Commit Graph

2209 Commits

Author SHA1 Message Date
Brian Behlendorf c60bc1fbf0 Remove dead ACL code
The following code was unused which caused gcc to complain.
Since it was deadcode it has simply been removed.
2011-02-10 09:21:43 -08:00
Brian Behlendorf 4e1b54fdde Remove zfs_parse_bootfs() support
Remove unneeded bootfs functions.  This support shouldn't be required
for the Linux port, and even if it is it would need to be reworked
to integrate cleanly with Linux.
2011-02-10 09:21:43 -08:00
Brian Behlendorf 9ee7fac531 VFS: Wrap with HAVE_SHARE
Certain NFS/SMB share functionality is not yet in place.  These
functions used to be wrapped with the generic HAVE_ZPL to prevent
them from being compiled.  I still don't want them compiled but
I'm working toward eliminating the use of HAVE_ZPL.  So I'm just
renaming the wrapper here to HAVE_SHARE.  They still won't be
compiled until all the share issues are worked through.  Share
support is the last missing piece from zfs_ioctl.c.
2011-02-10 09:21:43 -08:00
Brian Behlendorf bc3e15e386 Wrap with HAVE_MLSLABEL
The zfs_check_global_label() function is part of the HAVE_MLSLABEL
support which was previously commented out by a HAVE_ZPL check.
Since we're still deciding what to do about mls labels wrap it
with the preexisting macro to keep it compiled out.
2011-02-10 09:21:42 -08:00
Brian Behlendorf 5649246dd3 Remove znode move functionality
Unlike Solaris the Linux implementation embeds the inode in the
znode, and has no use for a vnode.  So while it's true that fragmention
of the znode cache may occur it should not be worse than any of the
other Linux FS inode caches.  Until proven that this is a problem it's
just added complexity we don't need.
2011-02-10 09:21:42 -08:00
Brian Behlendorf f30484afc3 Conserve stack in zfs_mkdir()
Move the sa_attrs array from the stack to the heap to minimize stack
space usage.
2011-02-10 09:21:42 -08:00
Brian Behlendorf 1ee1b76786 Conserve stack in zfs_sa_upgrade()
As always under Linux stack space is at a premium.  Relocate two
20 element sa_bulk_attr_t arrays in zfs_sa_upgrade() from the stack
to the heap.
2011-02-10 09:21:42 -08:00
Brian Behlendorf e5c39b95a7 Export required vfs/vn symbols 2011-02-10 09:21:42 -08:00
Brian Behlendorf 72d5e2da3e Add HAVE_SCANSTAMP
This functionality is not supported under Linux, perhaps it
will be some day if it's decided it's useful.
2011-02-10 09:20:33 -08:00
Brian Behlendorf 872e8d2697 Add initial rw_uio functions to the dmu
These functions were dropped originally because I felt they would
need to be rewritten anyway to avoid using uios.  However, this
patch readds then with they dea they can just be reworked and
the uio bits dropped.
2011-02-04 16:14:34 -08:00
Brian Behlendorf b4ead57cfb Remove HAVE_ZPL from commands and libraries
Thanks to the previous few commits we can now build all of the
user space commands and libraries with support for the zpl.
2011-02-04 16:14:34 -08:00
Brian Behlendorf 9a616b5d17 Documentation updates
Minor Linux specific documentation updates to the comments and
man pages.
2011-02-04 16:14:34 -08:00
Brian Behlendorf c5d915f423 Minimal libshare infrastructure
ZFS even under Solaris does not strictly require libshare to be
available.  The current implementation attempts to dlopen() the
library to access the needed symbols.  If this fails libshare
support is simply disabled.

This means that on Linux we only need the most minimal libshare
implementation.  In fact just enough to prevent the build from
failing.  Longer term we can decide if we want to implement a
libshare library like Solaris.  At best this would be an abstraction
layer between ZFS and NFS/SMB.  Alternately, we can drop libshare
entirely and directly integrate ZFS with Linux's NFS/SMB.

