]> nv-tegra.nvidia Code Review - linux-2.6.git/blobdiff - mm/shmem.c
memcg: ensure list is empty at rmdir
[linux-2.6.git] / mm / shmem.c
index bd20f8bb02aa7ac7d7dea5d581075309425d040c..eef4ebea51581f9aa8a6d2244f8ce5fa57f99c22 100644 (file)
@@ -29,7 +29,6 @@
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/swap.h>
-#include <linux/ima.h>
 
 static struct vfsmount *shm_mnt;
 
@@ -42,6 +41,7 @@ static struct vfsmount *shm_mnt;
 
 #include <linux/xattr.h>
 #include <linux/exportfs.h>
+#include <linux/posix_acl.h>
 #include <linux/generic_acl.h>
 #include <linux/mman.h>
 #include <linux/string.h>
@@ -49,7 +49,6 @@ static struct vfsmount *shm_mnt;
 #include <linux/backing-dev.h>
 #include <linux/shmem_fs.h>
 #include <linux/writeback.h>
-#include <linux/vfs.h>
 #include <linux/blkdev.h>
 #include <linux/security.h>
 #include <linux/swapops.h>
@@ -219,7 +218,7 @@ static const struct file_operations shmem_file_operations;
 static const struct inode_operations shmem_inode_operations;
 static const struct inode_operations shmem_dir_inode_operations;
 static const struct inode_operations shmem_special_inode_operations;
-static struct vm_operations_struct shmem_vm_ops;
+static const struct vm_operations_struct shmem_vm_ops;
 
 static struct backing_dev_info shmem_backing_dev_info  __read_mostly = {
        .ra_pages       = 0,    /* No readahead */
@@ -811,7 +810,7 @@ static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
                error = inode_setattr(inode, attr);
 #ifdef CONFIG_TMPFS_POSIX_ACL
        if (!error && (attr->ia_valid & ATTR_MODE))
-               error = generic_acl_chmod(inode, &shmem_acl_ops);
+               error = generic_acl_chmod(inode);
 #endif
        if (page)
                page_cache_release(page);
@@ -1018,7 +1017,14 @@ int shmem_unuse(swp_entry_t entry, struct page *page)
                        goto out;
        }
        mutex_unlock(&shmem_swaplist_mutex);
-out:   return found;   /* 0 or 1 or -ENOMEM */
+       /*
+        * Can some race bring us here?  We've been holding page lock,
+        * so I think not; but would rather try again later than BUG()
+        */
+       unlock_page(page);
+       page_cache_release(page);
+out:
+       return (found < 0) ? found : 0;
 }
 
 /*
@@ -1047,8 +1053,9 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
         * sync from ever calling shmem_writepage; but a stacking filesystem
         * may use the ->writepage of its underlying filesystem, in which case
         * tmpfs should write out to swap only in response to memory pressure,
-        * and not for pdflush or sync.  However, in those cases, we do still
-        * want to check if there's a redundant swappage to be discarded.
+        * and not for the writeback threads or sync.  However, in those cases,
+        * we do still want to check if there's a redundant swappage to be
+        * discarded.
         */
        if (wbc->for_reclaim)
                swap = get_swap_page();
@@ -1080,7 +1087,7 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
                else
                        inode = NULL;
                spin_unlock(&info->lock);
-               swap_duplicate(swap);
+               swap_shmem_alloc(swap);
                BUG_ON(page_mapped(page));
                page_cache_release(page);       /* pagecache ref */
                swap_writepage(page, wbc);
@@ -1097,6 +1104,10 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
        shmem_swp_unmap(entry);
 unlock:
        spin_unlock(&info->lock);
+       /*
+        * add_to_swap_cache() doesn't return -EEXIST, so we can safely
+        * clear SWAP_HAS_CACHE flag.
+        */
        swapcache_free(swap, NULL);
 redirty:
        set_page_dirty(page);
@@ -1630,8 +1641,8 @@ shmem_write_end(struct file *file, struct address_space *mapping,
        if (pos + copied > inode->i_size)
                i_size_write(inode, pos + copied);
 
