#include <linux/init.h>
#include <linux/module.h>
#include <linux/smp_lock.h>
+#include <linux/sysctl.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include "internal.h"
-struct proc_dir_entry *de_get(struct proc_dir_entry *de)
-{
- atomic_inc(&de->count);
- return de;
-}
-
-/*
- * Decrements the use count and checks for deferred deletion.
- */
-void de_put(struct proc_dir_entry *de)
-{
- lock_kernel();
- if (!atomic_read(&de->count)) {
- printk("de_put: entry %s already free!\n", de->name);
- unlock_kernel();
- return;
- }
-
- if (atomic_dec_and_test(&de->count))
- free_proc_entry(de);
- unlock_kernel();
-}
-
-/*
- * Decrement the use count of the proc_dir_entry.
- */
static void proc_delete_inode(struct inode *inode)
{
struct proc_dir_entry *de;
/* Let go of any associated proc directory entry */
de = PROC_I(inode)->pde;
- if (de) {
- if (de->owner)
- module_put(de->owner);
- de_put(de);
- }
+ if (de)
+ pde_put(de);
+ if (PROC_I(inode)->sysctl)
+ sysctl_head_put(PROC_I(inode)->sysctl);
clear_inode(inode);
}
ei->fd = 0;
ei->op.proc_get_link = NULL;
ei->pde = NULL;
+ ei->sysctl = NULL;
+ ei->sysctl_entry = NULL;
inode = &ei->vfs_inode;
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
return inode;
kmem_cache_free(proc_inode_cachep, PROC_I(inode));
}
-static void init_once(struct kmem_cache * cachep, void *foo)
+static void init_once(void *foo)
{
struct proc_inode *ei = (struct proc_inode *) foo;
inode_init_once(&ei->vfs_inode);
}
-int __init proc_init_inodecache(void)
+void __init proc_init_inodecache(void)
{
proc_inode_cachep = kmem_cache_create("proc_inode_cache",
sizeof(struct proc_inode),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD|SLAB_PANIC),
init_once);
- return 0;
-}
-
-static int proc_remount(struct super_block *sb, int *flags, char *data)
-{
- *flags |= MS_NODIRATIME;
- return 0;
}
static const struct super_operations proc_sops = {
.drop_inode = generic_delete_inode,
.delete_inode = proc_delete_inode,
.statfs = simple_statfs,
- .remount_fs = proc_remount,
};
-static void pde_users_dec(struct proc_dir_entry *pde)
+static void __pde_users_dec(struct proc_dir_entry *pde)
{
- spin_lock(&pde->pde_unload_lock);
pde->pde_users--;
if (pde->pde_unload_completion && pde->pde_users == 0)
complete(pde->pde_unload_completion);
+}
+
+void pde_users_dec(struct proc_dir_entry *pde)
+{
+ spin_lock(&pde->pde_unload_lock);
+ __pde_users_dec(pde);
spin_unlock(&pde->pde_unload_lock);
}
struct proc_dir_entry *pde = PDE(inode);
int rv = 0;
int (*open)(struct inode *, struct file *);
+ int (*release)(struct inode *, struct file *);
+ struct pde_opener *pdeo;
+
+ /*
+ * What for, you ask? Well, we can have open, rmmod, remove_proc_entry
+ * sequence. ->release won't be called because ->proc_fops will be
+ * cleared. Depending on complexity of ->release, consequences vary.
+ *
+ * We can't wait for mercy when close will be done for real, it's
+ * deadlockable: rmmod foo </proc/foo . So, we're going to do ->release
+ * by hand in remove_proc_entry(). For this, save opener's credentials
+ * for later.
+ */
+ pdeo = kmalloc(sizeof(struct pde_opener), GFP_KERNEL);
+ if (!pdeo)
+ return -ENOMEM;
spin_lock(&pde->pde_unload_lock);
if (!pde->proc_fops) {
spin_unlock(&pde->pde_unload_lock);
- return rv;
+ kfree(pdeo);
+ return -EINVAL;
}
pde->pde_users++;
open = pde->proc_fops->open;
+ release = pde->proc_fops->release;
spin_unlock(&pde->pde_unload_lock);
if (open)
rv = open(inode, file);
- pde_users_dec(pde);
+ spin_lock(&pde->pde_unload_lock);
+ if (rv == 0 && release) {
+ /* To know what to release. */
+ pdeo->inode = inode;
+ pdeo->file = file;
+ /* Strictly for "too late" ->release in proc_reg_release(). */
+ pdeo->release = release;
+ list_add(&pdeo->lh, &pde->pde_openers);
+ } else
+ kfree(pdeo);
+ __pde_users_dec(pde);
+ spin_unlock(&pde->pde_unload_lock);
return rv;
}
+static struct pde_opener *find_pde_opener(struct proc_dir_entry *pde,
+ struct inode *inode, struct file *file)
+{
+ struct pde_opener *pdeo;
+
+ list_for_each_entry(pdeo, &pde->pde_openers, lh) {
+ if (pdeo->inode == inode && pdeo->file == file)
+ return pdeo;
+ }
+ return NULL;
+}
+
static int proc_reg_release(struct inode *inode, struct file *file)
{
struct proc_dir_entry *pde = PDE(inode);
int rv = 0;
int (*release)(struct inode *, struct file *);
+ struct pde_opener *pdeo;
spin_lock(&pde->pde_unload_lock);
+ pdeo = find_pde_opener(pde, inode, file);
if (!pde->proc_fops) {
- spin_unlock(&pde->pde_unload_lock);
+ /*
+ * Can't simply exit, __fput() will think that everything is OK,
+ * and move on to freeing struct file. remove_proc_entry() will
+ * find slacker in opener's list and will try to do non-trivial
+ * things with struct file. Therefore, remove opener from list.
+ *
+ * But if opener is removed from list, who will ->release it?
+ */
+ if (pdeo) {
+ list_del(&pdeo->lh);
+ spin_unlock(&pde->pde_unload_lock);
+ rv = pdeo->release(inode, file);
+ kfree(pdeo);
+ } else
+ spin_unlock(&pde->pde_unload_lock);
return rv;
}
pde->pde_users++;
release = pde->proc_fops->release;
+ if (pdeo) {
+ list_del(&pdeo->lh);
+ kfree(pdeo);
+ }
spin_unlock(&pde->pde_unload_lock);
if (release)
{
struct inode * inode;
- if (!try_module_get(de->owner))
- goto out_mod;
-
inode = iget_locked(sb, ino);
if (!inode)
- goto out_ino;
+ return NULL;
if (inode->i_state & I_NEW) {
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
PROC_I(inode)->fd = 0;
}
unlock_new_inode(inode);
} else
- module_put(de->owner);
+ pde_put(de);
return inode;
-
-out_ino:
- module_put(de->owner);
-out_mod:
- return NULL;
}
int proc_fill_super(struct super_block *s)
s->s_op = &proc_sops;
s->s_time_gran = 1;
- de_get(&proc_root);
+ pde_get(&proc_root);
root_inode = proc_get_inode(s, PROC_ROOT_INO, &proc_root);
if (!root_inode)
goto out_no_root;
out_no_root:
printk("proc_read_super: get root inode failed\n");
iput(root_inode);
- de_put(&proc_root);
+ pde_put(&proc_root);
return -ENOMEM;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff