When I began work on the Posix layer it immediately became clear to
me that to integrate cleanly with the Linux VFS certain Solaris
specific things would have to go. One of these things was to elimate
as many Solaris specific types from the ZPL layer as possible. They
would be replaced with their Linux equivalents. This would not only
be good for performance, but for the general readability and health of
the code. The Solaris and Linux VFS are different beasts and should
be treated as such. Most of the code remains common for constructing
transactions and such, but there are subtle and important differenced
which need to be repsected.
This policy went quite for for certain types such as the vnode_t,
and it initially seemed to be working out well for the vattr_t. There
was a relatively small amount of related xvattr_t code I was forced to
comment out with HAVE_XVATTR. But it didn't look that hard to come
back soon and replace it all with a native Linux type.
However, after going doing this path with xvattr some distance it
clear that this code was woven in the ZPL more deeply than I thought.
In particular its hooks went very deep in to the ZPL replay code
and replacing it would not be as easy as I originally thought.
Rather than continue persuing replacing and removing this code I've
taken a step back and reevaluted things. This commit reverts many of
my previous commits which removed xvattr related code. It restores
much of the code to its original upstream state and now relies on
improved xvattr_t support in the zfs package itself.
The result of this is that much of the code which I had commented
out, which accidentally broke things like replay, is now back in
place and working. However, there may be a small performance
impact for getattr/setattr operations because they now require
a translation from native Linux to Solaris types. For now that's
a price I'm willing to pay. Once everything is completely functional
we can revisting the issue of removing the vattr_t/xvattr_t types.
Closes#111
With the removal of the minimal xvattr support from the spl this
support needs to be replaced in the zfs package. This is fairly
easily accomplished by directly adding portions of the sys/vnode.h
header from OpenSolaris. These xvattr additions have been placed
in the sys/xvattr.h header file and included as needed where simply
a sys/vnode.h was included before.
In additon to the xvattr types and helper macros two functions
were also included. The xva_init() and xva_getxoptattr() functions
were included as static inline functions in xvattr.h. They are
simple enough and it was simpler to place them here rather than
in their own .c file.
The xvattr support in the spl has always simply consisted of
defining a couple structures and a few #defines. This was enough
to enable compilation of code which just passed xvattr types
around but not enough to effectively manipulate them.
This change removes even this minimal support leaving it up
to packages which leverage the spl to prove the full xvattr
support. By removing it from the spl we ensure not conflict
with the higher level packages.
This just leaves minimal vnode support for basical manipulation
of files. This code is does have the proper support functions
in the spl and a set of regression tests.
Additionally, this change removed the unused 'caller_context_t *'
type and replaces it with a 'void *'.
Print the supported zpool and filesystem versions at module load
time. This change removes an ambiguity and adds information that
system administrators care about. The phrase "ZFS pool version %s"
is the same as zpool upgrade -v so that the operator is familiar
with the message.
ZFS: Loaded module v0.6.0, ZFS pool version 28, ZFS filesystem version 5
ZFS: Unloaded module v0.6.0
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
A zlib regression test has been added to verify the correct behavior
of z_compress_level() and z_uncompress. The test case simply takes
a 128k buffer, it compresses the buffer, it them uncompresses the
buffer, and finally it compares the buffers after the transform.
If the buffers match then everything is fine and no data was lost.
It performs this test for all 9 zlib compression levels.
While portions of the code needed to support z_compress_level() and
z_uncompress() where in place. In reality the current implementation
was non-functional, it just was compilable.
The critical missing component was to setup a workspace for the
compress/uncompress stream structures to use. A kmem_cache was
added for the workspace area because we require a large chunk
of memory. This avoids to need to continually alloc/free this
memory and vmap() the pages which is very slow. Several objects
will reside in the per-cpu kmem_cache making them quick to acquire
and release. A further optimization would be to adjust the
implementation to additional ensure the memory is local to the cpu.
Currently that may not be the case.
There were two cases when attempting to set the vdev block device
scheduler which would causes console warnings.
The first case was when the vdev used a loop, ram, dm, or other
such device which doesn't support a configurable scheduler. In
these cases attempting to set a scheduler is pointless and can
be safely skipped.
The secord case is slightly more troubling. We were seeing
transient cases where setting the elevator would return -EFAULT.
On retry everything is fine so there appears to be a small window
where this is possible. To handle that case we silently retry
up to three times before reporting the warning.
In all of the above cases the warning is harmless and at worse you
may see slightly different performance characteristics from one
or more of your vdevs.
This commit allows zvols with names longer than 32 characters, which
fixes issue on https://github.com/behlendorf/zfs/issues/#issue/102.
