If a vnode is released asynchronously through areleasef(), it is
possible for the user process to reuse the file descriptor before
areleasef is called. When this happens, getf() will return a stale
reference, any operations in the kernel on that file descriptor will
fail (as it is closed) and the operations meant for that fd will
never occur from userspace's perspective.
We correct this by detecting this condition in getf(), doing a putf
on the old file handle, updating the file descriptor and proceeding
as if everything was fine. When the areleasef() is done, it will
harmlessly decrement the reference counter on the Illumos file handle.
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#492
C type coercion rules require that negative numbers be converted into
positive numbers via wraparound such that a negative -1 becomes a
positive 1. This causes vn_getf to return a file handle when it should
return NULL whenever a positive file descriptor existed with the same
value. We should check for a negative file descriptor and return NULL
instead.
This was caught by ClusterHQ's unit testing.
Reference:
http://stackoverflow.com/questions/50605/signed-to-unsigned-conversion-in-c-is-it-always-safe
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Andriy Gapon <avg@FreeBSD.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#450
When layered on XFS the following warning will be emitted under CentOS7
when entering vfs_fsync() with PF_FSTRANS already set. This is not an
issue for other stock Linux file systems and the warning was removed
for newer kernels. However, to avoid triggering this error PF_FSTRANS
is cleared and then reset in vn_fsync().
WARNING: at fs/xfs/xfs_aops.c:968 xfs_vm_writepage+0x5ab/0x5c0
Call Trace:
[<ffffffff8105dee1>] warn_slowpath_common+0x61/0x80
[<ffffffffa01706fb>] xfs_vm_writepage+0x5ab/0x5c0 [xfs]
[<ffffffff8114b833>] __writepage+0x13/0x50
[<ffffffff8114c341>] write_cache_pages+0x251/0x4d0
[<ffffffff8114c60d>] generic_writepages+0x4d/0x80
[<ffffffffa016fc93>] xfs_vm_writepages+0x43/0x50 [xfs]
[<ffffffff8114d68e>] do_writepages+0x1e/0x40
[<ffffffff81142bd5>] __filemap_fdatawrite_range+0x65/0x80
[<ffffffff81142cea>] filemap_write_and_wait_range+0x2a/0x70
[<ffffffffa017a5b6>] xfs_file_fsync+0x66/0x1f0 [xfs]
[<ffffffff811df54b>] vfs_fsync+0x2b/0x40
[<ffffffffa03a88bd>] vn_fsync+0x2d/0x90 [spl]
[<ffffffffa0520c33>] spa_config_sync+0x503/0x680 [zfs]
[<ffffffffa0520ee4>] spa_config_update+0x134/0x170 [zfs]
[<ffffffffa0520eba>] spa_config_update+0x10a/0x170 [zfs]
[<ffffffffa051c54f>] spa_import+0x5bf/0x7b0 [zfs]
[<ffffffffa055c754>] zfs_ioc_pool_import+0x104/0x150 [zfs]
[<ffffffffa056294f>] zfsdev_ioctl+0x4cf/0x5c0 [zfs]
[<ffffffffa0562480>] ? pool_status_check+0xf0/0xf0 [zfs]
[<ffffffff811c2c85>] do_vfs_ioctl+0x2e5/0x4c0
[<ffffffff811c2f01>] SyS_ioctl+0xa1/0xc0
[<ffffffff815f3219>] system_call_fastpath+0x16/0x1b
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
The kmem_vasprintf(), kmem_vsprintf(), kobj_open_file(), and vn_openat()
functions should all use the kmem_flags_convert() function to generate
the GFP_* flags. This ensures that they can be safely called in any
context and the correct flags will be used.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#426
This change introduces no functional changes to the memory management
interfaces. It only restructures the existing codes by separating the
kmem, vmem, and kmem cache implementations in the separate source and
header files.
Splitting this functionality in to separate files required the addition
of spl_vmem_{init,fini}() and spl_kmem_cache_{initi,fini}() functions.
Additionally, several minor changes to the #include's were required to
accommodate the removal of extraneous header from kmem.h.
But again, while large this patch introduces no functional changes.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Don't include the compatibility code in linux/*_compat.h in the public
header sys/types.h. This causes problems when an external code base
includes the ZFS headers and has its own conflicting compatibility code.
Lustre, in particular, defined SHRINK_STOP for compatibility with
pre-3.12 kernels in a way that conflicted with the SPL's definition.
Because Lustre ZFS OSD includes ZFS headers it fails to build due to a
'"SHRINK_STOP" redefined' compiler warning. To avoid such conflicts
only include the compat headers from .c files or private headers.
