Re: [11/36] Use page_cache_xxx in fs/buffer.c

Dmitry Monakhov
2007-08-30T09:22:47Z

On 12:06 Tue 28 Aug , clameter@sgi.com wrote:
> Use page_cache_xxx in fs/buffer.c.
submit_bh wasn't changed this means what bio pages may have huge size
without respect to queue reqsrictions (q->max_hw_segments, and etc)
At least driver/md/raid0 will be broken by you'r patch.
>
> We have a special situation in set_bh_page() since reiserfs calls that
> function before setting up the mapping. So retrieve the page size
> from the page struct rather than the mapping.
>
> Signed-off-by: Christoph Lameter <clameter@sgi.com>
> ---
> fs/buffer.c | 110 +++++++++++++++++++++++++++++++++---------------------------
> 1 file changed, 62 insertions(+), 48 deletions(-)
>
> Index: linux-2.6/fs/buffer.c
> ===================================================================
> --- linux-2.6.orig/fs/buffer.c 2007-08-28 11:37:13.000000000 -0700
> +++ linux-2.6/fs/buffer.c 2007-08-28 11:37:58.000000000 -0700
> @@ -257,7 +257,7 @@ __find_get_block_slow(struct block_devic
> struct page *page;
> int all_mapped = 1;
>
> - index = block >> (PAGE_CACHE_SHIFT - bd_inode->i_blkbits);
> + index = block >> (page_cache_shift(bd_mapping) - bd_inode->i_blkbits);
> page = find_get_page(bd_mapping, index);
> if (!page)
> goto out;
> @@ -697,7 +697,7 @@ static int __set_page_dirty(struct page
>
> if (mapping_cap_account_dirty(mapping)) {
> __inc_zone_page_state(page, NR_FILE_DIRTY);
> - task_io_account_write(PAGE_CACHE_SIZE);
> + task_io_account_write(page_cache_size(mapping));
> }
> radix_tree_tag_set(&mapping->page_tree,
> page_index(page), PAGECACHE_TAG_DIRTY);
> @@ -891,10 +891,11 @@ struct buffer_head *alloc_page_buffers(s
> {
> struct buffer_head *bh, *head;
> long offset;
> + unsigned int page_size = page_cache_size(page->mapping);
>
> try_again:
> head = NULL;
> - offset = PAGE_SIZE;
> + offset = page_size;
> while ((offset -= size) >= 0) {
> bh = alloc_buffer_head(GFP_NOFS);
> if (!bh)
> @@ -1426,7 +1427,7 @@ void set_bh_page(struct buffer_head *bh,
> struct page *page, unsigned long offset)
> {
> bh->b_page = page;
> - BUG_ON(offset >= PAGE_SIZE);
> + BUG_ON(offset >= compound_size(page));
> if (PageHighMem(page))
> /*
> * This catches illegal uses and preserves the offset:
> @@ -1605,6 +1606,7 @@ static int __block_write_full_page(struc
> struct buffer_head *bh, *head;
> const unsigned blocksize = 1 << inode->i_blkbits;
> int nr_underway = 0;
> + struct address_space *mapping = inode->i_mapping;
>
> BUG_ON(!PageLocked(page));
>
> @@ -1625,7 +1627,8 @@ static int __block_write_full_page(struc
> * handle that here by just cleaning them.
