freebsd-dev/sys/fs/tmpfs
John Baldwin b501cc5da6 Rework pathconf handling for FIFOs.
On the one hand, FIFOs should respect other variables not supported by
the fifofs vnode operation (such as _PC_NAME_MAX, _PC_LINK_MAX, etc.).
These values are fs-specific and must come from a fs-specific method.
On the other hand, filesystems that support FIFOs are required to
support _PC_PIPE_BUF on directory vnodes that can contain FIFOs.
Given this latter requirement, once the fs-specific VOP_PATHCONF
method supports _PC_PIPE_BUF for directories, it is also suitable for
FIFOs permitting a single VOP_PATHCONF method to be used for both
FIFOs and non-FIFOs.

To that end, retire all of the FIFO-specific pathconf methods from
filesystems and change FIFO-specific vnode operation switches to use
the existing fs-specific VOP_PATHCONF method.  For fifofs, set it's
VOP_PATHCONF to VOP_PANIC since it should no longer be used.

While here, move _PC_PIPE_BUF handling out of vop_stdpathconf() so that
only filesystems supporting FIFOs will report a value.  In addition,
only report a valid _PC_PIPE_BUF for directories and FIFOs.

Discussed with:	bde
Reviewed by:	kib (part of a larger patch)
MFC after:	1 month
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D12572
2017-12-19 22:39:05 +00:00
..
tmpfs_fifoops.c Rework pathconf handling for FIFOs. 2017-12-19 22:39:05 +00:00
tmpfs_fifoops.h sys/fs: further adoption of SPDX licensing ID tags. 2017-11-27 15:15:37 +00:00
tmpfs_subr.c Update tmpfs link count handling for ino64. 2017-12-19 20:19:07 +00:00
tmpfs_vfsops.c Reduce pollution via tmpfs.h. 2017-12-06 00:42:08 +00:00
tmpfs_vnops.c Rework pathconf handling for FIFOs. 2017-12-19 22:39:05 +00:00
tmpfs_vnops.h Rework pathconf handling for FIFOs. 2017-12-19 22:39:05 +00:00
tmpfs.h Update tmpfs link count handling for ino64. 2017-12-19 20:19:07 +00:00