2218,7 +2208,7 @@ int cont_expand_zero(struct file *file, struct address_space *mapping,
&page, &fsdata);
if (err)
goto out;
zero_user_page(page, zerofrom, len, KM_USER0);
zero_user(page, zerofrom, len);
err = pagecache_write_end(file, mapping, curpos, len, len,
page, fsdata);
if (err < 0)
@ -2245,7 +2235,7 @@ int cont_expand_zero(struct file *file, struct address_space *mapping,
&page, &fsdata);
if (err)
goto out;
zero_user_page(page, zerofrom, len, KM_USER0);
zero_user(page, zerofrom, len);
err = pagecache_write_end(file, mapping, curpos, len, len,
page, fsdata);
if (err < 0)
@ -2422,7 +2412,6 @@ int nobh_write_begin(struct file *file, struct address_space *mapping,
unsigned block_in_page;
unsigned block_start, block_end;
sector_t block_in_file;
char *kaddr;
int nr_reads = 0;
int ret = 0;
int is_mapped_to_disk = 1;
@ -2493,13 +2482,8 @@ int nobh_write_begin(struct file *file, struct address_space *mapping,
continue;
}
if (buffer_new(bh) || !buffer_mapped(bh)) {
kaddr = kmap_atomic(page, KM_USER0);
if (block_start < from)
memset(kaddr+block_start, 0, from-block_start);
if (block_end > to)
memset(kaddr + to, 0, block_end - to);
flush_dcache_page(page);
kunmap_atomic(kaddr, KM_USER0);
zero_user_segments(page, block_start, from,
to, block_end);
continue;
}
if (buffer_uptodate(bh))
@ -2636,7 +2620,7 @@ int nobh_writepage(struct page *page, get_block_t *get_block,
* the page size, the remaining memory is zeroed when mapped, and
* writes to that region are not written out to the file."
*/
zero_user_page(page, offset, PAGE_CACHE_SIZE - offset, KM_USER0);
zero_user_segment(page, offset, PAGE_CACHE_SIZE);
out:
ret = mpage_writepage(page, get_block, wbc);
if (ret == -EAGAIN)
@ -2709,7 +2693,7 @@ has_buffers:
if (page_has_buffers(page))
goto has_buffers;
}
zero_user_page(page, offset, length, KM_USER0);
zero_user(page, offset, length);
set_page_dirty(page);
err = 0;
@ -2785,7 +2769,7 @@ int block_truncate_page(struct address_space *mapping,
goto unlock;
}
zero_user_page(page, offset, length, KM_USER0);
zero_user(page, offset, length);
mark_buffer_dirty(bh);
err = 0;
@ -2831,7 +2815,7 @@ int block_write_full_page(struct page *page, get_block_t *get_block,
* the page size, the remaining memory is zeroed when mapped, and
* writes to that region are not written out to the file."
*/
zero_user_page(page, offset, PAGE_CACHE_SIZE - offset, KM_USER0);
zero_user_segment(page, offset, PAGE_CACHE_SIZE);
return __block_write_full_page(inode, page, get_block, wbc);
}

2
fs/cifs/inode.c
Просмотреть файл

@ -1386,7 +1386,7 @@ static int cifs_truncate_page(struct address_space *mapping, loff_t from)
if (!page)
return -ENOMEM;
zero_user_page(page, offset, PAGE_CACHE_SIZE - offset, KM_USER0);
zero_user_segment(page, offset, PAGE_CACHE_SIZE);
unlock_page(page);
page_cache_release(page);
return rc;

4
fs/direct-io.c
Просмотреть файл

@ -878,8 +878,8 @@ do_holes:
page_cache_release(page);
goto out;
}
zero_user_page(page, block_in_page << blkbits,
1 << blkbits, KM_USER0);
zero_user(page, block_in_page << blkbits,
1 << blkbits);
dio->block_in_file++;
block_in_page++;
goto next_block;

5
fs/ecryptfs/mmap.c
Просмотреть файл

@ -257,8 +257,7 @@ static int fill_zeros_to_end_of_page(struct page *page, unsigned int to)
end_byte_in_page = i_size_read(inode) % PAGE_CACHE_SIZE;
if (to > end_byte_in_page)
end_byte_in_page = to;
zero_user_page(page, end_byte_in_page,
PAGE_CACHE_SIZE - end_byte_in_page, KM_USER0);
zero_user_segment(page, end_byte_in_page, PAGE_CACHE_SIZE);
out:
return 0;
}
@ -307,7 +306,7 @@ static int ecryptfs_prepare_write(struct file *file, struct page *page,
*/
if ((i_size_read(page->mapping->host) == prev_page_end_size) &&
(from != 0)) {
zero_user_page(page, 0, PAGE_CACHE_SIZE, KM_USER0);
zero_user(page, 0, PAGE_CACHE_SIZE);
}
out:
return rc;

