![Tejun Heo](/assets/img/avatar_default.png)
percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
324 lines
7.3 KiB
C
324 lines
7.3 KiB
C
/*
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* Resizable simple ram filesystem for Linux.
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*
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* Copyright (C) 2000 Linus Torvalds.
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* 2000 Transmeta Corp.
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*
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* Usage limits added by David Gibson, Linuxcare Australia.
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* This file is released under the GPL.
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*/
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/*
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* NOTE! This filesystem is probably most useful
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* not as a real filesystem, but as an example of
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* how virtual filesystems can be written.
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*
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* It doesn't get much simpler than this. Consider
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* that this file implements the full semantics of
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* a POSIX-compliant read-write filesystem.
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*
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* Note in particular how the filesystem does not
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* need to implement any data structures of its own
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* to keep track of the virtual data: using the VFS
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* caches is sufficient.
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*/
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#include <linux/module.h>
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#include <linux/fs.h>
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#include <linux/pagemap.h>
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#include <linux/highmem.h>
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#include <linux/time.h>
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#include <linux/init.h>
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#include <linux/string.h>
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#include <linux/backing-dev.h>
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#include <linux/ramfs.h>
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#include <linux/sched.h>
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#include <linux/parser.h>
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#include <linux/magic.h>
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#include <linux/slab.h>
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#include <asm/uaccess.h>
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#include "internal.h"
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#define RAMFS_DEFAULT_MODE 0755
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static const struct super_operations ramfs_ops;
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static const struct inode_operations ramfs_dir_inode_operations;
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static struct backing_dev_info ramfs_backing_dev_info = {
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.name = "ramfs",
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.ra_pages = 0, /* No readahead */
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.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK |
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BDI_CAP_MAP_DIRECT | BDI_CAP_MAP_COPY |
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BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP,
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};
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struct inode *ramfs_get_inode(struct super_block *sb, int mode, dev_t dev)
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{
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struct inode * inode = new_inode(sb);
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if (inode) {
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inode->i_mode = mode;
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inode->i_uid = current_fsuid();
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inode->i_gid = current_fsgid();
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inode->i_mapping->a_ops = &ramfs_aops;
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inode->i_mapping->backing_dev_info = &ramfs_backing_dev_info;
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mapping_set_gfp_mask(inode->i_mapping, GFP_HIGHUSER);
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mapping_set_unevictable(inode->i_mapping);
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inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
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switch (mode & S_IFMT) {
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default:
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init_special_inode(inode, mode, dev);
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break;
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case S_IFREG:
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inode->i_op = &ramfs_file_inode_operations;
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inode->i_fop = &ramfs_file_operations;
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break;
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case S_IFDIR:
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inode->i_op = &ramfs_dir_inode_operations;
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inode->i_fop = &simple_dir_operations;
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/* directory inodes start off with i_nlink == 2 (for "." entry) */
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inc_nlink(inode);
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break;
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case S_IFLNK:
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inode->i_op = &page_symlink_inode_operations;
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break;
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}
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}
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return inode;
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}
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/*
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* File creation. Allocate an inode, and we're done..
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*/
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/* SMP-safe */
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static int
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ramfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
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{
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struct inode * inode = ramfs_get_inode(dir->i_sb, mode, dev);
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int error = -ENOSPC;
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if (inode) {
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if (dir->i_mode & S_ISGID) {
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inode->i_gid = dir->i_gid;
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if (S_ISDIR(mode))
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inode->i_mode |= S_ISGID;
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}
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d_instantiate(dentry, inode);
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dget(dentry); /* Extra count - pin the dentry in core */
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error = 0;
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dir->i_mtime = dir->i_ctime = CURRENT_TIME;
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}
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return error;
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}
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static int ramfs_mkdir(struct inode * dir, struct dentry * dentry, int mode)
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{
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int retval = ramfs_mknod(dir, dentry, mode | S_IFDIR, 0);
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if (!retval)
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inc_nlink(dir);
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return retval;
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}
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static int ramfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd)
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{
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return ramfs_mknod(dir, dentry, mode | S_IFREG, 0);
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}
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static int ramfs_symlink(struct inode * dir, struct dentry *dentry, const char * symname)
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{
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struct inode *inode;
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int error = -ENOSPC;
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inode = ramfs_get_inode(dir->i_sb, S_IFLNK|S_IRWXUGO, 0);
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if (inode) {
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int l = strlen(symname)+1;
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error = page_symlink(inode, symname, l);
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if (!error) {
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if (dir->i_mode & S_ISGID)
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inode->i_gid = dir->i_gid;
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d_instantiate(dentry, inode);
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dget(dentry);
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dir->i_mtime = dir->i_ctime = CURRENT_TIME;
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} else
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iput(inode);
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}
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return error;
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}
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static const struct inode_operations ramfs_dir_inode_operations = {