Finally the bare bones user-libshare.m4 test was dropped.  If we
do decide to implement libshare at some point it will surely be
as part of this package so the check is not needed.
2011-02-04 16:14:29 -08:00
Brian Behlendorf 3fb1fcdea1 Add 'zfs mount' support
By design the zfs utility is supposed to handle mounting and unmounting
a zfs filesystem.  We could allow zfs to do this directly.  There are
system calls available to mount/umount a filesystem.  And there are
library calls available to manipulate /etc/mtab.  But there are a
couple very good reasons not to take this appraoch... for now.

Instead of directly calling the system and library calls to (u)mount
the filesystem we fork and exec a (u)mount process.  The principle
reason for this is to delegate the responsibility for locking and
updating /etc/mtab to (u)mount(8).  This ensures maximum portability
and ensures the right locking scheme for your version of (u)mount
will be used.  If we didn't do this we would have to resort to an
autoconf test to determine what locking mechanism is used.

The downside to using mount(8) instead of mount(2) is that we lose
the exact errno which was returned by the kernel.  The return code
from mount(8) provides some insight in to what went wrong but it
not quite as good.  For the moment this is translated as a best
guess in to a errno for the higher layers of zfs.

In the long term a shared library called libmount is under development
which provides a common API to address the locking and errno issues.
Once the standard mount utility has been updated to use this library
we can then leverage it.  Until then this is the only safe solution.

  http://www.kernel.org/pub/linux/utils/util-linux/libmount-docs/index.html
2011-02-04 16:11:58 -08:00
Brian Behlendorf feb46b92a7 Open up libzfs_run_process/libzfs_load_module
Recently helper functions were added to libzfs_util to load a kernel
module or execute a process.  Initially this functionality was limited
to libzfs but it has become clear there will be other consumers.  This
change opens up the interface so it may be used where appropriate.
2011-01-28 12:47:57 -08:00
Brian Behlendorf 95c4cae39f Disable umount.zfs helper
For the moment, the only advantage in registering a umount helper
would be to automatically unshare a zfs filesystem.  Since under
Linux this would be unexpected (but nice) behavior there is no
harm in disabling it.

This is desirable because the 'zfs unmount' path invokes the system
umount.  This is done to ensure correct mtab locking but has the
side effect that the umount.zfs helper would be called if it exists.
By default this helper calls back in to zfs to do the unmount on
Solaris which we don't want under Linux.

Once libmount is available and we have a safe way to correctly
lock and update the /etc/mtab file we can reconsider the need
for a umount helper.  Using libmount is the prefered solution.
2011-01-28 12:47:57 -08:00
Brian Behlendorf 3b8cfee8af Enable mount.zfs helper
While not strictly required to mount a zfs filesystem using a
mount helper has certain advantages.

First, we need it if we want to honor the mount behavior as found
on Solaris.  As part of the mount we need to validate that the
dataset has the legacy mount property set if we are using 'mount'
instead of 'zfs mount'.

Secondly, by using a mount helper we can automatically load the
zpl kernel module.  This way you can just issue a 'mount' or
'zfs mount' and it will just work.

Finally, it gives us common hook in user space to add any zfs
specific mount options we might want.  At the moment we don't
have any but now the infrastructure is at least in place.
2011-01-28 12:47:57 -08:00
Brian Behlendorf b3259b6a2b Autoconf selinux support
If libselinux is detected on your system at configure time link
against it.  This allows us to use a library call to detect if
selinux is enabled and if it is to pass the mount option:

  "context=\"system_u:object_r:file_t:s0"

For now this is required because none of the existing selinux
policies are aware of the zfs filesystem type.  Because of this
they do not properly enable xattr based labeling even though
zfs supports all of the required hooks.

Until distro's add zfs as a known xattr friendly fs type we
must use mntpoint labeling.  Alternately, end users could modify
their existing selinux policy with a little guidance.
2011-01-28 12:45:19 -08:00
Brian Behlendorf 95c73795b0 Fix ZVOL rename minor devices
During a rename we need to be careful to destroy and create a
new minor for the ZVOL _only_ if the rename succeeded.  The previous
code would both destroy you minor device unconditionally, it would
also fail to create the new minor device on success.
2011-01-07 12:26:02 -08:00
Brian Behlendorf 149e873ab1 Fix minor compiler warnings
These compiler warnings were introduced when code which was
previously #ifdef'ed out by HAVE_ZPL was re-added for use
by the posix layer.  All of the following changes should be
obviously correct and will cause no semantic changes.
2011-01-06 15:04:28 -08:00
Brian Behlendorf 683fe41fc7 Add missing mkdirp prototype
For while now mkdirp has been built as part of libspl however
the protoype was never added to libgen.h.  This went unnoticed
until enabling the mount support which uses mkdirp().
2010-12-14 10:06:44 -08:00
Brian Behlendorf 5b63b3eb6f Use cv_timedwait_interruptible in arc
The issue is that cv_timedwait() sleeps uninterruptibly to block signals
and avoid waking up early.  Under Linux this counts against the load
average keeping it artificially high.  This change allows the arc to
sleep interruptibly which mean it may be woken up early due to a signal.

Normally this means some extra care must be taken to handle a potential
signal.  But for the arcs usage of cv_timedwait() there is no harm in
waking up before the timeout expires so no extra handling is required.
2010-12-14 10:06:44 -08:00
Ricardo M. Correia 8d4e8140ef Fix block device-related issues in zdb.
Specifically, this fixes the two following errors in zdb when a pool
is composed of block devices:

1) 'Value too large for defined data type' when running 'zdb <dataset>'.
2) 'character device required' when running 'zdb -l <block-device>'.

Signed-off-by: Ricardo M. Correia <ricardo.correia@oracle.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2010-12-14 09:52:46 -08:00
Brian Behlendorf a7dc7e5d5a Enable rrwlock.c compilation
With the addition of the thread specific data interfaces to the
SPL it is safe to enable compilation of the re-enterant read
reader/writer locks.
2010-12-07 16:05:25 -08:00
Brian Behlendorf 135cf6a8ae Refresh autogen.sh products
Refresh the autogen.sh products based on the versions which are
installed by default in the GA RHEL6.0 release.

autoconf (GNU Autoconf) 2.63
automake (GNU automake) 1.11.1
ltmain.sh (GNU libtool) 2.2.6b
2010-12-07 15:33:12 -08:00
Ned Bass 31165fd9aa Remove partition from vdev name in zfault.sh
As of the 0.5.2 tag, names of whole-disk vdevs must be specified to
the command line tools without partition identifiers.  This commit
fixes a 'zpool online' command in zfault.sh that incorrectly includes
he partition in the vdev name, causing test 9 to fail.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2010-11-29 10:53:53 -08:00
Brian Behlendorf 5e7affae52 Skip /dev/hpet during 'zpool import'
If libblkid does not contain ZFS support, then 'zpool import' will scan
all block devices in /dev/ to determine which ones are components of a
ZFS filesystem.  It does this by opening all the devices and stat'ing
them to determine which ones are block devices.  If the device turns
out not to be a block device it is skipped.

Usually, this whole process is pretty harmless (although slow).  But
there are certain devices in /dev/ which must be handled in a very
specific way or your system may crash.  For example, if /dev/watchdog
is simply opened the watchdog timer will be started and your system
will panic when the timer expires.

It turns out the /dev/hpet causes similiar problems although only when
accessed under a virtual machine.  For some reason accessing /dev/hpet
causes qemu to crash.  To address this issue this commit adds /dev/hpet
to the device blacklist, it will be skipped solely based on its name.
2010-11-12 09:33:17 -08:00
Brian Behlendorf e0f3df67e5 Add '-ts' options to zconfig.sh/zfault.sh usage
When adding this functionality originally the options to only
run specific tests (-t), or conversely skip specific tests (-s)
were omitted from the usage page.  This commit adds the missing
documentation.
2010-11-11 11:40:06 -08:00
Brian Behlendorf 7dc3830c0f Remove spl/zfs modules as part of cleanup
The idea behind the '-c' flag is to cleanup everything from a
previous test run which might cause the test script to fail.
This should also include removing the previously loaded module.
This makes it a little easier to run 'zconfig.sh -c', however
remember this is a test script and it will take all of your
other zpools offline for the purposes of the test.  This notion
has also been extended to the default 'make check' behavior.
2010-11-11 11:40:06 -08:00
Brian Behlendorf cf47fad67d Unconditionally load core kernel modules
Loading and unloading the zlib modules as part of the zfs.sh
script has proven a little problematic for a few reasons.

