* Looks up the page cache slot at @mapping & @offset. If there is a
* page cache page, it is returned with an increased refcount.
*
- * If the slot holds a shadow entry of a previously evicted page, it
- * is returned.
+ * 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.
*/
if (radix_tree_deref_retry(page))
goto repeat;
/*
- * Otherwise, shmem/tmpfs must be storing a swap entry
- * here as an exceptional entry: so return it without
- * attempting to raise page count.
+ * A shadow entry of a recently evicted page,
+ * or a swap entry from shmem/tmpfs. Return
+ * it without attempting to raise page count.
*/
goto out;
}
* page cache page, it is returned locked and with an increased
* refcount.
*
- * If the slot holds a shadow entry of a previously evicted page, it
- * is returned.
+ * 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.
*
* with ascending indexes. There may be holes in the indices due to
* not-present pages.
*
- * Any shadow entries of evicted pages are included in the returned
- * array.
+ * 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.
if (radix_tree_deref_retry(page))
goto restart;
/*
- * Otherwise, we must be storing a swap entry
- * here as an exceptional entry: so return it
- * without attempting to raise page count.
+ * A shadow entry of a recently evicted page,
+ * or a swap entry from shmem/tmpfs. Return
+ * it without attempting to raise page count.
*/
goto export;
}
goto restart;
}
/*
- * Otherwise, shmem/tmpfs must be storing a swap entry
- * here as an exceptional entry: so skip over it -
- * we only reach this from invalidate_mapping_pages().
+ * A shadow entry of a recently evicted page,
+ * or a swap entry from shmem/tmpfs. Skip
+ * over it.
*/
continue;
}
goto restart;
}
/*
- * Otherwise, shmem/tmpfs must be storing a swap entry
- * here as an exceptional entry: so stop looking for
- * contiguous pages.
+ * A shadow entry of a recently evicted page,
+ * or a swap entry from shmem/tmpfs. Stop
+ * looking for contiguous pages.
*/
break;
}
goto restart;
}
/*
- * This function is never used on a shmem/tmpfs
- * mapping, so a swap entry won't be found here.
+ * A shadow entry of a recently evicted page.
+ *
+ * Those entries should never be tagged, but
+ * this tree walk is lockless and the tags are
+ * looked up in bulk, one radix tree node at a
+ * time, so there is a sizable window for page
+ * reclaim to evict a page we saw tagged.
+ *
+ * Skip over it.
*/
- BUG();
+ continue;
}
if (!page_cache_get_speculative(page))
EXPORT_SYMBOL(pagecache_write_end);
ssize_t
-generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
- unsigned long *nr_segs, loff_t pos,
- size_t count, size_t ocount)
+generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from,
+ loff_t pos, size_t count, size_t ocount)
{
struct file *file = iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
pgoff_t end;
if (count != ocount)
- *nr_segs = iov_shorten((struct iovec *)iov, *nr_segs, count);
+ from->nr_segs = iov_shorten((struct iovec *)from->iov, from->nr_segs, count);
- write_len = iov_length(iov, *nr_segs);
+ write_len = iov_length(from->iov, from->nr_segs);
end = (pos + write_len - 1) >> PAGE_CACHE_SHIFT;
written = filemap_write_and_wait_range(mapping, pos, pos + write_len - 1);
}
}
- written = mapping->a_ops->direct_IO(WRITE, iocb, iov, pos, *nr_segs);
+ written = mapping->a_ops->direct_IO(WRITE, iocb, from->iov, pos, from->nr_segs);
/*
* Finally, try again to invalidate clean pages which might have been
if (written > 0) {
pos += written;
+ iov_iter_advance(from, written);
if (pos > i_size_read(inode) && !S_ISBLK(inode->i_mode)) {
i_size_write(inode, pos);
mark_inode_dirty(inode);
* @iocb: IO state structure (file, offset, etc.)
* @iov: vector with data to write
* @nr_segs: number of segments in the vector
- * @ppos: position where to write
*
* This function does all the work needed for actually writing data to a
* file. It does all basic checks, removes SUID from the file, updates
if (unlikely(file->f_flags & O_DIRECT)) {
loff_t endbyte;
- written = generic_file_direct_write(iocb, iov, &from.nr_segs, pos,
+ written = generic_file_direct_write(iocb, &from, pos,
count, ocount);
if (written < 0 || written == count)
goto out;
- iov_iter_advance(&from, written);
/*
* direct-io write to a hole: fall through to buffered I/O
projects / linux.git / blobdiff