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authorTheodore Ts'o <tytso@mit.edu>2016-03-26 16:14:34 -0400
committerTheodore Ts'o <tytso@mit.edu>2016-03-26 16:14:34 -0400
commitc9af28fdd44922a6c10c9f8315718408af98e315 (patch)
treeb5bc491b5d141ba710bc6da44b00125b8d5d589c /fs/ext4/page-io.c
parent9e92f48c34eb2b9af9d12f892e2fe1fce5e8ce35 (diff)
ext4 crypto: don't let data integrity writebacks fail with ENOMEM
We don't want the writeback triggered from the journal commit (in data=writeback mode) to cause the journal to abort due to generic_writepages() returning an ENOMEM error. In addition, if fsync() fails with ENOMEM, most applications will probably not do the right thing. So if we are doing a data integrity sync, and ext4_encrypt() returns ENOMEM, we will submit any queued I/O to date, and then retry the allocation using GFP_NOFAIL. Google-Bug-Id: 27641567 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/page-io.c')
-rw-r--r--fs/ext4/page-io.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index d77d15f4b674..51b349211da7 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -23,6 +23,7 @@
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/mm.h>
+#include <linux/backing-dev.h>
#include "ext4_jbd2.h"
#include "xattr.h"
@@ -470,9 +471,20 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
if (ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode) &&
nr_to_submit) {
- data_page = ext4_encrypt(inode, page);
+ gfp_t gfp_flags = GFP_NOFS;
+
+ retry_encrypt:
+ data_page = ext4_encrypt(inode, page, gfp_flags);
if (IS_ERR(data_page)) {
ret = PTR_ERR(data_page);
+ if (ret == ENOMEM && wbc->sync_mode == WB_SYNC_ALL) {
+ if (io->io_bio) {
+ ext4_io_submit(io);
+ congestion_wait(BLK_RW_ASYNC, HZ/50);
+ }
+ gfp_flags |= __GFP_NOFAIL;
+ goto retry_encrypt;
+ }
data_page = NULL;
goto out;
}