Changes include:
- use /dev/zd* device names for zvol, where * is the device minor
(include/sys/fs/zfs.h, module/zfs/zvol.c).
- add BLKZNAME ioctl to get dataset name from userland
(include/sys/fs/zfs.h, module/zfs/zvol.c, cmd/zvol_id).
- add udev rule to create /dev/zvol/[dataset_name] and the legacy
/dev/[dataset_name] symlink. For partitions on zvol, it will create
/dev/zvol/[dataset_name]-part* (etc/udev/rules.d/60-zvol.rules,
cmd/zvol_id).
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Remove custom code to pack/unpack dev_t's. Under Linux all dev_t's
are an unsigned 32-bit value even on 64-bit platforms. The lower
20 bits are used for the minor number and the upper 12 for the major
number.
This means if your importing a pool from Solaris you may get strange
major/minor numbers. But it doesn't really matter because even if
we add compatibility code to translate the encoded Solaris major/minor
they won't do you any good under Linux. You will still need to
recreate the dev_t with a major/minor which maps to reserved major
numbers used under Linux.
Dropping this code also resolves 32-bit builds by removing the
offending 32-bit compatibility code.
ASSERT3P should be used instead of ASSERT3U when comparing
pointers. Using ASSERT3U with the cast causes a compiler
warning for 32-bit builds which is fatal with --enable-debug.
Rather than defining our own structure which will conflict with
Linux's version when building 32-bit. Simply setup a typedef
to always use the correct Linux version for both 32 ad 64-bit
builds.
The underlying storage pool actually uses multiple block
size. Under Solaris frsize (fragment size) is reported as
the smallest block size we support, and bsize (block size)
as the filesystem's maximum block size. Unfortunately,
under Linux the fragment size and block size are often used
interchangeably. Thus we are forced to report both of them
as the filesystem's maximum block size.
Closes#112
Because the secpolicy_* macros are all currently defined to (0).
And because the caller of this function does not check the return
code. The compiler complains that this statement has no effect
which is correct and OK. To suppress the warning explictly cast
the result to (void).
Generally it's a good idea to use enums for switch statements,
but in this case it causes warning because the enum is really a
set of flags. These flags are OR'ed together in some cases
resulting in values which are not part of the original enum.
This causes compiler warning such as this about invalid cases.
error: case value ‘33’ not in enumerated type ‘zprop_source_t’
To handle this we simply case the enum to an int for the switch
statement. This leaves all other enum type checking in place
and effectively disabled these warnings.
In the 2.6.37 kernel the function invalidate_inodes() is no longer
exported for use by modules. This memory management functionality
is needed to invalidate the inodes attached to a super block without
unmounting the filesystem.
Because this function still exists in the kernel and the prototype
is available is a common header all we strictly need is the symbol
address. The address is obtained using spl_kallsyms_lookup_name()
and assigned to the variable invalidate_inodes_fn. Then a #define
is used to replace all instances of invalidate_inodes() with a
call to the acquired address. All the complexity is hidden behind
HAVE_INVALIDATE_INODES and invalidate_inodes() can be used as usual.
Long term we should try to get this, or another, interface made
available to modules again.
The open_bdev_exclusive() function has been replaced (again) by the
more generic blkdev_get_by_path() function. Additionally, the
counterpart function close_bdev_exclusive() has been replaced by
blkdev_put(). Because these functions are more generic versions
of the functions they replaced the compatibility macro must add
the FMODE_EXCL mask to ensure they are exclusive.
Closes#114
For legacy reasons the zvol.c and vdev_disk.c Linux compatibility
code ended up in sys/blkdev.h and sys/vdev_disk.h headers. While
there are worse places for this code to live it should be in a
linux/blkdev_compat.h header. This change moves this block device
Linux compatibility code in to the linux/blkdev_compat.h header
and updates all the correct #include locations. This is not a
functional change or bug fix, it is just code cleanup.
Create the first 0.6.0 release candidate tag (rc1). The Posix
layer is now functional and passes fstest and several other
test suites cleanly. We now need this release candidate tag
to broaden the test coverage before we can release the official
zfs-0.6.0.
When changing the uid/gid of a file via zfs_setattr() use the
Posix id passed in iattr->ia_uid/gid. While the zfs_fuid_create()
code already had the fuid support disabled for Linux it was
returning the uid/gid from the credential. With this change
the 'chown' command which relies on setxattr is now working
properly.
Also remove a little stray white space which was in front of
zfs_update_inode() call and the end of zfs_setattr().
Under Linux sys_symlink(2) should result in a inode being created
with one reference for the inode itself, and a second reference on
the inode which is held by the new dentry. Under Solaris this
appears not to be the case. Their zfs_symlink() handler drops
the inode reference before returning.
