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| author | Theodore Ts'o <tytso@mit.edu> | 2016-03-26 23:14:34 +0300 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2016-03-26 23:14:34 +0300 |
| commit | c9af28fdd44922a6c10c9f8315718408af98e315 (patch) | |
| tree | b5bc491b5d141ba710bc6da44b00125b8d5d589c /fs/ext4/page-io.c | |
| parent | 9e92f48c34eb2b9af9d12f892e2fe1fce5e8ce35 (diff) | |
| download | linux-c9af28fdd44922a6c10c9f8315718408af98e315.tar.xz | |
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.c | 14 |
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; } |