[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: Dmitriy Monakhov <dmonakhov@openvz.org>
Acked-by: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index 7def4be..b731b09 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -446,6 +446,7 @@
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 @@
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 @@
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 rc = 0;
+retry:
*lower_page = grab_cache_page(lower_inode->i_mapping, lower_page_index);
if (!(*lower_page)) {
rc = -EINVAL;
@@ -578,18 +582,18 @@
byte_offset,
region_bytes);
if (rc) {
- ecryptfs_printk(KERN_ERR, "prepare_write for "
+ 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);
+ ecryptfs_release_lower_page(*lower_page, 1);
+ (*lower_page) = NULL;
+ }
}
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;
- }
return rc;
}