This is a note to let you know that I've just added the patch titled
fs/dax.c: fix inefficiency in dax_writeback_mapping_range()
to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: fs-dax.c-fix-inefficiency-in-dax_writeback_mapping_range.patch and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Mon Feb 26 20:55:53 CET 2018
From: Dan Williams dan.j.williams@intel.com Date: Fri, 23 Feb 2018 14:05:33 -0800 Subject: fs/dax.c: fix inefficiency in dax_writeback_mapping_range() To: gregkh@linuxfoundation.org Cc: Jan Kara jack@suse.cz, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Ross Zwisler ross.zwisler@linux.intel.com, Linus Torvalds torvalds@linux-foundation.org, Andrew Morton akpm@linux-foundation.org Message-ID: 151942353293.21775.3589635231521871832.stgit@dwillia2-desk3.amr.corp.intel.com
From: Jan Kara jack@suse.cz
commit 1eb643d02b21412e603b42cdd96010a2ac31c05f upstream.
dax_writeback_mapping_range() fails to update iteration index when searching radix tree for entries needing cache flushing. Thus each pagevec worth of entries is searched starting from the start which is inefficient and prone to livelocks. Update index properly.
Link: http://lkml.kernel.org/r/20170619124531.21491-1-jack@suse.cz Fixes: 9973c98ecfda3 ("dax: add support for fsync/sync") Signed-off-by: Jan Kara jack@suse.cz Reviewed-by: Ross Zwisler ross.zwisler@linux.intel.com Cc: Dan Williams dan.j.williams@intel.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/dax.c | 1 + 1 file changed, 1 insertion(+)
--- a/fs/dax.c +++ b/fs/dax.c @@ -785,6 +785,7 @@ int dax_writeback_mapping_range(struct a if (ret < 0) return ret; } + start_index = indices[pvec.nr - 1] + 1; } return 0; }
Patches currently in stable-queue which might be from dan.j.williams@intel.com are
queue-4.9/mm-fix-devm_memremap_pages-collision-handling.patch queue-4.9/ib-core-disable-memory-registration-of-filesystem-dax-vmas.patch queue-4.9/mm-avoid-spurious-bad-pmd-warning-messages.patch queue-4.9/mm-introduce-get_user_pages_longterm.patch queue-4.9/mm-fail-get_vaddr_frames-for-filesystem-dax-mappings.patch queue-4.9/fs-dax.c-fix-inefficiency-in-dax_writeback_mapping_range.patch queue-4.9/device-dax-implement-split-to-catch-invalid-munmap-attempts.patch queue-4.9/v4l2-disable-filesystem-dax-mapping-support.patch queue-4.9/libnvdimm-dax-fix-1gb-aligned-namespaces-vs-physical-misalignment.patch queue-4.9/x86-entry-64-clear-extra-registers-beyond-syscall-arguments-to-reduce-speculation-attack-surface.patch queue-4.9/libnvdimm-fix-integer-overflow-static-analysis-warning.patch