From 9651e6b2e20648d04d5e1fe6479a3056047e8781 Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Sun, 21 May 2017 22:35:23 -0400 Subject: [PATCH] ext4: handle the rest of ext4_mb_load_buddy() ENOMEM errors I've got another report about breaking ext4 by ENOMEM error returned from ext4_mb_load_buddy() caused by memory shortage in memory cgroup. This time inside ext4_discard_preallocations(). This patch replaces ext4_error() with ext4_warning() where errors returned from ext4_mb_load_buddy() are not fatal and handled by caller: * ext4_mb_discard_group_preallocations() - called before generating ENOSPC, we'll try to discard other group or return ENOSPC into user-space. * ext4_trim_all_free() - just stop trimming and return ENOMEM from ioctl. Some callers cannot handle errors, thus __GFP_NOFAIL is used for them: * ext4_discard_preallocations() * ext4_mb_discard_lg_preallocations() Fixes: adb7ef600cc9 ("ext4: use __GFP_NOFAIL in ext4_free_blocks()") Signed-off-by: Konstantin Khlebnikov Signed-off-by: Theodore Ts'o --- fs/ext4/mballoc.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 5083bce20ac4..b7928cddd539 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -3887,7 +3887,8 @@ ext4_mb_discard_group_preallocations(struct super_block *sb, err = ext4_mb_load_buddy(sb, group, &e4b); if (err) { - ext4_error(sb, "Error loading buddy information for %u", group); + ext4_warning(sb, "Error %d loading buddy information for %u", + err, group); put_bh(bitmap_bh); return 0; } @@ -4044,10 +4045,11 @@ repeat: BUG_ON(pa->pa_type != MB_INODE_PA); group = ext4_get_group_number(sb, pa->pa_pstart); - err = ext4_mb_load_buddy(sb, group, &e4b); + err = ext4_mb_load_buddy_gfp(sb, group, &e4b, + GFP_NOFS|__GFP_NOFAIL); if (err) { - ext4_error(sb, "Error loading buddy information for %u", - group); + ext4_error(sb, "Error %d loading buddy information for %u", + err, group); continue; } @@ -4303,11 +4305,14 @@ ext4_mb_discard_lg_preallocations(struct super_block *sb, spin_unlock(&lg->lg_prealloc_lock); list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) { + int err; group = ext4_get_group_number(sb, pa->pa_pstart); - if (ext4_mb_load_buddy(sb, group, &e4b)) { - ext4_error(sb, "Error loading buddy information for %u", - group); + err = ext4_mb_load_buddy_gfp(sb, group, &e4b, + GFP_NOFS|__GFP_NOFAIL); + if (err) { + ext4_error(sb, "Error %d loading buddy information for %u", + err, group); continue; } ext4_lock_group(sb, group); @@ -5127,8 +5132,8 @@ ext4_trim_all_free(struct super_block *sb, ext4_group_t group, ret = ext4_mb_load_buddy(sb, group, &e4b); if (ret) { - ext4_error(sb, "Error in loading buddy " - "information for %u", group); + ext4_warning(sb, "Error %d loading buddy information for %u", + ret, group); return ret; } bitmap = e4b.bd_bitmap; -- 2.39.2