  * First, your kernel may not need to load either zlib_inflate
    or zlib_deflate.  This functionality may be built directly in
    to your kernel.  It depends entirely on what your distribution
    decided was the right thing to do.

  * Second, even if you do manage to load the correct modules you
    may not be able to unload them.  There may other consumers
    of the modules with a reference preventing the unload.

To avoid both of these issues the test scripts have been updated to
attempt to unconditionally load all modules listed in KERNEL_MODULES.
If the module is successfully loaded you must have needed it. If
the module can't be loaded that almost certainly means either it is
built in to your kernel or is already being used by another consumer.
In both cases this is not an issue and we can move on to the spl/zfs
modules.

Finally, by removing these kernel modules from the MODULES list
we ensure they are never unloaded during 'zfs.sh -u'.  This avoids
the issue of the script failing because there is another consumer
using the module we were not aware of.  In other words the script
restricts unloading modules to only the spl/zfs modules.

Closes #78
2010-11-11 11:38:25 -08:00
Ned Bass e06be58641 Fix for access beyond end of device error
This commit fixes a sign extension bug affecting l2arc devices.  Extremely
large offsets may be passed down to the low level block device driver on
reads, generating errors similar to

    attempt to access beyond end of device
    sdbi1: rw=14, want=36028797014862705, limit=125026959

The unwanted sign extension occurrs because the function arc_read_nolock()
stores the offset as a daddr_t, a 32-bit signed int type in the Linux kernel.
This offset is then passed to zio_read_phys() as a uint64_t argument, causing
sign extension for values of 0x80000000 or greater.  To avoid this, we store
the offset in a uint64_t.

This change also changes a few daddr_t struct members to uint64_t in the libspl
headers to avoid similar bugs cropping up in the future.  We also add an ASSERT
to __vdev_disk_physio() to check for invalid offsets.

Closes #66
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2010-11-10 21:29:07 -08:00
Brian Behlendorf 1f30b9d432 Linux 2.6.36 compat, use fops->unlocked_ioctl()
As of linux-2.6.36 the last in-tree consumer of fops->ioctl() has
been removed and thus fops()->ioctl() has also been removed.  The
replacement hook is fops->unlocked_ioctl() which has existed in
kernel since 2.6.12.  Since the ZFS code only contains support
back to 2.6.18 vintage kernels, I'm not adding an autoconf check
for this and simply moving everything to use fops->unlocked_ioctl().
2010-11-10 17:01:08 -08:00
Brian Behlendorf 8326eb4605 Linux 2.6.36 compat, blk_* macros removed
Most of the blk_* macros were removed in 2.6.36.  Ostensibly this was
done to improve readability and allow easier grepping.  However, from
a portability stand point the macros are helpful.  Therefore the needed
macros are redefined here if they are missing from the kernel.
2010-11-10 17:00:40 -08:00
Brian Behlendorf 675de5aa37 Linux 2.6.36 compat, synchronous bio flag
The name of the flag used to mark a bio as synchronous has changed
again in the 2.6.36 kernel due to the unification of the BIO_RW_*
and REQ_* flags.  The new flag is called REQ_SYNC.  To simplify
checking this flag I have introduced the vdev_disk_dio_is_sync()
helper function.  Based on the results of several new autoconf
tests it uses the correct mask to check for a synchronous bio.

