Merge branch 'akpm' (aka "Andrew's patch-bomb, take two")

Andrew explains:

 - various misc stuff

 - Most of the rest of MM: memcg, threaded hugepages, others.

 - cpumask

 - kexec

 - kdump

 - some direct-io performance tweaking

 - radix-tree optimisations

 - new selftests code

   A note on this: often people will develop a new userspace-visible
   feature and will develop userspace code to exercise/test that
   feature.  Then they merge the patch and the selftest code dies.
   Sometimes we paste it into the changelog.  Sometimes the code gets
   thrown into Documentation/(!).

   This saddens me.  So this patch creates a bare-bones framework which
   will henceforth allow me to ask people to include their test apps in
   the kernel tree so we can keep them alive.  Then when people enhance
   or fix the feature, I can ask them to update the test app too.

   The infrastruture is terribly trivial at present - let's see how it
   evolves.

 - checkpoint/restart feature work.

   A note on this: this is a project by various mad Russians to perform
   c/r mainly from userspace, with various oddball helper code added
   into the kernel where the need is demonstrated.

   So rather than some large central lump of code, what we have is
   little bits and pieces popping up in various places which either
   expose something new or which permit something which is normally
   kernel-private to be modified.

   The overall project is an ongoing thing.  I've judged that the size
   and scope of the thing means that we're more likely to be successful
   with it if we integrate the support into mainline piecemeal rather
   than allowing it all to develop out-of-tree.

   However I'm less confident than the developers that it will all
   eventually work! So what I'm asking them to do is to wrap each piece
   of new code inside CONFIG_CHECKPOINT_RESTORE.  So if it all
   eventually comes to tears and the project as a whole fails, it should
   be a simple matter to go through and delete all trace of it.

This lot pretty much wraps up the -rc1 merge for me.

* akpm: (96 commits)
  unlzo: fix input buffer free
  ramoops: update parameters only after successful init
  ramoops: fix use of rounddown_pow_of_two()
  c/r: prctl: add PR_SET_MM codes to set up mm_struct entries
  c/r: procfs: add start_data, end_data, start_brk members to /proc/$pid/stat v4
  c/r: introduce CHECKPOINT_RESTORE symbol
  selftests: new x86 breakpoints selftest
  selftests: new very basic kernel selftests directory
  radix_tree: take radix_tree_path off stack
  radix_tree: remove radix_tree_indirect_to_ptr()
  dio: optimize cache misses in the submission path
  vfs: cache request_queue in struct block_device
  fs/direct-io.c: calculate fs_count correctly in get_more_blocks()
  drivers/parport/parport_pc.c: fix warnings
  panic: don't print redundant backtraces on oops
  sysctl: add the kernel.ns_last_pid control
  kdump: add udev events for memory online/offline
  include/linux/crash_dump.h needs elf.h
  kdump: fix crash_kexec()/smp_send_stop() race in panic()
  kdump: crashk_res init check for /sys/kernel/kexec_crash_size
  ...

10 files changed, 269 insertions, 50 deletions

diff --git a/fs/block_dev.c b/fs/block_dev.c
index afe74dda632b..0e575d1304b4 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1139,6 +1139,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
         mutex_lock_nested(&bdev->bd_mutex, for_part);
         if (!bdev->bd_openers) {
                 bdev->bd_disk = disk;
+                bdev->bd_queue = disk->queue;
                 bdev->bd_contains = bdev;
                 if (!partno) {
                         struct backing_dev_info *bdi;
@@ -1159,6 +1160,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
                                         disk_put_part(bdev->bd_part);
                                         bdev->bd_part = NULL;
                                         bdev->bd_disk = NULL;
+                                        bdev->bd_queue = NULL;
                                         mutex_unlock(&bdev->bd_mutex);
                                         disk_unblock_events(disk);
                                         put_disk(disk);
@@ -1232,6 +1234,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
         disk_put_part(bdev->bd_part);
         bdev->bd_disk = NULL;
         bdev->bd_part = NULL;
+        bdev->bd_queue = NULL;
         bdev_inode_switch_bdi(bdev->bd_inode, &default_backing_dev_info);
         if (bdev != bdev->bd_contains)
                 __blkdev_put(bdev->bd_contains, mode, 1);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index f99a099a7747..d8525662ca7a 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -872,7 +872,8 @@ static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 
 #ifdef CONFIG_MIGRATION
 static int btree_migratepage(struct address_space *mapping,
-                        struct page *newpage, struct page *page)
+                        struct page *newpage, struct page *page,
+                        enum migrate_mode mode)
 {
         /*
          * we can't safely write a btree page from here,
@@ -887,7 +888,7 @@ static int btree_migratepage(struct address_space *mapping,
         if (page_has_private(page) &&
             !try_to_release_page(page, GFP_KERNEL))
                 return -EAGAIN;
-        return migrate_page(mapping, newpage, page);
+        return migrate_page(mapping, newpage, page, mode);
 }
 #endif
 
