Commit graph

165 commits

Author SHA1 Message Date
Mateusz Guzik
d90f2c3617 ufs: clean up empty lines in .c and .h files 2020-09-01 21:23:00 +00:00
Kirk McKusick
513274c79c Clear the IN_SIZEMOD and IN_IBLKDATA flags only when doing a
synchronous inode update.

The IN_SIZEMOD and IN_IBLKDATA flags indicate changes to the
file size and block pointer fields in the inode. When these
fields have been changed, the fsync() and fsyncdata() system
calls must write the inode to ensure their semantics that the
file is on stable store.

The IN_SIZEMOD and IN_IBLKDATA flags cannot be cleared until
a synchronous write of the inode is done. If they are cleared
on an asynchronous write, then the inode may not yet have been
written to the disk when an fsync() or fsyncdata() call is done.
Absent these flags, these calls would not know that they needed
to write the inode. Thus, these flags only can be cleared on
synchronous writes of the inode. Since the inode will be locked
for the duration of the I/O that writes it to disk, no fsync()
or fsyncdata() will be able to run before the on-disk inode
is complete.

Reviewed by: kib
MFC with: -r361785
Differential revision:  https://reviews.freebsd.org/D25072
2020-06-06 20:17:56 +00:00
Kirk McKusick
52488b5148 Further evaluation of the POSIX spec for fdatasync() shows that it
requires that new data on growing files be accessible. Thus, the
the fsyncdata() system call must update the on-disk inode when the
size of the file has changed.

This commit adds another inode update flag, IN_SIZEMOD, that gets
set any time that the file size changes. If either the IN_IBLKDATA
or the IN_SIZEMOD flag is set when fdatasync() is called, the
associated inode is synchronously written to disk. We could have
overloaded the IN_IBLKDATA flag to also track size changes since
the only (current) use case for these flags are for fsyncdata(),
but it does seem useful for possible future uses to separately
track the file size changes and the inode block pointer changes.

Reviewed by: kib
MFC with: -r361785
Differential revision:  https://reviews.freebsd.org/D25072
2020-06-05 01:00:55 +00:00
Konstantin Belousov
7428630b75 UFS: write inode block for fdatasync(2) if pointers in inode where allocated
The fdatasync() description in POSIX specifies that
    all I/O operations shall be completed as defined for synchronized I/O
    data integrity completion.
and then the explanation of Synchronized I/O Data Integrity Completion says
    The write is complete only when the data specified in the write
    request is successfully transferred and all file system
    information required to retrieve the data is successfully
    transferred.

For UFS this means that all pointers must be on disk. Indirect
pointers already contribute to the list of dirty data blocks, so only
direct blocks and root pointers to indirect blocks, both of which
reside in the inode block, should be taken care of. In ffs_balloc(),
mark the inode with the new flag IN_IBLKDATA that specifies that
ffs_syncvnode(DATA_ONLY) needs a call to ffs_update() to flush the
inode block.

Reviewed by:	mckusick
Discussed with:	tmunro
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D25072
2020-06-04 12:23:15 +00:00
Chuck Silvers
d79ff54b5c This commit enables a UFS filesystem to do a forcible unmount when
the underlying media fails or becomes inaccessible. For example
when a USB flash memory card hosting a UFS filesystem is unplugged.

The strategy for handling disk I/O errors when soft updates are
enabled is to stop writing to the disk of the affected file system
but continue to accept I/O requests and report that all future
writes by the file system to that disk actually succeed. Then
initiate an asynchronous forced unmount of the affected file system.

There are two cases for disk I/O errors:

   - ENXIO, which means that this disk is gone and the lower layers
     of the storage stack already guarantee that no future I/O to
     this disk will succeed.

   - EIO (or most other errors), which means that this particular
     I/O request has failed but subsequent I/O requests to this
     disk might still succeed.

For ENXIO, we can just clear the error and continue, because we
know that the file system cannot affect the on-disk state after we
see this error. For EIO or other errors, we arrange for the geom_vfs
layer to reject all future I/O requests with ENXIO just like is
done when the geom_vfs is orphaned. In both cases, the file system
code can just clear the error and proceed with the forcible unmount.

