aboutsummaryrefslogtreecommitdiffstats
path: root/mm/shmem.c
diff options
context:
space:
mode:
authorMatt Mackall <mpm@selenic.com>2009-01-06 17:40:20 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-06 18:59:08 -0500
commit853ac43ab194f5051b27a55060215d696dc9480d (patch)
tree1f60fd49d516b7b242781a77446993b1dfb5bb66 /mm/shmem.c
parent69e9930993cfd70d82c8d9dd96fc3a88854d06fc (diff)
shmem: unify regular and tiny shmem
tiny-shmem shares most of its 130 lines of code with shmem and tends to break when particular bits of shmem get modified. Unifying saves code and makes keeping these two in sync much easier. before: 14367 392 24 14783 39bf mm/shmem.o 396 72 8 476 1dc mm/tiny-shmem.o after: 14367 392 24 14783 39bf mm/shmem.o 412 72 8 492 1ec mm/shmem.o tiny Signed-off-by: Matt Mackall <mpm@selenic.com> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/shmem.c')
-rw-r--r--mm/shmem.c81
1 files changed, 71 insertions, 10 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index 24f18fdee6e..5941f980136 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -14,31 +14,39 @@
14 * Copyright (c) 2004, Luke Kenneth Casson Leighton <lkcl@lkcl.net> 14 * Copyright (c) 2004, Luke Kenneth Casson Leighton <lkcl@lkcl.net>
15 * Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> 15 * Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
16 * 16 *
17 * tiny-shmem:
18 * Copyright (c) 2004, 2008 Matt Mackall <mpm@selenic.com>
19 *
17 * This file is released under the GPL. 20 * This file is released under the GPL.
18 */ 21 */
19 22
23#include <linux/fs.h>
24#include <linux/init.h>
25#include <linux/vfs.h>
26#include <linux/mount.h>
27#include <linux/file.h>
28#include <linux/mm.h>
29#include <linux/module.h>
30#include <linux/swap.h>
31
32static struct vfsmount *shm_mnt;
33
34#ifdef CONFIG_SHMEM
20/* 35/*
21 * This virtual memory filesystem is heavily based on the ramfs. It 36 * This virtual memory filesystem is heavily based on the ramfs. It
22 * extends ramfs by the ability to use swap and honor resource limits 37 * extends ramfs by the ability to use swap and honor resource limits
23 * which makes it a completely usable filesystem. 38 * which makes it a completely usable filesystem.
24 */ 39 */
25 40
26#include <linux/module.h>
27#include <linux/init.h>
28#include <linux/fs.h>
29#include <linux/xattr.h> 41#include <linux/xattr.h>
30#include <linux/exportfs.h> 42#include <linux/exportfs.h>
31#include <linux/generic_acl.h> 43#include <linux/generic_acl.h>
32#include <linux/mm.h>
33#include <linux/mman.h> 44#include <linux/mman.h>
34#include <linux/file.h>
35#include <linux/swap.h>
36#include <linux/pagemap.h> 45#include <linux/pagemap.h>
37#include <linux/string.h> 46#include <linux/string.h>
38#include <linux/slab.h> 47#include <linux/slab.h>
39#include <linux/backing-dev.h> 48#include <linux/backing-dev.h>
40#include <linux/shmem_fs.h> 49#include <linux/shmem_fs.h>
41#include <linux/mount.h>
42#include <linux/writeback.h> 50#include <linux/writeback.h>
43#include <linux/vfs.h> 51#include <linux/vfs.h>
44#include <linux/blkdev.h> 52#include <linux/blkdev.h>
@@ -2485,7 +2493,6 @@ static struct file_system_type tmpfs_fs_type = {
2485 .get_sb = shmem_get_sb, 2493 .get_sb = shmem_get_sb,
2486 .kill_sb = kill_litter_super, 2494 .kill_sb = kill_litter_super,
2487}; 2495};
2488static struct vfsmount *shm_mnt;
2489 2496
2490static int __init init_tmpfs(void) 2497static int __init init_tmpfs(void)
2491{ 2498{
@@ -2524,7 +2531,51 @@ out4:
2524 shm_mnt = ERR_PTR(error); 2531 shm_mnt = ERR_PTR(error);
2525 return error; 2532 return error;
2526} 2533}
2527module_init(init_tmpfs) 2534
2535#else /* !CONFIG_SHMEM */
2536
2537/*
2538 * tiny-shmem: simple shmemfs and tmpfs using ramfs code
2539 *
2540 * This is intended for small system where the benefits of the full
2541 * shmem code (swap-backed and resource-limited) are outweighed by
2542 * their complexity. On systems without swap this code should be
2543 * effectively equivalent, but much lighter weight.
2544 */
2545
2546#include <linux/ramfs.h>
2547
2548static struct file_system_type tmpfs_fs_type = {
2549 .name = "tmpfs",
2550 .get_sb = ramfs_get_sb,
2551 .kill_sb = kill_litter_super,
2552};
2553
2554static int __init init_tmpfs(void)
2555{
2556 BUG_ON(register_filesystem(&tmpfs_fs_type) != 0);
2557
2558 shm_mnt = kern_mount(&tmpfs_fs_type);
2559 BUG_ON(IS_ERR(shm_mnt));
2560
2561 return 0;
2562}
2563
2564int shmem_unuse(swp_entry_t entry, struct page *page)
2565{
2566 return 0;
2567}
2568
2569#define shmem_file_operations ramfs_file_operations
2570#define shmem_vm_ops generic_file_vm_ops
2571#define shmem_get_inode ramfs_get_inode
2572#define shmem_acct_size(a, b) 0
2573#define shmem_unacct_size(a, b) do {} while (0)
2574#define SHMEM_MAX_BYTES LLONG_MAX
2575
2576#endif /* CONFIG_SHMEM */
2577
2578/* common code */
2528 2579
2529/** 2580/**
2530 * shmem_file_setup - get an unlinked file living in tmpfs 2581 * shmem_file_setup - get an unlinked file living in tmpfs
@@ -2568,12 +2619,20 @@ struct file *shmem_file_setup(char *name, loff_t size, unsigned long flags)
2568 if (!inode) 2619 if (!inode)
2569 goto close_file; 2620 goto close_file;
2570 2621
2622#ifdef CONFIG_SHMEM
2571 SHMEM_I(inode)->flags = flags & VM_ACCOUNT; 2623 SHMEM_I(inode)->flags = flags & VM_ACCOUNT;
2624#endif
2572 d_instantiate(dentry, inode); 2625 d_instantiate(dentry, inode);
2573 inode->i_size = size; 2626 inode->i_size = size;
2574 inode->i_nlink = 0; /* It is unlinked */ 2627 inode->i_nlink = 0; /* It is unlinked */
2575 init_file(file, shm_mnt, dentry, FMODE_WRITE | FMODE_READ, 2628 init_file(file, shm_mnt, dentry, FMODE_WRITE | FMODE_READ,
2576 &shmem_file_operations); 2629 &shmem_file_operations);
2630
2631#ifndef CONFIG_MMU
2632 error = ramfs_nommu_expand_for_mapping(inode, size);
2633 if (error)
2634 goto close_file;
2635#endif
2577 return file; 2636 return file;
2578 2637
2579close_file: 2638close_file:
@@ -2605,3 +2664,5 @@ int shmem_zero_setup(struct vm_area_struct *vma)
2605 vma->vm_ops = &shmem_vm_ops; 2664 vma->vm_ops = &shmem_vm_ops;
2606 return 0; 2665 return 0;
2607} 2666}
2667
2668module_init(init_tmpfs)