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| author | Christoph Hellwig <hch@lst.de> | 2015-01-14 10:42:32 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2015-01-20 14:02:58 -0700 |
| commit | b4caecd48005fbed3949dde6c1cb233142fd69e9 (patch) | |
| tree | 1fdd9b7c15568c79eb3c1ed84a39858ddbcbc88b /fs/romfs | |
| parent | 97b713ba3ebaa6c8d84c2c720f5468a7c6a6eb4e (diff) | |
| download | linux-b4caecd48005fbed3949dde6c1cb233142fd69e9.tar.bz2 | |
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/romfs')
| -rw-r--r-- | fs/romfs/mmap-nommu.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/fs/romfs/mmap-nommu.c b/fs/romfs/mmap-nommu.c index ea06c7554860..7da9e2153953 100644 --- a/fs/romfs/mmap-nommu.c +++ b/fs/romfs/mmap-nommu.c @@ -70,6 +70,15 @@ static int romfs_mmap(struct file *file, struct vm_area_struct *vma) return vma->vm_flags & (VM_SHARED | VM_MAYSHARE) ? 0 : -ENOSYS; } +static unsigned romfs_mmap_capabilities(struct file *file) +{ + struct mtd_info *mtd = file_inode(file)->i_sb->s_mtd; + + if (!mtd) + return NOMMU_MAP_COPY; + return mtd_mmap_capabilities(mtd); +} + const struct file_operations romfs_ro_fops = { .llseek = generic_file_llseek, .read = new_sync_read, @@ -77,4 +86,5 @@ const struct file_operations romfs_ro_fops = { .splice_read = generic_file_splice_read, .mmap = romfs_mmap, .get_unmapped_area = romfs_get_unmapped_area, + .mmap_capabilities = romfs_mmap_capabilities, }; |