{
/*
* per-block data is stored in the head page. Callers should
- * not be dealing with tail pages (and if they are, they can
+ * not be dealing with tail pages, and if they are, they can
* call thp_head() first.
*/
VM_BUG_ON_PGFLAGS(PageTail(page), page);
unsigned last = (poff + plen - 1) >> block_bits;
/*
- * If the block size is smaller than the page size we need to check the
+ * If the block size is smaller than the page size, we need to check the
* per-block uptodate status and adjust the offset and length if needed
* to avoid reading in already uptodate ranges.
*/
}
/*
- * If the extent spans the block that contains the i_size we need to
+ * If the extent spans the block that contains the i_size, we need to
* handle both halves separately so that we properly zero data in the
* page cache for blocks that are entirely outside of i_size.
*/
done:
/*
* Move the caller beyond our range so that it keeps making progress.
- * For that we have to include any leading non-uptodate ranges, but
+ * For that, we have to include any leading non-uptodate ranges, but
* we can skip trailing ones as they will be handled in the next
* iteration.
*/
}
/*
- * Just like mpage_readahead and block_read_full_page we always
+ * Just like mpage_readahead and block_read_full_page, we always
* return 0 and just mark the page as PageError on errors. This
- * should be cleaned up all through the stack eventually.
+ * should be cleaned up throughout the stack eventually.
*/
return 0;
}
/*
* mm accommodates an old ext3 case where clean pages might not have had
* the dirty bit cleared. Thus, it can send actual dirty pages to
- * ->releasepage() via shrink_active_list(), skip those here.
+ * ->releasepage() via shrink_active_list(); skip those here.
*/
if (PageDirty(page) || PageWriteback(page))
return 0;
trace_iomap_invalidatepage(page->mapping->host, offset, len);
/*
- * If we are invalidating the entire page, clear the dirty state from it
+ * If we're invalidating the entire page, clear the dirty state from it
* and release it to avoid unnecessary buildup of the LRU.
*/
if (offset == 0 && len == PAGE_SIZE) {
/*
* The blocks that were entirely written will now be uptodate, so we
* don't have to worry about a readpage reading them and overwriting a
- * partial write. However if we have encountered a short write and only
+ * partial write. However, if we've encountered a short write and only
* partially written into a block, it will not be marked uptodate, so a
* readpage might come in and destroy our partial write.
*
- * Do the simplest thing, and just treat any short write to a non
- * uptodate page as a zero-length write, and force the caller to redo
- * the whole thing.
+ * Do the simplest thing and just treat any short write to a
+ * non-uptodate page as a zero-length write, and force the caller to
+ * redo the whole thing.
*/
if (unlikely(copied < len && !PageUptodate(page)))
return 0;
bytes = length;
/*
- * Bring in the user page that we will copy from _first_.
+ * Bring in the user page that we'll copy from _first_.
* Otherwise there's a nasty deadlock on copying from the
* same page as we're writing to, without it being marked
* up-to-date.
* Submit the final bio for an ioend.
*
* If @error is non-zero, it means that we have a situation where some part of
- * the submission process has failed after we have marked paged for writeback
+ * the submission process has failed after we've marked pages for writeback
* and unlocked them. In this situation, we need to fail the bio instead of
* submitting it. This typically only happens on a filesystem shutdown.
*/
error = wpc->ops->prepare_ioend(ioend, error);
if (error) {
/*
- * If we are failing the IO now, just mark the ioend with an
+ * If we're failing the IO now, just mark the ioend with an
* error and finish it. This will run IO completion immediately
* as there is only one reference to the ioend at this point in
* time.
/*
* Allocate a new bio, and chain the old bio to the new one.
*
- * Note that we have to do perform the chaining in this unintuitive order
+ * Note that we have to perform the chaining in this unintuitive order
* so that the bi_private linkage is set up in the right direction for the
* traversal in iomap_finish_ioend().
*/
/*
* Test to see if we have an existing ioend structure that we could append to
- * first, otherwise finish off the current ioend and start another.
+ * first; otherwise finish off the current ioend and start another.
*/
static void
iomap_add_to_ioend(struct inode *inode, loff_t offset, struct page *page,
/*
* We implement an immediate ioend submission policy here to avoid needing to
* chain multiple ioends and hence nest mempool allocations which can violate
- * forward progress guarantees we need to provide. The current ioend we are
- * adding blocks to is cached on the writepage context, and if the new block
- * does not append to the cached ioend it will create a new ioend and cache that
+ * the forward progress guarantees we need to provide. The current ioend we're
+ * adding blocks to is cached in the writepage context, and if the new block
+ * doesn't append to the cached ioend, it will create a new ioend and cache that
* instead.
*
* If a new ioend is created and cached, the old ioend is returned and queued
if (unlikely(error)) {
/*
* Let the filesystem know what portion of the current page
- * failed to map. If the page wasn't been added to ioend, it
+ * failed to map. If the page hasn't been added to ioend, it
* won't be affected by I/O completion and we must unlock it
* now.
*/
unlock_page(page);
/*
- * Preserve the original error if there was one, otherwise catch
+ * Preserve the original error if there was one; catch
* submission errors here and propagate into subsequent ioend
* submissions.
*/
/*
* Write out a dirty page.
*
- * For delalloc space on the page we need to allocate space and flush it.
- * For unwritten space on the page we need to start the conversion to
+ * For delalloc space on the page, we need to allocate space and flush it.
+ * For unwritten space on the page, we need to start the conversion to
* regular allocated space.
*/
static int
trace_iomap_writepage(inode, page_offset(page), PAGE_SIZE);
/*
- * Refuse to write the page out if we are called from reclaim context.
+ * Refuse to write the page out if we're called from reclaim context.
*
* This avoids stack overflows when called from deeply used stacks in
* random callers for direct reclaim or memcg reclaim. We explicitly
unsigned offset_into_page = offset & (PAGE_SIZE - 1);
/*
- * Skip the page if it is fully outside i_size, e.g. due to a
- * truncate operation that is in progress. We must redirty the
+ * Skip the page if it's fully outside i_size, e.g. due to a
+ * truncate operation that's in progress. We must redirty the
* page so that reclaim stops reclaiming it. Otherwise
* iomap_vm_releasepage() is called on it and gets confused.
*
- * Note that the end_index is unsigned long, it would overflow
- * if the given offset is greater than 16TB on 32-bit system
- * and if we do check the page is fully outside i_size or not
- * via "if (page->index >= end_index + 1)" as "end_index + 1"
- * will be evaluated to 0. Hence this page will be redirtied
- * and be written out repeatedly which would result in an
- * infinite loop, the user program that perform this operation
- * will hang. Instead, we can verify this situation by checking
- * if the page to write is totally beyond the i_size or if it's
+ * Note that the end_index is unsigned long. If the given
+ * offset is greater than 16TB on a 32-bit system then if we
+ * checked if the page is fully outside i_size with
+ * "if (page->index >= end_index + 1)", "end_index + 1" would
+ * overflow and evaluate to 0. Hence this page would be
+ * redirtied and written out repeatedly, which would result in
+ * an infinite loop; the user program performing this operation
+ * would hang. Instead, we can detect this situation by
+ * checking if the page is totally beyond i_size or if its
* offset is just equal to the EOF.
*/
if (page->index > end_index ||
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