Also, for consistency, include sys/*.h before linux/*.h then sort by
header name.
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#411
When the SPL was originally written Linux tracepoints were still
in their infancy. Therefore, an entire debugging subsystem was
added to facilite tracing which served us well for many years.
Now that Linux tracepoints have matured they provide all the
functionality of the previous tracing subsystem. Rather than
maintain parallel functionality it makes sense to fully adopt
tracepoints. Therefore, this patch retires the legacy debugging
infrastructure.
See zfsonlinux/zfs@bc9f413 for the tracepoint changes.
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#408
The kern_path() function has been available since Linux 2.6.28.
There is no longer a need to maintain this compatibility code.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
This function has never been exported by any mainline and was only
briefly available under RHEL5. Therefore this check is being removed
and the code update to always use the wrapper function.
The next step will be to eliminate all this code. If ZFS were updated
not to assume that it's pwd was / there would be no need for this.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
The user_path_dir() function has been available since Linux 2.6.27.
There is no longer a need to maintain this compatibility code.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
The inode structure has used i_mutex as its internal locking
primitive since 2.6.16. The compatibility code to check for
the previous semaphore primitive has been removed. However,
the wrapper function itself is being kept because it's entirely
possible this primitive will change again to allow finer grained
locking.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
zfsonlinux/spl#bcb15891ab394e11615eee08bba1fd85ac32e158 implemented
Linux 3.6+ support by adding duplicate vn_rename and vn_remove
functions. The new ones were cleaner, but the duplicate functions made
the codebase less maintainable. This adds some compatibility shims that
allow us to retire the older vn_rename and vn_remove in favor of the new
ones on old kernels. The result is a net 143 line reduction in lines of
code and a cleaner codebase.
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#370
Detect the updated vfs_rename() interface and call it with an
extra flags argument.
References:
torvalds/linux@520c8b1
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #355
This check was originally added for SLES10, a093c6a, to check for
a 'struct vfsmount *' argument which they added. However, since
SLES10 is based on a 2.6.16 kernel which is no longer supported
this functionality was dropped. The checks were refactored to
support Linux 3.13 without concern for historical versions.
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#312
When CONFIG_UIDGID_STRICT_TYPE_CHECKS is enabled uid_t/git_t are
replaced by kuid_t/kgid_t, which are structures instead of integral
types. This causes any code that uses an integral type to fail to build.
The User Namespace functionality introduced in Linux 3.8 requires
CONFIG_UIDGID_STRICT_TYPE_CHECKS, so we could not build against any
kernel that supported it.
We resolve this by converting between the new kuid_t/kgid_t structures
and the original uid_t/gid_t types.
Original-patch-by: DHE
Rewrite-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#260
This was a suggestion that Brian Behlendorf made when reviewing an early
pull request for Linux 3.9 support. This commit was made intentionally
easy to revert should we ever have a reason to reintroduce support for
older kernels.
Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
torvalds/linux@dcf787f391 enforces
const-correctness in passing struct path *.
Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
The function prototype of vfs_getattr previoulsy took struct vfsmount *
and struct dentry * as arguments. These would always be defined together
in a struct path *.
torvalds/linux@3dadecce20 modified
vfs_getattr to take struct path * is taken as an argument instead.
Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
torvalds/linux@182be68478 removed the
preprocessor definition for f_vfsmnt. The ability to access the
mountpoint via ->f_path.mnt has been stable for a long time, so we
switch to that.
Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Update links to refer to the official ZFS on Linux website instead of
@behlendorf's personal fork on github.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
In the upstream kernel the FALLOC_FL_PUNCH_HOLE #define was
introduced after the fallocate() function was moved from the
inode_operations to the file_operations structure. Therefore,
the SPL code assumed that if FALLOC_FL_PUNCH_HOLE was defined
it was safe to use f_ops->fallocate().
Unfortunately, the RHEL6.4 kernel has only backported the
FALLOC_FL_PUNCH_HOLE #define and not the fallocate() change.
To address this compatibility issue the spl_filp_fallocate()
helper function was added to properly detect which interface
is available.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
When the Linux 3.6 KERN_PATH_LOCKED compatibility code was added
by commit bcb1589 an entirely new vn_remove() implementation was
added. That function did not properly handle an error from
spl_kern_path_locked() which would result in an panic. This
patch addresses the issue by returning the error to the caller.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#187
The kern_path_parent() function was removed from Linux 3.6 because
it was observed that all the callers just want the parent dentry.
The simpler kern_path_locked() function replaces kern_path_parent()
and does the lookup while holding the ->i_mutex lock.
This is good news for the vn implementation because it removes the
need for us to handle the locking. However, it makes it harder to
implement a single readable vn_remove()/vn_rename() function which
is usually what we prefer.