4
fs/ext3/inode.c
Просмотреть файл

@ -1845,7 +1845,7 @@ static int ext3_block_truncate_page(handle_t *handle, struct page *page,
*/
if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH) &&
ext3_should_writeback_data(inode) && PageUptodate(page)) {
zero_user_page(page, offset, length, KM_USER0);
zero_user(page, offset, length);
set_page_dirty(page);
goto unlock;
}
@ -1898,7 +1898,7 @@ static int ext3_block_truncate_page(handle_t *handle, struct page *page,
goto unlock;
}
zero_user_page(page, offset, length, KM_USER0);
zero_user(page, offset, length);
BUFFER_TRACE(bh, "zeroed end of block");
err = 0;

4
fs/ext4/inode.c
Просмотреть файл

@ -1840,7 +1840,7 @@ int ext4_block_truncate_page(handle_t *handle, struct page *page,
*/
if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH) &&
ext4_should_writeback_data(inode) && PageUptodate(page)) {
zero_user_page(page, offset, length, KM_USER0);
zero_user(page, offset, length);
set_page_dirty(page);
goto unlock;
}
@ -1893,7 +1893,7 @@ int ext4_block_truncate_page(handle_t *handle, struct page *page,
goto unlock;
}
zero_user_page(page, offset, length, KM_USER0);
zero_user(page, offset, length);
BUFFER_TRACE(bh, "zeroed end of block");

2
fs/gfs2/bmap.c
Просмотреть файл

@ -932,7 +932,7 @@ static int gfs2_block_truncate_page(struct address_space *mapping)
if (!gfs2_is_writeback(ip))
gfs2_trans_add_bh(ip->i_gl, bh, 0);
zero_user_page(page, offset, length, KM_USER0);
zero_user(page, offset, length);
unlock:
unlock_page(page);

2
fs/gfs2/ops_address.c
Просмотреть файл

@ -446,7 +446,7 @@ static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
* so we need to supply one here. It doesn't happen often.
*/
if (unlikely(page->index)) {
zero_user_page(page, 0, PAGE_CACHE_SIZE, KM_USER0);
zero_user(page, 0, PAGE_CACHE_SIZE);
return 0;
}

11
fs/libfs.c
Просмотреть файл

@ -341,13 +341,10 @@ int simple_prepare_write(struct file *file, struct page *page,
unsigned from, unsigned to)
{
if (!PageUptodate(page)) {
if (to - from != PAGE_CACHE_SIZE) {
void *kaddr = kmap_atomic(page, KM_USER0);
memset(kaddr, 0, from);
memset(kaddr + to, 0, PAGE_CACHE_SIZE - to);
flush_dcache_page(page);
kunmap_atomic(kaddr, KM_USER0);
}
if (to - from != PAGE_CACHE_SIZE)
zero_user_segments(page,
0, from,
to, PAGE_CACHE_SIZE);
}
return 0;
}

7
fs/mpage.c
Просмотреть файл

@ -276,9 +276,7 @@ do_mpage_readpage(struct bio *bio, struct page *page, unsigned nr_pages,
}
if (first_hole != blocks_per_page) {
zero_user_page(page, first_hole << blkbits,
PAGE_CACHE_SIZE - (first_hole << blkbits),
KM_USER0);
zero_user_segment(page, first_hole << blkbits, PAGE_CACHE_SIZE);
if (first_hole == 0) {
SetPageUptodate(page);
unlock_page(page);
@ -571,8 +569,7 @@ page_is_mapped:
if (page->index > end_index || !offset)
goto confused;
zero_user_page(page, offset, PAGE_CACHE_SIZE - offset,
KM_USER0);
zero_user_segment(page, offset, PAGE_CACHE_SIZE);
}
/*

