1 files changed, 97 insertions, 43 deletions

diff --git a/mm/shmem.c b/mm/shmem.c
index eef4ebea5158..7e5030ae18ff 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -433,8 +433,6 @@ static swp_entry_t *shmem_swp_alloc(struct shmem_inode_info *info, unsigned long
 
                 spin_unlock(&info->lock);
                 page = shmem_dir_alloc(mapping_gfp_mask(inode->i_mapping));
-                if (page)
-                        set_page_private(page, 0);
                 spin_lock(&info->lock);
 
                 if (!page) {
@@ -729,10 +727,11 @@ done2:
         if (inode->i_mapping->nrpages && (info->flags & SHMEM_PAGEIN)) {
                 /*
                  * Call truncate_inode_pages again: racing shmem_unuse_inode
-                 * may have swizzled a page in from swap since vmtruncate or
-                 * generic_delete_inode did it, before we lowered next_index.
-                 * Also, though shmem_getpage checks i_size before adding to
-                 * cache, no recheck after: so fix the narrow window there too.
+                 * may have swizzled a page in from swap since
+                 * truncate_pagecache or generic_delete_inode did it, before we
+                 * lowered next_index.  Also, though shmem_getpage checks
+                 * i_size before adding to cache, no recheck after: so fix the
+                 * narrow window there too.
                  *
                  * Recalling truncate_inode_pages_range and unmap_mapping_range
                  * every time for punch_hole (which never got a chance to clear
@@ -762,19 +761,16 @@ done2:
         }
 }
 
-static void shmem_truncate(struct inode *inode)
-{
-        shmem_truncate_range(inode, inode->i_size, (loff_t)-1);
-}
-
 static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
 {
         struct inode *inode = dentry->d_inode;
-        struct page *page = NULL;
         int error;
 
         if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
-                if (attr->ia_size < inode->i_size) {
+                loff_t newsize = attr->ia_size;
+                struct page *page = NULL;
+
+                if (newsize < inode->i_size) {
                         /*
                          * If truncating down to a partial page, then
                          * if that page is already allocated, hold it
@@ -782,9 +778,9 @@ static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
                          * truncate_partial_page cannnot miss it were
                          * it assigned to swap.
                          */
-                        if (attr->ia_size & (PAGE_CACHE_SIZE-1)) {
+                        if (newsize & (PAGE_CACHE_SIZE-1)) {
                                 (void) shmem_getpage(inode,
-                                        attr->ia_size>>PAGE_CACHE_SHIFT,
+                                        newsize >> PAGE_CACHE_SHIFT,
                                                 &page, SGP_READ, NULL);
                                 if (page)
                                         unlock_page(page);
@@ -796,24 +792,29 @@ static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
                          * if it's being fully truncated to zero-length: the
                          * nrpages check is efficient enough in that case.
                          */
-                        if (attr->ia_size) {
+                        if (newsize) {
                                 struct shmem_inode_info *info = SHMEM_I(inode);
                                 spin_lock(&info->lock);
                                 info->flags &= ~SHMEM_PAGEIN;
                                 spin_unlock(&info->lock);
                         }
                 }
+
+                error = simple_setsize(inode, newsize);
+                if (page)
+                        page_cache_release(page);
+                if (error)
+                        return error;
+                shmem_truncate_range(inode, newsize, (loff_t)-1);
         }
 
         error = inode_change_ok(inode, attr);
         if (!error)
-                error = inode_setattr(inode, attr);
+                generic_setattr(inode, attr);
 #ifdef CONFIG_TMPFS_POSIX_ACL
         if (!error && (attr->ia_valid & ATTR_MODE))
                 error = generic_acl_chmod(inode);
 #endif
-        if (page)
-                page_cache_release(page);
         return error;
 }
 
@@ -821,11 +822,11 @@ static void shmem_delete_inode(struct inode *inode)
 {
         struct shmem_inode_info *info = SHMEM_I(inode);
 
-        if (inode->i_op->truncate == shmem_truncate) {
+        if (inode->i_mapping->a_ops == &shmem_aops) {
                 truncate_inode_pages(inode->i_mapping, 0);
                 shmem_unacct_size(info->flags, inode->i_size);
                 inode->i_size = 0;
-                shmem_truncate(inode);
+                shmem_truncate_range(inode, 0, (loff_t)-1);
                 if (!list_empty(&info->swaplist)) {
                         mutex_lock(&shmem_swaplist_mutex);
                         list_del_init(&info->swaplist);
@@ -1545,8 +1546,8 @@ static int shmem_mmap(struct file *file, struct vm_area_struct *vma)
         return 0;
 }
 
