* ->swap_lock (try_to_unmap_one)
* ->private_lock (try_to_unmap_one)
* ->i_pages lock (try_to_unmap_one)
- * ->zone_lru_lock(zone) (follow_page->mark_page_accessed)
- * ->zone_lru_lock(zone) (check_pte_range->isolate_lru_page)
+ * ->pgdat->lru_lock (follow_page->mark_page_accessed)
+ * ->pgdat->lru_lock (check_pte_range->isolate_lru_page)
* ->private_lock (page_remove_rmap->set_page_dirty)
* ->i_pages lock (page_remove_rmap->set_page_dirty)
* bdi.wb->list_lock (page_remove_rmap->set_page_dirty)
* opposed to a regular memory cleansing writeback. The difference between
* these two operations is that if a dirty page/buffer is encountered, it must
* be waited upon, and not just skipped over.
+ *
+ * Return: %0 on success, negative error code otherwise.
*/
int __filemap_fdatawrite_range(struct address_space *mapping, loff_t start,
loff_t end, int sync_mode)
*
* This is a mostly non-blocking flush. Not suitable for data-integrity
* purposes - I/O may not be started against all dirty pages.
+ *
+ * Return: %0 on success, negative error code otherwise.
*/
int filemap_flush(struct address_space *mapping)
{
*
* Find at least one page in the range supplied, usually used to check if
* direct writing in this range will trigger a writeback.
+ *
+ * Return: %true if at least one page exists in the specified range,
+ * %false otherwise.
*/
bool filemap_range_has_page(struct address_space *mapping,
loff_t start_byte, loff_t end_byte)
* Since the error status of the address space is cleared by this function,
* callers are responsible for checking the return value and handling and/or
* reporting the error.
+ *
+ * Return: error status of the address space.
*/
int filemap_fdatawait_range(struct address_space *mapping, loff_t start_byte,
loff_t end_byte)
* Since the error status of the file is advanced by this function,
* callers are responsible for checking the return value and handling and/or
* reporting the error.
+ *
+ * Return: error status of the address space vs. the file->f_wb_err cursor.
*/
int file_fdatawait_range(struct file *file, loff_t start_byte, loff_t end_byte)
{
* Use this function if callers don't handle errors themselves. Expected
* call sites are system-wide / filesystem-wide data flushers: e.g. sync(2),
* fsfreeze(8)
+ *
+ * Return: error status of the address space.
*/
int filemap_fdatawait_keep_errors(struct address_space *mapping)
{
*
* Note that @lend is inclusive (describes the last byte to be written) so
* that this function can be used to write to the very end-of-file (end = -1).
+ *
+ * Return: error status of the address space.
*/
int filemap_write_and_wait_range(struct address_space *mapping,
loff_t lstart, loff_t lend)
* While we handle mapping->wb_err with atomic operations, the f_wb_err
* value is protected by the f_lock since we must ensure that it reflects
* the latest value swapped in for this file descriptor.
+ *
+ * Return: %0 on success, negative error code otherwise.
*/
int file_check_and_advance_wb_err(struct file *file)
{
*
* After writing out and waiting on the data, we check and advance the
* f_wb_err cursor to the latest value, and return any errors detected there.
+ *
+ * Return: %0 on success, negative error code otherwise.
*/
int file_write_and_wait_range(struct file *file, loff_t lstart, loff_t lend)
{
* caller must do that.
*
* The remove + add is atomic. This function cannot fail.
+ *
+ * Return: %0
*/
int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
{
*
* This function is used to add a page to the pagecache. It must be locked.
* This function does not add the page to the LRU. The caller must do that.
+ *
+ * Return: %0 on success, negative error code otherwise.
*/
int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
pgoff_t offset, gfp_t gfp_mask)
* If the slot holds a shadow entry of a previously evicted page, or a
* swap entry from shmem/tmpfs, it is returned.
*
- * Otherwise, %NULL is returned.
+ * Return: the found page or shadow entry, %NULL if nothing is found.
*/
struct page *find_get_entry(struct address_space *mapping, pgoff_t offset)
{
* If the slot holds a shadow entry of a previously evicted page, or a
* swap entry from shmem/tmpfs, it is returned.
*
- * Otherwise, %NULL is returned.
- *
* find_lock_entry() may sleep.
+ *
+ * Return: the found page or shadow entry, %NULL if nothing is found.
*/
struct page *find_lock_entry(struct address_space *mapping, pgoff_t offset)
{
* - FGP_CREAT: If page is not present then a new page is allocated using
* @gfp_mask and added to the page cache and the VM's LRU
* list. The page is returned locked and with an increased
- * refcount. Otherwise, NULL is returned.
+ * refcount.
*
* If FGP_LOCK or FGP_CREAT are specified then the function may sleep even
* if the GFP flags specified for FGP_CREAT are atomic.
*
* If there is a page cache page, it is returned with an increased refcount.
+ *
+ * Return: the found page or %NULL otherwise.
*/
struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset,
int fgp_flags, gfp_t gfp_mask)
* Any shadow entries of evicted pages, or swap entries from
* shmem/tmpfs, are included in the returned array.
*
- * find_get_entries() returns the number of pages and shadow entries
- * which were found.
+ * Return: the number of pages and shadow entries which were found.
*/
unsigned find_get_entries(struct address_space *mapping,
pgoff_t start, unsigned int nr_entries,
* indexes. There may be holes in the indices due to not-present pages.
