Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394...
[pandora-kernel.git] / mm / shmem.c
index eef4ebe..f65f840 100644 (file)
@@ -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 +761,17 @@ 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;
+       loff_t newsize = attr->ia_size;
        int error;
 
-       if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
-               if (attr->ia_size < inode->i_size) {
+       if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)
+                                       && newsize != inode->i_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 +779,9 @@ 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 +793,29 @@ 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 +823,11 @@ 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 +1547,8 @@ 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 +1559,7 @@ 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 +1814,7 @@ 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 +1833,6 @@ 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 +1952,7 @@ 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 +1987,6 @@ 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 +2026,6 @@ 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 +2063,14 @@ 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 +2358,7 @@ 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 +2436,13 @@ 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 +2561,45 @@ 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 +2639,34 @@ 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 +2710,7 @@ 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;