Merge branch 'akpm' (patches from Andrew)

Merge misc patches from Andrew Morton:

- a little bit more MM

- a few fixups

[ The "little bit more MM" is actually just one of the three patches
  Andrew sent for mm/filemap.c, I'm still mulling over two more of them
  from Josef Bacik     - Linus ]

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  include/linux/swap.h: use offsetof() instead of custom __swapoffset macro
  tools/testing/selftests/proc/proc-pid-vm.c: test with vsyscall in mind
  zram: default to lzo-rle instead of lzo
  filemap: pass vm_fault to the mmap ra helpers

drivers/block/zram/zram_drv.c

@@ -41,7 +41,7 @@ static DEFINE_IDR(zram_index_idr);
 static DEFINE_MUTEX(zram_index_mutex);
 
 static int zram_major;
-static const char *default_compressor = "lzo";
+static const char *default_compressor = "lzo-rle";
 
 /* Module params (documentation at end) */
 static unsigned int num_devices = 1;

include/linux/swap.h

@@ -157,9 +157,9 @@ struct swap_extent {
 /*
  * Max bad pages in the new format..
  */
-#define __swapoffset(x) ((unsigned long)&((union swap_header *)0)->x)
 #define MAX_SWAP_BADPAGES \
-	((__swapoffset(magic.magic) - __swapoffset(info.badpages)) / sizeof(int))
+	((offsetof(union swap_header, magic.magic) - \
+	  offsetof(union swap_header, info.badpages)) / sizeof(int))
 
 enum {
 	SWP_USED	= (1 << 0),	/* is slot in swap_info[] used? */

mm/filemap.c

@@ -2420,20 +2420,20 @@ static int page_cache_read(struct file *file, pgoff_t offset, gfp_t gfp_mask)
  * Synchronous readahead happens when we don't even find
  * a page in the page cache at all.
  */
-static void do_sync_mmap_readahead(struct vm_area_struct *vma,
-				   struct file_ra_state *ra,
-				   struct file *file,
-				   pgoff_t offset)
+static void do_sync_mmap_readahead(struct vm_fault *vmf)
 {
+	struct file *file = vmf->vma->vm_file;
+	struct file_ra_state *ra = &file->f_ra;
 	struct address_space *mapping = file->f_mapping;
+	pgoff_t offset = vmf->pgoff;
 
 	/* If we don't want any read-ahead, don't bother */
-	if (vma->vm_flags & VM_RAND_READ)
+	if (vmf->vma->vm_flags & VM_RAND_READ)
 		return;
 	if (!ra->ra_pages)
 		return;
 
-	if (vma->vm_flags & VM_SEQ_READ) {
+	if (vmf->vma->vm_flags & VM_SEQ_READ) {
 		page_cache_sync_readahead(mapping, ra, file, offset,
 					  ra->ra_pages);
 		return;
@@ -2463,16 +2463,16 @@ static void do_sync_mmap_readahead(struct vm_area_struct *vma,
  * Asynchronous readahead happens when we find the page and PG_readahead,
  * so we want to possibly extend the readahead further..
  */
-static void do_async_mmap_readahead(struct vm_area_struct *vma,
-				    struct file_ra_state *ra,
-				    struct file *file,
-				    struct page *page,
-				    pgoff_t offset)
+static void do_async_mmap_readahead(struct vm_fault *vmf,
+				    struct page *page)
 {
+	struct file *file = vmf->vma->vm_file;
+	struct file_ra_state *ra = &file->f_ra;
 	struct address_space *mapping = file->f_mapping;
+	pgoff_t offset = vmf->pgoff;
 
