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authorChristoph Hellwig <hch@lst.de>2015-01-14 10:42:32 +0100
committerJens Axboe <axboe@fb.com>2015-01-20 14:02:58 -0700
commitb4caecd48005fbed3949dde6c1cb233142fd69e9 (patch)
tree1fdd9b7c15568c79eb3c1ed84a39858ddbcbc88b /fs/ramfs
parent97b713ba3ebaa6c8d84c2c720f5468a7c6a6eb4e (diff)
downloadlinux-stericsson-b4caecd48005fbed3949dde6c1cb233142fd69e9.tar.gz
fs: introduce f_op->mmap_capabilities for nommu mmap support
Since "BDI: Provide backing device capability information [try #3]" the backing_dev_info structure also provides flags for the kind of mmap operation available in a nommu environment, which is entirely unrelated to it's original purpose. Introduce a new nommu-only file operation to provide this information to the nommu mmap code instead. Splitting this from the backing_dev_info structure allows to remove lots of backing_dev_info instance that aren't otherwise needed, and entirely gets rid of the concept of providing a backing_dev_info for a character device. It also removes the need for the mtd_inodefs filesystem. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Tejun Heo <tj@kernel.org> Acked-by: Brian Norris <computersforpeace@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'fs/ramfs')
-rw-r--r--fs/ramfs/file-nommu.c7
-rw-r--r--fs/ramfs/inode.c22
2 files changed, 9 insertions, 20 deletions
diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c
index bbafbde3471a..f6ab41b39612 100644
--- a/fs/ramfs/file-nommu.c
+++ b/fs/ramfs/file-nommu.c
@@ -34,7 +34,14 @@ static unsigned long ramfs_nommu_get_unmapped_area(struct file *file,
unsigned long flags);
static int ramfs_nommu_mmap(struct file *file, struct vm_area_struct *vma);
+static unsigned ramfs_mmap_capabilities(struct file *file)
+{
+ return NOMMU_MAP_DIRECT | NOMMU_MAP_COPY | NOMMU_MAP_READ |
+ NOMMU_MAP_WRITE | NOMMU_MAP_EXEC;
+}
+
const struct file_operations ramfs_file_operations = {
+ .mmap_capabilities = ramfs_mmap_capabilities,
.mmap = ramfs_nommu_mmap,
.get_unmapped_area = ramfs_nommu_get_unmapped_area,
.read = new_sync_read,
diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c
index d365b1c4eb3c..ad4d712002f4 100644
--- a/fs/ramfs/inode.c
+++ b/fs/ramfs/inode.c
@@ -50,14 +50,6 @@ static const struct address_space_operations ramfs_aops = {
.set_page_dirty = __set_page_dirty_no_writeback,
};
-static struct backing_dev_info ramfs_backing_dev_info = {
- .name = "ramfs",
- .ra_pages = 0, /* No readahead */
- .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK |
- BDI_CAP_MAP_DIRECT | BDI_CAP_MAP_COPY |
- BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP,
-};
-
struct inode *ramfs_get_inode(struct super_block *sb,
const struct inode *dir, umode_t mode, dev_t dev)
{
@@ -67,7 +59,7 @@ struct inode *ramfs_get_inode(struct super_block *sb,
inode->i_ino = get_next_ino();
inode_init_owner(inode, dir, mode);
inode->i_mapping->a_ops = &ramfs_aops;
- inode->i_mapping->backing_dev_info = &ramfs_backing_dev_info;
+ inode->i_mapping->backing_dev_info = &noop_backing_dev_info;
mapping_set_gfp_mask(inode->i_mapping, GFP_HIGHUSER);
mapping_set_unevictable(inode->i_mapping);
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
@@ -267,19 +259,9 @@ static struct file_system_type ramfs_fs_type = {
int __init init_ramfs_fs(void)
{
static unsigned long once;
- int err;
if (test_and_set_bit(0, &once))
return 0;
-
- err = bdi_init(&ramfs_backing_dev_info);
- if (err)
- return err;
-
- err = register_filesystem(&ramfs_fs_type);
- if (err)
- bdi_destroy(&ramfs_backing_dev_info);
-
- return err;
+ return register_filesystem(&ramfs_fs_type);
}
fs_initcall(init_ramfs_fs);