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![Christoph Lameter](/assets/img/avatar_default.png)
I have never seen a use of SLAB_DEBUG_INITIAL. It is only supported by SLAB. I think its purpose was to have a callback after an object has been freed to verify that the state is the constructor state again? The callback is performed before each freeing of an object. I would think that it is much easier to check the object state manually before the free. That also places the check near the code object manipulation of the object. Also the SLAB_DEBUG_INITIAL callback is only performed if the kernel was compiled with SLAB debugging on. If there would be code in a constructor handling SLAB_DEBUG_INITIAL then it would have to be conditional on SLAB_DEBUG otherwise it would just be dead code. But there is no such code in the kernel. I think SLUB_DEBUG_INITIAL is too problematic to make real use of, difficult to understand and there are easier ways to accomplish the same effect (i.e. add debug code before kfree). There is a related flag SLAB_CTOR_VERIFY that is frequently checked to be clear in fs inode caches. Remove the pointless checks (they would even be pointless without removeal of SLAB_DEBUG_INITIAL) from the fs constructors. This is the last slab flag that SLUB did not support. Remove the check for unimplemented flags from SLUB. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
217 lines
4.4 KiB
C
217 lines
4.4 KiB
C
/*
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* linux/fs/proc/inode.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*/
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#include <linux/time.h>
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#include <linux/proc_fs.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/string.h>
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#include <linux/stat.h>
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#include <linux/file.h>
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#include <linux/limits.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/smp_lock.h>
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#include <asm/system.h>
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#include <asm/uaccess.h>
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#include "internal.h"
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static inline struct proc_dir_entry * de_get(struct proc_dir_entry *de)
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{
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if (de)
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atomic_inc(&de->count);
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return de;
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}
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/*
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* Decrements the use count and checks for deferred deletion.
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*/
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static void de_put(struct proc_dir_entry *de)
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{
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if (de) {
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lock_kernel();
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if (!atomic_read(&de->count)) {
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printk("de_put: entry %s already free!\n", de->name);
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unlock_kernel();
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return;
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}
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if (atomic_dec_and_test(&de->count)) {
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if (de->deleted) {
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printk("de_put: deferred delete of %s\n",
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de->name);
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free_proc_entry(de);
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}
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}
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unlock_kernel();
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}
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}
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/*
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* Decrement the use count of the proc_dir_entry.
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*/
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static void proc_delete_inode(struct inode *inode)
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{
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struct proc_dir_entry *de;
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truncate_inode_pages(&inode->i_data, 0);
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/* Stop tracking associated processes */
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put_pid(PROC_I(inode)->pid);
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/* Let go of any associated proc directory entry */
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de = PROC_I(inode)->pde;
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if (de) {
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if (de->owner)
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module_put(de->owner);
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de_put(de);
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}
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clear_inode(inode);
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}
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struct vfsmount *proc_mnt;
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static void proc_read_inode(struct inode * inode)
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{
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inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
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}
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static struct kmem_cache * proc_inode_cachep;
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static struct inode *proc_alloc_inode(struct super_block *sb)
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{
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struct proc_inode *ei;
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struct inode *inode;
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ei = (struct proc_inode *)kmem_cache_alloc(proc_inode_cachep, GFP_KERNEL);
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if (!ei)
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return NULL;
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ei->pid = NULL;
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ei->fd = 0;
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ei->op.proc_get_link = NULL;
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ei->pde = NULL;
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inode = &ei->vfs_inode;
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inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
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return inode;
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}
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static void proc_destroy_inode(struct inode *inode)
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{
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kmem_cache_free(proc_inode_cachep, PROC_I(inode));
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}
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static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
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{
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struct proc_inode *ei = (struct proc_inode *) foo;
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if (flags & SLAB_CTOR_CONSTRUCTOR)
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inode_init_once(&ei->vfs_inode);
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}
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int __init proc_init_inodecache(void)
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{
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proc_inode_cachep = kmem_cache_create("proc_inode_cache",
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sizeof(struct proc_inode),
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0, (SLAB_RECLAIM_ACCOUNT|
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SLAB_MEM_SPREAD),
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init_once, NULL);
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if (proc_inode_cachep == NULL)
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return -ENOMEM;
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return 0;
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}
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static int proc_remount(struct super_block *sb, int *flags, char *data)
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{
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*flags |= MS_NODIRATIME;
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return 0;
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}
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static const struct super_operations proc_sops = {
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.alloc_inode = proc_alloc_inode,
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.destroy_inode = proc_destroy_inode,
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.read_inode = proc_read_inode,
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.drop_inode = generic_delete_inode,
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.delete_inode = proc_delete_inode,
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.statfs = simple_statfs,
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.remount_fs = proc_remount,
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};
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struct inode *proc_get_inode(struct super_block *sb, unsigned int ino,
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struct proc_dir_entry *de)
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{
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struct inode * inode;
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/*
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* Increment the use count so the dir entry can't disappear.
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*/
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de_get(de);
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WARN_ON(de && de->deleted);
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if (de != NULL && !try_module_get(de->owner))
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goto out_mod;
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inode = iget(sb, ino);
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if (!inode)
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goto out_ino;
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PROC_I(inode)->fd = 0;
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PROC_I(inode)->pde = de;
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if (de) {
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if (de->mode) {
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inode->i_mode = de->mode;
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inode->i_uid = de->uid;
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inode->i_gid = de->gid;
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}
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if (de->size)
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inode->i_size = de->size;
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if (de->nlink)
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inode->i_nlink = de->nlink;
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if (de->proc_iops)
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inode->i_op = de->proc_iops;
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if (de->proc_fops)
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inode->i_fop = de->proc_fops;
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}
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return inode;
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out_ino:
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if (de != NULL)
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module_put(de->owner);
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out_mod:
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de_put(de);
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return NULL;
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}
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int proc_fill_super(struct super_block *s, void *data, int silent)
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{
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struct inode * root_inode;
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s->s_flags |= MS_NODIRATIME | MS_NOSUID | MS_NOEXEC;
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s->s_blocksize = 1024;
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s->s_blocksize_bits = 10;
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s->s_magic = PROC_SUPER_MAGIC;
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s->s_op = &proc_sops;
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s->s_time_gran = 1;
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root_inode = proc_get_inode(s, PROC_ROOT_INO, &proc_root);
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if (!root_inode)
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goto out_no_root;
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root_inode->i_uid = 0;
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root_inode->i_gid = 0;
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s->s_root = d_alloc_root(root_inode);
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if (!s->s_root)
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goto out_no_root;
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return 0;
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out_no_root:
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printk("proc_read_super: get root inode failed\n");
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iput(root_inode);
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return -ENOMEM;
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}
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MODULE_LICENSE("GPL");
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