diff options
Diffstat (limited to 'fs/proc/proc_sysctl.c')
| -rw-r--r-- | fs/proc/proc_sysctl.c | 142 |
1 files changed, 61 insertions, 81 deletions
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index 5851eb5bc726..8038833ff5b0 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -841,7 +841,6 @@ static int proc_sys_setattr(struct mnt_idmap *idmap, return error; setattr_copy(&nop_mnt_idmap, inode, attr); - mark_inode_dirty(inode); return 0; } @@ -1283,11 +1282,43 @@ out: return err; } +/* Find the directory for the ctl_table. If one is not found create it. */ +static struct ctl_dir *sysctl_mkdir_p(struct ctl_dir *dir, const char *path) +{ + const char *name, *nextname; + + for (name = path; name; name = nextname) { + int namelen; + nextname = strchr(name, '/'); + if (nextname) { + namelen = nextname - name; + nextname++; + } else { + namelen = strlen(name); + } + if (namelen == 0) + continue; + + /* + * namelen ensures if name is "foo/bar/yay" only foo is + * registered first. We traverse as if using mkdir -p and + * return a ctl_dir for the last directory entry. + */ + dir = get_subdir(dir, name, namelen); + if (IS_ERR(dir)) + break; + } + return dir; +} + /** * __register_sysctl_table - register a leaf sysctl table * @set: Sysctl tree to register on * @path: The path to the directory the sysctl table is in. - * @table: the top-level table structure + * @table: the top-level table structure without any child. This table + * should not be free'd after registration. So it should not be + * used on stack. It can either be a global or dynamically allocated + * by the caller and free'd later after sysctl unregistration. * * Register a sysctl table hierarchy. @table should be a filled in ctl_table * array. A completely 0 filled entry terminates the table. @@ -1308,9 +1339,12 @@ out: * proc_handler - the text handler routine (described below) * * extra1, extra2 - extra pointers usable by the proc handler routines + * XXX: we should eventually modify these to use long min / max [0] + * [0] https://lkml.kernel.org/87zgpte9o4.fsf@email.froward.int.ebiederm.org * * Leaf nodes in the sysctl tree will be represented by a single file - * under /proc; non-leaf nodes will be represented by directories. + * under /proc; non-leaf nodes (where child is not NULL) are not allowed, + * sysctl_check_table() verifies this. * * There must be a proc_handler routine for any terminal nodes. * Several default handlers are available to cover common cases - @@ -1331,7 +1365,6 @@ struct ctl_table_header *__register_sysctl_table( { struct ctl_table_root *root = set->dir.header.root; struct ctl_table_header *header; - const char *name, *nextname; struct ctl_dir *dir; struct ctl_table *entry; struct ctl_node *node; @@ -1352,28 +1385,13 @@ struct ctl_table_header *__register_sysctl_table( spin_lock(&sysctl_lock); dir = &set->dir; - /* Reference moved down the diretory tree get_subdir */ + /* Reference moved down the directory tree get_subdir */ dir->header.nreg++; spin_unlock(&sysctl_lock); - /* Find the directory for the ctl_table */ - for (name = path; name; name = nextname) { - int namelen; - nextname = strchr(name, '/'); - if (nextname) { - namelen = nextname - name; - nextname++; - } else { - namelen = strlen(name); - } - if (namelen == 0) - continue; - - dir = get_subdir(dir, name, namelen); - if (IS_ERR(dir)) - goto fail; - } - + dir = sysctl_mkdir_p(dir, path); + if (IS_ERR(dir)) + goto fail; spin_lock(&sysctl_lock); if (insert_header(dir, header)) goto fail_put_dir_locked; @@ -1394,8 +1412,15 @@ fail: /** * register_sysctl - register a sysctl table - * @path: The path to the directory the sysctl table is in. - * @table: the table structure + * @path: The path to the directory the sysctl table is in. If the path + * doesn't exist we will create it for you. + * @table: the table structure. The calller must ensure the life of the @table + * will be kept during the lifetime use of the syctl. It must not be freed + * until unregister_sysctl_table() is called with the given returned table + * with this registration. If your code is non modular then you don't need + * to call unregister_sysctl_table() and can instead use something like + * register_sysctl_init() which does not care for the result of the syctl + * registration. * * Register a sysctl table. @table should be a filled in ctl_table * array. A completely 0 filled entry terminates the table. @@ -1411,8 +1436,11 @@ EXPORT_SYMBOL(register_sysctl); /** * __register_sysctl_init() - register sysctl table to path - * @path: path name for sysctl base - * @table: This is the sysctl table that needs to be registered to the path + * @path: path name for sysctl base. If that path doesn't exist we will create + * it for you. + * @table: This is the sysctl table that needs to be registered to the path. + * The caller must ensure the life of the @table will be kept during the + * lifetime use of the sysctl. * @table_name: The name of sysctl table, only used for log printing when * registration fails * @@ -1424,10 +1452,7 @@ EXPORT_SYMBOL(register_sysctl); * register_sysctl() failing on init are extremely low, and so for both reasons * this function does not return any error as it is used by initialization code. * - * Context: Can only be called after your respective sysctl base path has been - * registered. So for instance, most base directories are registered early on - * init before init levels are processed through proc_sys_init() and - * sysctl_init_bases(). + * Context: if your base directory does not exist it will be created for you. */ void __init __register_sysctl_init(const char *path, struct ctl_table *table, const char *table_name) @@ -1550,24 +1575,18 @@ out: } /** - * __register_sysctl_paths - register a sysctl table hierarchy - * @set: Sysctl tree to register on - * @path: The path to the directory the sysctl table is in. + * register_sysctl_table - register a sysctl table hierarchy * @table: the top-level table structure * * Register a sysctl table hierarchy. @table should be a filled in ctl_table * array. A completely 0 filled entry terminates the table. - * - * See __register_sysctl_table for more details. + * We are slowly deprecating this call so avoid its use. */ -struct ctl_table_header *__register_sysctl_paths( - struct ctl_table_set *set, - const struct ctl_path *path, struct ctl_table *table) +struct ctl_table_header *register_sysctl_table(struct ctl_table *table) { struct ctl_table *ctl_table_arg = table; int nr_subheaders = count_subheaders(table); struct ctl_table_header *header = NULL, **subheaders, **subheader; - const struct ctl_path *component; char *new_path, *pos; pos = new_path = kmalloc(PATH_MAX, GFP_KERNEL); @@ -1575,11 +1594,6 @@ struct ctl_table_header *__register_sysctl_paths( return NULL; pos[0] = '\0'; - for (component = path; component->procname; component++) { - pos = append_path(new_path, pos, component->procname); - if (!pos) - goto out; - } while (table->procname && table->child && !table[1].procname) { pos = append_path(new_path, pos, table->procname); if (!pos) @@ -1587,7 +1601,7 @@ struct ctl_table_header *__register_sysctl_paths( table = table->child; } if (nr_subheaders == 1) { - header = __register_sysctl_table(set, new_path, table); + header = __register_sysctl_table(&sysctl_table_root.default_set, new_path, table); if (header) header->ctl_table_arg = ctl_table_arg; } else { @@ -1601,7 +1615,7 @@ struct ctl_table_header *__register_sysctl_paths( header->ctl_table_arg = ctl_table_arg; if (register_leaf_sysctl_tables(new_path, pos, &subheader, - set, table)) + &sysctl_table_root.default_set, table)) goto err_register_leaves; } @@ -1620,40 +1634,6 @@ err_register_leaves: header = NULL; goto out; } - -/** - * register_sysctl_paths - register a sysctl table hierarchy - * @path: The path to the directory the sysctl table is in. - * @table: the top-level table structure - * - * Register a sysctl table hierarchy. @table should be a filled in ctl_table - * array. A completely 0 filled entry terminates the table. - * - * See __register_sysctl_paths for more details. - */ -struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, - struct ctl_table *table) -{ - return __register_sysctl_paths(&sysctl_table_root.default_set, - path, table); -} -EXPORT_SYMBOL(register_sysctl_paths); - -/** - * register_sysctl_table - register a sysctl table hierarchy - * @table: the top-level table structure - * - * Register a sysctl table hierarchy. @table should be a filled in ctl_table - * array. A completely 0 filled entry terminates the table. - * - * See register_sysctl_paths for more details. - */ -struct ctl_table_header *register_sysctl_table(struct ctl_table *table) -{ - static const struct ctl_path null_path[] = { {} }; - - return register_sysctl_paths(null_path, table); -} EXPORT_SYMBOL(register_sysctl_table); int __register_sysctl_base(struct ctl_table *base_table) |