Therefore, we implement a new version of vn_remove()/vn_rename()
for Linux 3.6 and newer kernels. This allows us to leave the
existing working implementation untouched, and to add a simpler
version for newer kernels.
Long term I would very much like to see all of the vn code removed
since what this code enabled is generally frowned upon in the kernel.
But that can't happen util we either abondon the zpool.cache file
or implement alternate infrastructure to update is correctly in
user space.
Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#154
This adds an interface to "punch holes" (deallocate space) in VFS
files. The interface is identical to the Solaris VOP_SPACE interface.
This interface is necessary for TRIM support on file vdevs.
This is implemented using Linux fallocate(FALLOC_FL_PUNCH_HOLE), which
was introduced in 2.6.38. For a brief time before 2.6.38 this was done
using the truncate_range inode operation, which was quickly deprecated.
This patch only supports FALLOC_FL_PUNCH_HOLE.
This adds support for the truncate_range() inode operation to
VOP_SPACE() for file hole punching. This API is deprecated and removed
in 3.5, so it's only useful for old kernels.
On tmpfs, the truncate_range() inode operation translates to
shmem_truncate_range(). Unfortunately, this function expects the end
offset to be inclusive and aligned to the end of a page. If it is not,
the kernel will stop with a BUG_ON().
This patch fixes the issue by adapting to the constraints set forth by
shmem_truncate_range().
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#168
In the module unload path the vm_file_cache was being destroyed
under a spin lock. Because this operation might sleep it was
possible, although very very unlikely, that this could result
in a deadlock.
This issue was indentified by using a Linux debug kernel and
has been fixed by moving the kmem_cache_destroy() out from under
the spin lock. There is no need to lock this operation here.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closeszfsonlinux/zfs#771
Prior to Linux 3.1 the kern_path_parent symbol was exported for
use by kernel modules. As of Linux 3.1 it is now longer easily
available. To handle this case the spl will now dynamically
look up address of the missing symbol at module load time.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #52
This would cause problems when using 'zfs send' with a file as the
target (rather than a pipe or a socket as is usually the case) as
for each write the destination offset in the file would be 0.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes ZFS issue #391
File descriptors are a per-process resource. The same descriptor
in different processes can refer to different files. find_file()
incorrectly assumed that file descriptors are globally unique.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes ZFS issue #386
The path_lookup() function has been renamed to kern_path_parent()
and the flags argument has been removed. The only behavior now
offered is that of LOOKUP_PARENT. The spl already always passed
this flag so dropping the flag does not impact us.
This is a long over due compatibility change. Way, way, way back
in 2007 there was a push to remove all consumers of SPIN_LOCK_UNLOCKED.
Finally, in 2011 with 2.6.39 all the consumers have been updated
and SPIN_LOCK_UNLOCKED was removed. It's about time we use the
new API as well, this change does exactly that. DEFINE_SPINLOCK()
was available as far back as 2.6.12 so there doesn't need to be
any additional autoconf-foo for this change.
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 *'.
Both of these caches were previously allowed to be either a
vmem or kmem cache based on the size of the object involved.
Since we know the object won't be to large and performce is
much better for a kmem cache for them to be kmem backed.
Create spl_inode_lock/spl_inode_unlock compability macros to simply
access to the inode mutex/sem. This avoids the need to have to ugly
up the code with the required #define's at every call site. At the
moment the SPL only uses this in one place but higher layers can
benefit from the macro.
In the linux-2.6.36 kernel the fs_struct lock was changed from a
rwlock_t to a spinlock_t. If the kernel would export the set_fs_pwd()
symbol by default this would not have caused us any issues, but they
don't. So we're forced to add a new autoconf check which sets the
HAVE_FS_STRUCT_SPINLOCK define when a spinlock_t is used. We can
then correctly use either spin_lock or write_lock in our custom
set_fs_pwd() implementation.
Unless __GFP_IO and __GFP_FS are removed from the file mapping gfp
mask we may enter memory reclaim during IO. In this case shrink_slab()
entered another file system which is notoriously hungry for stack.
This additional stack usage may cause a stack overflow. This patch
removes __GFP_IO and __GFP_FS from the mapping gfp mask of each file
during vn_open() to avoid any reclaim in the vn_rdwr() IO path. The
original mask is then restored at vn_close() time. Hats off to the
loop driver which does something similiar for the same reason.