diff --git a/fs/direct-io.c b/fs/direct-io.c
index d740ab67ff6e..4a588dbd11bf 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -36,6 +36,7 @@
 #include <linux/rwsem.h>
 #include <linux/uio.h>
 #include <linux/atomic.h>
+#include <linux/prefetch.h>
 
 /*
  * How many user pages to map in one call to get_user_pages().  This determines
@@ -580,9 +581,8 @@ static int get_more_blocks(struct dio *dio, struct dio_submit *sdio,
 {
         int ret;
         sector_t fs_startblk;   /* Into file, in filesystem-sized blocks */
+        sector_t fs_endblk;     /* Into file, in filesystem-sized blocks */
         unsigned long fs_count; /* Number of filesystem-sized blocks */
-        unsigned long dio_count;/* Number of dio_block-sized blocks */
-        unsigned long blkmask;
         int create;
 
         /*
@@ -593,11 +593,9 @@ static int get_more_blocks(struct dio *dio, struct dio_submit *sdio,
         if (ret == 0) {
                 BUG_ON(sdio->block_in_file >= sdio->final_block_in_request);
                 fs_startblk = sdio->block_in_file >> sdio->blkfactor;
-                dio_count = sdio->final_block_in_request - sdio->block_in_file;
-                fs_count = dio_count >> sdio->blkfactor;
-                blkmask = (1 << sdio->blkfactor) - 1;
-                if (dio_count & blkmask)        
-                        fs_count++;
+                fs_endblk = (sdio->final_block_in_request - 1) >>
+                                        sdio->blkfactor;
+                fs_count = fs_endblk - fs_startblk + 1;
 
                 map_bh->b_state = 0;
                 map_bh->b_size = fs_count << dio->inode->i_blkbits;
@@ -1090,8 +1088,8 @@ static inline int drop_refcount(struct dio *dio)
  * individual fields and will generate much worse code. This is important
  * for the whole file.
  */
-ssize_t
-__blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
+static inline ssize_t
+do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
         struct block_device *bdev, const struct iovec *iov, loff_t offset, 
         unsigned long nr_segs, get_block_t get_block, dio_iodone_t end_io,
         dio_submit_t submit_io, int flags)
@@ -1100,7 +1098,6 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
         size_t size;
         unsigned long addr;
         unsigned blkbits = inode->i_blkbits;
-        unsigned bdev_blkbits = 0;
         unsigned blocksize_mask = (1 << blkbits) - 1;
         ssize_t retval = -EINVAL;
         loff_t end = offset;
@@ -1113,12 +1110,14 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
         if (rw & WRITE)
                 rw = WRITE_ODIRECT;
 
-        if (bdev)
-                bdev_blkbits = blksize_bits(bdev_logical_block_size(bdev));
+        /*
+         * Avoid references to bdev if not absolutely needed to give
+         * the early prefetch in the caller enough time.
+         */
 