-static struct inode *shmem_get_inode(struct super_block *sb, int mode,
-                                        dev_t dev, unsigned long flags)
+static struct inode *shmem_get_inode(struct super_block *sb, const struct inode *dir,
+                                     int mode, dev_t dev, unsigned long flags)
 {
         struct inode *inode;
         struct shmem_inode_info *info;
@@ -1557,9 +1558,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, int mode,
 
         inode = new_inode(sb);
         if (inode) {
-                inode->i_mode = mode;
-                inode->i_uid = current_fsuid();
-                inode->i_gid = current_fsgid();
+                inode_init_owner(inode, dir, mode);
                 inode->i_blocks = 0;
                 inode->i_mapping->backing_dev_info = &shmem_backing_dev_info;
                 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
@@ -1814,7 +1813,7 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
         struct inode *inode;
         int error = -ENOSPC;
 
-        inode = shmem_get_inode(dir->i_sb, mode, dev, VM_NORESERVE);
+        inode = shmem_get_inode(dir->i_sb, dir, mode, dev, VM_NORESERVE);
         if (inode) {
                 error = security_inode_init_security(inode, dir, NULL, NULL,
                                                      NULL);
@@ -1833,11 +1832,6 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
 #else
                 error = 0;
 #endif
-                if (dir->i_mode & S_ISGID) {
-                        inode->i_gid = dir->i_gid;
-                        if (S_ISDIR(mode))
-                                inode->i_mode |= S_ISGID;
-                }
                 dir->i_size += BOGO_DIRENT_SIZE;
                 dir->i_ctime = dir->i_mtime = CURRENT_TIME;
                 d_instantiate(dentry, inode);
@@ -1957,7 +1951,7 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
         if (len > PAGE_CACHE_SIZE)
                 return -ENAMETOOLONG;
 
-        inode = shmem_get_inode(dir->i_sb, S_IFLNK|S_IRWXUGO, 0, VM_NORESERVE);
+        inode = shmem_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0, VM_NORESERVE);
         if (!inode)
                 return -ENOSPC;
 
@@ -1992,8 +1986,6 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
                 unlock_page(page);
                 page_cache_release(page);
         }
-        if (dir->i_mode & S_ISGID)
-                inode->i_gid = dir->i_gid;
         dir->i_size += BOGO_DIRENT_SIZE;
         dir->i_ctime = dir->i_mtime = CURRENT_TIME;
         d_instantiate(dentry, inode);
@@ -2033,7 +2025,6 @@ static const struct inode_operations shmem_symlink_inline_operations = {
 };
 
 static const struct inode_operations shmem_symlink_inode_operations = {
-        .truncate       = shmem_truncate,
         .readlink       = generic_readlink,
         .follow_link    = shmem_follow_link,
         .put_link       = shmem_put_link,
@@ -2071,14 +2062,14 @@ static int shmem_xattr_security_set(struct dentry *dentry, const char *name,
                                           size, flags);
 }
 
-static struct xattr_handler shmem_xattr_security_handler = {
+static const struct xattr_handler shmem_xattr_security_handler = {
         .prefix = XATTR_SECURITY_PREFIX,
         .list   = shmem_xattr_security_list,
         .get    = shmem_xattr_security_get,
         .set    = shmem_xattr_security_set,
 };
 
-static struct xattr_handler *shmem_xattr_handlers[] = {
+static const struct xattr_handler *shmem_xattr_handlers[] = {
         &generic_acl_access_handler,
         &generic_acl_default_handler,
         &shmem_xattr_security_handler,
@@ -2366,7 +2357,7 @@ int shmem_fill_super(struct super_block *sb, void *data, int silent)
         sb->s_flags |= MS_POSIXACL;
 #endif
 
