--- /dev/null
+From 28cb13f29faf6290597b24b728dc3100c019356f Mon Sep 17 00:00:00 2001
+From: Filipe Manana <fdmanana@suse.com>
+Date: Tue, 18 Jun 2024 12:15:01 +0100
+Subject: btrfs: don't BUG_ON() when 0 reference count at btrfs_lookup_extent_info()
+
+From: Filipe Manana <fdmanana@suse.com>
+
+commit 28cb13f29faf6290597b24b728dc3100c019356f upstream.
+
+Instead of doing a BUG_ON() handle the error by returning -EUCLEAN,
+aborting the transaction and logging an error message.
+
+Reviewed-by: Qu Wenruo <wqu@suse.com>
+Signed-off-by: Filipe Manana <fdmanana@suse.com>
+Signed-off-by: David Sterba <dsterba@suse.com>
+[Minor conflict resolved due to code context change.]
+Signed-off-by: Jianqi Ren <jianqi.ren.cn@windriver.com>
+Signed-off-by: He Zhe <zhe.he@windriver.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ fs/btrfs/extent-tree.c | 25 ++++++++++++++++++++-----
+ 1 file changed, 20 insertions(+), 5 deletions(-)
+
+--- a/fs/btrfs/extent-tree.c
++++ b/fs/btrfs/extent-tree.c
+@@ -174,6 +174,14 @@ search_again:
+ ei = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_extent_item);
+ num_refs = btrfs_extent_refs(leaf, ei);
++ if (unlikely(num_refs == 0)) {
++ ret = -EUCLEAN;
++ btrfs_err(fs_info,
++ "unexpected zero reference count for extent item (%llu %u %llu)",
++ key.objectid, key.type, key.offset);
++ btrfs_abort_transaction(trans, ret);
++ goto out_free;
++ }
+ extent_flags = btrfs_extent_flags(leaf, ei);
+ } else {
+ ret = -EINVAL;
+@@ -185,8 +193,6 @@ search_again:
+
+ goto out_free;
+ }
+-
+- BUG_ON(num_refs == 0);
+ } else {
+ num_refs = 0;
+ extent_flags = 0;
+@@ -216,10 +222,19 @@ search_again:
+ goto search_again;
+ }
+ spin_lock(&head->lock);
+- if (head->extent_op && head->extent_op->update_flags)
++ if (head->extent_op && head->extent_op->update_flags) {
+ extent_flags |= head->extent_op->flags_to_set;
+- else
+- BUG_ON(num_refs == 0);
++ } else if (unlikely(num_refs == 0)) {
++ spin_unlock(&head->lock);
++ mutex_unlock(&head->mutex);
++ spin_unlock(&delayed_refs->lock);
++ ret = -EUCLEAN;
++ btrfs_err(fs_info,
++ "unexpected zero reference count for extent %llu (%s)",
++ bytenr, metadata ? "metadata" : "data");
++ btrfs_abort_transaction(trans, ret);
++ goto out_free;
++ }
+
+ num_refs += head->ref_mod;
+ spin_unlock(&head->lock);
--- /dev/null
+From ab00ddd802f80e31fc9639c652d736fe3913feae Mon Sep 17 00:00:00 2001
+From: Feng Tang <feng.tang@linux.alibaba.com>
+Date: Wed, 23 Apr 2025 18:36:45 +0800
+Subject: selftests/mm: compaction_test: support platform with huge mount of memory
+
+From: Feng Tang <feng.tang@linux.alibaba.com>
+
+commit ab00ddd802f80e31fc9639c652d736fe3913feae upstream.
+
+When running mm selftest to verify mm patches, 'compaction_test' case
+failed on an x86 server with 1TB memory. And the root cause is that it
+has too much free memory than what the test supports.
+
+The test case tries to allocate 100000 huge pages, which is about 200 GB
+for that x86 server, and when it succeeds, it expects it's large than 1/3
+of 80% of the free memory in system. This logic only works for platform
+with 750 GB ( 200 / (1/3) / 80% ) or less free memory, and may raise false
+alarm for others.
+
+Fix it by changing the fixed page number to self-adjustable number
+according to the real number of free memory.
+
+Link: https://lkml.kernel.org/r/20250423103645.2758-1-feng.tang@linux.alibaba.com
+Fixes: bd67d5c15cc1 ("Test compaction of mlocked memory")
+Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com>
+Acked-by: Dev Jain <dev.jain@arm.com>
+Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
+Tested-by: Baolin Wang <baolin.wang@inux.alibaba.com>
+Cc: Shuah Khan <shuah@kernel.org>
+Cc: Sri Jayaramappa <sjayaram@akamai.com>
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ tools/testing/selftests/vm/compaction_test.c | 19 ++++++++++++++-----
+ 1 file changed, 14 insertions(+), 5 deletions(-)
+
+--- a/tools/testing/selftests/vm/compaction_test.c
++++ b/tools/testing/selftests/vm/compaction_test.c
+@@ -89,6 +89,8 @@ int check_compaction(unsigned long mem_f
+ int compaction_index = 0;
+ char initial_nr_hugepages[20] = {0};
+ char nr_hugepages[20] = {0};
++ char target_nr_hugepages[24] = {0};
++ int slen;
+
+ /* We want to test with 80% of available memory. Else, OOM killer comes
+ in to play */
+@@ -118,11 +120,18 @@ int check_compaction(unsigned long mem_f
+
+ lseek(fd, 0, SEEK_SET);
+
+- /* Request a large number of huge pages. The Kernel will allocate
+- as much as it can */
+- if (write(fd, "100000", (6*sizeof(char))) != (6*sizeof(char))) {
+- ksft_test_result_fail("Failed to write 100000 to /proc/sys/vm/nr_hugepages: %s\n",
+- strerror(errno));
++ /*
++ * Request huge pages for about half of the free memory. The Kernel
++ * will allocate as much as it can, and we expect it will get at least 1/3
++ */
++ nr_hugepages_ul = mem_free / hugepage_size / 2;
++ snprintf(target_nr_hugepages, sizeof(target_nr_hugepages),
++ "%lu", nr_hugepages_ul);
++
++ slen = strlen(target_nr_hugepages);
++ if (write(fd, target_nr_hugepages, slen) != slen) {
++ ksft_test_result_fail("Failed to write %lu to /proc/sys/vm/nr_hugepages: %s\n",
++ nr_hugepages_ul, strerror(errno));
+ goto close_fd;
+ }
+
projects / thirdparty / kernel / stable-queue.git / commitdiff