         if (offset & blocksize_mask) {
                 if (bdev)
-                         blkbits = bdev_blkbits;
+                        blkbits = blksize_bits(bdev_logical_block_size(bdev));
                 blocksize_mask = (1 << blkbits) - 1;
                 if (offset & blocksize_mask)
                         goto out;
@@ -1129,11 +1128,13 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
                 addr = (unsigned long)iov[seg].iov_base;
                 size = iov[seg].iov_len;
                 end += size;
-                if ((addr & blocksize_mask) || (size & blocksize_mask))  {
+                if (unlikely((addr & blocksize_mask) ||
+                             (size & blocksize_mask))) {
                         if (bdev)
-                                 blkbits = bdev_blkbits;
+                                blkbits = blksize_bits(
+                                         bdev_logical_block_size(bdev));
                         blocksize_mask = (1 << blkbits) - 1;
-                        if ((addr & blocksize_mask) || (size & blocksize_mask))  
+                        if ((addr & blocksize_mask) || (size & blocksize_mask))
                                 goto out;
                 }
         }
@@ -1316,6 +1317,30 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
 out:
         return retval;
 }
+
+ssize_t
+__blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
+        struct block_device *bdev, const struct iovec *iov, loff_t offset,
+        unsigned long nr_segs, get_block_t get_block, dio_iodone_t end_io,
+        dio_submit_t submit_io, int flags)
+{
+        /*
+         * The block device state is needed in the end to finally
+         * submit everything.  Since it's likely to be cache cold
+         * prefetch it here as first thing to hide some of the
+         * latency.
+         *
+         * Attempt to prefetch the pieces we likely need later.
+         */
+        prefetch(&bdev->bd_disk->part_tbl);
+        prefetch(bdev->bd_queue);
+        prefetch((char *)bdev->bd_queue + SMP_CACHE_BYTES);
+
+        return do_blockdev_direct_IO(rw, iocb, inode, bdev, iov, offset,
+                                     nr_segs, get_block, end_io,
+                                     submit_io, flags);
+}
+
 EXPORT_SYMBOL(__blockdev_direct_IO);
 
 static __init int dio_init(void)
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 828e750af23a..aabdfc38cf24 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -197,6 +197,12 @@ struct eventpoll {
 
         /* The user that created the eventpoll descriptor */
         struct user_struct *user;
+
+        struct file *file;
+
+        /* used to optimize loop detection check */
+        int visited;
+        struct list_head visited_list_link;
 };
 
 /* Wait structure used by the poll hooks */
@@ -255,6 +261,15 @@ static struct kmem_cache *epi_cache __read_mostly;
 /* Slab cache used to allocate "struct eppoll_entry" */
 static struct kmem_cache *pwq_cache __read_mostly;
 
+/* Visited nodes during ep_loop_check(), so we can unset them when we finish */
+static LIST_HEAD(visited_list);
+
+/*
+ * List of files with newly added links, where we may need to limit the number
+ * of emanating paths. Protected by the epmutex.
+ */
+static LIST_HEAD(tfile_check_list);
+
 #ifdef CONFIG_SYSCTL
 
 #include <linux/sysctl.h>
@@ -276,6 +291,12 @@ ctl_table epoll_table[] = {
 };
 #endif /* CONFIG_SYSCTL */
 
+static const struct file_operations eventpoll_fops;
+
+static inline int is_file_epoll(struct file *f)
+{
+        return f->f_op == &eventpoll_fops;
+}
 
 /* Setup the structure that is used as key for the RB tree */
 static inline void ep_set_ffd(struct epoll_filefd *ffd,
@@ -711,12 +732,6 @@ static const struct file_operations eventpoll_fops = {
         .llseek         = noop_llseek,
 };
 
-/* Fast test to see if the file is an eventpoll file */
-static inline int is_file_epoll(struct file *f)
-{
-        return f->f_op == &eventpoll_fops;
-}
-
 /*
  * This is called from eventpoll_release() to unlink files from the eventpoll
  * interface. We need to have this facility to cleanup correctly files that are
@@ -926,6 +941,99 @@ static void ep_rbtree_insert(struct eventpoll *ep, struct epitem *epi)
         rb_insert_color(&epi->rbn, &ep->rbr);
 }
 