Preferred interface for flagging a synchronous bio:
  2.6.12-2.6.29: BIO_RW_SYNC
  2.6.30-2.6.35: BIO_RW_SYNCIO
  2.6.36-2.6.xx: REQ_SYNC
2010-11-10 17:00:33 -08:00
Brian Behlendorf f4af6bb783 Linux 2.6.36 compat, use REQ_FAILFAST_MASK
As of linux-2.6.36 the BIO_RW_FAILFAST and REQ_FAILFAST flags
have been unified under the REQ_* names.  These flags always had
to be kept in-sync so this is a nice step forward, unfortunately
it means we need to be careful to only use the new unified flags
when the BIO_RW_* flags are not defined.  Additional autoconf
checks were added for this and if it is ever unclear which method
to use no flags are set.  This is safe but may result in longer
delays before a disk is failed.

Perferred interface for setting FAILFAST on a bio:
  2.6.12-2.6.27: BIO_RW_FAILFAST
  2.6.28-2.6.35: BIO_RW_FAILFAST_{DEV|TRANSPORT|DRIVER}
  2.6.36-2.6.xx: REQ_FAILFAST_{DEV|TRANSPORT|DRIVER}
2010-11-10 16:59:49 -08:00
Ned Bass b04cffc9b0 Remove inconsistent use of EOPNOTSUPP
Commit 3ee56c292b changed an ENOTSUP return value
in one location to ENOTSUPP to fix user programs seeing an invalid ioctl()
error code.  However, use of ENOTSUP is widespread in the zfs module.  Instead
of changing all of those uses, we fixed the ENOTSUP definition in the SPL to be
consistent with user space.  The changed return value in the above commit is
therefore no longer needed, so this commit reverses it to maintain consistency.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2010-11-10 13:26:56 -08:00
Brian Behlendorf 8c3ab23f4b Add lustre zpios-test workload
The lustre zpios-test simulates a reasonable lustre workload.  It will
create 128 threads, the same as a Lustre OSS, and then 4096 individual
objects.  Each objects is 16MiB in size and will be written/read in 1MiB
from a random thread.  This is fundamentally how we expect Lustre to behave
for large IO intensive workloads.
2010-11-08 14:03:36 -08:00
Brian Behlendorf a8179b5139 Prep for 0.5.2 tag
Update META file to prep for 0.5.2 tag.
2010-11-08 14:03:36 -08:00
Brian Behlendorf cb39a6c6aa Replace custom zpool configs with generic configs
To streamline testing I have in the past added several custom configs
to the zpool-config directory.  This change reverts those custom configs
and replaces them with three generic config which can do the same thing.
The generic config behavior can be set by setting various environment
variables when calling either the zpool-create.sh or zpios.sh scripts.

For example if you wanted to create and test a single 4-disk Raid-Z2
configuration using disks [A-D]1 with dedicated ZIL and L2ARC devices
you could run the following.

$ ZIL="log A2" L2ARC="cache B2" RANKS=1 CHANNELS=4 LEVEL=2 \
  zpool-create.sh -c zpool-raidz

$ zpool status tank
  pool: tank
 state: ONLINE
 scan: none requested
config:

      NAME        STATE     READ WRITE CKSUM
      tank        ONLINE       0     0     0
        raidz2-0  ONLINE       0     0     0
          A1      ONLINE       0     0     0
          B1      ONLINE       0     0     0
          C1      ONLINE       0     0     0
          D1      ONLINE       0     0     0
      logs
        A2        ONLINE       0     0     0
      cache
        B2        ONLINE       0     0     0

errors: No known data errors
2010-11-08 14:03:36 -08:00
Ned Bass 3ee56c292b Make rollbacks fail gracefully
Support for rolling back datasets require a functional ZPL, which we currently
do not have.  The zfs command does not check for ZPL support before attempting
a rollback, and in preparation for rolling back a zvol it removes the minor
node of the device.  To prevent the zvol device node from disappearing after a
failed rollback operation, this change wraps the zfs_do_rollback() function in
an #ifdef HAVE_ZPL and returns ENOSYS in the absence of a ZPL.  This is
consistent with the behavior of other ZPL dependent commands such as mount.