The result of this under Linux is that the reference count for
symlinks is always one smaller than it should have been. This
results in a BUG() when the symlink is unlinked. To handle this
the Linux port now keeps the inode reference which differs from
the Solaris behavior. This results in correct reference counts.
Closes#96
The zfs_readlink() function returns a Solaris positive error value
and that needs to be converted to a Linux negative error value.
While in this case nothing would actually go wrong, it's still
incorrect and should be fixed if for no other reason than clarity.
There are three improvements here to 'zpool import' proposed by Fajar
in Github issue #98. They are all good so I'm commiting all three.
1) Add descriptions for "hpet" and "core" blacklist entries.
2) Add "core" to the blacklist, as described in the issue accessing
this device will crash Xen dom0.
3) Refine probing behavior to use fstatat64(). This allows us to
determine if a device is a block device or a regular file without
having to open it. This is the safest appraoch when probing /dev/
because the simple act of opening a device may have unexpected
consequences.
Closes#98
This patch addresses three issues related to symlinks.
1) Revert the zfs_follow_link() function to a modified version
of the original zfs_readlink(). The only changes from the
original OpenSolaris version relate to using Linux types.
For the moment this means no vnode's and no zfsvfs_t. The
caller zpl_follow_link() was also updated accordingly. This
change was reverted because it was slightly gratuitious.
2) Update zpl_follow_link() to use local variables for the
link buffer. I'd forgotten that iov.iov_base is updated by
uiomove() so after the call to zfs_readlink() it can not longer
be used. We need our own private copy of the link pointer.
3) Allocate MAXPATHLEN instead of MAXPATHLEN+1. By default
MAXPATHLEN is 4096 bytes which is a full page, adding one to
it pushes it slightly over a page. That means you'll likely
end up allocating 2 pages which is wasteful of memory and
possibly slightly slower.
This adds an API to wait for pending commit callbacks of already-synced
transactions to finish processing. This is needed by the DMU-OSD in
Lustre during device finalization when some callbacks may still not be
called, this leads to non-zero reference count errors. See lustre.org
bug 23931.
Before it is safe to unload the zfs module stack all mounted
zfs filesystems must be unmounted. If they are not unmounted,
there will be references held on the modules and the stack cannot
be removed. To handle this have 'zfs.sh -u' which is used by all
of the test scripts umount all zfs filesystem before attempting
to unload the module stack.
Until code is added to support automatically sharing datasets
we should return success instead of failure. This prevents the
command line tools from returning a non-zero error code. While
a user likely won't notice this, test scripts like zconfig.sh
do and correctly fail because of it.
While the attr/xattr hooks were already in place for regular
files this hooks can also apply to directories and special files.
While they aren't typically used in this way, it should be
supported. This patch registers these additional callbacks
for both directory and special inode types.
Under Linux when creating a fifo or socket type device in the ZFS
filesystem it's critical that the rdev is stored in a SA. This
was already being correctly done for character and block devices,
but that logic needed to be extended to include FIFOs and sockets.
This patch takes care of device creation but a follow on patch
may still be required to verify that the dev_t is being correctly
packed/unpacked from the SA.
It was noticed that when you have zvols in multiple datasets
not all of the zvol devices are created at module load time.
Fajarnugraha did the leg work to identify that the root cause of
this bug is a non-zero return value from zvol_create_minors_cb().
Returning a non-zero value from the dmu_objset_find_spa() callback
function results in aborting processing the remaining children in
a dataset. Since we want to ensure that the callback in run on
all children regardless of error simply unconditionally return
zero from the zvol_create_minors_cb(). This callback function
is solely used for this purpose so surpressing the error is safe.
Closes#96
The new prefered inteface for evicting an inode from the inode cache
is the ->evict_inode() callback. It replaces both the ->delete_inode()
and ->clear_inode() callbacks which were previously used for this.
The xattr handler prototypes were sanitized with the idea being that
the same handlers could be used for multiple methods. The result of
this was the inode type was changes to a dentry, and both the get()
and set() hooks had a handler_flags argument added. The list()
callback was similiarly effected but no autoconf check was added
because we do not use the list() callback.
The fsync() callback in the file_operations structure used to take
3 arguments. The callback now only takes 2 arguments because the
dentry argument was determined to be unused by all consumers. To
handle this a compatibility prototype was added to ensure the right
prototype is used. Our implementation never used the dentry argument
either so it's just a matter of using the right prototype.
The const keyword was added to the 'struct xattr_handler' in the
generic Linux super_block structure. To handle this we define an
appropriate xattr_handler_t typedef which can be used. This was
the preferred solution because it keeps the code clean and readable.