[...]
shrink_slab+0xdc/0x153
try_to_free_pages+0x1da/0x2d7
__alloc_pages+0x1d7/0x2da
do_generic_mapping_read+0x2c9/0x36f
file_read_actor+0x0/0x145
__generic_file_aio_read+0x14f/0x19b
generic_file_aio_read+0x34/0x39
do_sync_read+0xc7/0x104
vfs_read+0xcb/0x171
:spl:vn_rdwr+0x2b8/0x402
:zfs:vdev_file_io_start+0xad/0xe1
[...]
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
In cmd/splat.c there was a comparison between an __u32 and an int. To
resolve the issue simply use a __u32 and strtoul() when converting the
provided user string.
In module/spl/spl-vnode.c we should explicitly cast nd->last.name to
a const char * which is what is expected by the prototype.
To avoid conflicts with symbols defined by dependent packages
all debugging symbols have been prefixed with a 'S' for SPL.
Any dependent package needing to integrate with the SPL debug
should include the spl-debug.h header and use the 'S' prefixed
macros. They must also build with DEBUG defined.
To avoid symbol conflicts with dependent packages the debug
header must be split in to several parts. The <sys/debug.h>
header now only contains the Solaris macro's such as ASSERT
and VERIFY. The spl-debug.h header contain the spl specific
debugging infrastructure and should be included by any package
which needs to use the spl logging. Finally the spl-trace.h
header contains internal data structures only used for the log
facility and should not be included by anythign by spl-debug.c.
This way dependent packages can include the standard Solaris
headers without picking up any SPL debug macros. However, if
the dependant package want to integrate with the SPL debugging
subsystem they can then explicitly include spl-debug.h.
Along with this change I have dropped the CHECK_STACK macros
because the upstream Linux kernel now has much better stack
depth checking built in and we don't need this complexity.
Additionally SBUG has been replaced with PANIC and provided as
part of the Solaris macro set. While the Solaris version is
really panic() that conflicts with the Linux kernel so we'll
just have to make due to PANIC. It should rarely be called
directly, the prefered usage would be an ASSERT or VERIFY.
There's lots of change here but this cleanup was overdue.
The prototype for filp_fsync() drop the unused argument 'stuct dentry *'.
I've fixed this by adding the needed autoconf check and moving all of
those filp related functions to file_compat.h. This will simplify
handling any further API changes in the future.
I didn't notice at the time but user_path_dir() was not introduced
at the same time as set_fs_pwd() change. I had lumped the two
together but in fact user_path_dir() was introduced in 2.6.27 and
set_fs_pwd() taking 2 args was introduced in 2.6.25. This means
builds against 2.6.25-2.6.26 kernels were broken.
To fix this I've added a check for user_path_dir() and no longer
assume that if set_fs_pwd() takes 2 args then user_path_dir() is
also available.
Updated AUTHORS, COPYING, DISCLAIMER, and INSTALL files. Added
standardized headers to all source file to clearly indicate the
copyright, license, and to give credit where credit is due.
During module init spl_setup()->The vn_set_pwd("/") was failing
with -EFAULT because user_path_dir() and __user_walk() both
expect 'filename' to be a user space address and it's not in
this case. To handle this the data segment size is increased
to to ensure strncpy_from_user() does not fail with -EFAULT.
Additionally, I've added a printk() warning to catch this and
log it to the console if it ever reoccurs. I thought everything
was working properly here because there consequences of this
failing are subtle and usually non-critical.
Ricardo has pointed out that under Solaris the cwd is set to '/'
during module load, while under Linux it is set to the callers cwd.
To handle this cleanly I've reworked the module *_init()/_exit()
macros so they call a *_setup()/_cleanup() function when any SPL
dependent module is loaded or unloaded. This gives us a chance to
perform any needed modification of the process, in this case changing
the cwd. It also handily provides a way to avoid creating wrapper
init()/exit() functions because the Solaris and Linux prototypes
differ slightly. All dependent modules should now call the spl
helper macros spl_module_{init,exit}() instead of the native linux
versions.
Unfortunately, it appears that under Linux there has been no consistent
API in the kernel to set the cwd in a module. Because of this I have
had to add more autoconf magic than I'd like. However, what I have
done is correct and has been tested on RHEL5, SLES11, FC11, and CHAOS
kernels.
In addition, I have change the rootdir type from a 'void *' to the
correct 'vnode_t *' type. And I've set rootdir to a non-NULL value.
- Configure check for SLES specific API change to vfs_unlink()
and vfs_rename() which added a 'struct vfsmount *' argument.
This was for something called the linux-security-module, but
it appears that it was never adopted upstream.
Richard Yao
Brian Behlendorf
Ned Bass
Richard Yao
Chunwei Chen
Richard Yao
Yuxuan Shui
Etienne Dechamps
Gunnar Beutner
Li Wei
Ricardo Correia