+
+
+#define PATH_ARR_SIZE 5
+/*
+ * These are the number paths of length 1 to 5, that we are allowing to emanate
+ * from a single file of interest. For example, we allow 1000 paths of length
+ * 1, to emanate from each file of interest. This essentially represents the
+ * potential wakeup paths, which need to be limited in order to avoid massive
+ * uncontrolled wakeup storms. The common use case should be a single ep which
+ * is connected to n file sources. In this case each file source has 1 path
+ * of length 1. Thus, the numbers below should be more than sufficient. These
+ * path limits are enforced during an EPOLL_CTL_ADD operation, since a modify
+ * and delete can't add additional paths. Protected by the epmutex.
+ */
+static const int path_limits[PATH_ARR_SIZE] = { 1000, 500, 100, 50, 10 };
+static int path_count[PATH_ARR_SIZE];
+
+static int path_count_inc(int nests)
+{
+        if (++path_count[nests] > path_limits[nests])
+                return -1;
+        return 0;
+}
+
+static void path_count_init(void)
+{
+        int i;
+
+        for (i = 0; i < PATH_ARR_SIZE; i++)
+                path_count[i] = 0;
+}
+
+static int reverse_path_check_proc(void *priv, void *cookie, int call_nests)
+{
+        int error = 0;
+        struct file *file = priv;
+        struct file *child_file;
+        struct epitem *epi;
+
+        list_for_each_entry(epi, &file->f_ep_links, fllink) {
+                child_file = epi->ep->file;
+                if (is_file_epoll(child_file)) {
+                        if (list_empty(&child_file->f_ep_links)) {
+                                if (path_count_inc(call_nests)) {
+                                        error = -1;
+                                        break;
+                                }
+                        } else {
+                                error = ep_call_nested(&poll_loop_ncalls,
+                                                        EP_MAX_NESTS,
+                                                        reverse_path_check_proc,
+                                                        child_file, child_file,
+                                                        current);
+                        }
+                        if (error != 0)
+                                break;
+                } else {
+                        printk(KERN_ERR "reverse_path_check_proc: "
+                                "file is not an ep!\n");
+                }
+        }
+        return error;
+}
+
+/**
+ * reverse_path_check - The tfile_check_list is list of file *, which have
+ *                      links that are proposed to be newly added. We need to
+ *                      make sure that those added links don't add too many
+ *                      paths such that we will spend all our time waking up
+ *                      eventpoll objects.
+ *
+ * Returns: Returns zero if the proposed links don't create too many paths,
+ *          -1 otherwise.
+ */
+static int reverse_path_check(void)
+{
+        int length = 0;
+        int error = 0;
+        struct file *current_file;
+
+        /* let's call this for all tfiles */
+        list_for_each_entry(current_file, &tfile_check_list, f_tfile_llink) {
+                length++;
+                path_count_init();
+                error = ep_call_nested(&poll_loop_ncalls, EP_MAX_NESTS,
+                                        reverse_path_check_proc, current_file,
+                                        current_file, current);
+                if (error)
+                        break;
+        }
+        return error;
+}
+
 /*
  * Must be called with "mtx" held.
  */
@@ -987,6 +1095,11 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event,
          */
         ep_rbtree_insert(ep, epi);
 
+        /* now check if we've created too many backpaths */
+        error = -EINVAL;
+        if (reverse_path_check())
+                goto error_remove_epi;
+
         /* We have to drop the new item inside our item list to keep track of it */
         spin_lock_irqsave(&ep->lock, flags);
 
@@ -1011,6 +1124,14 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event,
 
         return 0;
 
+error_remove_epi:
+        spin_lock(&tfile->f_lock);
+        if (ep_is_linked(&epi->fllink))
+                list_del_init(&epi->fllink);
+        spin_unlock(&tfile->f_lock);
+
+        rb_erase(&epi->rbn, &ep->rbr);
+
 error_unregister:
         ep_unregister_pollwait(ep, epi);
 
@@ -1275,18 +1396,36 @@ static int ep_loop_check_proc(void *priv, void *cookie, int call_nests)
         int error = 0;
         struct file *file = priv;
         struct eventpoll *ep = file->private_data;
+        struct eventpoll *ep_tovisit;
         struct rb_node *rbp;
         struct epitem *epi;
 
