iofunc_chmod()

Handle an _IO_CHMOD message

Synopsis:

#include <sys/iofunc.h>

int iofunc_chmod ( resmgr_context_t *ctp,
                   io_chmod_t *msg,
                   iofunc_ocb_t *ocb,
                   iofunc_attr_t *attr );

Library:

libc

Description:

The iofunc_chmod() function implements POSIX semantics for the client's chmod() call, which is received as an _IO_CHMOD message by the resource manager.

The iofunc_chmod() function verifies that the client has the necessary permissions to effect a chmod() on the attribute. If so, the chmod() is performed, modifying elements of the ocb->attr structure. This function takes care of updating the IOFUNC_ATTR_CTIME, IOFUNC_ATTR_DIRTY_TIME, and IOFUNC_ATTR_DIRTY_MODE bits in ocb->attr->flags. The iofunc_time_update() function can be used to update the appropriate time fields in ocb->attr.

This function can be used, for example, in a filesystem manager, where an _IO_CHMOD message was received, and the filesystem code must now write the values to the medium. The filesystem code may wish to block the client thread until the data was actually written to the medium. Contrast this scenario to the behavior of iofunc_chmod_default(), which calls this routine, and replies to the client thread.

Returns:

EOK

Successful completion.

EROFS

An attempt was made to chmod on a read-only filesystem.

EACCES

The client doesn't have permissions to do the operation.

EPERM

The group ID or owner ID didn't match.

Classification:

QNX 6

See also:

iofunc_chmod_default(), iofunc_chown_default(), iofunc_close_dup_default(), iofunc_close_ocb_default(), iofunc_devctl_default(), iofunc_lock_default(), iofunc_lseek_default(), iofunc_mmap_default(), iofunc_open_default(), iofunc_pathconf_default(), iofunc_stat_default(), iofunc_time_update(), iofunc_unblock_default(), iofunc_utime_default(), resmgr_attach()