10
fs/nfs/read.c
Просмотреть файл

@ -79,7 +79,7 @@ void nfs_readdata_release(void *data)
static
int nfs_return_empty_page(struct page *page)
{
zero_user_page(page, 0, PAGE_CACHE_SIZE, KM_USER0);
zero_user(page, 0, PAGE_CACHE_SIZE);
SetPageUptodate(page);
unlock_page(page);
return 0;
@ -103,10 +103,10 @@ static void nfs_readpage_truncate_uninitialised_page(struct nfs_read_data *data)
pglen = PAGE_CACHE_SIZE - base;
for (;;) {
if (remainder <= pglen) {
zero_user_page(*pages, base, remainder, KM_USER0);
zero_user(*pages, base, remainder);
break;
}
zero_user_page(*pages, base, pglen, KM_USER0);
zero_user(*pages, base, pglen);
pages++;
remainder -= pglen;
pglen = PAGE_CACHE_SIZE;
@ -130,7 +130,7 @@ static int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
return PTR_ERR(new);
}
if (len < PAGE_CACHE_SIZE)
zero_user_page(page, len, PAGE_CACHE_SIZE - len, KM_USER0);
zero_user_segment(page, len, PAGE_CACHE_SIZE);
nfs_list_add_request(new, &one_request);
if (NFS_SERVER(inode)->rsize < PAGE_CACHE_SIZE)
@ -532,7 +532,7 @@ readpage_async_filler(void *data, struct page *page)
goto out_error;
if (len < PAGE_CACHE_SIZE)
zero_user_page(page, len, PAGE_CACHE_SIZE - len, KM_USER0);
zero_user_segment(page, len, PAGE_CACHE_SIZE);
nfs_pageio_add_request(desc->pgio, new);
return 0;
out_error:

4
fs/nfs/write.c
Просмотреть файл

@ -665,9 +665,7 @@ zero_page:
* then we need to zero any uninitalised data. */
if (req->wb_pgbase == 0 && req->wb_bytes != PAGE_CACHE_SIZE
&& !PageUptodate(req->wb_page))
zero_user_page(req->wb_page, req->wb_bytes,
PAGE_CACHE_SIZE - req->wb_bytes,
KM_USER0);
zero_user_segment(req->wb_page, req->wb_bytes, PAGE_CACHE_SIZE);
return req;
}

20
fs/ntfs/aops.c
Просмотреть файл

@ -87,13 +87,17 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
/* Check for the current buffer head overflowing. */
if (unlikely(file_ofs + bh->b_size > init_size)) {
int ofs;
void *kaddr;
ofs = 0;
if (file_ofs < init_size)
ofs = init_size - file_ofs;
local_irq_save(flags);
zero_user_page(page, bh_offset(bh) + ofs,
bh->b_size - ofs, KM_BIO_SRC_IRQ);
kaddr = kmap_atomic(page, KM_BIO_SRC_IRQ);
memset(kaddr + bh_offset(bh) + ofs, 0,
bh->b_size - ofs);
flush_dcache_page(page);
kunmap_atomic(kaddr, KM_BIO_SRC_IRQ);
local_irq_restore(flags);
}
} else {
@ -334,7 +338,7 @@ handle_hole:
bh->b_blocknr = -1UL;
clear_buffer_mapped(bh);
handle_zblock:
zero_user_page(page, i * blocksize, blocksize, KM_USER0);
zero_user(page, i * blocksize, blocksize);
if (likely(!err))
set_buffer_uptodate(bh);
} while (i++, iblock++, (bh = bh->b_this_page) != head);
@ -410,7 +414,7 @@ retry_readpage:
/* Is the page fully outside i_size? (truncate in progress) */
if (unlikely(page->index >= (i_size + PAGE_CACHE_SIZE - 1) >>
PAGE_CACHE_SHIFT)) {
zero_user_page(page, 0, PAGE_CACHE_SIZE, KM_USER0);
zero_user(page, 0, PAGE_CACHE_SIZE);
ntfs_debug("Read outside i_size - truncated?");
goto done;
}
@ -459,7 +463,7 @@ retry_readpage:
* ok to ignore the compressed flag here.
*/
if (unlikely(page->index > 0)) {
zero_user_page(page, 0, PAGE_CACHE_SIZE, KM_USER0);
zero_user(page, 0, PAGE_CACHE_SIZE);
goto done;
}
if (!NInoAttr(ni))
@ -788,8 +792,7 @@ lock_retry_remap:
if (err == -ENOENT || lcn == LCN_ENOENT) {
bh->b_blocknr = -1;
clear_buffer_dirty(bh);
zero_user_page(page, bh_offset(bh), blocksize,
KM_USER0);
zero_user(page, bh_offset(bh), blocksize);
set_buffer_uptodate(bh);
err = 0;
continue;
@ -1414,8 +1417,7 @@ retry_writepage:
if (page->index >= (i_size >> PAGE_CACHE_SHIFT)) {
/* The page straddles i_size. */
unsigned int ofs = i_size & ~PAGE_CACHE_MASK;
zero_user_page(page, ofs, PAGE_CACHE_SIZE - ofs,
KM_USER0);
zero_user_segment(page, ofs, PAGE_CACHE_SIZE);
}
/* Handle mst protected attributes. */
if (NInoMstProtected(ni))