         mutex_lock_nested(&ep->mtx, call_nests + 1);
+        ep->visited = 1;
+        list_add(&ep->visited_list_link, &visited_list);
         for (rbp = rb_first(&ep->rbr); rbp; rbp = rb_next(rbp)) {
                 epi = rb_entry(rbp, struct epitem, rbn);
                 if (unlikely(is_file_epoll(epi->ffd.file))) {
+                        ep_tovisit = epi->ffd.file->private_data;
+                        if (ep_tovisit->visited)
+                                continue;
                         error = ep_call_nested(&poll_loop_ncalls, EP_MAX_NESTS,
-                                               ep_loop_check_proc, epi->ffd.file,
-                                               epi->ffd.file->private_data, current);
+                                        ep_loop_check_proc, epi->ffd.file,
+                                        ep_tovisit, current);
                         if (error != 0)
                                 break;
+                } else {
+                        /*
+                         * If we've reached a file that is not associated with
+                         * an ep, then we need to check if the newly added
+                         * links are going to add too many wakeup paths. We do
+                         * this by adding it to the tfile_check_list, if it's
+                         * not already there, and calling reverse_path_check()
+                         * during ep_insert().
+                         */
+                        if (list_empty(&epi->ffd.file->f_tfile_llink))
+                                list_add(&epi->ffd.file->f_tfile_llink,
+                                         &tfile_check_list);
                 }
         }
         mutex_unlock(&ep->mtx);
@@ -1307,8 +1446,31 @@ static int ep_loop_check_proc(void *priv, void *cookie, int call_nests)
  */
 static int ep_loop_check(struct eventpoll *ep, struct file *file)
 {
-        return ep_call_nested(&poll_loop_ncalls, EP_MAX_NESTS,
+        int ret;
+        struct eventpoll *ep_cur, *ep_next;
+
+        ret = ep_call_nested(&poll_loop_ncalls, EP_MAX_NESTS,
                               ep_loop_check_proc, file, ep, current);
+        /* clear visited list */
+        list_for_each_entry_safe(ep_cur, ep_next, &visited_list,
+                                                        visited_list_link) {
+                ep_cur->visited = 0;
+                list_del(&ep_cur->visited_list_link);
+        }
+        return ret;
+}
+
+static void clear_tfile_check_list(void)
+{
+        struct file *file;
+
+        /* first clear the tfile_check_list */
+        while (!list_empty(&tfile_check_list)) {
+                file = list_first_entry(&tfile_check_list, struct file,
+                                        f_tfile_llink);
+                list_del_init(&file->f_tfile_llink);
+        }
+        INIT_LIST_HEAD(&tfile_check_list);
 }
 
 /*
@@ -1316,8 +1478,9 @@ static int ep_loop_check(struct eventpoll *ep, struct file *file)
  */
 SYSCALL_DEFINE1(epoll_create1, int, flags)
 {
-        int error;
+        int error, fd;
         struct eventpoll *ep = NULL;
+        struct file *file;
 
         /* Check the EPOLL_* constant for consistency.  */
         BUILD_BUG_ON(EPOLL_CLOEXEC != O_CLOEXEC);
@@ -1334,11 +1497,25 @@ SYSCALL_DEFINE1(epoll_create1, int, flags)
          * Creates all the items needed to setup an eventpoll file. That is,
          * a file structure and a free file descriptor.
          */
-        error = anon_inode_getfd("[eventpoll]", &eventpoll_fops, ep,
+        fd = get_unused_fd_flags(O_RDWR | (flags & O_CLOEXEC));
+        if (fd < 0) {
+                error = fd;
+                goto out_free_ep;
+        }
+        file = anon_inode_getfile("[eventpoll]", &eventpoll_fops, ep,
                                  O_RDWR | (flags & O_CLOEXEC));
-        if (error < 0)
-                ep_free(ep);
-
+        if (IS_ERR(file)) {
+                error = PTR_ERR(file);
+                goto out_free_fd;
+        }
+        fd_install(fd, file);
+        ep->file = file;
+        return fd;
+
+out_free_fd:
+        put_unused_fd(fd);
+out_free_ep:
+        ep_free(ep);
         return error;
 }
 
@@ -1404,21 +1581,27 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
         /*
          * When we insert an epoll file descriptor, inside another epoll file
          * descriptor, there is the change of creating closed loops, which are
-         * better be handled here, than in more critical paths.
+         * better be handled here, than in more critical paths. While we are
+         * checking for loops we also determine the list of files reachable
+         * and hang them on the tfile_check_list, so we can check that we
+         * haven't created too many possible wakeup paths.
          *
-         * We hold epmutex across the loop check and the insert in this case, in
-         * order to prevent two separate inserts from racing and each doing the
-         * insert "at the same time" such that ep_loop_check passes on both
-         * before either one does the insert, thereby creating a cycle.
+         * We need to hold the epmutex across both ep_insert and ep_remove
+         * b/c we want to make sure we are looking at a coherent view of
+         * epoll network.
          */
-        if (unlikely(is_file_epoll(tfile) && op == EPOLL_CTL_ADD)) {
+        if (op == EPOLL_CTL_ADD || op == EPOLL_CTL_DEL) {
                 mutex_lock(&epmutex);
                 did_lock_epmutex = 1;
-                error = -ELOOP;
-                if (ep_loop_check(ep, tfile) != 0)
-                        goto error_tgt_fput;
         }
-
+        if (op == EPOLL_CTL_ADD) {
+                if (is_file_epoll(tfile)) {
+                        error = -ELOOP;
+                        if (ep_loop_check(ep, tfile) != 0)
+                                goto error_tgt_fput;
+                } else
+                        list_add(&tfile->f_tfile_llink, &tfile_check_list);
+        }
 
         mutex_lock_nested(&ep->mtx, 0);
 
