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Commit a969e903 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Linus Torvalds
Browse files

kill generic_file_direct_IO() 



generic_file_direct_IO is a common helper around the invocation of
->direct_IO.  But there's almost nothing shared between the read and write
side, so we're better off without this helper.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 75353bed

mm/filemap.c

+51 −66
Original line number Diff line number Diff line
@@ -42,9 +42,6 @@ 


#include <asm/mman.h>



static ssize_t

generic_file_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,

	loff_t offset, unsigned long nr_segs);



/*

 * Shared mappings implemented 30.11.1994. It's not fully working yet,
@@ -1205,8 +1202,11 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov, 
			goto out; /* skip atime */

		size = i_size_read(inode);

		if (pos < size) {

			retval = generic_file_direct_IO(READ, iocb,

			retval = filemap_write_and_wait(mapping);

			if (!retval) {

				retval = mapping->a_ops->direct_IO(READ, iocb,

							iov, pos, nr_segs);

			}

			if (retval > 0)

				*ppos = pos + retval;

		}
@@ -2004,11 +2004,55 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov, 
	struct address_space *mapping = file->f_mapping;

	struct inode	*inode = mapping->host;

	ssize_t		written;

	size_t		write_len;

	pgoff_t		end;



	if (count != ocount)

		*nr_segs = iov_shorten((struct iovec *)iov, *nr_segs, count);



	written = generic_file_direct_IO(WRITE, iocb, iov, pos, *nr_segs);

	/*

	 * Unmap all mmappings of the file up-front.

	 *

	 * This will cause any pte dirty bits to be propagated into the

	 * pageframes for the subsequent filemap_write_and_wait().

	 */

	write_len = iov_length(iov, *nr_segs);

	end = (pos + write_len - 1) >> PAGE_CACHE_SHIFT;

	if (mapping_mapped(mapping))

		unmap_mapping_range(mapping, pos, write_len, 0);



	written = filemap_write_and_wait(mapping);

	if (written)

		goto out;



	/*

	 * After a write we want buffered reads to be sure to go to disk to get

	 * the new data.  We invalidate clean cached page from the region we're

	 * about to write.  We do this *before* the write so that we can return

	 * -EIO without clobbering -EIOCBQUEUED from ->direct_IO().

	 */

	if (mapping->nrpages) {

		written = invalidate_inode_pages2_range(mapping,

					pos >> PAGE_CACHE_SHIFT, end);

		if (written)

			goto out;

	}



	written = mapping->a_ops->direct_IO(WRITE, iocb, iov, pos, *nr_segs);



	/*

	 * Finally, try again to invalidate clean pages which might have been

	 * cached by non-direct readahead, or faulted in by get_user_pages()

	 * if the source of the write was an mmap'ed region of the file

	 * we're writing.  Either one is a pretty crazy thing to do,

	 * so we don't support it 100%.  If this invalidation

	 * fails, tough, the write still worked...

	 */

	if (mapping->nrpages) {

		invalidate_inode_pages2_range(mapping,

					      pos >> PAGE_CACHE_SHIFT, end);

	}



	if (written > 0) {

		loff_t end = pos + written;

		if (end > i_size_read(inode) && !S_ISBLK(inode->i_mode)) {
@@ -2024,6 +2068,7 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov, 
	 * i_mutex is held, which protects generic_osync_inode() from

	 * livelocking.  AIO O_DIRECT ops attempt to sync metadata here.

	 */

out:

	if ((written >= 0 || written == -EIOCBQUEUED) &&

	    ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {

		int err = generic_osync_inode(inode, mapping, OSYNC_METADATA);
@@ -2511,66 +2556,6 @@ ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, 
}

EXPORT_SYMBOL(generic_file_aio_write);



/*

 * Called under i_mutex for writes to S_ISREG files.   Returns -EIO if something

 * went wrong during pagecache shootdown.

 */

static ssize_t

generic_file_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,

	loff_t offset, unsigned long nr_segs)

{

	struct file *file = iocb->ki_filp;

	struct address_space *mapping = file->f_mapping;

	ssize_t retval;

	size_t write_len;

	pgoff_t end = 0; /* silence gcc */



	/*

	 * If it's a write, unmap all mmappings of the file up-front.  This

	 * will cause any pte dirty bits to be propagated into the pageframes

	 * for the subsequent filemap_write_and_wait().

	 */

	if (rw == WRITE) {

		write_len = iov_length(iov, nr_segs);

		end = (offset + write_len - 1) >> PAGE_CACHE_SHIFT;

	       	if (mapping_mapped(mapping))

			unmap_mapping_range(mapping, offset, write_len, 0);

	}



	retval = filemap_write_and_wait(mapping);

	if (retval)

		goto out;



	/*

	 * After a write we want buffered reads to be sure to go to disk to get

	 * the new data.  We invalidate clean cached page from the region we're

	 * about to write.  We do this *before* the write so that we can return

	 * -EIO without clobbering -EIOCBQUEUED from ->direct_IO().

	 */

	if (rw == WRITE && mapping->nrpages) {

		retval = invalidate_inode_pages2_range(mapping,

					offset >> PAGE_CACHE_SHIFT, end);

		if (retval)

			goto out;

	}



	retval = mapping->a_ops->direct_IO(rw, iocb, iov, offset, nr_segs);



	/*

	 * Finally, try again to invalidate clean pages which might have been

	 * cached by non-direct readahead, or faulted in by get_user_pages()

	 * if the source of the write was an mmap'ed region of the file

	 * we're writing.  Either one is a pretty crazy thing to do,

	 * so we don't support it 100%.  If this invalidation

	 * fails, tough, the write still worked...

	 */

	if (rw == WRITE && mapping->nrpages) {

		invalidate_inode_pages2_range(mapping, offset >> PAGE_CACHE_SHIFT, end);

	}

out:

	return retval;

}



/**

 * try_to_release_page() - release old fs-specific metadata on a page

 *