X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fproc%2Fgeneric.c;h=480cb1065eec8a65d9224075ffc66858dd4d738f;hb=e071041be037eca208b62b84469a06bdfc692bea;hp=20e5c4509a43896255af91cc4a50a50426069828;hpb=fee781e6c25772db862d3322b4745a896022a4f1;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/proc/generic.c b/fs/proc/generic.c index 20e5c45..480cb10 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -14,42 +14,33 @@ #include #include #include -#include #include #include #include #include +#include +#include #include #include "internal.h" -static ssize_t proc_file_read(struct file *file, char __user *buf, - size_t nbytes, loff_t *ppos); -static ssize_t proc_file_write(struct file *file, const char __user *buffer, - size_t count, loff_t *ppos); -static loff_t proc_file_lseek(struct file *, loff_t, int); +DEFINE_SPINLOCK(proc_subdir_lock); -int proc_match(int len, const char *name, struct proc_dir_entry *de) +static int proc_match(int len, const char *name, struct proc_dir_entry *de) { if (de->namelen != len) return 0; return !memcmp(name, de->name, len); } -static struct file_operations proc_file_operations = { - .llseek = proc_file_lseek, - .read = proc_file_read, - .write = proc_file_write, -}; - /* buffer size is one page but our output routines use some slack for overruns */ #define PROC_BLOCK_SIZE (PAGE_SIZE - 1024) static ssize_t -proc_file_read(struct file *file, char __user *buf, size_t nbytes, +__proc_file_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) { - struct inode * inode = file->f_dentry->d_inode; + struct inode * inode = file->f_path.dentry->d_inode; char *page; ssize_t retval=0; int eof=0; @@ -70,19 +61,14 @@ proc_file_read(struct file *file, char __user *buf, size_t nbytes, nbytes = MAX_NON_LFS - pos; dp = PDE(inode); - if (!(page = (char*) __get_free_page(GFP_KERNEL))) + if (!(page = (char*) __get_free_page(GFP_TEMPORARY))) return -ENOMEM; while ((nbytes > 0) && !eof) { count = min_t(size_t, PROC_BLOCK_SIZE, nbytes); start = NULL; - if (dp->get_info) { - /* Handle old net routines */ - n = dp->get_info(page, &start, *ppos, count); - if (n < count) - eof = 1; - } else if (dp->read_proc) { + if (dp->read_proc) { /* * How to be a proc read function * ------------------------------ @@ -197,19 +183,47 @@ proc_file_read(struct file *file, char __user *buf, size_t nbytes, } static ssize_t +proc_file_read(struct file *file, char __user *buf, size_t nbytes, + loff_t *ppos) +{ + struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); + ssize_t rv = -EIO; + + spin_lock(&pde->pde_unload_lock); + if (!pde->proc_fops) { + spin_unlock(&pde->pde_unload_lock); + return rv; + } + pde->pde_users++; + spin_unlock(&pde->pde_unload_lock); + + rv = __proc_file_read(file, buf, nbytes, ppos); + + pde_users_dec(pde); + return rv; +} + +static ssize_t proc_file_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) { - struct inode *inode = file->f_dentry->d_inode; - struct proc_dir_entry * dp; - - dp = PDE(inode); - - if (!dp->write_proc) - return -EIO; + struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); + ssize_t rv = -EIO; + + if (pde->write_proc) { + spin_lock(&pde->pde_unload_lock); + if (!pde->proc_fops) { + spin_unlock(&pde->pde_unload_lock); + return rv; + } + pde->pde_users++; + spin_unlock(&pde->pde_unload_lock); - /* FIXME: does this routine need ppos? probably... */ - return dp->write_proc(file, buffer, count, dp->data); + /* FIXME: does this routine need ppos? probably... */ + rv = pde->write_proc(file, buffer, count, pde->data); + pde_users_dec(pde); + } + return rv; } @@ -229,6 +243,12 @@ proc_file_lseek(struct file *file, loff_t offset, int orig) return retval; } +static const struct file_operations proc_file_operations = { + .llseek = proc_file_lseek, + .read = proc_file_read, + .write = proc_file_write, +}; + static int proc_notify_change(struct dentry *dentry, struct iattr *iattr) { struct inode *inode = dentry->d_inode; @@ -262,7 +282,7 @@ static int proc_getattr(struct vfsmount *mnt, struct dentry *dentry, return 0; } -static struct inode_operations proc_file_inode_operations = { +static const struct inode_operations proc_file_inode_operations = { .setattr = proc_notify_change, }; @@ -277,8 +297,13 @@ static int xlate_proc_name(const char *name, const char *cp = name, *next; struct proc_dir_entry *de; int len; + int rtn = 0; + + de = *ret; + if (!de) + de = &proc_root; - de = &proc_root; + spin_lock(&proc_subdir_lock); while (1) { next = strchr(cp, '/'); if (!next) @@ -289,56 +314,73 @@ static int xlate_proc_name(const char *name, if (proc_match(len, cp, de)) break; } - if (!de) - return -ENOENT; + if (!de) { + rtn = -ENOENT; + goto out; + } cp += len + 1; } *residual = cp; *ret = de; - return 0; +out: + spin_unlock(&proc_subdir_lock); + return rtn; } -static DEFINE_IDR(proc_inum_idr); +static DEFINE_IDA(proc_inum_ida); static DEFINE_SPINLOCK(proc_inum_lock); /* protects the above */ -#define PROC_DYNAMIC_FIRST 0xF0000000UL +#define PROC_DYNAMIC_FIRST 0xF0000000U /* * Return an inode number between PROC_DYNAMIC_FIRST and * 0xffffffff, or zero on failure. + * + * Current inode allocations in the proc-fs (hex-numbers): + * + * 00000000 reserved + * 00000001-00000fff static entries (goners) + * 001 root-ino + * + * 00001000-00001fff unused + * 0001xxxx-7fffxxxx pid-dir entries for pid 1-7fff + * 80000000-efffffff unused + * f0000000-ffffffff dynamic entries + * + * Goal: + * Once we split the thing into several virtual filesystems, + * we will get rid of magical ranges (and this comment, BTW). */ static unsigned int get_inode_number(void) { - int i, inum = 0; + unsigned int i; int error; retry: - if (idr_pre_get(&proc_inum_idr, GFP_KERNEL) == 0) + if (ida_pre_get(&proc_inum_ida, GFP_KERNEL) == 0) return 0; spin_lock(&proc_inum_lock); - error = idr_get_new(&proc_inum_idr, NULL, &i); + error = ida_get_new(&proc_inum_ida, &i); spin_unlock(&proc_inum_lock); if (error == -EAGAIN) goto retry; else if (error) return 0; - inum = (i & MAX_ID_MASK) + PROC_DYNAMIC_FIRST; - - /* inum will never be more than 0xf0ffffff, so no check - * for overflow. - */ - - return inum; + if (i > UINT_MAX - PROC_DYNAMIC_FIRST) { + spin_lock(&proc_inum_lock); + ida_remove(&proc_inum_ida, i); + spin_unlock(&proc_inum_lock); + return 0; + } + return PROC_DYNAMIC_FIRST + i; } static void release_inode_number(unsigned int inum) { - int id = (inum - PROC_DYNAMIC_FIRST) | ~MAX_ID_MASK; - spin_lock(&proc_inum_lock); - idr_remove(&proc_inum_idr, id); + ida_remove(&proc_inum_ida, inum - PROC_DYNAMIC_FIRST); spin_unlock(&proc_inum_lock); } @@ -348,7 +390,7 @@ static void *proc_follow_link(struct dentry *dentry, struct nameidata *nd) return NULL; } -static struct inode_operations proc_link_inode_operations = { +static const struct inode_operations proc_link_inode_operations = { .readlink = generic_readlink, .follow_link = proc_follow_link, }; @@ -364,7 +406,7 @@ static int proc_delete_dentry(struct dentry * dentry) return 1; } -static struct dentry_operations proc_dentry_operations = +static const struct dentry_operations proc_dentry_operations = { .d_delete = proc_delete_dentry, }; @@ -373,37 +415,46 @@ static struct dentry_operations proc_dentry_operations = * Don't create negative dentries here, return -ENOENT by hand * instead. */ -struct dentry *proc_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd) +struct dentry *proc_lookup_de(struct proc_dir_entry *de, struct inode *dir, + struct dentry *dentry) { struct inode *inode = NULL; - struct proc_dir_entry * de; int error = -ENOENT; - lock_kernel(); - de = PDE(dir); - if (de) { - for (de = de->subdir; de ; de = de->next) { - if (de->namelen != dentry->d_name.len) - continue; - if (!memcmp(dentry->d_name.name, de->name, de->namelen)) { - unsigned int ino = de->low_ino; - - error = -EINVAL; - inode = proc_get_inode(dir->i_sb, ino, de); - break; - } + spin_lock(&proc_subdir_lock); + for (de = de->subdir; de ; de = de->next) { + if (de->namelen != dentry->d_name.len) + continue; + if (!memcmp(dentry->d_name.name, de->name, de->namelen)) { + unsigned int ino; + + ino = de->low_ino; + pde_get(de); + spin_unlock(&proc_subdir_lock); + error = -EINVAL; + inode = proc_get_inode(dir->i_sb, ino, de); + goto out_unlock; } } - unlock_kernel(); + spin_unlock(&proc_subdir_lock); +out_unlock: if (inode) { dentry->d_op = &proc_dentry_operations; d_add(dentry, inode); return NULL; } + if (de) + pde_put(de); return ERR_PTR(error); } +struct dentry *proc_lookup(struct inode *dir, struct dentry *dentry, + struct nameidata *nd) +{ + return proc_lookup_de(PDE(dir), dir, dentry); +} + /* * This returns non-zero if at EOF, so that the /proc * root directory can use this and check if it should @@ -413,23 +464,15 @@ struct dentry *proc_lookup(struct inode * dir, struct dentry *dentry, struct nam * value of the readdir() call, as long as it's non-negative * for success.. */ -int proc_readdir(struct file * filp, - void * dirent, filldir_t filldir) +int proc_readdir_de(struct proc_dir_entry *de, struct file *filp, void *dirent, + filldir_t filldir) { - struct proc_dir_entry * de; unsigned int ino; int i; - struct inode *inode = filp->f_dentry->d_inode; + struct inode *inode = filp->f_path.dentry->d_inode; int ret = 0; - lock_kernel(); - ino = inode->i_ino; - de = PDE(inode); - if (!de) { - ret = -EINVAL; - goto out; - } i = filp->f_pos; switch (i) { case 0: @@ -440,18 +483,20 @@ int proc_readdir(struct file * filp, /* fall through */ case 1: if (filldir(dirent, "..", 2, i, - parent_ino(filp->f_dentry), + parent_ino(filp->f_path.dentry), DT_DIR) < 0) goto out; i++; filp->f_pos++; /* fall through */ default: + spin_lock(&proc_subdir_lock); de = de->subdir; i -= 2; for (;;) { if (!de) { ret = 1; + spin_unlock(&proc_subdir_lock); goto out; } if (!i) @@ -461,24 +506,43 @@ int proc_readdir(struct file * filp, } do { + struct proc_dir_entry *next; + + /* filldir passes info to user space */ + pde_get(de); + spin_unlock(&proc_subdir_lock); if (filldir(dirent, de->name, de->namelen, filp->f_pos, - de->low_ino, de->mode >> 12) < 0) + de->low_ino, de->mode >> 12) < 0) { + pde_put(de); goto out; + } + spin_lock(&proc_subdir_lock); filp->f_pos++; - de = de->next; + next = de->next; + pde_put(de); + de = next; } while (de); + spin_unlock(&proc_subdir_lock); } ret = 1; -out: unlock_kernel(); +out: return ret; } +int proc_readdir(struct file *filp, void *dirent, filldir_t filldir) +{ + struct inode *inode = filp->f_path.dentry->d_inode; + + return proc_readdir_de(PDE(inode), filp, dirent, filldir); +} + /* * These are the generic /proc directory operations. They * use the in-memory "struct proc_dir_entry" tree to parse * the /proc directory. */ -static struct file_operations proc_dir_operations = { +static const struct file_operations proc_dir_operations = { + .llseek = generic_file_llseek, .read = generic_read_dir, .readdir = proc_readdir, }; @@ -486,7 +550,7 @@ static struct file_operations proc_dir_operations = { /* * proc directories can do almost nothing.. */ -static struct inode_operations proc_dir_inode_operations = { +static const struct inode_operations proc_dir_inode_operations = { .lookup = proc_lookup, .getattr = proc_getattr, .setattr = proc_notify_change, @@ -495,14 +559,13 @@ static struct inode_operations