From: mhocko@kernel.org Subject: [RFC 4/8] jbd, jbd2: Do not fail journal because of frozen_buffer allocation failure Date: Wed, 5 Aug 2015 11:51:20 +0200 Message-ID: <1438768284-30927-5-git-send-email-mhocko@kernel.org> References: <1438768284-30927-1-git-send-email-mhocko@kernel.org> Cc: , , Andrew Morton , Johannes Weiner , Tetsuo Handa , Dave Chinner , "Theodore Ts'o" , linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, Jan Kara , Michal Hocko To: LKML Return-path: In-Reply-To: <1438768284-30927-1-git-send-email-mhocko@kernel.org> Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org From: Michal Hocko 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 --- 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__); -- 2.5.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org