VOP_DEALLOCATE(9)      FreeBSD Kernel Developer's Manual     VOP_DEALLOCATE(9)

NAME

     VOP_DEALLOCATE - zero and/or deallocate storage from a file

SYNOPSIS

     #include <sys/param.h>
     #include <sys/vnode.h>

     int
     VOP_DEALLOCATE(struct vnode *vp, off_t *offset, off_t *len, int flags,
         int ioflag, struct ucred *cred);

DESCRIPTION

     This VOP call zeroes/deallocates storage for an offset range in a file.
     It is used to implement the fspacectl(2) system call.

     Its arguments are:

     vp      The vnode of the file.

     offset  The start of the range to deallocate storage in the file.

     len     The length of the range to deallocate storage in the file.

     flags   The flags of this call.  This should be set to 0 for now.

     ioflag  Directives and hints to be given to the file system.

     cred    The credentials of the caller.

     *offset and *len are updated to reflect the portion of the range that
     still needs to be zeroed/deallocated on return.  Partial result is
     considered a successful operation.  For a non-partial successful
     completion, *len is updated to be the value 0, and *offset is incremented
     by the number of bytes zeroed before the end-of-file.

LOCKS

     The vnode should be locked on entry and will still be locked on exit.

RETURN VALUES

     Zero is returned if the call is successful, otherwise an appropriate
     error code is returned.

ERRORS

     [EINVAL]           Invalid offset, len or flags parameters are passed
                        into this VOP call.

     [ENODEV]           The vnode type is not supported by this VOP call.

     [ENOSPC]           The file system is full.

     [EPERM]            An append-only flag is set on the file, but the caller
                        is attempting to zero before the current end of file.

SEE ALSO

     vnode(9)

AUTHORS

     VOP_DEALLOCATE and this manual page was written by Ka Ho Ng
     <khng@FreeBSD.org> under sponsorship from the FreeBSD Foundation.

FreeBSD 15.1-STABLE-HBSD        August 25, 2021              VOP_DEALLOCATE(9)