| Message ID | 20210714023440.2608690-2-david@fromorbit.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | xfs, mm: memory allocation improvements | expand |
On Wed, Jul 14, 2021 at 12:34:38PM +1000, Dave Chinner wrote: > From: Dave Chinner <dchinner@redhat.com> > > During log recovery of an XFS filesystem with 64kB directory > buffers, rebuilding a buffer split across two log records results > in a memory allocation warning from krealloc like this: > > xfs filesystem being mounted at /mnt/scratch supports timestamps until 2038 (0x7fffffff) > XFS (dm-0): Unmounting Filesystem > XFS (dm-0): Mounting V5 Filesystem > XFS (dm-0): Starting recovery (logdev: internal) > ------------[ cut here ]------------ > WARNING: CPU: 5 PID: 3435170 at mm/page_alloc.c:3539 get_page_from_freelist+0xdee/0xe40 > ..... > RIP: 0010:get_page_from_freelist+0xdee/0xe40 > Call Trace: > ? complete+0x3f/0x50 > __alloc_pages+0x16f/0x300 > alloc_pages+0x87/0x110 > kmalloc_order+0x2c/0x90 > kmalloc_order_trace+0x1d/0x90 > __kmalloc_track_caller+0x215/0x270 > ? xlog_recover_add_to_cont_trans+0x63/0x1f0 > krealloc+0x54/0xb0 > xlog_recover_add_to_cont_trans+0x63/0x1f0 > xlog_recovery_process_trans+0xc1/0xd0 > xlog_recover_process_ophdr+0x86/0x130 > xlog_recover_process_data+0x9f/0x160 > xlog_recover_process+0xa2/0x120 > xlog_do_recovery_pass+0x40b/0x7d0 > ? __irq_work_queue_local+0x4f/0x60 > ? irq_work_queue+0x3a/0x50 > xlog_do_log_recovery+0x70/0x150 > xlog_do_recover+0x38/0x1d0 > xlog_recover+0xd8/0x170 > xfs_log_mount+0x181/0x300 > xfs_mountfs+0x4a1/0x9b0 > xfs_fs_fill_super+0x3c0/0x7b0 > get_tree_bdev+0x171/0x270 > ? suffix_kstrtoint.constprop.0+0xf0/0xf0 > xfs_fs_get_tree+0x15/0x20 > vfs_get_tree+0x24/0xc0 > path_mount+0x2f5/0xaf0 > __x64_sys_mount+0x108/0x140 > do_syscall_64+0x3a/0x70 > entry_SYSCALL_64_after_hwframe+0x44/0xae > > Essentially, we are taking a multi-order allocation from kmem_alloc() > (which has an open coded no fail, no warn loop) and then > reallocating it out to 64kB using krealloc(__GFP_NOFAIL) and that is > then triggering the above warning. > > This is a regression caused by converting this code from an open > coded no fail/no warn reallocation loop to using __GFP_NOFAIL. > > What we actually need here is kvrealloc(), so that if contiguous > page allocation fails we fall back to vmalloc() and we don't > get nasty warnings happening in XFS. > > Fixes: 771915c4f688 ("xfs: remove kmem_realloc()") > Signed-off-by: Dave Chinner <dchinner@redhat.com> Acked-by: Mel Gorman <mgorman@techsingularity.net>
On Wed, Jul 14, 2021 at 12:34:38PM +1000, Dave Chinner wrote: > From: Dave Chinner <dchinner@redhat.com> > > During log recovery of an XFS filesystem with 64kB directory > buffers, rebuilding a buffer split across two log records results > in a memory allocation warning from krealloc like this: > > xfs filesystem being mounted at /mnt/scratch supports timestamps until 2038 (0x7fffffff) > XFS (dm-0): Unmounting Filesystem > XFS (dm-0): Mounting V5 Filesystem > XFS (dm-0): Starting recovery (logdev: internal) > ------------[ cut here ]------------ > WARNING: CPU: 5 PID: 3435170 at mm/page_alloc.c:3539 get_page_from_freelist+0xdee/0xe40 > ..... > RIP: 0010:get_page_from_freelist+0xdee/0xe40 > Call Trace: > ? complete+0x3f/0x50 > __alloc_pages+0x16f/0x300 > alloc_pages+0x87/0x110 > kmalloc_order+0x2c/0x90 > kmalloc_order_trace+0x1d/0x90 > __kmalloc_track_caller+0x215/0x270 > ? xlog_recover_add_to_cont_trans+0x63/0x1f0 > krealloc+0x54/0xb0 > xlog_recover_add_to_cont_trans+0x63/0x1f0 > xlog_recovery_process_trans+0xc1/0xd0 > xlog_recover_process_ophdr+0x86/0x130 > xlog_recover_process_data+0x9f/0x160 > xlog_recover_process+0xa2/0x120 > xlog_do_recovery_pass+0x40b/0x7d0 > ? __irq_work_queue_local+0x4f/0x60 > ? irq_work_queue+0x3a/0x50 > xlog_do_log_recovery+0x70/0x150 > xlog_do_recover+0x38/0x1d0 > xlog_recover+0xd8/0x170 > xfs_log_mount+0x181/0x300 > xfs_mountfs+0x4a1/0x9b0 > xfs_fs_fill_super+0x3c0/0x7b0 > get_tree_bdev+0x171/0x270 > ? suffix_kstrtoint.constprop.0+0xf0/0xf0 > xfs_fs_get_tree+0x15/0x20 > vfs_get_tree+0x24/0xc0 > path_mount+0x2f5/0xaf0 > __x64_sys_mount+0x108/0x140 > do_syscall_64+0x3a/0x70 > entry_SYSCALL_64_after_hwframe+0x44/0xae > > Essentially, we are taking a multi-order allocation from kmem_alloc() > (which has an open coded no fail, no warn loop) and then > reallocating it out to 64kB using krealloc(__GFP_NOFAIL) and that is > then triggering the above warning. > > This is a regression caused by converting this code from an open > coded no fail/no warn reallocation loop to using __GFP_NOFAIL. > > What we actually need here is kvrealloc(), so that if contiguous > page allocation fails we fall back to vmalloc() and we don't > get nasty warnings happening in XFS. > > Fixes: 771915c4f688 ("xfs: remove kmem_realloc()") > Signed-off-by: Dave Chinner <dchinner@redhat.com> Looks good now, Reviewed-by: Darrick J. Wong <djwong@kernel.org> --D > --- > fs/xfs/xfs_log_recover.c | 4 +++- > include/linux/mm.h | 2 ++ > mm/util.c | 15 +++++++++++++++ > 3 files changed, 20 insertions(+), 1 deletion(-) > > diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c > index 1721fce2ec94..3c08d495844d 100644 > --- a/fs/xfs/xfs_log_recover.c > +++ b/fs/xfs/xfs_log_recover.c > @@ -2062,7 +2062,9 @@ xlog_recover_add_to_cont_trans( > old_ptr = item->ri_buf[item->ri_cnt-1].i_addr; > old_len = item->ri_buf[item->ri_cnt-1].i_len; > > - ptr = krealloc(old_ptr, len + old_len, GFP_KERNEL | __GFP_NOFAIL); > + ptr = kvrealloc(old_ptr, old_len, len + old_len, GFP_KERNEL); > + if (!ptr) > + return -ENOMEM; > memcpy(&ptr[old_len], dp, len); > item->ri_buf[item->ri_cnt-1].i_len += len; > item->ri_buf[item->ri_cnt-1].i_addr = ptr; > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 57453dba41b9..ff9c00bfb76d 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -829,6 +829,8 @@ static inline void *kvcalloc(size_t n, size_t size, gfp_t flags) > return kvmalloc_array(n, size, flags | __GFP_ZERO); > } > > +extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, > + gfp_t flags); > extern void kvfree(const void *addr); > extern void kvfree_sensitive(const void *addr, size_t len); > > diff --git a/mm/util.c b/mm/util.c > index 99c6cc77de9e..b7698d6b2226 100644 > --- a/mm/util.c > +++ b/mm/util.c > @@ -635,6 +635,21 @@ void kvfree_sensitive(const void *addr, size_t len) > } > EXPORT_SYMBOL(kvfree_sensitive); > > +void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags) > +{ > + void *newp; > + > + if (oldsize >= newsize) > + return (void *)p; > + newp = kvmalloc(newsize, flags); > + if (!newp) > + return NULL; > + memcpy(newp, p, oldsize); > + kvfree(p); > + return newp; > +} > +EXPORT_SYMBOL(kvrealloc); > + > static inline void *__page_rmapping(struct page *page) > { > unsigned long mapping; > -- > 2.31.1 >
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c index 1721fce2ec94..3c08d495844d 100644 --- a/fs/xfs/xfs_log_recover.c +++ b/fs/xfs/xfs_log_recover.c @@ -2062,7 +2062,9 @@ xlog_recover_add_to_cont_trans( old_ptr = item->ri_buf[item->ri_cnt-1].i_addr; old_len = item->ri_buf[item->ri_cnt-1].i_len; - ptr = krealloc(old_ptr, len + old_len, GFP_KERNEL | __GFP_NOFAIL); + ptr = kvrealloc(old_ptr, old_len, len + old_len, GFP_KERNEL); + if (!ptr) + return -ENOMEM; memcpy(&ptr[old_len], dp, len); item->ri_buf[item->ri_cnt-1].i_len += len; item->ri_buf[item->ri_cnt-1].i_addr = ptr; diff --git a/include/linux/mm.h b/include/linux/mm.h index 57453dba41b9..ff9c00bfb76d 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -829,6 +829,8 @@ static inline void *kvcalloc(size_t n, size_t size, gfp_t flags) return kvmalloc_array(n, size, flags | __GFP_ZERO); } +extern void *kvrealloc(const void *p, size_t oldsize, size_t newsize, + gfp_t flags); extern void kvfree(const void *addr); extern void kvfree_sensitive(const void *addr, size_t len); diff --git a/mm/util.c b/mm/util.c index 99c6cc77de9e..b7698d6b2226 100644 --- a/mm/util.c +++ b/mm/util.c @@ -635,6 +635,21 @@ void kvfree_sensitive(const void *addr, size_t len) } EXPORT_SYMBOL(kvfree_sensitive); +void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags) +{ + void *newp; + + if (oldsize >= newsize) + return (void *)p; + newp = kvmalloc(newsize, flags); + if (!newp) + return NULL; + memcpy(newp, p, oldsize); + kvfree(p); + return newp; +} +EXPORT_SYMBOL(kvrealloc); + static inline void *__page_rmapping(struct page *page) { unsigned long mapping;