Preferentially use the /lib/modules/$(uname -r)/source and
/lib/modules/$(uname -r)/build links. Only if neither of these
links exist fallback to alternate methods for deducing which
kernel to build with. This resolves the need to manually
specify --with-linux= and --with-linux-obj= on Debian systems.
Preferentially use the /lib/modules/$(uname -r)/source and
/lib/modules/$(uname -r)/build links. Only if neither of these
links exist fallback to alternate methods for deducing which
kernel to build with. This resolves the need to manually
specify --with-linux= and --with-linux-obj= on Debian systems.
It turns out that older versions of the glibc headers do not
properly define MS_DIRSYNC despite it being explicitly mentioned
in the man pages. They instead call it S_WRITE, so for system
where this is not correct defined map MS_DIRSYNC to S_WRITE.
At the time of this commit both Ubuntu Lucid, and Debian Squeeze
both use the out of date glibc headers.
As for MS_REC this field is also not available in the older headers.
Since there is no obvious mapping in this case we simply disable
the recursive mount option which used it.
The inclusion on dlsym(), dlopen(), and dlclose() symbols require
us to link against the dl library. Be careful to add the flag to
both the libzfs library and the commands which depend on the library.
This file has gotten stale and needed to be updated. There are
individuals who deserve to be recognized for their contributions
to the project. I've done my best to assemble names from the
commit logs of those who have submitted patches. This list may
not be comprehensive, if you feel I've overlooked your contribution
please let me know and we can get your name added.
Initial testing has shown the the right IO scheduler to use under Linux
is noop. This strikes the ideal balance by allowing the zfs elevator
to do all request ordering and prioritization. While allowing the
Linux elevator to do the maximum front/back merging allowed by the
physical device. This yields the largest possible requests for the
device with the lowest total overhead.
While 'noop' should be right for your system you can choose a different
IO scheduler with the 'zfs_vdev_scheduler' option. You may set this
value to any of the standard Linux schedulers: noop, cfq, deadline,
anticipatory. In addition, if you choose 'none' zfs will not attempt
to change the IO scheduler for the block device.
The following warning was observed under normal operation. It's
not fatal but it's something to be addressed long term. Flag the
offending allocation with KM_NODEBUG to suppress the warning and
flag the call site.
SPL: Showing stack for process 21761
Pid: 21761, comm: iozone Tainted: P ----------------
2.6.32-71.14.1.el6.x86_64 #1
Call Trace:
[<ffffffffa05465a7>] spl_debug_dumpstack+0x27/0x40 [spl]
[<ffffffffa054a84d>] kmem_alloc_debug+0x11d/0x130 [spl]
[<ffffffffa05de166>] dmu_buf_hold_array_by_dnode+0xa6/0x4e0 [zfs]
[<ffffffffa05de825>] dmu_buf_hold_array+0x65/0x90 [zfs]
[<ffffffffa05de891>] dmu_read_uio+0x41/0xd0 [zfs]
[<ffffffffa0654827>] zfs_read+0x147/0x470 [zfs]
[<ffffffffa06644a2>] zpl_read_common+0x52/0x70 [zfs]
[<ffffffffa0664503>] zpl_read+0x43/0x70 [zfs]
[<ffffffff8116d905>] vfs_read+0xb5/0x1a0
[<ffffffff8116da41>] sys_read+0x51/0x90
[<ffffffff81013172>] system_call_fastpath+0x16/0x1b
When performing a 'zfs rollback' it's critical to invalidate
the previous dcache and inode cache. If we don't there will
stale cache entries which when accessed will result in EIOs.
These two warnings in libefi serve no real purpose. When running
without DEBUG they are already supressed, and even when DEBUG is
enabled all they indicate is the device doesn't already have an
EFI label. For a Linux machine this is probably the common case.
With the recent SPL change (d599e4fa) that forces cv_destroy()
to block until all waiters have been woken. It is now unsafe
to call cv_destroy() under the zp->z_range_lock() because it
is used as the condition variable mutex. If there are waiters
cv_destroy() will block until they wake up and aquire the mutex.
However, they will never aquire the mutex because cv_destroy()
will not return allowing it's caller to drop the lock. Deadlock.
To avoid this cv_destroy() is now run asynchronously in a taskq.
This solves two problems:
1) It is no longer run under the zp->z_range_lock so no deadlock.
2) Since cv_destroy() may now block we don't want this slowing
down zfs_range_unlock() and throttling the system.
This was not as much of an issue under OpenSolaris because their
cv_destroy() implementation does not do anything. They do however
risk a bad paging request if cv_destroy() returns, the memory holding
the condition variable is free'd, and then the waiters wake up and
try to reference it. It's a very small unlikely race, but it is
possible.
Brian Behlendorf
Darik Horn
Fajar A. Nugraha
Ricardo M. Correia