From b0e15190ead07056ab0c3844a499ff35e66d27cc Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 6 Jan 2006 00:11:42 -0800 Subject: [PATCH] NOMMU: Make SYSV IPC SHM use ramfs facilities on NOMMU 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/nommu.c | 7 +++++++ mm/shmem.c | 2 +- mm/tiny-shmem.c | 29 ++++++++++++++++++++++++++++- 3 files changed, 36 insertions(+), 2 deletions(-) (limited to 'mm') diff --git a/mm/nommu.c b/mm/nommu.c index c1196812876b..c10262d68232 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -1177,3 +1177,10 @@ int in_gate_area_no_task(unsigned long addr) { return 0; } + +struct page *filemap_nopage(struct vm_area_struct *area, + unsigned long address, int *type) +{ + BUG(); + return NULL; +} diff --git a/mm/shmem.c b/mm/shmem.c index 65c148efa2ed..a1f2f02af724 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1270,7 +1270,7 @@ out_nomem: return retval; } -static int shmem_mmap(struct file *file, struct vm_area_struct *vma) +int shmem_mmap(struct file *file, struct vm_area_struct *vma) { file_accessed(file); vma->vm_ops = &shmem_vm_ops; diff --git a/mm/tiny-shmem.c b/mm/tiny-shmem.c index b58abcf44ed6..cdc6d431972b 100644 --- a/mm/tiny-shmem.c +++ b/mm/tiny-shmem.c @@ -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 -- cgit v1.2.3