Commit a8fa74ab authored by Dmitriy Monakhov's avatar Dmitriy Monakhov Committed by Linus Torvalds
Browse files

[PATCH] ecryptfs: handle AOP_TRUNCATED_PAGE better 



- In fact we don't have to fail if AOP_TRUNCATED_PAGE was returned from
  prepare_write or commit_write. It is beter to retry attempt where it
  is possible.

- Rearange ecryptfs_get_lower_page() error handling logic, make it more clean.

Signed-off-by: default avatarDmitriy Monakhov <dmonakhov@openvz.org>
Acked-by: default avatarMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 82b16528

fs/ecryptfs/mmap.c

+16 −12
Original line number Diff line number Diff line
@@ -446,6 +446,7 @@ static int ecryptfs_write_inode_size_to_header(struct file *lower_file, 
	const struct address_space_operations *lower_a_ops;

	u64 file_size;



retry:

	header_page = grab_cache_page(lower_inode->i_mapping, 0);

	if (!header_page) {

		ecryptfs_printk(KERN_ERR, "grab_cache_page for "
@@ -456,9 +457,10 @@ static int ecryptfs_write_inode_size_to_header(struct file *lower_file, 
	lower_a_ops = lower_inode->i_mapping->a_ops;

	rc = lower_a_ops->prepare_write(lower_file, header_page, 0, 8);

	if (rc) {

		if (rc == AOP_TRUNCATED_PAGE)

		if (rc == AOP_TRUNCATED_PAGE) {

			ecryptfs_release_lower_page(header_page, 0);

		else

			goto retry;

		} else

			ecryptfs_release_lower_page(header_page, 1);

		goto out;

	}
@@ -473,9 +475,10 @@ static int ecryptfs_write_inode_size_to_header(struct file *lower_file, 
	if (rc < 0)

		ecryptfs_printk(KERN_ERR, "Error commiting header page "

				"write\n");

	if (rc == AOP_TRUNCATED_PAGE)

	if (rc == AOP_TRUNCATED_PAGE) {

		ecryptfs_release_lower_page(header_page, 0);

	else

		goto retry;

	} else

		ecryptfs_release_lower_page(header_page, 1);

	lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME;

	mark_inode_dirty_sync(inode);
@@ -565,6 +568,7 @@ int ecryptfs_get_lower_page(struct page **lower_page, struct inode *lower_inode, 
{

	int rc = 0;



retry:

	*lower_page = grab_cache_page(lower_inode->i_mapping, lower_page_index);

	if (!(*lower_page)) {

		rc = -EINVAL;
@@ -578,18 +582,18 @@ int ecryptfs_get_lower_page(struct page **lower_page, struct inode *lower_inode, 
							  byte_offset,

							  region_bytes);

	if (rc) {

		if (rc == AOP_TRUNCATED_PAGE) {

			ecryptfs_release_lower_page(*lower_page, 0);

			goto retry;

		} else {

			ecryptfs_printk(KERN_ERR, "prepare_write for "

				"lower_page_index = [0x%.16x] failed; rc = "

				"[%d]\n", lower_page_index, rc);

	}

out:

	if (rc && (*lower_page)) {

		if (rc == AOP_TRUNCATED_PAGE)

			ecryptfs_release_lower_page(*lower_page, 0);

		else

			ecryptfs_release_lower_page(*lower_page, 1);

			(*lower_page) = NULL;

		}

	}

out:

	return rc;

}

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