-        inode = shmem_get_inode(sb, S_IFDIR | sbinfo->mode, 0, VM_NORESERVE);
+        inode = shmem_get_inode(sb, NULL, S_IFDIR | sbinfo->mode, 0, VM_NORESERVE);
         if (!inode)
                 goto failed;
         inode->i_uid = sbinfo->uid;
@@ -2444,14 +2435,13 @@ static const struct file_operations shmem_file_operations = {
         .write          = do_sync_write,
         .aio_read       = shmem_file_aio_read,
         .aio_write      = generic_file_aio_write,
-        .fsync          = simple_sync_file,
+        .fsync          = noop_fsync,
         .splice_read    = generic_file_splice_read,
         .splice_write   = generic_file_splice_write,
 #endif
 };
 
 static const struct inode_operations shmem_inode_operations = {
-        .truncate       = shmem_truncate,
         .setattr        = shmem_notify_change,
         .truncate_range = shmem_truncate_range,
 #ifdef CONFIG_TMPFS_POSIX_ACL
@@ -2570,6 +2560,45 @@ out4:
         return error;
 }
 
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+/**
+ * mem_cgroup_get_shmem_target - find a page or entry assigned to the shmem file
+ * @inode: the inode to be searched
+ * @pgoff: the offset to be searched
+ * @pagep: the pointer for the found page to be stored
+ * @ent: the pointer for the found swap entry to be stored
+ *
+ * If a page is found, refcount of it is incremented. Callers should handle
+ * these refcount.
+ */
+void mem_cgroup_get_shmem_target(struct inode *inode, pgoff_t pgoff,
+                                        struct page **pagep, swp_entry_t *ent)
+{
+        swp_entry_t entry = { .val = 0 }, *ptr;
+        struct page *page = NULL;
+        struct shmem_inode_info *info = SHMEM_I(inode);
+
+        if ((pgoff << PAGE_CACHE_SHIFT) >= i_size_read(inode))
+                goto out;
+
+        spin_lock(&info->lock);
+        ptr = shmem_swp_entry(info, pgoff, NULL);
+#ifdef CONFIG_SWAP
+        if (ptr && ptr->val) {
+                entry.val = ptr->val;
+                page = find_get_page(&swapper_space, entry.val);
+        } else
+#endif
+                page = find_get_page(inode->i_mapping, pgoff);
+        if (ptr)
+                shmem_swp_unmap(ptr);
+        spin_unlock(&info->lock);
+out:
+        *pagep = page;
+        *ent = entry;
+}
+#endif
+
 #else /* !CONFIG_SHMEM */
 
 /*
@@ -2609,9 +2638,34 @@ int shmem_lock(struct file *file, int lock, struct user_struct *user)
         return 0;
 }
 
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+/**
+ * mem_cgroup_get_shmem_target - find a page or entry assigned to the shmem file
+ * @inode: the inode to be searched
+ * @pgoff: the offset to be searched
+ * @pagep: the pointer for the found page to be stored
+ * @ent: the pointer for the found swap entry to be stored
+ *
+ * If a page is found, refcount of it is incremented. Callers should handle
+ * these refcount.
+ */
+void mem_cgroup_get_shmem_target(struct inode *inode, pgoff_t pgoff,
+                                        struct page **pagep, swp_entry_t *ent)
+{
+        struct page *page = NULL;
+
+        if ((pgoff << PAGE_CACHE_SHIFT) >= i_size_read(inode))
+                goto out;
+        page = find_get_page(inode->i_mapping, pgoff);
+out:
+        *pagep = page;
+        *ent = (swp_entry_t){ .val = 0 };
+}
+#endif
+
 #define shmem_vm_ops                            generic_file_vm_ops
 #define shmem_file_operations                   ramfs_file_operations
-#define shmem_get_inode(sb, mode, dev, flags)   ramfs_get_inode(sb, mode, dev)
+#define shmem_get_inode(sb, dir, mode, dev, flags)      ramfs_get_inode(sb, dir, mode, dev)
 #define shmem_acct_size(flags, size)            0
 #define shmem_unacct_size(flags, size)          do {} while (0)
 #define SHMEM_MAX_BYTES                         MAX_LFS_FILESIZE
@@ -2655,7 +2709,7 @@ struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags
         path.mnt = mntget(shm_mnt);
 
         error = -ENOSPC;
-        inode = shmem_get_inode(root->d_sb, S_IFREG | S_IRWXUGO, 0, flags);
+        inode = shmem_get_inode(root->d_sb, NULL, S_IFREG | S_IRWXUGO, 0, flags);
         if (!inode)
                 goto put_dentry;