> */
>
> - block = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
> + block = (sector_t)page->index <<
> + (page_cache_shift(mapping) - inode->i_blkbits);
> head = page_buffers(page);
> bh = head;
>
> @@ -1742,7 +1745,7 @@ recover:
> } while ((bh = bh->b_this_page) != head);
> SetPageError(page);
> BUG_ON(PageWriteback(page));
> - mapping_set_error(page->mapping, err);
> + mapping_set_error(mapping, err);
> set_page_writeback(page);
> do {
> struct buffer_head *next = bh->b_this_page;
> @@ -1767,8 +1770,8 @@ static int __block_prepare_write(struct
> struct buffer_head *bh, *head, *wait[2], **wait_bh=wait;
>
> BUG_ON(!PageLocked(page));
> - BUG_ON(from > PAGE_CACHE_SIZE);
> - BUG_ON(to > PAGE_CACHE_SIZE);
> + BUG_ON(from > page_cache_size(inode->i_mapping));
> + BUG_ON(to > page_cache_size(inode->i_mapping));
> BUG_ON(from > to);
>
> blocksize = 1 << inode->i_blkbits;
> @@ -1777,7 +1780,8 @@ static int __block_prepare_write(struct
> head = page_buffers(page);
>
> bbits = inode->i_blkbits;
> - block = (sector_t)page->index << (PAGE_CACHE_SHIFT - bbits);
> + block = (sector_t)page->index <<
> + (page_cache_shift(inode->i_mapping) - bbits);
>
> for(bh = head, block_start = 0; bh != head || !block_start;
> block++, block_start=block_end, bh = bh->b_this_page) {
> @@ -1921,7 +1925,8 @@ int block_read_full_page(struct page *pa
> create_empty_buffers(page, blocksize, 0);
> head = page_buffers(page);
>
> - iblock = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
> + iblock = (sector_t)page->index <<
> + (page_cache_shift(page->mapping) - inode->i_blkbits);
> lblock = (i_size_read(inode)+blocksize-1) >> inode->i_blkbits;
> bh = head;
> nr = 0;
> @@ -2045,7 +2050,7 @@ int generic_cont_expand(struct inode *in
> pgoff_t index;
> unsigned int offset;
>
> - offset = (size & (PAGE_CACHE_SIZE - 1)); /* Within page */
> + offset = page_cache_offset(inode->i_mapping, size); /* Within page */
>
> /* ugh. in prepare/commit_write, if from==to==start of block, we
> ** skip the prepare. make sure we never send an offset for the start
> @@ -2055,7 +2060,7 @@ int generic_cont_expand(struct inode *in
> /* caller must handle this extra byte. */
> offset++;
> }
> - index = size >> PAGE_CACHE_SHIFT;
> + index = page_cache_index(inode->i_mapping, size);
>
> return __generic_cont_expand(inode, size, index, offset);
> }
> @@ -2063,8 +2068,8 @@ int generic_cont_expand(struct inode *in
> int generic_cont_expand_simple(struct inode *inode, loff_t size)
> {
> loff_t pos = size - 1;
> - pgoff_t index = pos >> PAGE_CACHE_SHIFT;
> - unsigned int offset = (pos & (PAGE_CACHE_SIZE - 1)) + 1;
> + pgoff_t index = page_cache_index(inode->i_mapping, pos);
> + unsigned int offset = page_cache_offset(inode->i_mapping, pos) + 1;
>
> /* prepare/commit_write can handle even if from==to==start of block. */
> return __generic_cont_expand(inode, size, index, offset);
> @@ -2086,28 +2091,28 @@ int cont_prepare_write(struct page *page
> unsigned zerofrom;
> unsigned blocksize = 1 << inode->i_blkbits;
>
> - while(page->index > (pgpos = *bytes>>PAGE_CACHE_SHIFT)) {
> + while (page->index > (pgpos = page_cache_index(mapping, *bytes))) {
> status = -ENOMEM;
> new_page = grab_cache_page(mapping, pgpos);
> if (!new_page)
> goto out;
> /* we might sleep */
> - if (*bytes>>PAGE_CACHE_SHIFT != pgpos) {
> + if (page_cache_index(mapping, *bytes) != pgpos) {
> unlock_page(new_page);
> page_cache_release(new_page);
> continue;
> }
> - zerofrom = *bytes & ~PAGE_CACHE_MASK;
> + zerofrom = page_cache_offset(mapping, *bytes);
> if (zerofrom & (blocksize-1)) {
> *bytes |= (blocksize-1);
> (*bytes)++;
> }
> status = __block_prepare_write(inode, new_page, zerofrom,
> - PAGE_CACHE_SIZE, get_block);
> + page_cache_size(mapping), get_block);
> if (status)
> goto out_unmap;
> - zero_user_segment(new_page, zerofrom, PAGE_CACHE_SIZE);
> - generic_commit_write(NULL, new_page, zerofrom, PAGE_CACHE_SIZE);
> + zero_user_segment(new_page, zerofrom, page_cache_size(mapping));
> + generic_commit_write(NULL, new_page, zerofrom, page_cache_size(mapping));
> unlock_page(new_page);
> page_cache_release(new_page);
> }
> @@ -2117,7 +2122,7 @@ int cont_prepare_write(struct page *page
> zerofrom = offset;
> } else {
> /* page covers the boundary, find the boundary offset */
> - zerofrom = *bytes & ~PAGE_CACHE_MASK;
> + zerofrom = page_cache_offset(mapping, *bytes);
>
> /* if we will expand the thing last block will be filled */