2
fs/ntfs/compress.c
Просмотреть файл

@ -565,7 +565,7 @@ int ntfs_read_compressed_block(struct page *page)
if (xpage >= max_page) {
kfree(bhs);
kfree(pages);
zero_user_page(page, 0, PAGE_CACHE_SIZE, KM_USER0);
zero_user(page, 0, PAGE_CACHE_SIZE);
ntfs_debug("Compressed read outside i_size - truncated?");
SetPageUptodate(page);
unlock_page(page);

32
fs/ntfs/file.c
Просмотреть файл

@ -607,8 +607,8 @@ do_next_page:
ntfs_submit_bh_for_read(bh);
*wait_bh++ = bh;
} else {
zero_user_page(page, bh_offset(bh),
blocksize, KM_USER0);
zero_user(page, bh_offset(bh),
blocksize);
set_buffer_uptodate(bh);
}
}
@ -683,9 +683,8 @@ map_buffer_cached:
ntfs_submit_bh_for_read(bh);
*wait_bh++ = bh;
} else {
zero_user_page(page,
bh_offset(bh),
blocksize, KM_USER0);
zero_user(page, bh_offset(bh),
blocksize);
set_buffer_uptodate(bh);
}
}
@ -703,8 +702,8 @@ map_buffer_cached:
*/
if (bh_end <= pos || bh_pos >= end) {
if (!buffer_uptodate(bh)) {
zero_user_page(page, bh_offset(bh),
blocksize, KM_USER0);
zero_user(page, bh_offset(bh),
blocksize);
set_buffer_uptodate(bh);
}
mark_buffer_dirty(bh);
@ -743,8 +742,7 @@ map_buffer_cached:
if (!buffer_uptodate(bh))
set_buffer_uptodate(bh);
} else if (!buffer_uptodate(bh)) {
zero_user_page(page, bh_offset(bh), blocksize,
KM_USER0);
zero_user(page, bh_offset(bh), blocksize);
set_buffer_uptodate(bh);
}
continue;
@ -868,8 +866,8 @@ rl_not_mapped_enoent:
if (!buffer_uptodate(bh))
set_buffer_uptodate(bh);
} else if (!buffer_uptodate(bh)) {
zero_user_page(page, bh_offset(bh),
blocksize, KM_USER0);
zero_user(page, bh_offset(bh),
blocksize);
set_buffer_uptodate(bh);
}
continue;
@ -1128,8 +1126,8 @@ rl_not_mapped_enoent:
if (likely(bh_pos < initialized_size))
ofs = initialized_size - bh_pos;
zero_user_page(page, bh_offset(bh) + ofs,
blocksize - ofs, KM_USER0);
zero_user_segment(page, bh_offset(bh) + ofs,
blocksize);
}
} else /* if (unlikely(!buffer_uptodate(bh))) */
err = -EIO;
@ -1269,8 +1267,8 @@ rl_not_mapped_enoent:
if (PageUptodate(page))
set_buffer_uptodate(bh);
else {
zero_user_page(page, bh_offset(bh),
blocksize, KM_USER0);
zero_user(page, bh_offset(bh),
blocksize);
set_buffer_uptodate(bh);
}
}
@ -1330,7 +1328,7 @@ err_out:
len = PAGE_CACHE_SIZE;
if (len > bytes)
len = bytes;
zero_user_page(*pages, 0, len, KM_USER0);
zero_user(*pages, 0, len);
}
goto out;
}
@ -1451,7 +1449,7 @@ err_out:
len = PAGE_CACHE_SIZE;
if (len > bytes)
len = bytes;
zero_user_page(*pages, 0, len, KM_USER0);
zero_user(*pages, 0, len);
}
goto out;
}

2
fs/ocfs2/alloc.c
Просмотреть файл

@ -5670,7 +5670,7 @@ static void ocfs2_map_and_dirty_page(struct inode *inode, handle_t *handle,
mlog_errno(ret);
if (zero)
zero_user_page(page, from, to - from, KM_USER0);
zero_user_segment(page, from, to);
/*
* Need to set the buffers we zero'd into uptodate