* We also update @start to index the next page for the traversal.
*
- * find_get_pages_range() returns the number of pages which were found. If this
- * number is smaller than @nr_pages, the end of specified range has been
+ * Return: the number of pages which were found. If this number is
+ * smaller than @nr_pages, the end of specified range has been
* reached.
*/
unsigned find_get_pages_range(struct address_space *mapping, pgoff_t *start,
pages[ret] = page;
if (++ret == nr_pages) {
- *start = page->index + 1;
+ *start = xas.xa_index + 1;
goto out;
}
continue;
* find_get_pages_contig() works exactly like find_get_pages(), except
* that the returned number of pages are guaranteed to be contiguous.
*
- * find_get_pages_contig() returns the number of pages which were found.
+ * Return: the number of pages which were found.
*/
unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t index,
unsigned int nr_pages, struct page **pages)
if (unlikely(page != xas_reload(&xas)))
goto put_page;
- /*
- * must check mapping and index after taking the ref.
- * otherwise we can get both false positives and false
- * negatives, which is just confusing to the caller.
- */
- if (!page->mapping || page_to_pgoff(page) != xas.xa_index) {
- put_page(page);
- break;
- }
-
pages[ret] = page;
if (++ret == nr_pages)
break;
*
* Like find_get_pages, except we only return pages which are tagged with
* @tag. We update @index to index the next page for the traversal.
+ *
+ * Return: the number of pages which were found.
*/
unsigned find_get_pages_range_tag(struct address_space *mapping, pgoff_t *index,
pgoff_t end, xa_mark_t tag, unsigned int nr_pages,
pages[ret] = page;
if (++ret == nr_pages) {
- *index = page->index + 1;
+ *index = xas.xa_index + 1;
goto out;
}
continue;
*
* Like find_get_entries, except we only return entries which are tagged with
* @tag.
+ *
+ * Return: the number of entries which were found.
*/
unsigned find_get_entries_tag(struct address_space *mapping, pgoff_t start,
xa_mark_t tag, unsigned int nr_entries,
*
* This is really ugly. But the goto's actually try to clarify some
* of the logic when it comes to error handling etc.
+ *
+ * Return:
+ * * total number of bytes copied, including those the were already @written
+ * * negative error code if nothing was copied
*/
static ssize_t generic_file_buffered_read(struct kiocb *iocb,
struct iov_iter *iter, ssize_t written)
*
* This is the "read_iter()" routine for all filesystems
* that can use the page cache directly.
+ * Return:
+ * * number of bytes copied, even for partial reads
+ * * negative error code if nothing was read
*/
ssize_t
generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
*
* This adds the requested page to the page cache if it isn't already there,
* and schedules an I/O to read in its contents from disk.
+ *
+ * Return: %0 on success, negative error code otherwise.
*/
static int page_cache_read(struct file *file, pgoff_t offset, gfp_t gfp_mask)
{
* has not been released.
*
* We never return with VM_FAULT_RETRY and a bit from VM_FAULT_ERROR set.
+ *
+ * Return: bitwise-OR of %VM_FAULT_ codes.
*/
vm_fault_t filemap_fault(struct vm_fault *vmf)
{
* not set, try to fill the page and wait for it to become unlocked.
*
* If the page does not get brought uptodate, return -EIO.
+ *
+ * Return: up to date page on success, ERR_PTR() on failure.
*/
struct page *read_cache_page(struct address_space *mapping,
pgoff_t index,
* any new page allocations done using the specified allocation flags.
*
* If the page does not get brought uptodate, return -EIO.
+ *
+ * Return: up to date page on success, ERR_PTR() on failure.
*/
struct page *read_cache_page_gfp(struct address_space *mapping,
pgoff_t index,
if (iocb->ki_flags & IOCB_NOWAIT) {
/* If there are pages to writeback, return */
if (filemap_range_has_page(inode->i_mapping, pos,
- pos + write_len))
+ pos + write_len - 1))
return -EAGAIN;
} else {
written = filemap_write_and_wait_range(mapping, pos,
* This function does *not* take care of syncing data in case of O_SYNC write.
* A caller has to handle it. This is mainly due to the fact that we want to
* avoid syncing under i_mutex.
+ *
+ * Return:
+ * * number of bytes written, even for truncated writes
+ * * negative error code if no data has been written at all
*/
ssize_t __generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
* This is a wrapper around __generic_file_write_iter() to be used by most
* filesystems. It takes care of syncing the file in case of O_SYNC file
* and acquires i_mutex as needed.
+ * Return:
+ * * negative error code if no data has been written at all of
+ * vfs_fsync_range() failed for a synchronous write
+ * * number of bytes written, even for truncated writes
*/
ssize_t generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
* @gfp_mask: memory allocation flags (and I/O mode)
*
* The address_space is to try to release any data against the page
- * (presumably at page->private). If the release was successful, return '1'.
- * Otherwise return zero.
+ * (presumably at page->private).
*
* This may also be called if PG_fscache is set on a page, indicating that the
* page is known to the local caching routines.
* The @gfp_mask argument specifies whether I/O may be performed to release
* this page (__GFP_IO), and whether the call may block (__GFP_RECLAIM & __GFP_FS).
*
+ * Return: %1 if the release was successful, otherwise return zero.
*/
int try_to_release_page(struct page *page, gfp_t gfp_mask)
{
git.samba.org / sfrench / cifs-2.6.git / blobdiff