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[PATCH] NOMMU: Make SYSV IPC SHM use ramfs facilities on NOMMU

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The attached patch makes the SYSV IPC shared memory facilities use the new
ramfs facilities on a no-MMU kernel.

The following changes are made:

 (1) There are now shmem_mmap() and shmem_get_unmapped_area() functions to
     allow the IPC SHM facilities to commune with the tiny-shmem and shmem
     code.

 (2) ramfs files now need resizing using do_truncate() rather than by modifying
     the inode size directly (see shmem_file_setup()). This causes ramfs to
     attempt to bind a block of pages of sufficient size to the inode.

 (3) CONFIG_SYSVIPC is no longer contingent on CONFIG_MMU.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
David Howells
2006-01-06 00:11:42 -08:00
committed by Linus Torvalds
parent 642fb4d1f1
commit b0e15190ea
6 changed files with 58 additions and 8 deletions
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29
mm/tiny-shmem.c
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@ -81,13 +81,19 @@ struct file *shmem_file_setup(char *name, loff_t size, unsigned long flags)
goto close_file;
d_instantiate(dentry, inode);
inode->i_size = size;
inode->i_nlink = 0; /* It is unlinked */
file->f_vfsmnt = mntget(shm_mnt);
file->f_dentry = dentry;
file->f_mapping = inode->i_mapping;
file->f_op = &ramfs_file_operations;
file->f_mode = FMODE_WRITE | FMODE_READ;
/* notify everyone as to the change of file size */
error = do_truncate(dentry, size, file);
if (error < 0)
goto close_file;
return file;
close_file:
@ -123,3 +129,24 @@ int shmem_unuse(swp_entry_t entry, struct page *page)
{
return 0;
}
int shmem_mmap(struct file *file, struct vm_area_struct *vma)
{
file_accessed(file);
#ifndef CONFIG_MMU
return ramfs_nommu_mmap(file, vma);
#else
return 0;
#endif
}
#ifndef CONFIG_MMU
unsigned long shmem_get_unmapped_area(struct file *file,
unsigned long addr,
unsigned long len,
unsigned long pgoff,
unsigned long flags)
{
return ramfs_nommu_get_unmapped_area(file, addr, len, pgoff, flags);
}
#endif