usbnet: ratelimit warning messages invoked from callback handler

[safe/jmp/linux-2.6] / mm / shmem.c

diff --git a/mm/shmem.c b/mm/shmem.c
index 4103a23..b25f95c 100644 (file)
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -24,10 +24,12 @@
 #include <linux/init.h>
 #include <linux/vfs.h>
 #include <linux/mount.h>
+#include <linux/pagemap.h>
 #include <linux/file.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/swap.h>
+#include <linux/ima.h>
 
 static struct vfsmount *shm_mnt;
 
@@ -42,7 +44,6 @@ static struct vfsmount *shm_mnt;
 #include <linux/exportfs.h>
 #include <linux/generic_acl.h>
 #include <linux/mman.h>
-#include <linux/pagemap.h>
 #include <linux/string.h>
 #include <linux/slab.h>
 #include <linux/backing-dev.h>
@@ -64,13 +65,28 @@ static struct vfsmount *shm_mnt;
 #include <asm/div64.h>
 #include <asm/pgtable.h>
 
+/*
+ * The maximum size of a shmem/tmpfs file is limited by the maximum size of
+ * its triple-indirect swap vector - see illustration at shmem_swp_entry().
+ *
+ * With 4kB page size, maximum file size is just over 2TB on a 32-bit kernel,
+ * but one eighth of that on a 64-bit kernel.  With 8kB page size, maximum
+ * file size is just over 4TB on a 64-bit kernel, but 16TB on a 32-bit kernel,
+ * MAX_LFS_FILESIZE being then more restrictive than swap vector layout.
+ *
+ * We use / and * instead of shifts in the definitions below, so that the swap
+ * vector can be tested with small even values (e.g. 20) for ENTRIES_PER_PAGE.
+ */
 #define ENTRIES_PER_PAGE (PAGE_CACHE_SIZE/sizeof(unsigned long))
-#define ENTRIES_PER_PAGEPAGE (ENTRIES_PER_PAGE*ENTRIES_PER_PAGE)
-#define BLOCKS_PER_PAGE  (PAGE_CACHE_SIZE/512)
+#define ENTRIES_PER_PAGEPAGE ((unsigned long long)ENTRIES_PER_PAGE*ENTRIES_PER_PAGE)
+
+#define SHMSWP_MAX_INDEX (SHMEM_NR_DIRECT + (ENTRIES_PER_PAGEPAGE/2) * (ENTRIES_PER_PAGE+1))
+#define SHMSWP_MAX_BYTES (SHMSWP_MAX_INDEX << PAGE_CACHE_SHIFT)
 
-#define SHMEM_MAX_INDEX  (SHMEM_NR_DIRECT + (ENTRIES_PER_PAGEPAGE/2) * (ENTRIES_PER_PAGE+1))
-#define SHMEM_MAX_BYTES  ((unsigned long long)SHMEM_MAX_INDEX << PAGE_CACHE_SHIFT)
+#define SHMEM_MAX_BYTES  min_t(unsigned long long, SHMSWP_MAX_BYTES, MAX_LFS_FILESIZE)
+#define SHMEM_MAX_INDEX  ((unsigned long)((SHMEM_MAX_BYTES+1) >> PAGE_CACHE_SHIFT))
 
+#define BLOCKS_PER_PAGE  (PAGE_CACHE_SIZE/512)
 #define VM_ACCT(size)    (PAGE_CACHE_ALIGN(size) >> PAGE_SHIFT)
 
 /* info->flags needs VM_flags to handle pagein/truncate races efficiently */
@@ -1067,8 +1083,7 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
                swap_duplicate(swap);
                BUG_ON(page_mapped(page));
                page_cache_release(page);       /* pagecache ref */
-               set_page_dirty(page);
-               unlock_page(page);
+               swap_writepage(page, wbc);
                if (inode) {
                        mutex_lock(&shmem_swaplist_mutex);
                        /* move instead of add in case we're racing */
@@ -1325,8 +1340,12 @@ repeat:
                        shmem_swp_unmap(entry);
                        spin_unlock(&info->lock);
                        if (error == -ENOMEM) {
-                               /* allow reclaim from this memory cgroup */
-                               error = mem_cgroup_shrink_usage(swappage,
+                               /*
+                                * reclaim from proper memory cgroup and
+                                * call memcg's OOM if needed.
+                                */
+                               error = mem_cgroup_shmem_charge_fallback(
+                                                               swappage,
                                                                current->mm,
                                                                gfp);
                                if (error) {
@@ -2581,7 +2600,7 @@ int shmem_unuse(swp_entry_t entry, struct page *page)
 #define shmem_get_inode(sb, mode, dev, flags)  ramfs_get_inode(sb, mode, dev)
 #define shmem_acct_size(flags, size)           0
 #define shmem_unacct_size(flags, size)         do {} while (0)
-#define SHMEM_MAX_BYTES                                LLONG_MAX
+#define SHMEM_MAX_BYTES                                MAX_LFS_FILESIZE
 
 #endif /* CONFIG_SHMEM */
 
@@ -2665,6 +2684,7 @@ int shmem_zero_setup(struct vm_area_struct *vma)
        if (IS_ERR(file))
                return PTR_ERR(file);
 
+       ima_shm_check(file);
        if (vma->vm_file)
                fput(vma->vm_file);
        vma->vm_file = file;