6
fs/ocfs2/aops.c
Просмотреть файл

@ -307,7 +307,7 @@ static int ocfs2_readpage(struct file *file, struct page *page)
* XXX sys_readahead() seems to get that wrong?
*/
if (start >= i_size_read(inode)) {
zero_user_page(page, 0, PAGE_SIZE, KM_USER0);
zero_user(page, 0, PAGE_SIZE);
SetPageUptodate(page);
ret = 0;
goto out_alloc;
@ -869,7 +869,7 @@ int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
if (block_start >= to)
break;
zero_user_page(page, block_start, bh->b_size, KM_USER0);
zero_user(page, block_start, bh->b_size);
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
@ -1034,7 +1034,7 @@ static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to
start = max(from, block_start);
end = min(to, block_end);
zero_user_page(page, start, end - start, KM_USER0);
zero_user_segment(page, start, end);
set_buffer_uptodate(bh);
}

4
fs/reiserfs/inode.c
Просмотреть файл

@ -2143,7 +2143,7 @@ int reiserfs_truncate_file(struct inode *p_s_inode, int update_timestamps)
/* if we are not on a block boundary */
if (length) {
length = blocksize - length;
zero_user_page(page, offset, length, KM_USER0);
zero_user(page, offset, length);
if (buffer_mapped(bh) && bh->b_blocknr != 0) {
mark_buffer_dirty(bh);
}
@ -2367,7 +2367,7 @@ static int reiserfs_write_full_page(struct page *page,
unlock_page(page);
return 0;
}
zero_user_page(page, last_offset, PAGE_CACHE_SIZE - last_offset, KM_USER0);
zero_user_segment(page, last_offset, PAGE_CACHE_SIZE);
}
bh = head;
block = page->index << (PAGE_CACHE_SHIFT - s->s_blocksize_bits);

2
fs/xfs/linux-2.6/xfs_lrw.c
Просмотреть файл

@ -155,7 +155,7 @@ xfs_iozero(
if (status)
break;
zero_user_page(page, offset, bytes, KM_USER0);
zero_user(page, offset, bytes);
status = pagecache_write_end(NULL, mapping, pos, bytes, bytes,
page, fsdata);

48
include/linux/highmem.h
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@ -124,28 +124,40 @@ static inline void clear_highpage(struct page *page)
kunmap_atomic(kaddr, KM_USER0);
}
/*
* Same but also flushes aliased cache contents to RAM.
*
* This must be a macro because KM_USER0 and friends aren't defined if
* !CONFIG_HIGHMEM
*/
#define zero_user_page(page, offset, size, km_type) \
do { \
void *kaddr; \
\
BUG_ON((offset) + (size) > PAGE_SIZE); \
\
kaddr = kmap_atomic(page, km_type); \
memset((char *)kaddr + (offset), 0, (size)); \
flush_dcache_page(page); \
kunmap_atomic(kaddr, (km_type)); \
} while (0)
static inline void zero_user_segments(struct page *page,
unsigned start1, unsigned end1,
unsigned start2, unsigned end2)
{
void *kaddr = kmap_atomic(page, KM_USER0);
BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE);
if (end1 > start1)
memset(kaddr + start1, 0, end1 - start1);
if (end2 > start2)
memset(kaddr + start2, 0, end2 - start2);
kunmap_atomic(kaddr, KM_USER0);
flush_dcache_page(page);
}
static inline void zero_user_segment(struct page *page,
unsigned start, unsigned end)
{
zero_user_segments(page, start, end, 0, 0);
}
static inline void zero_user(struct page *page,
unsigned start, unsigned size)
{
zero_user_segments(page, start, start + size, 0, 0);
}
static inline void __deprecated memclear_highpage_flush(struct page *page,
unsigned int offset, unsigned int size)
{
zero_user_page(page, offset, size, KM_USER0);
zero_user(page, offset, size);
}
#ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE

2
mm/filemap_xip.c
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@ -431,7 +431,7 @@ xip_truncate_page(struct address_space *mapping, loff_t from)
else
return PTR_ERR(page);
}
zero_user_page(page, offset, length, KM_USER0);
zero_user(page, offset, length);
return 0;
}
EXPORT_SYMBOL_GPL(xip_truncate_page);

2
mm/truncate.c
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@ -48,7 +48,7 @@ void do_invalidatepage(struct page *page, unsigned long offset)
static inline void truncate_partial_page(struct page *page, unsigned partial)
{
zero_user_page(page, partial, PAGE_CACHE_SIZE - partial, KM_USER0);
zero_user_segment(page, partial, PAGE_CACHE_SIZE);
if (PagePrivate(page))
do_invalidatepage(page, partial);
}