-       unlock_page(page);
        set_page_dirty(page);
+       unlock_page(page);
        page_cache_release(page);
 
        return copied;
@@ -1813,11 +1824,15 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
                                return error;
                        }
                }
-               error = shmem_acl_init(inode, dir);
+#ifdef CONFIG_TMPFS_POSIX_ACL
+               error = generic_acl_init(inode, dir);
                if (error) {
                        iput(inode);
                        return error;
                }
+#else
+               error = 0;
+#endif
                if (dir->i_mode & S_ISGID) {
                        inode->i_gid = dir->i_gid;
                        if (S_ISDIR(mode))
@@ -1968,13 +1983,13 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
                        iput(inode);
                        return error;
                }
-               unlock_page(page);
                inode->i_mapping->a_ops = &shmem_aops;
                inode->i_op = &shmem_symlink_inode_operations;
                kaddr = kmap_atomic(page, KM_USER0);
                memcpy(kaddr, symname, len);
                kunmap_atomic(kaddr, KM_USER0);
                set_page_dirty(page);
+               unlock_page(page);
                page_cache_release(page);
        }
        if (dir->i_mode & S_ISGID)
@@ -2032,27 +2047,28 @@ static const struct inode_operations shmem_symlink_inode_operations = {
  * filesystem level, though.
  */
 
-static size_t shmem_xattr_security_list(struct inode *inode, char *list,
+static size_t shmem_xattr_security_list(struct dentry *dentry, char *list,
                                        size_t list_len, const char *name,
-                                       size_t name_len)
+                                       size_t name_len, int handler_flags)
 {
-       return security_inode_listsecurity(inode, list, list_len);
+       return security_inode_listsecurity(dentry->d_inode, list, list_len);
 }
 
-static int shmem_xattr_security_get(struct inode *inode, const char *name,
-                                   void *buffer, size_t size)
+static int shmem_xattr_security_get(struct dentry *dentry, const char *name,
+               void *buffer, size_t size, int handler_flags)
 {
        if (strcmp(name, "") == 0)
                return -EINVAL;
-       return xattr_getsecurity(inode, name, buffer, size);
+       return xattr_getsecurity(dentry->d_inode, name, buffer, size);
 }
 
-static int shmem_xattr_security_set(struct inode *inode, const char *name,
-                                   const void *value, size_t size, int flags)
+static int shmem_xattr_security_set(struct dentry *dentry, const char *name,
+               const void *value, size_t size, int flags, int handler_flags)
 {
        if (strcmp(name, "") == 0)
                return -EINVAL;
-       return security_inode_setsecurity(inode, name, value, size, flags);
+       return security_inode_setsecurity(dentry->d_inode, name, value,
+                                         size, flags);
 }
 
 static struct xattr_handler shmem_xattr_security_handler = {
@@ -2063,8 +2079,8 @@ static struct xattr_handler shmem_xattr_security_handler = {
 };
 
 static struct xattr_handler *shmem_xattr_handlers[] = {
-       &shmem_xattr_acl_access_handler,
-       &shmem_xattr_acl_default_handler,
+       &generic_acl_access_handler,
+       &generic_acl_default_handler,
        &shmem_xattr_security_handler,
        NULL
 };
@@ -2306,17 +2322,14 @@ int shmem_fill_super(struct super_block *sb, void *data, int silent)
        int err = -ENOMEM;
 
        /* Round up to L1_CACHE_BYTES to resist false sharing */
-       sbinfo = kmalloc(max((int)sizeof(struct shmem_sb_info),
+       sbinfo = kzalloc(max((int)sizeof(struct shmem_sb_info),
                                L1_CACHE_BYTES), GFP_KERNEL);
        if (!sbinfo)
                return -ENOMEM;
 
-       sbinfo->max_blocks = 0;
-       sbinfo->max_inodes = 0;
        sbinfo->mode = S_IRWXUGO | S_ISVTX;
        sbinfo->uid = current_fsuid();
        sbinfo->gid = current_fsgid();
-       sbinfo->mpol = NULL;
        sb->s_fs_info = sbinfo;
 
