X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fproc%2Finode.c;h=d78ade305541d84a0a7b7682f203cd649c1e5a6a;hb=fb92a4b068be96799da3748c11cbd69760e44d7b;hp=0e4d37c93eea70208a82a5861735817209082fd7;hpb=dd23aae4f5edf4e1dbd8f7f8013a754ba3253f48;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/proc/inode.c b/fs/proc/inode.c index 0e4d37c..d78ade3 100644 --- a/fs/proc/inode.c +++ b/fs/proc/inode.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include @@ -25,8 +26,7 @@ struct proc_dir_entry *de_get(struct proc_dir_entry *de) { - if (de) - atomic_inc(&de->count); + atomic_inc(&de->count); return de; } @@ -35,23 +35,13 @@ struct proc_dir_entry *de_get(struct proc_dir_entry *de) */ void de_put(struct proc_dir_entry *de) { - if (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)) { - if (de->deleted) { - printk("de_put: deferred delete of %s\n", - de->name); - free_proc_entry(de); - } - } - unlock_kernel(); + if (!atomic_read(&de->count)) { + printk("de_put: entry %s already free!\n", de->name); + return; } + + if (atomic_dec_and_test(&de->count)) + free_proc_entry(de); } /* @@ -68,21 +58,15 @@ static void proc_delete_inode(struct inode *inode) /* Let go of any associated proc directory entry */ de = PROC_I(inode)->pde; - if (de) { - if (de->owner) - module_put(de->owner); + if (de) de_put(de); - } + if (PROC_I(inode)->sysctl) + sysctl_head_put(PROC_I(inode)->sysctl); clear_inode(inode); } struct vfsmount *proc_mnt; -static void proc_read_inode(struct inode * inode) -{ - inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; -} - static struct kmem_cache * proc_inode_cachep; static struct inode *proc_alloc_inode(struct super_block *sb) @@ -97,6 +81,8 @@ static struct inode *proc_alloc_inode(struct super_block *sb) 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; @@ -107,47 +93,41 @@ static void proc_destroy_inode(struct inode *inode) kmem_cache_free(proc_inode_cachep, PROC_I(inode)); } -static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags) +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_MEM_SPREAD|SLAB_PANIC), init_once); - if (proc_inode_cachep == NULL) - return -ENOMEM; - 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 = { .alloc_inode = proc_alloc_inode, .destroy_inode = proc_destroy_inode, - .read_inode = proc_read_inode, .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); } @@ -334,36 +314,97 @@ static int proc_reg_open(struct inode *inode, struct file *file) 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 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) @@ -405,16 +446,14 @@ struct inode *proc_get_inode(struct super_block *sb, unsigned int ino, { struct inode * inode; - if (de != NULL && !try_module_get(de->owner)) - goto out_mod; - - inode = iget(sb, ino); + 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; + PROC_I(inode)->pde = de; - PROC_I(inode)->fd = 0; - PROC_I(inode)->pde = de; - if (de) { if (de->mode) { inode->i_mode = de->mode; inode->i_uid = de->uid; @@ -435,22 +474,17 @@ struct inode *proc_get_inode(struct super_block *sb, unsigned int ino, else #endif inode->i_fop = &proc_reg_file_ops; - } - else + } else { inode->i_fop = de->proc_fops; + } } - } - + unlock_new_inode(inode); + } else + de_put(de); return inode; - -out_ino: - if (de != NULL) - module_put(de->owner); -out_mod: - return NULL; } -int proc_fill_super(struct super_block *s, void *data, int silent) +int proc_fill_super(struct super_block *s) { struct inode * root_inode; @@ -478,4 +512,3 @@ out_no_root: de_put(&proc_root); return -ENOMEM; } -MODULE_LICENSE("GPL");