diff options
| -rw-r--r-- | Documentation/filesystems/debugfs.txt | 16 | ||||
| -rw-r--r-- | fs/debugfs/file.c | 77 |
2 files changed, 44 insertions, 49 deletions
diff --git a/Documentation/filesystems/debugfs.txt b/Documentation/filesystems/debugfs.txt index 4f45f71149cb..4a0a9c3f4af6 100644 --- a/Documentation/filesystems/debugfs.txt +++ b/Documentation/filesystems/debugfs.txt @@ -31,10 +31,10 @@ This call, if successful, will make a directory called name underneath the indicated parent directory. If parent is NULL, the directory will be created in the debugfs root. On success, the return value is a struct dentry pointer which can be used to create files in the directory (and to -clean it up at the end). A NULL return value indicates that something went -wrong. If ERR_PTR(-ENODEV) is returned, that is an indication that the -kernel has been built without debugfs support and none of the functions -described below will work. +clean it up at the end). An ERR_PTR(-ERROR) return value indicates that +something went wrong. If ERR_PTR(-ENODEV) is returned, that is an +indication that the kernel has been built without debugfs support and none +of the functions described below will work. The most general way to create a file within a debugfs directory is with: @@ -48,8 +48,9 @@ should hold the file, data will be stored in the i_private field of the resulting inode structure, and fops is a set of file operations which implement the file's behavior. At a minimum, the read() and/or write() operations should be provided; others can be included as needed. Again, -the return value will be a dentry pointer to the created file, NULL for -error, or ERR_PTR(-ENODEV) if debugfs support is missing. +the return value will be a dentry pointer to the created file, +ERR_PTR(-ERROR) on error, or ERR_PTR(-ENODEV) if debugfs support is +missing. Create a file with an initial size, the following function can be used instead: @@ -214,7 +215,8 @@ can be removed with: void debugfs_remove(struct dentry *dentry); -The dentry value can be NULL, in which case nothing will be removed. +The dentry value can be NULL or an error value, in which case nothing will +be removed. Once upon a time, debugfs users were required to remember the dentry pointer for every debugfs file they created so that all files could be diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index 4fce1da7db23..ddd708b09fa1 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -394,12 +394,11 @@ DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n"); * This function will return a pointer to a dentry if it succeeds. This * pointer must be passed to the debugfs_remove() function when the file is * to be removed (no automatic cleanup happens if your module is unloaded, - * you are responsible here.) If an error occurs, %NULL will be returned. + * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be + * returned. * - * If debugfs is not enabled in the kernel, the value -%ENODEV will be - * returned. It is not wise to check for this value, but rather, check for - * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling - * code. + * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will + * be returned. */ struct dentry *debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent, u8 *value) @@ -440,12 +439,11 @@ DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n"); * This function will return a pointer to a dentry if it succeeds. This * pointer must be passed to the debugfs_remove() function when the file is * to be removed (no automatic cleanup happens if your module is unloaded, - * you are responsible here.) If an error occurs, %NULL will be returned. + * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be + * returned. * - * If debugfs is not enabled in the kernel, the value -%ENODEV will be - * returned. It is not wise to check for this value, but rather, check for - * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling - * code. + * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will + * be returned. */ struct dentry *debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent, u16 *value) @@ -486,12 +484,11 @@ DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n"); * This function will return a pointer to a dentry if it succeeds. This * pointer must be passed to the debugfs_remove() function when the file is * to be removed (no automatic cleanup happens if your module is unloaded, - * you are responsible here.) If an error occurs, %NULL will be returned. + * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be + * returned. * - * If debugfs is not enabled in the kernel, the value -%ENODEV will be - * returned. It is not wise to check for this value, but rather, check for - * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling - * code. + * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will + * be returned. */ struct dentry *debugfs_create_u32(const char *name, umode_t mode, struct dentry *parent, u32 *value) @@ -533,12 +530,11 @@ DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n"); * This function will return a pointer to a dentry if it succeeds. This * pointer must be passed to the debugfs_remove() function when the file is * to be removed (no automatic cleanup happens if your module is unloaded, - * you are responsible here.) If an error occurs, %NULL will be returned. + * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be + * returned. * - * If debugfs is not enabled in the kernel, the value -%ENODEV will be - * returned. It is not wise to check for this value, but rather, check for - * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling - * code. + * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will + * be returned. */ struct dentry *debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent, u64 *value) @@ -582,12 +578,11 @@ DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_wo, NULL, debugfs_ulong_set, "%llu\n"); * This function will return a pointer to a dentry if it succeeds. This * pointer must be passed to the debugfs_remove() function when the file is * to be removed (no automatic cleanup happens if your module is unloaded, - * you are responsible here.) If an error occurs, %NULL will be returned. + * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be + * returned. * - * If debugfs is not enabled in the kernel, the value -%ENODEV will be - * returned. It is not wise to check for this value, but rather, check for - * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling - * code. + * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will + * be returned. */ struct dentry *debugfs_create_ulong(const char *name, umode_t mode, struct dentry *parent, unsigned long *value) @@ -850,12 +845,11 @@ static const struct file_operations fops_bool_wo = { * This function will return a pointer to a dentry if it succeeds. This * pointer must be passed to the debugfs_remove() function when the file is * to be removed (no automatic cleanup happens if your module is unloaded, - * you are responsible here.) If an error occurs, %NULL will be returned. + * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be + * returned. * - * If debugfs is not enabled in the kernel, the value -%ENODEV will be - * returned. It is not wise to check for this value, but rather, check for - * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling - * code. + * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will + * be returned. */ struct dentry *debugfs_create_bool(const char *name, umode_t mode, struct dentry *parent, bool *value) @@ -904,12 +898,11 @@ static const struct file_operations fops_blob = { * This function will return a pointer to a dentry if it succeeds. This * pointer must be passed to the debugfs_remove() function when the file is * to be removed (no automatic cleanup happens if your module is unloaded, - * you are responsible here.) If an error occurs, %NULL will be returned. + * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be + * returned. * - * If debugfs is not enabled in the kernel, the value -%ENODEV will be - * returned. It is not wise to check for this value, but rather, check for - * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling - * code. + * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will + * be returned. */ struct dentry *debugfs_create_blob(const char *name, umode_t mode, struct dentry *parent, @@ -1005,8 +998,9 @@ static const struct file_operations u32_array_fops = { * Writing is not supported. Seek within the file is also not supported. * Once array is created its size can not be changed. * - * The function returns a pointer to dentry on success. If debugfs is not - * enabled in the kernel, the value -%ENODEV will be returned. + * The function returns a pointer to dentry on success. If an error occurs, + * %ERR_PTR(-ERROR) or NULL will be returned. If debugfs is not enabled in + * the kernel, the value %ERR_PTR(-ENODEV) will be returned. */ struct dentry *debugfs_create_u32_array(const char *name, umode_t mode, struct dentry *parent, @@ -1102,12 +1096,11 @@ static const struct file_operations fops_regset32 = { * This function will return a pointer to a dentry if it succeeds. This * pointer must be passed to the debugfs_remove() function when the file is * to be removed (no automatic cleanup happens if your module is unloaded, - * you are responsible here.) If an error occurs, %NULL will be returned. + * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be + * returned. * - * If debugfs is not enabled in the kernel, the value -%ENODEV will be - * returned. It is not wise to check for this value, but rather, check for - * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling - * code. + * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will + * be returned. */ struct dentry *debugfs_create_regset32(const char *name, umode_t mode, struct dentry *parent, |