> if (to > zerofrom && (zerofrom & (blocksize-1))) {
> @@ -2169,8 +2174,9 @@ int block_commit_write(struct page *page
> int generic_commit_write(struct file *file, struct page *page,
> unsigned from, unsigned to)
> {
> - struct inode *inode = page->mapping->host;
> - loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
> + struct address_space *mapping = page->mapping;
> + struct inode *inode = mapping->host;
> + loff_t pos = page_cache_pos(mapping, page->index, to);
> __block_commit_write(inode,page,from,to);
> /*
> * No need to use i_size_read() here, the i_size
> @@ -2206,20 +2212,22 @@ block_page_mkwrite(struct vm_area_struct
> unsigned long end;
> loff_t size;
> int ret = -EINVAL;
> + struct address_space *mapping;
>
> lock_page(page);
> + mapping = page->mapping;
> size = i_size_read(inode);
> - if ((page->mapping != inode->i_mapping) ||
> + if ((mapping != inode->i_mapping) ||
> (page_offset(page) > size)) {
> /* page got truncated out from underneath us */
> goto out_unlock;
> }
>
> /* page is wholly or partially inside EOF */
> - if (((page->index + 1) << PAGE_CACHE_SHIFT) > size)
> - end = size & ~PAGE_CACHE_MASK;
> + if (page_cache_pos(mapping, page->index + 1, 0) > size)
> + end = page_cache_offset(mapping, size);
> else
> - end = PAGE_CACHE_SIZE;
> + end = page_cache_size(mapping);
>
> ret = block_prepare_write(page, 0, end, get_block);
> if (!ret)
> @@ -2258,6 +2266,7 @@ static void end_buffer_read_nobh(struct
> int nobh_prepare_write(struct page *page, unsigned from, unsigned to,
> get_block_t *get_block)
> {
> + struct address_space *mapping = page->mapping;
> struct inode *inode = page->mapping->host;
> const unsigned blkbits = inode->i_blkbits;
> const unsigned blocksize = 1 << blkbits;
> @@ -2265,6 +2274,7 @@ int nobh_prepare_write(struct page *page
> struct buffer_head *read_bh[MAX_BUF_PER_PAGE];
> unsigned block_in_page;
> unsigned block_start;
> + unsigned page_size = page_cache_size(mapping);
> sector_t block_in_file;
> int nr_reads = 0;
> int i;
> @@ -2274,7 +2284,8 @@ int nobh_prepare_write(struct page *page
> if (PageMappedToDisk(page))
> return 0;
>
> - block_in_file = (sector_t)page->index << (PAGE_CACHE_SHIFT - blkbits);
> + block_in_file = (sector_t)page->index <<
> + (page_cache_shift(mapping) - blkbits);
> map_bh.b_page = page;
>
> /*
> @@ -2283,7 +2294,7 @@ int nobh_prepare_write(struct page *page
> * page is fully mapped-to-disk.
> */
> for (block_start = 0, block_in_page = 0;
> - block_start < PAGE_CACHE_SIZE;
> + block_start < page_size;
> block_in_page++, block_start += blocksize) {
> unsigned block_end = block_start + blocksize;
> int create;
> @@ -2372,7 +2383,7 @@ failed:
> * Error recovery is pretty slack. Clear the page and mark it dirty
> * so we'll later zero out any blocks which _were_ allocated.
> */
> - zero_user(page, 0, PAGE_CACHE_SIZE);
> + zero_user(page, 0, page_size);
> SetPageUptodate(page);
> set_page_dirty(page);
> return ret;
> @@ -2386,8 +2397,9 @@ EXPORT_SYMBOL(nobh_prepare_write);
> int nobh_commit_write(struct file *file, struct page *page,
> unsigned from, unsigned to)
> {
> - struct inode *inode = page->mapping->host;
> - loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
> + struct address_space *mapping = page->mapping;
> + struct inode *inode = mapping->host;
> + loff_t pos = page_cache_pos(mapping, page->index, to);
>
> SetPageUptodate(page);
> set_page_dirty(page);
> @@ -2407,9 +2419,10 @@ EXPORT_SYMBOL(nobh_commit_write);
> int nobh_writepage(struct page *page, get_block_t *get_block,
> struct writeback_control *wbc)
> {
> - struct inode * const inode = page->mapping->host;
> + struct address_space *mapping = page->mapping;
> + struct inode * const inode = mapping->host;
> loff_t i_size = i_size_read(inode);
> - const pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
> + const pgoff_t end_index = page_cache_offset(mapping, i_size);
> unsigned offset;
> int ret;
>
> @@ -2418,7 +2431,7 @@ int nobh_writepage(struct page *page, ge
> goto out;
>
> /* Is the page fully outside i_size? (truncate in progress) */
> - offset = i_size & (PAGE_CACHE_SIZE-1);
> + offset = page_cache_offset(mapping, i_size);
> if (page->index >= end_index+1 || !offset) {
> /*
> * The page may have dirty, unmapped buffers. For example,
> @@ -2441,7 +2454,7 @@ int nobh_writepage(struct page *page, ge
> * the page size, the remaining memory is zeroed when mapped, and
> * writes to that region are not written out to the file."
> */
> - zero_user_segment(page, offset, PAGE_CACHE_SIZE);
> + zero_user_segment(page, offset, page_cache_size(mapping));
> out:
> ret = mpage_writepage(page, get_block, wbc);
> if (ret == -EAGAIN)
> @@ -2457,8 +2470,8 @@ int nobh_truncate_page(struct address_sp
> {
> struct inode *inode = mapping->host;
> unsigned blocksize = 1 << inode->i_blkbits;
> - pgoff_t index = from >> PAGE_CACHE_SHIFT;
> - unsigned offset = from & (PAGE_CACHE_SIZE-1);
> + pgoff_t index = page_cache_index(mapping, from);
> + unsigned offset = page_cache_offset(mapping, from);
> unsigned to;
> struct page *page;
> const struct address_space_operations *a_ops = mapping->a_ops;
> @@ -2475,7 +2488,7 @@ int nobh_truncate_page(struct address_sp
> to = (offset + blocksize) & ~(blocksize - 1);
> ret = a_ops->prepare_write(NULL, page, offset, to);
> if (ret == 0) {
> - zero_user_segment(page, offset, PAGE_CACHE_SIZE);
> + zero_user_segment(page, offset, page_cache_size(mapping));
> /*
> * It would be more correct to call aops->commit_write()
> * here, but this is more efficient.
> @@ -2493,8 +2506,8 @@ EXPORT_SYMBOL(nobh_truncate_page);
> int block_truncate_page(struct address_space *mapping,
> loff_t from, get_block_t *get_block)
> {
> - pgoff_t index = from >> PAGE_CACHE_SHIFT;
> - unsigned offset = from & (PAGE_CACHE_SIZE-1);
> + pgoff_t index = page_cache_index(mapping, from);
> + unsigned offset = page_cache_offset(mapping, from);
> unsigned blocksize;
> sector_t iblock;
> unsigned length, pos;
> @@ -2511,8 +2524,8 @@ int block_truncate_page(struct address_s
> return 0;
>
> length = blocksize - length;
> - iblock = (sector_t)index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
> -
> + iblock = (sector_t)index <<
> + (page_cache_shift(mapping) - inode->i_blkbits);
> page = grab_cache_page(mapping, index);
> err = -ENOMEM;
> if (!page)
> @@ -2571,9 +2584,10 @@ out:
> int block_write_full_page(struct page *page, get_block_t *get_block,
> struct writeback_control *wbc)
> {
> - struct inode * const inode = page->mapping->host;
> + struct address_space *mapping = page->mapping;
> + struct inode * const inode = mapping->host;
> loff_t i_size = i_size_read(inode);
> - const pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
> + const pgoff_t end_index = page_cache_index(mapping, i_size);
> unsigned offset;
>
> /* Is the page fully inside i_size? */
> @@ -2581,7 +2595,7 @@ int block_write_full_page(struct page *p
> return __block_write_full_page(inode, page, get_block, wbc);
>
> /* Is the page fully outside i_size? (truncate in progress) */
> - offset = i_size & (PAGE_CACHE_SIZE-1);
> + offset = page_cache_offset(mapping, i_size);
> if (page->index >= end_index+1 || !offset) {
> /*
> * The page may have dirty, unmapped buffers. For example,
> @@ -2600,7 +2614,7 @@ int block_write_full_page(struct page *p
> * the page size, the remaining memory is zeroed when mapped, and
> * writes to that region are not written out to the file."
> */
> - zero_user_segment(page, offset, PAGE_CACHE_SIZE);
> + zero_user_segment(page, offset, page_cache_size(mapping));
> return __block_write_full_page(inode, page, get_block, wbc);
> }
>
> @@ -2854,7 +2868,7 @@ int try_to_free_buffers(struct page *pag
> * dirty bit from being lost.
> */
> if (ret)
> - cancel_dirty_page(page, PAGE_CACHE_SIZE);
> + cancel_dirty_page(page, page_cache_size(mapping));
> spin_unlock(&mapping->private_lock);
> out:
> if (buffers_to_free) {
>
> --
> -
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