diff options
Diffstat (limited to 'fs/anon_inodes.c')
| -rw-r--r-- | fs/anon_inodes.c | 84 |
1 files changed, 67 insertions, 17 deletions
diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c index d26222b7eefe..42bd1cb7c9cd 100644 --- a/fs/anon_inodes.c +++ b/fs/anon_inodes.c @@ -79,7 +79,7 @@ static struct file *__anon_inode_getfile(const char *name, const struct file_operations *fops, void *priv, int flags, const struct inode *context_inode, - bool secure) + bool make_inode) { struct inode *inode; struct file *file; @@ -87,7 +87,7 @@ static struct file *__anon_inode_getfile(const char *name, if (fops->owner && !try_module_get(fops->owner)) return ERR_PTR(-ENOENT); - if (secure) { + if (make_inode) { inode = anon_inode_make_secure_inode(name, context_inode); if (IS_ERR(inode)) { file = ERR_CAST(inode); @@ -149,13 +149,42 @@ struct file *anon_inode_getfile(const char *name, EXPORT_SYMBOL_GPL(anon_inode_getfile); /** - * anon_inode_getfile_secure - Like anon_inode_getfile(), but creates a new + * anon_inode_getfile_fmode - creates a new file instance by hooking it up to an + * anonymous inode, and a dentry that describe the "class" + * of the file + * + * @name: [in] name of the "class" of the new file + * @fops: [in] file operations for the new file + * @priv: [in] private data for the new file (will be file's private_data) + * @flags: [in] flags + * @f_mode: [in] fmode + * + * Creates a new file by hooking it on a single inode. This is useful for files + * that do not need to have a full-fledged inode in order to operate correctly. + * All the files created with anon_inode_getfile() will share a single inode, + * hence saving memory and avoiding code duplication for the file/inode/dentry + * setup. Allows setting the fmode. Returns the newly created file* or an error + * pointer. + */ +struct file *anon_inode_getfile_fmode(const char *name, + const struct file_operations *fops, + void *priv, int flags, fmode_t f_mode) +{ + struct file *file; + + file = __anon_inode_getfile(name, fops, priv, flags, NULL, false); + if (!IS_ERR(file)) + file->f_mode |= f_mode; + + return file; +} +EXPORT_SYMBOL_GPL(anon_inode_getfile_fmode); + +/** + * anon_inode_create_getfile - Like anon_inode_getfile(), but creates a new * !S_PRIVATE anon inode rather than reuse the * singleton anon inode and calls the - * inode_init_security_anon() LSM hook. This - * allows for both the inode to have its own - * security context and for the LSM to enforce - * policy on the inode's creation. + * inode_init_security_anon() LSM hook. * * @name: [in] name of the "class" of the new file * @fops: [in] file operations for the new file @@ -164,11 +193,21 @@ EXPORT_SYMBOL_GPL(anon_inode_getfile); * @context_inode: * [in] the logical relationship with the new inode (optional) * + * Create a new anonymous inode and file pair. This can be done for two + * reasons: + * + * - for the inode to have its own security context, so that LSMs can enforce + * policy on the inode's creation; + * + * - if the caller needs a unique inode, for example in order to customize + * the size returned by fstat() + * * The LSM may use @context_inode in inode_init_security_anon(), but a - * reference to it is not held. Returns the newly created file* or an error - * pointer. See the anon_inode_getfile() documentation for more information. + * reference to it is not held. + * + * Returns the newly created file* or an error pointer. */ -struct file *anon_inode_getfile_secure(const char *name, +struct file *anon_inode_create_getfile(const char *name, const struct file_operations *fops, void *priv, int flags, const struct inode *context_inode) @@ -176,12 +215,13 @@ struct file *anon_inode_getfile_secure(const char *name, return __anon_inode_getfile(name, fops, priv, flags, context_inode, true); } +EXPORT_SYMBOL_GPL(anon_inode_create_getfile); static int __anon_inode_getfd(const char *name, const struct file_operations *fops, void *priv, int flags, const struct inode *context_inode, - bool secure) + bool make_inode) { int error, fd; struct file *file; @@ -192,7 +232,7 @@ static int __anon_inode_getfd(const char *name, fd = error; file = __anon_inode_getfile(name, fops, priv, flags, context_inode, - secure); + make_inode); if (IS_ERR(file)) { error = PTR_ERR(file); goto err_put_unused_fd; @@ -231,10 +271,9 @@ int anon_inode_getfd(const char *name, const struct file_operations *fops, EXPORT_SYMBOL_GPL(anon_inode_getfd); /** - * anon_inode_getfd_secure - Like anon_inode_getfd(), but creates a new + * anon_inode_create_getfd - Like anon_inode_getfd(), but creates a new * !S_PRIVATE anon inode rather than reuse the singleton anon inode, and calls - * the inode_init_security_anon() LSM hook. This allows the inode to have its - * own security context and for a LSM to reject creation of the inode. + * the inode_init_security_anon() LSM hook. * * @name: [in] name of the "class" of the new file * @fops: [in] file operations for the new file @@ -243,16 +282,27 @@ EXPORT_SYMBOL_GPL(anon_inode_getfd); * @context_inode: * [in] the logical relationship with the new inode (optional) * + * Create a new anonymous inode and file pair. This can be done for two + * reasons: + * + * - for the inode to have its own security context, so that LSMs can enforce + * policy on the inode's creation; + * + * - if the caller needs a unique inode, for example in order to customize + * the size returned by fstat() + * * The LSM may use @context_inode in inode_init_security_anon(), but a * reference to it is not held. + * + * Returns a newly created file descriptor or an error code. */ -int anon_inode_getfd_secure(const char *name, const struct file_operations *fops, +int anon_inode_create_getfd(const char *name, const struct file_operations *fops, void *priv, int flags, const struct inode *context_inode) { return __anon_inode_getfd(name, fops, priv, flags, context_inode, true); } -EXPORT_SYMBOL_GPL(anon_inode_getfd_secure); + static int __init anon_inode_init(void) { |