From: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Subject: mm/shmem: add __rcu annotations and properly deref radix entry Patch series "restructure memfd code", v4. This patch (of 3): In preparation for memfd code restucture, clean up sparse warnings. Most changes required adding __rcu annotations. The routine find_swap_entry was modified to properly deference radix tree entries. Link: http://lkml.kernel.org/r/20180415182119.4517-2-mike.kravetz@xxxxxxxxxx Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Marc-Andr Lureau <marcandre.lureau@xxxxxxxxx> Cc: David Herrmann <dh.herrmann@xxxxxxxxx> Cc: Khalid Aziz <khalid.aziz@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/shmem.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff -puN mm/shmem.c~mm-shmem-add-__rcu-annotations-and-properly-deref-radix-entry mm/shmem.c --- a/mm/shmem.c~mm-shmem-add-__rcu-annotations-and-properly-deref-radix-entry +++ a/mm/shmem.c @@ -327,7 +327,7 @@ static int shmem_radix_tree_replace(stru pgoff_t index, void *expected, void *replacement) { struct radix_tree_node *node; - void **pslot; + void __rcu **pslot; void *item; VM_BUG_ON(!expected); @@ -395,7 +395,7 @@ static bool shmem_confirm_swap(struct ad #ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE /* ifdef here to avoid bloating shmem.o when not necessary */ -int shmem_huge __read_mostly; +static int shmem_huge __read_mostly; #if defined(CONFIG_SYSFS) || defined(CONFIG_TMPFS) static int shmem_parse_huge(const char *str) @@ -682,7 +682,7 @@ unsigned long shmem_partial_swap_usage(s pgoff_t start, pgoff_t end) { struct radix_tree_iter iter; - void **slot; + void __rcu **slot; struct page *page; unsigned long swapped = 0; @@ -1098,13 +1098,19 @@ static void shmem_evict_inode(struct ino static unsigned long find_swap_entry(struct radix_tree_root *root, void *item) { struct radix_tree_iter iter; - void **slot; + void __rcu **slot; unsigned long found = -1; unsigned int checked = 0; rcu_read_lock(); radix_tree_for_each_slot(slot, root, &iter, 0) { - if (*slot == item) { + void *entry = radix_tree_deref_slot(slot); + + if (radix_tree_deref_retry(entry)) { + slot = radix_tree_iter_retry(&iter); + continue; + } + if (entry == item) { found = iter.index; break; } @@ -2622,7 +2628,7 @@ static loff_t shmem_file_llseek(struct f static void shmem_tag_pins(struct address_space *mapping) { struct radix_tree_iter iter; - void **slot; + void __rcu **slot; pgoff_t start; struct page *page; @@ -2664,7 +2670,7 @@ static void shmem_tag_pins(struct addres static int shmem_wait_for_pins(struct address_space *mapping) { struct radix_tree_iter iter; - void **slot; + void __rcu **slot; pgoff_t start; struct page *page; int error, scan; _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