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.create = ramfs_create,
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.lookup = simple_lookup,
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.link = simple_link,
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.unlink = simple_unlink,
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.symlink = ramfs_symlink,
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.mkdir = ramfs_mkdir,
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.rmdir = simple_rmdir,
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.mknod = ramfs_mknod,
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.rename = simple_rename,
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};
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static const struct super_operations ramfs_ops = {
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.statfs = simple_statfs,
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.drop_inode = generic_delete_inode,
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.show_options = generic_show_options,
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};
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struct ramfs_mount_opts {
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umode_t mode;
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};
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enum {
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Opt_mode,
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Opt_err
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};
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static const match_table_t tokens = {
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{Opt_mode, "mode=%o"},
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{Opt_err, NULL}
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};
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struct ramfs_fs_info {
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struct ramfs_mount_opts mount_opts;
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};
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static int ramfs_parse_options(char *data, struct ramfs_mount_opts *opts)
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{
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substring_t args[MAX_OPT_ARGS];
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int option;
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int token;
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char *p;
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opts->mode = RAMFS_DEFAULT_MODE;
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while ((p = strsep(&data, ",")) != NULL) {
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if (!*p)
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continue;
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token = match_token(p, tokens, args);
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switch (token) {
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case Opt_mode:
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if (match_octal(&args[0], &option))
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return -EINVAL;
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opts->mode = option & S_IALLUGO;
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break;
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/*
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* We might like to report bad mount options here;
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* but traditionally ramfs has ignored all mount options,
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* and as it is used as a !CONFIG_SHMEM simple substitute
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* for tmpfs, better continue to ignore other mount options.
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*/
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}
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}
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return 0;
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}
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static int ramfs_fill_super(struct super_block * sb, void * data, int silent)
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{
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struct ramfs_fs_info *fsi;
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struct inode *inode = NULL;
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struct dentry *root;
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int err;
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save_mount_options(sb, data);
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fsi = kzalloc(sizeof(struct ramfs_fs_info), GFP_KERNEL);
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sb->s_fs_info = fsi;
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if (!fsi) {
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err = -ENOMEM;
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goto fail;
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}
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err = ramfs_parse_options(data, &fsi->mount_opts);
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if (err)
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goto fail;
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sb->s_maxbytes = MAX_LFS_FILESIZE;
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sb->s_blocksize = PAGE_CACHE_SIZE;
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sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
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sb->s_magic = RAMFS_MAGIC;
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sb->s_op = &ramfs_ops;
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sb->s_time_gran = 1;
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inode = ramfs_get_inode(sb, S_IFDIR | fsi->mount_opts.mode, 0);
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if (!inode) {
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err = -ENOMEM;
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goto fail;
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}
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root = d_alloc_root(inode);
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sb->s_root = root;
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if (!root) {
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err = -ENOMEM;
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goto fail;
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}
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return 0;
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fail:
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kfree(fsi);
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sb->s_fs_info = NULL;
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iput(inode);
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return err;
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}
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int ramfs_get_sb(struct file_system_type *fs_type,
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int flags, const char *dev_name, void *data, struct vfsmount *mnt)
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{
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return get_sb_nodev(fs_type, flags, data, ramfs_fill_super, mnt);
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}
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static int rootfs_get_sb(struct file_system_type *fs_type,
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int flags, const char *dev_name, void *data, struct vfsmount *mnt)
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{
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return get_sb_nodev(fs_type, flags|MS_NOUSER, data, ramfs_fill_super,
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mnt);
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}
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static void ramfs_kill_sb(struct super_block *sb)
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{
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kfree(sb->s_fs_info);
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kill_litter_super(sb);
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}
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static struct file_system_type ramfs_fs_type = {
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.name = "ramfs",
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.get_sb = ramfs_get_sb,
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.kill_sb = ramfs_kill_sb,
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};
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static struct file_system_type rootfs_fs_type = {
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.name = "rootfs",
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.get_sb = rootfs_get_sb,
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.kill_sb = kill_litter_super,
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};
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static int __init init_ramfs_fs(void)
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{
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return register_filesystem(&ramfs_fs_type);
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}
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static void __exit exit_ramfs_fs(void)
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{
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unregister_filesystem(&ramfs_fs_type);
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}
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module_init(init_ramfs_fs)
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module_exit(exit_ramfs_fs)
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int __init init_rootfs(void)
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{
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int err;
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err = bdi_init(&ramfs_backing_dev_info);
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if (err)
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return err;
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err = register_filesystem(&rootfs_fs_type);
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if (err)
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bdi_destroy(&ramfs_backing_dev_info);
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return err;
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}
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MODULE_LICENSE("GPL");
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