The orginal error message observed with this bug was rather confusing:

    internal error: Unknown error 524
    Aborted

This was because zfs_ioc_rollback() returns ENOTSUP if we don't HAVE_ZPL, but
Linux actually has no such error code.  It should instead return EOPNOTSUPP, as
that is how ENOTSUP is defined in user space.  With that we would have gotten
the somewhat more helpful message

    cannot rollback 'tank/fish': unsupported version

This is rather a moot point with the above changes since we will no longer make
that ioctl call without a ZPL.  But, this change updates the error code just in
case.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2010-11-08 14:03:36 -08:00
Brian Behlendorf 7e55f4e00c Increate zio write interrupt thread count.
Increasing the default zio_wr_int thread count from 8 to 16 improves
write performence by 13% on large systems.  More testing need to be
done but I suspect the ideal tuning here is ZTI_BATCH() with a minimum
of 8 threads.
2010-11-08 14:03:35 -08:00
Brian Behlendorf 451041db53 Shorten zio_* thread names
Linux kernel thread names are expected to be short.  This change shortens
the zio thread names to 10 characters leaving a few chracters to append
the /<cpuid> to which the thread is bound.  For example: z_wr_iss/0.
2010-11-08 14:03:35 -08:00
Ned Bass b1c5821375 Fix panic mounting unformatted zvol
On some older kernels, i.e. 2.6.18, zvol_ioctl_by_inode() may get passed a NULL
file pointer if the user tries to mount a zvol without a filesystem on it.
This change adds checks to prevent a null pointer dereference.

Closes #73.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2010-10-29 14:46:33 -07:00
Ned Bass 6ee71f5ce3 Call modprobe with absolute path
Some sudo configurations may not include /sbin in the PATH.
libzfs_load_module() currently does not call modprobe with an absolute path, so
it may fail under such configurations if called under sudo.  This change adds
the absolute path to modprobe so we no longer rely on how PATH is set.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2010-10-22 12:39:57 -07:00
Ned Bass d877ac6bfe Fix intermittent 'zpool add' failures
Creating whole-disk vdevs can intermittently fail if a udev-managed symlink to
the disk partition is already in place.  To avoid this, we now remove any such
symlink before partitioning the disk.  This makes zpool_label_disk_wait() truly
wait for the new link to show up instead of returning if it finds an old link
still in place.  Otherwise there is a window between when udev deletes and
recreates the link during which access attempts will fail with ENOENT.

Also, clean up a comment about waiting for udev to create symlinks.  It no
longer needs to describe the special cases for the link names, since that is
now handled in a separate helper function.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2010-10-22 12:38:58 -07:00
Ned Bass d4055aac3c Add zconfig test for adding and removing vdevs
This test performs a sanity check of the zpool add and remove commands.  It
tests adding and removing both a cache disk and a log disk to and from a zpool.
Usage of both a shorthand device path and a full path is covered.  The test
uses a scsi_debug device as the disk to be added and removed.  This is done so
that zpool will see it as a whole disk and partition it, which it does not
currently done for loopback devices.  We want to verify that the manipulation
done to whole disks paths to hide the parition information does not break the
add/remove interface.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2010-10-22 12:41:57 -07:00
Ned Bass 4682b8c14e Remove solaris-specific code from make_leaf_vdev()
Portability between Solaris and Linux isn't really an issue for us anymore, and
removing sections like this one helps simplify the code.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2010-10-22 12:25:58 -07:00
Ned Bass a2c6816c34 Support shorthand names with zpool remove
zpool status displays abbreviated vdev names without leading path components
and, in the case of whole disks, without partition information.  Also, the
zpool subcommands 'create' and 'add' support using shorthand devices names
without qualified paths.  Prior to this change, however, removing a device
generally required specifying its name as it is stored in the vdev label.  So
while zpool status might list a cache disk with a name like A16, removing it
would require a full path such as /dev/disk/zpool/A16-part1, which is
non-intuitive.

This change adds support for shorthand device names with the remove subcommand
so one can simply type, for example,

        zpool remove tank A16

A consequence of this change is that including the partition information when
removing a whole-disk vdev now results in an error.  While this is arguably the
correct behavior, it is a departure from how zpool previously worked in this
project.

