DCMD_FSYS_FSNOTIFY

QNX SDP8.0Devctl and Ioctl CommandsDeveloper

Notify the filesystem event policy manager

Synopsis:

#include <sys/dcmd_blk.h>

#define DCMD_FSYS_FSNOTIFY    __DIOTF(_DCMD_FSYS, 29, uint32_t)

Arguments to devctl():


Argument	Value
`filedes`	A file descriptor that you obtained by opening the device.
`dcmd`	DCMD_FSYS_FSNOTIFY
`dev_data_ptr`	Depends on the request; see below
`n_bytes`	Depends on the request; see below
`dev_info_ptr`	NULL

Description:

The filesystem event policy manager, fsevmgr sends these commands to all of the io-blk.so mountpoints to make requests:

FSNOTIFY_REQ_ENABLE

Enable the fsnotify module. The dev_data_ptr argument must be a pointer to a uint32_t.

FSNOTIFY_REQ_INFO

Get information about the mountpoint. The dev_data_ptr argument must be a pointer to a fsnotify_info_t structure:

typedef struct _fsnotify_info_s {
        uint32_t command;   /* Structure type command */
        uint32_t uid;       /* Mountpoint unique ID */
} fsnotify_info_t;

FSNOTIFY_REQ_WATCH_ADD

Add a watch. The dev_data_ptr argument must be a pointer to a fsnotify_watch_cmd_t structure:

typedef struct fsnotify_watch_cmd_s {
        uint32_t command;   /* Structure type command */
        uint32_t muid;      /* Receiving mailbox unique ID */
        uint32_t wuid;      /* Watch unique ID */
        uint32_t mask;      /* inotify watch mask */
        uint64_t inode;     /* inode being watched */
        uint32_t mpuid;     /* Mountpoint unique ID */
} fsnotify_watch_cmd_t;

FSNOTIFY_REQ_RWATCH_ADD

Add a recursive watch. The dev_data_ptr argument must be a pointer to a fsnotify_watch_cmd_t structure, just as for FSNOTIFY_REQ_WATCH_ADD.

Input:

The input depends on the request, but includes at least the FSNOTIFY_REQ_* command itself:

FSNOTIFY_REQ_ENABLE: Set the uint32_t to FSNOTIFY_REQ_ENABLE.
FSNOTIFY_REQ_INFO: Set the command member to FSNOTIFY_REQ_INFO.
FSNOTIFY_REQ_WATCH_ADD, FSNOTIFY_REQ_RWATCH_ADD: Set the command member to FSNOTIFY_REQ_WATCH_ADD or FSNOTIFY_REQ_RWATCH_ADD. Fill in the muid, wuid, and mask fields.

Output:

The input depends on the request:

FSNOTIFY_REQ_ENABLE: None.
FSNOTIFY_REQ_INFO: The mountpoint's ID.
FSNOTIFY_REQ_WATCH_ADD, FSNOTIFY_REQ_RWATCH_ADD: The inode and mpuid members.

Errors:

The devctl() function can return the following, in addition to the error codes listed in its entry in the C Library Reference:

EINVAL: The size of the data structure isn't correct for the given request.