mho...@kernel.org wrote:

> From: Michal Hocko <mho...@suse.com>
>
> Journal transaction might fail prematurely because the frozen_buffer
> is allocated by GFP_NOFS request:
> [   72.440013] do_get_write_access: OOM for frozen_buffer
> [   72.440014] EXT4-fs: ext4_reserve_inode_write:4729: aborting transaction: 
> Out of memory in __ext4_journal_get_write_access
> [   72.440015] EXT4-fs error (device sda1) in ext4_reserve_inode_write:4735: 
> Out of memory
> (...snipped....)
> [   72.495559] do_get_write_access: OOM for frozen_buffer
> [   72.495560] EXT4-fs: ext4_reserve_inode_write:4729: aborting transaction: 
> Out of memory in __ext4_journal_get_write_access
> [   72.496839] do_get_write_access: OOM for frozen_buffer
> [   72.496841] EXT4-fs: ext4_reserve_inode_write:4729: aborting transaction: 
> Out of memory in __ext4_journal_get_write_access
> [   72.505766] Aborting journal on device sda1-8.
> [   72.505851] EXT4-fs (sda1): Remounting filesystem read-only
>
> This wasn't a problem until "mm: page_alloc: do not lock up GFP_NOFS
> allocations upon OOM" because small GPF_NOFS allocations never failed.
> This allocation seems essential for the journal and GFP_NOFS is too
> restrictive to the memory allocator so let's use __GFP_NOFAIL here to
> emulate the previous behavior.
>
> jbd code has the very same issue so let's do the same there as well.
>
> Signed-off-by: Michal Hocko <mho...@suse.com>
> ---
>  fs/jbd/transaction.c  | 11 +----------
>  fs/jbd2/transaction.c | 14 +++-----------
>  2 files changed, 4 insertions(+), 21 deletions(-)
>
> diff --git a/fs/jbd/transaction.c b/fs/jbd/transaction.c
> index 1695ba8334a2..bf7474deda2f 100644
> --- a/fs/jbd/transaction.c
> +++ b/fs/jbd/transaction.c
> @@ -673,16 +673,7 @@ do_get_write_access(handle_t *handle, struct 
> journal_head *jh,
>                               jbd_unlock_bh_state(bh);
>                               frozen_buffer =
>                                       jbd_alloc(jh2bh(jh)->b_size,
> -                                                      GFP_NOFS);
> -                             if (!frozen_buffer) {
> -                                     printk(KERN_ERR
> -                                            "%s: OOM for frozen_buffer\n",
> -                                            __func__);
> -                                     JBUFFER_TRACE(jh, "oom!");
> -                                     error = -ENOMEM;
> -                                     jbd_lock_bh_state(bh);
> -                                     goto done;
> -                             }
> +                                                      GFP_NOFS|__GFP_NOFAIL);
>                               goto repeat;
>                       }
>                       jh->b_frozen_data = frozen_buffer;
> diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
> index ff2f2e6ad311..bff071e21553 100644
> --- a/fs/jbd2/transaction.c
> +++ b/fs/jbd2/transaction.c
> @@ -923,16 +923,7 @@ do_get_write_access(handle_t *handle, struct 
> journal_head *jh,
>                               jbd_unlock_bh_state(bh);
>                               frozen_buffer =
>                                       jbd2_alloc(jh2bh(jh)->b_size,
> -                                                      GFP_NOFS);
> -                             if (!frozen_buffer) {
> -                                     printk(KERN_ERR
> -                                            "%s: OOM for frozen_buffer\n",
> -                                            __func__);
> -                                     JBUFFER_TRACE(jh, "oom!");
> -                                     error = -ENOMEM;
> -                                     jbd_lock_bh_state(bh);
> -                                     goto done;
> -                             }
> +                                                      GFP_NOFS|__GFP_NOFAIL);
>                               goto repeat;
>                       }
>                       jh->b_frozen_data = frozen_buffer;
> @@ -1157,7 +1148,8 @@ int jbd2_journal_get_undo_access(handle_t *handle, 
> struct buffer_head *bh)
>  
>  repeat:
>       if (!jh->b_committed_data) {
> -             committed_data = jbd2_alloc(jh2bh(jh)->b_size, GFP_NOFS);
> +             committed_data = jbd2_alloc(jh2bh(jh)->b_size,
> +                                         GFP_NOFS|__GFP_NOFAIL);
>               if (!committed_data) {
>                       printk(KERN_ERR "%s: No memory for committed data\n",
>                               __func__);

Is this "if (!committed_data) {" check now dead code?

I also see other similar suspected dead sites in the rest of the series.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to