This change removes the only reference to ctd_check_path(), so that function is
also removed to avoid compiler warnings.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2010-10-22 12:25:46 -07:00
Ned Bass 79e7242a91 Add helper functions for manipulating device names
This change adds two helper functions for working with vdev names and paths.
zfs_resolve_shortname() resolves a shorthand vdev name to an absolute path
of a file in /dev, /dev/disk/by-id, /dev/disk/by-label, /dev/disk/by-path,
/dev/disk/by-uuid, /dev/disk/zpool.  This was previously done only in the
function is_shorthand_path(), but we need a general helper function to
implement shorthand names for additional zpool subcommands like remove.
is_shorthand_path() is accordingly updated to call the helper function.

There is a minor change in the way zfs_resolve_shortname() tests if a file
exists.  is_shorthand_path() effectively used open() and stat64() to test for
file existence, since its scope includes testing if a device is a whole disk
and collecting file status information.  zfs_resolve_shortname(), on the other
hand, only uses access() to test for existence and leaves it to the caller to
perform any additional file operations.  This seemed like the most general and
lightweight approach, and still preserves the semantics of is_shorthand_path().

zfs_append_partition() appends a partition suffix to a device path.  This
should be used to generate the name of a whole disk as it is stored in the vdev
label. The user-visible names of whole disks do not contain the partition
information, while the name in the vdev label does.   The code was lifted from
the function make_disks(), which now just calls the helper function.  Again,
having a helper function to do this supports general handling of shorthand
names in the user interface.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
2010-10-22 12:25:30 -07:00
Brian Behlendorf 0ee8118bd3 Add zfault zpool configurations and tests
Eleven new zpool configurations were added to allow testing of various
failure cases.  The first 5 zpool configurations leverage the 'faulty'
md device type which allow us to simuluate IO errors at the block layer.
The last 6 zpool configurations leverage the scsi_debug module provided
by modern kernels.  This device allows you to create virtual scsi
devices which are backed by a ram disk.  With this setup we can verify
the full IO stack by injecting faults at the lowest layer.  Both methods
of fault injection are important to verifying the IO stack.

The zfs code itself also provides a mechanism for error injection
via the zinject command line tool.  While we should also take advantage
of this appraoch to validate the code it does not address any of the
Linux integration issues which are the most concerning.  For the
moment we're trusting that the upstream Solaris guys are running
zinject and would have caught internal zfs logic errors.

Currently, there are 6 r/w test cases layered on top of the 'faulty'
md devices.  They include 3 writes tests for soft/transient errors,
hard/permenant errors, and all writes error to the device.  There
are 3 matching read tests for soft/transient errors, hard/permenant
errors, and fixable read error with a write.  Although for this last
case zfs doesn't do anything special.

The seventh test case verifies zfs detects and corrects checksum
errors.  In this case one of the drives is extensively damaged and
by dd'ing over large sections of it.  We then ensure zfs logs the
issue and correctly rebuilds the damage.

The next  test cases use the scsi_debug configuration to injects error
at the bottom of the scsi stack.  This ensures we find any flaws in the
scsi midlayer or our usage of it.  Plus it stresses the device specific
retry, timeout, and error handling outside of zfs's control.

The eighth test case is to verify that the system correctly handles an
intermittent device timeout.  Here the scsi_debug device drops 1 in N
requests resulting in a retry either at the block level.  The ZFS code
does specify the FAILFAST option but it turns out that for this case
the Linux IO stack with still retry the command.  The FAILFAST logic
located in scsi_noretry_cmd() does no seem to apply to the simply
timeout case.  It appears to be more targeted to specific device or
transport errors from the lower layers.

The ninth test case handles a persistent failure in which the device
is removed from the system by Linux.  The test verifies that the failure
is detected, the device is made unavailable, and then can be successfully
re-add when brought back online.  Additionally, it ensures that errors
and events are logged to the correct places and the no data corruption
has occured due to the failure.
2010-10-12 15:20:03 -07:00