Merge tag 'efi-urgent-2020-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git...

[linux.git] / fs / ext4 / page-io.c

diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index 24aeedb8fc752cf193d636b8a1cee445cb61787b..68b39e75446a158d4bc8db2381f6072c5bb2ffb0 100644 (file)
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -512,17 +512,26 @@ int ext4_bio_write_page(struct ext4_io_submit *io,
                gfp_t gfp_flags = GFP_NOFS;
                unsigned int enc_bytes = round_up(len, i_blocksize(inode));
 
+               /*
+                * Since bounce page allocation uses a mempool, we can only use
+                * a waiting mask (i.e. request guaranteed allocation) on the
+                * first page of the bio.  Otherwise it can deadlock.
+                */
+               if (io->io_bio)
+                       gfp_flags = GFP_NOWAIT | __GFP_NOWARN;
        retry_encrypt:
                bounce_page = fscrypt_encrypt_pagecache_blocks(page, enc_bytes,
                                                               0, gfp_flags);
                if (IS_ERR(bounce_page)) {
                        ret = PTR_ERR(bounce_page);
-                       if (ret == -ENOMEM && wbc->sync_mode == WB_SYNC_ALL) {
-                               if (io->io_bio) {
+                       if (ret == -ENOMEM &&
+                           (io->io_bio || wbc->sync_mode == WB_SYNC_ALL)) {
+                               gfp_flags = GFP_NOFS;
+                               if (io->io_bio)
                                        ext4_io_submit(io);
-                                       congestion_wait(BLK_RW_ASYNC, HZ/50);
-                               }
-                               gfp_flags |= __GFP_NOFAIL;
+                               else
+                                       gfp_flags |= __GFP_NOFAIL;
+                               congestion_wait(BLK_RW_ASYNC, HZ/50);
                                goto retry_encrypt;
                        }