proc_dir_inode_operations = { static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp) { unsigned int i; + struct proc_dir_entry *tmp; i = get_inode_number(); if (i == 0) return -EAGAIN; dp->low_ino = i; - dp->next = dir->subdir; - dp->parent = dir; - dir->subdir = dp; + if (S_ISDIR(dp->mode)) { if (dp->proc_iops == NULL) { dp->proc_fops = &proc_dir_operations; @@ -518,40 +581,25 @@ static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp if (dp->proc_iops == NULL) dp->proc_iops = &proc_file_inode_operations; } - return 0; -} -/* - * Kill an inode that got unregistered.. - */ -static void proc_kill_inodes(struct proc_dir_entry *de) -{ - struct list_head *p; - struct super_block *sb = proc_mnt->mnt_sb; + spin_lock(&proc_subdir_lock); - /* - * Actually it's a partial revoke(). - */ - file_list_lock(); - list_for_each(p, &sb->s_files) { - struct file * filp = list_entry(p, struct file, f_u.fu_list); - struct dentry * dentry = filp->f_dentry; - struct inode * inode; - struct file_operations *fops; - - if (dentry->d_op != &proc_dentry_operations) - continue; - inode = dentry->d_inode; - if (PDE(inode) != de) - continue; - fops = filp->f_op; - filp->f_op = NULL; - fops_put(fops); - } - file_list_unlock(); + for (tmp = dir->subdir; tmp; tmp = tmp->next) + if (strcmp(tmp->name, dp->name) == 0) { + WARN(1, KERN_WARNING "proc_dir_entry '%s/%s' already registered\n", + dir->name, dp->name); + break; + } + + dp->next = dir->subdir; + dp->parent = dir; + dir->subdir = dp; + spin_unlock(&proc_subdir_lock); + + return 0; } -static struct proc_dir_entry *proc_create(struct proc_dir_entry **parent, +static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent, const char *name, mode_t mode, nlink_t nlink) @@ -563,7 +611,7 @@ static struct proc_dir_entry *proc_create(struct proc_dir_entry **parent, /* make sure name is valid */ if (!name || !strlen(name)) goto out; - if (!(*parent) && xlate_proc_name(name, parent, &fn) != 0) + if (xlate_proc_name(name, parent, &fn) != 0) goto out; /* At this point there must not be any '/' characters beyond *fn */ @@ -581,6 +629,11 @@ static struct proc_dir_entry *proc_create(struct proc_dir_entry **parent, ent->namelen = len; ent->mode = mode; ent->nlink = nlink; + atomic_set(&ent->count, 1); + ent->pde_users = 0; + spin_lock_init(&ent->pde_unload_lock); + ent->pde_unload_completion = NULL; + INIT_LIST_HEAD(&ent->pde_openers); out: return ent; } @@ -590,7 +643,7 @@ struct proc_dir_entry *proc_symlink(const char *name, { struct proc_dir_entry *ent; - ent = proc_create(&parent,name, + ent = __proc_create(&parent, name, (S_IFLNK | S_IRUGO | S_IWUGO | S_IXUGO),1); if (ent) { @@ -615,11 +668,24 @@ struct proc_dir_entry *proc_mkdir_mode(const char *name, mode_t mode, { struct proc_dir_entry *ent; - ent = proc_create(&parent, name, S_IFDIR | mode, 2); + ent = __proc_create(&parent, name, S_IFDIR | mode, 2); if (ent) { - ent->proc_fops = &proc_dir_operations; - ent->proc_iops = &proc_dir_inode_operations; + if (proc_register(parent, ent) < 0) { + kfree(ent); + ent = NULL; + } + } + return ent; +} + +struct proc_dir_entry *proc_net_mkdir(struct net *net, const char *name, + struct proc_dir_entry *parent) +{ + struct proc_dir_entry *ent; + ent = __proc_create(&parent, name, S_IFDIR | S_IRUGO | S_IXUGO, 2); + if (ent) { + ent->data = net; if (proc_register(parent, ent) < 0) { kfree(ent); ent = NULL; @@ -627,6 +693,7 @@ struct proc_dir_entry *proc_mkdir_mode(const char *name, mode_t mode, } return ent; } +EXPORT_SYMBOL_GPL(proc_net_mkdir); struct proc_dir_entry *proc_mkdir(const char *name, struct proc_dir_entry *parent) @@ -652,12 +719,8 @@ struct proc_dir_entry *create_proc_entry(const char *name, mode_t mode, nlink = 1; } - ent = proc_create(&parent,name,mode,nlink); + ent = __proc_create(&parent, name, mode, nlink); if (ent) { - if (S_ISDIR(mode)) { - ent->proc_fops = &proc_dir_operations; - ent->proc_iops = &proc_dir_inode_operations; - } if (proc_register(parent, ent) < 0) { kfree(ent); ent = NULL; @@ -666,7 +729,41 @@ struct proc_dir_entry *create_proc_entry(const char *name, mode_t mode, return ent; } -void free_proc_entry(struct proc_dir_entry *de) +struct proc_dir_entry *proc_create_data(const char *name, mode_t mode, + struct proc_dir_entry *parent, + const struct file_operations *proc_fops, + void *data) +{ + struct proc_dir_entry *pde; + nlink_t nlink; + + if (S_ISDIR(mode)) { + if ((mode & S_IALLUGO) == 0) + mode |= S_IRUGO | S_IXUGO; + nlink = 2; + } else { + if ((mode & S_IFMT) == 0) + mode |= S_IFREG; + if ((mode & S_IALLUGO) == 0) + mode |= S_IRUGO; + nlink = 1; + } + + pde = __proc_create(&parent, name, mode, nlink); + if (!pde) + goto out; + pde->proc_fops = proc_fops; + pde->data = data; + if (proc_register(parent, pde) < 0) + goto out_free; + return pde; +out_free: + kfree(pde); +out: + return NULL; +} + +static void free_proc_entry(struct proc_dir_entry *de) { unsigned int ino = de->low_ino; @@ -675,45 +772,84 @@ void free_proc_entry(struct proc_dir_entry *de) release_inode_number(ino); - if (S_ISLNK(de->mode) && de->data) + if (S_ISLNK(de->mode)) kfree(de->data); kfree(de); } +void pde_put(struct proc_dir_entry *pde) +{ + if (atomic_dec_and_test(&pde->count)) + free_proc_entry(pde); +} + /* * Remove a /proc entry and free it if it's not currently in use. - * If it is in use, we set the 'deleted' flag. */ void remove_proc_entry(const char *name, struct proc_dir_entry *parent) { struct proc_dir_entry **p; - struct proc_dir_entry *de; + struct proc_dir_entry *de = NULL; const char *fn = name; int len; - if (!parent && xlate_proc_name(name, &parent, &fn) != 0) - goto out; + if (xlate_proc_name(name, &parent, &fn) != 0) + return; len = strlen(fn); + + spin_lock(&proc_subdir_lock); for (p = &parent->subdir; *p; p=&(*p)->next ) { - if (!proc_match(len, fn, *p)) - continue; - de = *p; - *p = de->next; - de->next = NULL; - if (S_ISDIR(de->mode)) - parent->nlink--; - proc_kill_inodes(de); - de->nlink = 0; - WARN_ON(de->subdir); - if (!atomic_read(&de->count)) - free_proc_entry(de); - else { - de->deleted = 1; - printk("remove_proc_entry: %s/%s busy, count=%d\n", - parent->name, de->name, atomic_read(&de->count)); + if (proc_match(len, fn, *p)) { + de = *p; + *p = de->next; + de->next = NULL; + break; } - break; } -out: - return; + spin_unlock(&proc_subdir_lock); + if (!de) + return; + + spin_lock(&de->pde_unload_lock); + /* + * Stop accepting new callers into module. If you're + * dynamically allocating ->proc_fops, save a pointer somewhere. + */ + de->proc_fops = NULL; + /* Wait until all existing callers into module are done. */ + if (de->pde_users > 0) { + DECLARE_COMPLETION_ONSTACK(c); + + if (!de->pde_unload_completion) + de->pde_unload_completion = &c; + + spin_unlock(&de->pde_unload_lock); + + wait_for_completion(de->pde_unload_completion); + + goto continue_removing; + } + spin_unlock(&de->pde_unload_lock); + +continue_removing: + spin_lock(&de->pde_unload_lock); + while (!list_empty(&de->pde_openers)) { + struct pde_opener *pdeo; + + pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh); + list_del(&pdeo->lh); + spin_unlock(&de->pde_unload_lock); + pdeo->release(pdeo->inode, pdeo->file); + kfree(pdeo); + spin_lock(&de->pde_unload_lock); + } + spin_unlock(&de->pde_unload_lock); + + if (S_ISDIR(de->mode)) + parent->nlink--; + de->nlink = 0; + WARN(de->subdir, KERN_WARNING "%s: removing non-empty directory " + "'%s/%s', leaking at least '%s'\n", __func__, + de->parent->name, de->name, de->subdir->name); + pde_put(de); }