mm: move filemap_range_needs_writeback() into header

No functional changes in this patch, just in preparation for efficiently
calling this light function from the block O_DIRECT handling.

Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2021-10-28 08:47:05 -06:00
parent a08ed9aae8
commit 4bdcd1dd4d
4 changed files with 33 additions and 31 deletions

View File

@ -6,6 +6,7 @@
#include <linux/module.h>
#include <linux/compiler.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/iomap.h>
#include <linux/backing-dev.h>
#include <linux/uio.h>

View File

@ -2847,8 +2847,6 @@ static inline int filemap_fdatawait(struct address_space *mapping)
extern bool filemap_range_has_page(struct address_space *, loff_t lstart,
loff_t lend);
extern bool filemap_range_needs_writeback(struct address_space *,
loff_t lstart, loff_t lend);
extern int filemap_write_and_wait_range(struct address_space *mapping,
loff_t lstart, loff_t lend);
extern int __filemap_fdatawrite_range(struct address_space *mapping,

View File

@ -963,6 +963,35 @@ static inline int add_to_page_cache(struct page *page,
int __filemap_add_folio(struct address_space *mapping, struct folio *folio,
pgoff_t index, gfp_t gfp, void **shadowp);
bool filemap_range_has_writeback(struct address_space *mapping,
loff_t start_byte, loff_t end_byte);
/**
* filemap_range_needs_writeback - check if range potentially needs writeback
* @mapping: address space within which to check
* @start_byte: offset in bytes where the range starts
* @end_byte: offset in bytes where the range ends (inclusive)
*
* Find at least one page in the range supplied, usually used to check if
* direct writing in this range will trigger a writeback. Used by O_DIRECT
* read/write with IOCB_NOWAIT, to see if the caller needs to do
* filemap_write_and_wait_range() before proceeding.
*
* Return: %true if the caller should do filemap_write_and_wait_range() before
* doing O_DIRECT to a page in this range, %false otherwise.
*/
static inline bool filemap_range_needs_writeback(struct address_space *mapping,
loff_t start_byte,
loff_t end_byte)
{
if (!mapping->nrpages)
return false;
if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
!mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK))
return false;
return filemap_range_has_writeback(mapping, start_byte, end_byte);
}
/**
* struct readahead_control - Describes a readahead request.
*

View File

@ -646,8 +646,8 @@ static bool mapping_needs_writeback(struct address_space *mapping)
return mapping->nrpages;
}
static bool filemap_range_has_writeback(struct address_space *mapping,
loff_t start_byte, loff_t end_byte)
bool filemap_range_has_writeback(struct address_space *mapping,
loff_t start_byte, loff_t end_byte)
{
XA_STATE(xas, &mapping->i_pages, start_byte >> PAGE_SHIFT);
pgoff_t max = end_byte >> PAGE_SHIFT;
@ -667,34 +667,8 @@ static bool filemap_range_has_writeback(struct address_space *mapping,
}
rcu_read_unlock();
return page != NULL;
}
/**
* filemap_range_needs_writeback - check if range potentially needs writeback
* @mapping: address space within which to check
* @start_byte: offset in bytes where the range starts
* @end_byte: offset in bytes where the range ends (inclusive)
*
* Find at least one page in the range supplied, usually used to check if
* direct writing in this range will trigger a writeback. Used by O_DIRECT
* read/write with IOCB_NOWAIT, to see if the caller needs to do
* filemap_write_and_wait_range() before proceeding.
*
* Return: %true if the caller should do filemap_write_and_wait_range() before
* doing O_DIRECT to a page in this range, %false otherwise.
*/
bool filemap_range_needs_writeback(struct address_space *mapping,
loff_t start_byte, loff_t end_byte)
{
if (!mapping_needs_writeback(mapping))
return false;
if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
!mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK))
return false;
return filemap_range_has_writeback(mapping, start_byte, end_byte);
}
EXPORT_SYMBOL_GPL(filemap_range_needs_writeback);
EXPORT_SYMBOL_GPL(filemap_range_has_writeback);
/**
* filemap_write_and_wait_range - write out & wait on a file range