diff options
| author | Jeremy Fitzhardinge <jeremy@goop.org> | 2009-02-09 12:05:49 -0800 |
|---|---|---|
| committer | Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> | 2010-10-20 16:22:30 -0700 |
| commit | 24a89b5be4cf2b7f1b49b56b6cb4a7b71fccf241 (patch) | |
| tree | cb19b4d662cce8e2f0a62e467bc83848863bccb6 | |
| parent | 1c5de1939c204bde9cce87f4eb3d26e9f9eb732b (diff) | |
xen/privcmd: create address space to allow writable mmaps
These are necessary to allow writeable mmap of the privcmd node to
succeed without being marked read-only for writenotify purposes. Which
in turn is necessary to allow mappings of foreign guest pages
[ Impact: bugfix: allow writable mappings ]
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
| -rw-r--r-- | drivers/xen/xenfs/super.c | 42 |
1 files changed, 38 insertions, 4 deletions
diff --git a/drivers/xen/xenfs/super.c b/drivers/xen/xenfs/super.c index 8c7462866e9..23f1cca5a2e 100644 --- a/drivers/xen/xenfs/super.c +++ b/drivers/xen/xenfs/super.c @@ -12,6 +12,8 @@ #include <linux/module.h> #include <linux/fs.h> #include <linux/magic.h> +#include <linux/mm.h> +#include <linux/backing-dev.h> #include <xen/xen.h> @@ -22,12 +24,30 @@ MODULE_DESCRIPTION("Xen filesystem"); MODULE_LICENSE("GPL"); +static int xenfs_set_page_dirty(struct page *page) +{ + if (!PageDirty(page)) + SetPageDirty(page); + return 0; +} + +static const struct address_space_operations xenfs_aops = { + .set_page_dirty = xenfs_set_page_dirty, +}; + +static struct backing_dev_info xenfs_backing_dev_info = { + .ra_pages = 0, /* No readahead */ + .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK, +}; + static struct inode *xenfs_make_inode(struct super_block *sb, int mode) { struct inode *ret = new_inode(sb); if (ret) { ret->i_mode = mode; + ret->i_mapping->a_ops = &xenfs_aops; + ret->i_mapping->backing_dev_info = &xenfs_backing_dev_info; ret->i_uid = ret->i_gid = 0; ret->i_blocks = 0; ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME; @@ -119,11 +139,25 @@ static struct file_system_type xenfs_type = { static int __init xenfs_init(void) { - if (xen_domain()) - return register_filesystem(&xenfs_type); + int err; + if (!xen_domain()) { + printk(KERN_INFO "xenfs: not registering filesystem on non-xen platform\n"); + return 0; + } - printk(KERN_INFO "XENFS: not registering filesystem on non-xen platform\n"); - return 0; + err = register_filesystem(&xenfs_type); + if (err) { + printk(KERN_ERR "xenfs: Unable to register filesystem!\n"); + goto out; + } + + err = bdi_init(&xenfs_backing_dev_info); + if (err) + unregister_filesystem(&xenfs_type); + + out: + + return err; } static void __exit xenfs_exit(void) |