diff options
author | Matt Mackall <mpm@selenic.com> | 2004-08-30 20:34:47 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2004-08-30 20:34:47 -0700 |
commit | 14ef4d0a5b1213a0ebac1bcc5b28298a357cfc80 (patch) | |
tree | f57087b8c5fdb398d424a69a5ff8e821d0c6c83a /mm | |
parent | 59835997b54000eb1e8a6606ac0c4dcd5a4ba5d9 (diff) | |
download | history-14ef4d0a5b1213a0ebac1bcc5b28298a357cfc80.tar.gz |
[PATCH] tiny shmem/tmpfs replacement
A patch to replace tmpfs/shmem with ramfs for systems without swap,
incorporating the suggestions from Andi and Hugh. It uses ramfs instead.
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/Makefile | 5 | ||||
-rw-r--r-- | mm/filemap.c | 2 | ||||
-rw-r--r-- | mm/tiny-shmem.c | 124 |
3 files changed, 129 insertions, 2 deletions
diff --git a/mm/Makefile b/mm/Makefile index 366e50de11bd54..7cea59b58bccf4 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -5,7 +5,7 @@ mmu-y := nommu.o mmu-$(CONFIG_MMU) := fremap.o highmem.o madvise.o memory.o mincore.o \ mlock.o mmap.o mprotect.o mremap.o msync.o rmap.o \ - shmem.o vmalloc.o + vmalloc.o obj-y := bootmem.o filemap.o mempool.o oom_kill.o fadvise.o \ page_alloc.o page-writeback.o pdflush.o prio_tree.o \ @@ -15,3 +15,6 @@ obj-y := bootmem.o filemap.o mempool.o oom_kill.o fadvise.o \ obj-$(CONFIG_SWAP) += page_io.o swap_state.o swapfile.o thrash.o obj-$(CONFIG_HUGETLBFS) += hugetlb.o obj-$(CONFIG_NUMA) += mempolicy.o +obj-$(CONFIG_SHMEM) += shmem.o +obj-$(CONFIG_TINY_SHMEM) += tiny-shmem.o + diff --git a/mm/filemap.c b/mm/filemap.c index 16db7c62b3fba8..36e34ed27657ad 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1488,7 +1488,7 @@ repeat: return 0; } -static struct vm_operations_struct generic_file_vm_ops = { +struct vm_operations_struct generic_file_vm_ops = { .nopage = filemap_nopage, .populate = filemap_populate, }; diff --git a/mm/tiny-shmem.c b/mm/tiny-shmem.c new file mode 100644 index 00000000000000..90abc63db367da --- /dev/null +++ b/mm/tiny-shmem.c @@ -0,0 +1,124 @@ +/* + * tiny-shmem.c: simple shmemfs and tmpfs using ramfs code + * + * Matt Mackall <mpm@selenic.com> January, 2004 + * derived from mm/shmem.c and fs/ramfs/inode.c + * + * This is intended for small system where the benefits of the full + * shmem code (swap-backed and resource-limited) are outweighed by + * their complexity. On systems without swap this code should be + * effectively equivalent, but much lighter weight. + */ + +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/devfs_fs_kernel.h> +#include <linux/vfs.h> +#include <linux/mount.h> +#include <linux/file.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/swap.h> +#include <linux/ramfs.h> + +static struct file_system_type tmpfs_fs_type = { + .name = "tmpfs", + .get_sb = ramfs_get_sb, + .kill_sb = kill_litter_super, +}; + +static struct vfsmount *shm_mnt; + +static int __init init_tmpfs(void) +{ + register_filesystem(&tmpfs_fs_type); +#ifdef CONFIG_TMPFS + devfs_mk_dir("shm"); +#endif + shm_mnt = kern_mount(&tmpfs_fs_type); + return 0; +} +module_init(init_tmpfs) + +/* + * shmem_file_setup - get an unlinked file living in tmpfs + * + * @name: name for dentry (to be seen in /proc/<pid>/maps + * @size: size to be set for the file + * + */ +struct file *shmem_file_setup(char *name, loff_t size, unsigned long flags) +{ + int error; + struct file *file; + struct inode *inode; + struct dentry *dentry, *root; + struct qstr this; + + if (IS_ERR(shm_mnt)) + return (void *)shm_mnt; + + error = -ENOMEM; + this.name = name; + this.len = strlen(name); + this.hash = 0; /* will go */ + root = shm_mnt->mnt_root; + dentry = d_alloc(root, &this); + if (!dentry) + goto put_memory; + + error = -ENFILE; + file = get_empty_filp(); + if (!file) + goto put_dentry; + + error = -ENOSPC; + inode = ramfs_get_inode(root->d_sb, S_IFREG | S_IRWXUGO, 0); + if (!inode) + 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; + return file; + +close_file: + put_filp(file); +put_dentry: + dput(dentry); +put_memory: + return ERR_PTR(error); +} + +/* + * shmem_zero_setup - setup a shared anonymous mapping + * + * @vma: the vma to be mmapped is prepared by do_mmap_pgoff + */ +int shmem_zero_setup(struct vm_area_struct *vma) +{ + struct file *file; + loff_t size = vma->vm_end - vma->vm_start; + + file = shmem_file_setup("dev/zero", size, vma->vm_flags); + if (IS_ERR(file)) + return PTR_ERR(file); + + if (vma->vm_file) + fput(vma->vm_file); + vma->vm_file = file; + vma->vm_ops = &generic_file_vm_ops; + return 0; +} + +int shmem_unuse(swp_entry_t entry, struct page *page) +{ + return 0; +} + +EXPORT_SYMBOL(shmem_file_setup); |