a snapshot. As part of taking a snapshot of a filesystem, the kernel
builds up a list of the filesystem metadata (such as the cylinder
group bitmaps) that are contained in the snapshot. When doing a
copy-on-write check, the list is first consulted. If the block being
written is found on the list, then the full snapshot lookup can be
avoided. Besides providing an important performance speedup this
check also avoids a potential deadlock between the code creating
the snapshot and the bufdaemon trying to cleanup snapshot related
buffers. This fix creates a temporary list containing the key
metadata blocks that can cause the deadlock. This temporary list
is used between the time that the snapshot is first enabled and the
time that the fully complete list is built.
Reported by: Attila Nagy <bra@fsn.hu>
Sponsored by: DARPA & NAI Labs.
is being taken from panicing with either "freeing free block" or
"freeing free inode". The problem arises when the snapshot code
is scanning the filesystem looking for inodes with a reference
count of zero (e.g., unlinked but still open) so that it can
expunge them from its view. If it encounters a reclaimed vnode
and has to restart its scan, then it will panic if it encounters
and tries to free an inode that it has already processed. The fix
is to check each candidate inode to see if it has already been
processed before trying to delete it from the snapshot image.
Sponsored by: DARPA & NAI Labs.
that they convert to 64-bit values before shifting rather than
afterwards. Once fixed, they can be used rather than inline expanded.
Sponsored by: DARPA & NAI Labs.
Retire the "d_dump_t" and use the "dumper_t" type instead.
Dumper_t takes a void * as first arg which is more general than the
dev_t taken by d_dump_t. (Remember: we could have net-dumpers if
somebody wrote us one!)
Define the convention for GEOM controlled disk devices to be that the
first argument to the dumper function is the struct disk pointer.
Change device drivers accordingly.
If we have no UFS_ACL kernel, users who already uses UFS1/2 attributes
get confused since no access control is performed for an update install.
Still, pc98 and alpha doesn't have UFS_ACL since I don't know about them.
Nyan-san, if kern.flp on tatsu has enough spaces (4k or more spaces),
please back UFS_ACL for pc98 also.
Data collected from: 5.0-CURRENT-20030221-JPSNAP on snapshots.jp.FreeBSD.org
Change the argument to disk_destroy() to be the same struct disk * as
disk_create() takes.
This enables drivers to ignore the (now) bogus dev_t which disk_create()
returns.
a number of related problems along the way.
- Automatically detect CDROM drives that can't handle 6 byte mode
sense and mode select, and adjust our command size accordingly.
We have to handle this in the cd(4) driver (where the buffers are
allocated), since the parameter list length is different for the
6 and 10 byte mode sense commands.
- Remove MODE_SENSE and MODE_SELECT translation removed in ATAPICAM
and in the umass(4) driver, since there's no way for that to work
properly.
- Add a quirk entry for CDROM drives that just hang when they get a 6
byte mode sense or mode select. The reason for the quirk must be
documented in a PR, and all quirks must be approved by
ken@FreeBSD.org. This is to make sure that we fully understand why
each quirk is needed. Once the CAM_NEW_TRAN_CODE is finished, we
should be able to remove any such quirks, since we'll know what
protocol the drive speaks (SCSI, ATAPI, etc.) and therefore whether
we should use 6 or 10 byte mode sense/select commands.
- Change the way the da(4) handles the no_6_byte sysctl. There is
now a per-drive sysctl to set the minimum command size for that
particular disk. (Since you could have multiple disks with
multiple requirements in one system.)
- Loader tunable support for all the sysctls in the da(4) and cd(4)
drivers.
- Add a CDIOCCLOSE ioctl for cd(4) (bde pointed this out a long
time ago).
- Add a media validation routine (cdcheckmedia()) to the cd(4)
driver, to fix some problems bde pointed out a long time ago. We
now allow open() to succeed no matter what, but if we don't detect
valid media, the user can only issue CDIOCCLOSE or CDIOCEJECT
ioctls.
- The media validation routine also reads the table of contents off
the drive. We use the table of contents to implement the
CDIOCPLAYTRACKS ioctl using the PLAY AUDIO MSF command. The
PLAY AUDIO TRACK INDEX command that we previously used was
deprecated after SCSI-2. It works in every SCSI CDROM I've tried,
but doesn't seem to work on ATAPI CDROM drives. We still use the
play audio track index command if we don't have a valid TOC, but
I suppose it'll fail anyway in that case.
- Add _len() versions of scsi_mode_sense() and scsi_mode_select() so
that we can specify the minimum command length.
- Fix a couple of formatting problems in the sense printing code.
MFC after: 4 weeks
OSes has probably caused more problems than it ever solved. Allow the
user to retire the old behavior by specifying their own privileged
range with,
net.inet.ip.portrange.reservedhigh default = IPPORT_RESERVED - 1
net.inet.ip.portrange.reservedlo default = 0
Now you can run that webserver without ever needing root at all. Or
just imagine, an ftpd that can really drop privileges, rather than
just set the euid, and still do PORT data transfers from 20/tcp.
Two edge cases to note,
# sysctl net.inet.ip.portrange.reservedhigh=0
Opens all ports to everyone, and,
# sysctl net.inet.ip.portrange.reservedhigh=65535
Locks all network activity to root only (which could actually have
been achieved before with ipfw(8), but is somewhat more
complicated).
For those who stick to the old religion that 0-1023 belong to root and
root alone, don't touch the knobs (or even lock them by raising
securelevel(8)), and nothing changes.
Some drives seem to be confused by simultaneous probes.
Tested by: marcel
As a side effect, logical units whose lun is greater than 0 might not be
probed correctly if the lun of 0 doesn't exist in the target because
CAM doesn't scan such luns.
I have a SCSI-FireWire bridge which maps SCSI-ID to LUN and it is an
example of such targets.
dev_t to the method functions.
The dev_t can still be found at struct consdev *->cn_dev.
Add a void *cn_arg element to struct consdev which the drivers can use
for retrieving their softc.
This moves all chipset specific code to a new file 'ata-chipset.c'.
Extensive use of tables and pointers to avoid having the same switch
on chipset type in several places, and to allow substituting various
functions for different HW arch needs.
Added PIO mode setup and all DMA modes.
Support for all known SiS chipsets. Thanks to Christoph Kukulies for
sponsoring a nice ASUS P4S8X SiS648 based board for this work!
Tested on: i386, PC98, alpha and sparc64
This moves all chipset specific code to a new file 'ata-chipset.c'.
Extensive use of tables and pointers to avoid having the same switch
on chipset type in several places, and to allow substituting various
functions for different HW arch needs.
Added PIO mode setup and all DMA modes.
Support for all known SiS chipsets. Thanks to Christoph Kukulies for
sponsoring a nice ASUS P4S8X SiS648 based board for this work!
Tested on: i386, PC98, alpha and sparc64
In devsw() return dead_cdevsw instead of NULL in case the dev_t does not
have a si_devsw.
This may improve our survival chances with devices which go away unexpectedly.