@@ -1437,6 +1620,7 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
                         error = ep_insert(ep, &epds, tfile, fd);
                 } else
                         error = -EEXIST;
+                clear_tfile_check_list();
                 break;
         case EPOLL_CTL_DEL:
                 if (epi)
@@ -1455,7 +1639,7 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
         mutex_unlock(&ep->mtx);
 
 error_tgt_fput:
-        if (unlikely(did_lock_epmutex))
+        if (did_lock_epmutex)
                 mutex_unlock(&epmutex);
 
         fput(tfile);
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index e425ad9d0490..1e85a7ac0217 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -583,7 +583,8 @@ static int hugetlbfs_set_page_dirty(struct page *page)
 }
 
 static int hugetlbfs_migrate_page(struct address_space *mapping,
-                                struct page *newpage, struct page *page)
+                                struct page *newpage, struct page *page,
+                                enum migrate_mode mode)
 {
         int rc;
 
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 5ee92538b063..8102db9b926c 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -332,7 +332,7 @@ void nfs_commit_release_pages(struct nfs_write_data *data);
 
 #ifdef CONFIG_MIGRATION
 extern int nfs_migrate_page(struct address_space *,
-                struct page *, struct page *);
+                struct page *, struct page *, enum migrate_mode);
 #else
 #define nfs_migrate_page NULL
 #endif
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 0c3885255f97..834f0fe96f89 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1688,7 +1688,7 @@ out_error:
 
 #ifdef CONFIG_MIGRATION
 int nfs_migrate_page(struct address_space *mapping, struct page *newpage,
-                struct page *page)
+                struct page *page, enum migrate_mode mode)
 {
         /*
          * If PagePrivate is set, then the page is currently associated with
@@ -1703,7 +1703,7 @@ int nfs_migrate_page(struct address_space *mapping, struct page *newpage,
 
         nfs_fscache_release_page(page, GFP_KERNEL);
 
-        return migrate_page(mapping, newpage, page);
+        return migrate_page(mapping, newpage, page, mode);
 }
 #endif
 
diff --git a/fs/pipe.c b/fs/pipe.c
index f0e485d54e64..a932ced92a16 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -1137,7 +1137,7 @@ static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long nr_pages)
         if (nr_pages < pipe->nrbufs)
                 return -EBUSY;
 
-        bufs = kcalloc(nr_pages, sizeof(struct pipe_buffer), GFP_KERNEL);
+        bufs = kcalloc(nr_pages, sizeof(*bufs), GFP_KERNEL | __GFP_NOWARN);
         if (unlikely(!bufs))
                 return -ENOMEM;
 
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 8c344f037bd0..9252ee3b71e3 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -464,7 +464,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
 
         seq_printf(m, "%d (%s) %c %d %d %d %d %d %u %lu \
 %lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
-%lu %lu %lu %lu %lu %lu %lu %lu %d %d %u %u %llu %lu %ld\n",
+%lu %lu %lu %lu %lu %lu %lu %lu %d %d %u %u %llu %lu %ld %lu %lu %lu\n",
                 pid_nr_ns(pid, ns),
                 tcomm,
                 state,
@@ -511,7 +511,10 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
                 task->policy,
                 (unsigned long long)delayacct_blkio_ticks(task),
                 cputime_to_clock_t(gtime),
-                cputime_to_clock_t(cgtime));
+                cputime_to_clock_t(cgtime),
+                (mm && permitted) ? mm->start_data : 0,
+                (mm && permitted) ? mm->end_data : 0,
+                (mm && permitted) ? mm->start_brk : 0);
         if (mm)
                 mmput(mm);
         return 0;
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 8173dfd89cb2..5485a5388ecb 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -654,6 +654,8 @@ static int proc_pid_permission(struct inode *inode, int mask)
         bool has_perms;
 
         task = get_proc_task(inode);
+        if (!task)
+                return -ESRCH;
         has_perms = has_pid_permissions(pid, task, 1);
         put_task_struct(task);