 	/* If we don't want any read-ahead, don't bother */
-	if (vma->vm_flags & VM_RAND_READ)
+	if (vmf->vma->vm_flags & VM_RAND_READ)
 		return;
 	if (ra->mmap_miss > 0)
 		ra->mmap_miss--;
@@ -2531,10 +2531,10 @@ vm_fault_t filemap_fault(struct vm_fault *vmf)
 		 * We found the page, so try async readahead before
 		 * waiting for the lock.
 		 */
-		do_async_mmap_readahead(vmf->vma, ra, file, page, offset);
+		do_async_mmap_readahead(vmf, page);
 	} else if (!page) {
 		/* No page in the page cache at all */
-		do_sync_mmap_readahead(vmf->vma, ra, file, offset);
+		do_sync_mmap_readahead(vmf);
 		count_vm_event(PGMAJFAULT);
 		count_memcg_event_mm(vmf->vma->vm_mm, PGMAJFAULT);
 		ret = VM_FAULT_MAJOR;

tools/testing/selftests/proc/proc-pid-vm.c

@@ -29,6 +29,7 @@
 #include <errno.h>
 #include <sched.h>
 #include <signal.h>
+#include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <string.h>
@@ -36,11 +37,14 @@
 #include <sys/mount.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/wait.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <sys/syscall.h>
 #include <sys/uio.h>
 #include <linux/kdev_t.h>
+#include <sys/time.h>
+#include <sys/resource.h>
 
 static inline long sys_execveat(int dirfd, const char *pathname, char **argv, char **envp, int flags)
 {
@@ -205,12 +209,44 @@ static int make_exe(const uint8_t *payload, size_t len)
 }
 #endif
 
+static bool g_vsyscall = false;
+
+static const char str_vsyscall[] =
+"ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0                  [vsyscall]\n";
+
 #ifdef __x86_64__
+/*
+ * vsyscall page can't be unmapped, probe it with memory load.
+ */
+static void vsyscall(void)
+{
+	pid_t pid;
+	int wstatus;
+
+	pid = fork();
+	if (pid < 0) {
+		fprintf(stderr, "fork, errno %d\n", errno);
+		exit(1);
+	}
+	if (pid == 0) {
+		struct rlimit rlim = {0, 0};
+		(void)setrlimit(RLIMIT_CORE, &rlim);
+		*(volatile int *)0xffffffffff600000UL;
+		exit(0);
+	}
+	wait(&wstatus);
+	if (WIFEXITED(wstatus)) {
+		g_vsyscall = true;
+	}
+}
+
 int main(void)
 {
 	int pipefd[2];
 	int exec_fd;
 
+	vsyscall();
+
 	atexit(ate);
 
 	make_private_tmp();
@@ -261,9 +297,9 @@ int main(void)
 	snprintf(buf0 + MAPS_OFFSET, sizeof(buf0) - MAPS_OFFSET,
 		 "/tmp/#%llu (deleted)\n", (unsigned long long)st.st_ino);
 
-
 	/* Test /proc/$PID/maps */
 	{
+		const size_t len = strlen(buf0) + (g_vsyscall ? strlen(str_vsyscall) : 0);
 		char buf[256];
 		ssize_t rv;
 		int fd;
@@ -274,13 +310,16 @@ int main(void)
 			return 1;
 		}
 		rv = read(fd, buf, sizeof(buf));
-		assert(rv == strlen(buf0));
+		assert(rv == len);
 		assert(memcmp(buf, buf0, strlen(buf0)) == 0);
+		if (g_vsyscall) {
+			assert(memcmp(buf + strlen(buf0), str_vsyscall, strlen(str_vsyscall)) == 0);
+		}
 	}
 
 	/* Test /proc/$PID/smaps */
 	{
-		char buf[1024];
+		char buf[4096];
 		ssize_t rv;
 		int fd;
 
@@ -319,6 +358,10 @@ int main(void)
 		for (i = 0; i < sizeof(S)/sizeof(S[0]); i++) {
 			assert(memmem(buf, rv, S[i], strlen(S[i])));
 		}
+
+		if (g_vsyscall) {
+			assert(memmem(buf, rv, str_vsyscall, strlen(str_vsyscall)));
+		}
 	}
 
 	/* Test /proc/$PID/smaps_rollup */