 #ifdef CONFIG_TMPFS
@@ -2420,6 +2433,7 @@ static const struct address_space_operations shmem_aops = {
        .write_end      = shmem_write_end,
 #endif
        .migratepage    = migrate_page,
+       .error_remove_page = generic_error_remove_page,
 };
 
 static const struct file_operations shmem_file_operations = {
@@ -2445,7 +2459,7 @@ static const struct inode_operations shmem_inode_operations = {
        .getxattr       = generic_getxattr,
        .listxattr      = generic_listxattr,
        .removexattr    = generic_removexattr,
-       .check_acl      = shmem_check_acl,
+       .check_acl      = generic_check_acl,
 #endif
 
 };
@@ -2468,7 +2482,7 @@ static const struct inode_operations shmem_dir_inode_operations = {
        .getxattr       = generic_getxattr,
        .listxattr      = generic_listxattr,
        .removexattr    = generic_removexattr,
-       .check_acl      = shmem_check_acl,
+       .check_acl      = generic_check_acl,
 #endif
 };
 
@@ -2479,7 +2493,7 @@ static const struct inode_operations shmem_special_inode_operations = {
        .getxattr       = generic_getxattr,
        .listxattr      = generic_listxattr,
        .removexattr    = generic_removexattr,
-       .check_acl      = shmem_check_acl,
+       .check_acl      = generic_check_acl,
 #endif
 };
 
@@ -2496,7 +2510,7 @@ static const struct super_operations shmem_ops = {
        .put_super      = shmem_put_super,
 };
 
-static struct vm_operations_struct shmem_vm_ops = {
+static const struct vm_operations_struct shmem_vm_ops = {
        .fault          = shmem_fault,
 #ifdef CONFIG_NUMA
        .set_policy     = shmem_set_policy,
@@ -2590,6 +2604,11 @@ int shmem_unuse(swp_entry_t entry, struct page *page)
        return 0;
 }
 
+int shmem_lock(struct file *file, int lock, struct user_struct *user)
+{
+       return 0;
+}
+
 #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)
@@ -2612,7 +2631,8 @@ struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags
        int error;
        struct file *file;
        struct inode *inode;
-       struct dentry *dentry, *root;
+       struct path path;
+       struct dentry *root;
        struct qstr this;
 
        if (IS_ERR(shm_mnt))
@@ -2629,38 +2649,35 @@ struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags
        this.len = strlen(name);
        this.hash = 0; /* will go */
        root = shm_mnt->mnt_root;
-       dentry = d_alloc(root, &this);
-       if (!dentry)
+       path.dentry = d_alloc(root, &this);
+       if (!path.dentry)
                goto put_memory;
-
-       error = -ENFILE;
-       file = get_empty_filp();
-       if (!file)
-               goto put_dentry;
+       path.mnt = mntget(shm_mnt);
 
        error = -ENOSPC;
        inode = shmem_get_inode(root->d_sb, S_IFREG | S_IRWXUGO, 0, flags);
        if (!inode)
-               goto close_file;
+               goto put_dentry;
 
-       d_instantiate(dentry, inode);
+       d_instantiate(path.dentry, inode);
        inode->i_size = size;
        inode->i_nlink = 0;     /* It is unlinked */
-       init_file(file, shm_mnt, dentry, FMODE_WRITE | FMODE_READ,
-                 &shmem_file_operations);
-
 #ifndef CONFIG_MMU
        error = ramfs_nommu_expand_for_mapping(inode, size);
        if (error)
-               goto close_file;
+               goto put_dentry;
 #endif
-       ima_counts_get(file);
+
+       error = -ENFILE;
+       file = alloc_file(&path, FMODE_WRITE | FMODE_READ,
+                 &shmem_file_operations);
+       if (!file)
+               goto put_dentry;
+
        return file;
 
-close_file:
-       put_filp(file);
 put_dentry:
-       dput(dentry);
+       path_put(&path);
 put_memory:
        shmem_unacct_size(flags, size);
        return ERR_PTR(error);