This new treatment of I/O errors is needed for writes of any buffer
that is involved in a dependency. Most dependencies are described
by a structure attached to the buffer's b_dep field. But some are
created and processed as a result of the completion of the dependencies
attached to the buffer.

Clearing of some dependencies require a read. For example if there
is a dependency that requires an inode to be written, the disk block
containing that inode must be read, the updated inode copied into
place in that buffer, and the buffer then written back to disk.

Often the needed buffer is already in memory and can be used. But
if it needs to be read from the disk, the read will fail, so we
fabricate a buffer full of zeroes and pretend that the read succeeded.
This zero'ed buffer can be updated and written back to disk.

The only case where a buffer full of zeros causes the code to do
the wrong thing is when reading an inode buffer containing an inode
that still has an inode dependency in memory that will reinitialize
the effective link count (i_effnlink) based on the actual link count
(i_nlink) that we read. To handle this case we now store the i_nlink
value that we wrote in the inode dependency so that it can be
restored into the zero'ed buffer thus keeping the tracking of the
inode link count consistent.

Because applications depend on knowing when an attempt to write
their data to stable storage has failed, the fsync(2) and msync(2)
system calls need to return errors if data fails to be written to
stable storage. So these operations return ENXIO for every call
made on files in a file system where we have otherwise been ignoring
I/O errors.

Coauthered by: mckusick
Reviewed by:   kib
Tested by:     Peter Holm
Approved by:   mckusick (mentor)
Sponsored by:  Netflix
Differential Revision:  https://reviews.freebsd.org/D24088
2020-05-25 23:47:31 +00:00
Kirk McKusick
621a274820 Fixing the soft update macros in -r359612 triggered a previously
hidden bug in the file truncation code. Until that bug is tracked
down and fixed, revert to the old behavior.

Reported by: Peter Holm
Reviewed by: kib, Chuck Silvers
2020-04-09 23:51:18 +00:00
Kirk McKusick
c79f5a4328 Revert -r359612 as it can cause other panics.
An updated version will be made when the issue has been resolved.

Reported by: Peter Holm
2020-04-06 20:23:47 +00:00
Kirk McKusick
2baca88584 When shrinking the size of a directory it is sometimes necessary to
sync it to disk before shrinking it. Complete the sync before getting
the buffer for the block to be updated to do the shrink to avoid
panicing with a recursive lock on one of the directory's buffers.

Reviewed by:  Chuck Silvers (chs)
MFC after:    3 days
Sponsored by: Netflix
2020-04-03 20:43:25 +00:00
Mateusz Guzik
ac4ec14188 ufs: add a setter for inode i_flag field
This will be used later to add vnodes to the lazy list.

Reviewed by:	kib (previous version), jeff
Tested by:	pho (in a larger patch)
Differential Revision:	https://reviews.freebsd.org/D22994
2020-01-13 02:31:51 +00:00
Mateusz Guzik
b249ce48ea vfs: drop the mostly unused flags argument from VOP_UNLOCK
Filesystems which want to use it in limited capacity can employ the
VOP_UNLOCK_FLAGS macro.

Reviewed by:	kib (previous version)
Differential Revision:	https://reviews.freebsd.org/D21427
2020-01-03 22:29:58 +00:00
Mateusz Guzik
abd80ddb94 vfs: introduce v_irflag and make v_type smaller
The current vnode layout is not smp-friendly by having frequently read data
avoidably sharing cachelines with very frequently modified fields. In
particular v_iflag inspected for VI_DOOMED can be found in the same line with
v_usecount. Instead make it available in the same cacheline as the v_op, v_data
and v_type which all get read all the time.

v_type is avoidably 4 bytes while the necessary data will easily fit in 1.
Shrinking it frees up 3 bytes, 2 of which get used here to introduce a new
flag field with a new value: VIRF_DOOMED.

Reviewed by:	kib, jeff
Differential Revision:	https://reviews.freebsd.org/D22715
2019-12-08 21:30:04 +00:00
Kirk McKusick
d00066a5f9 Currently the breadn_flags() and getblkx() interfaces are passed
the vnode, logical block number, and size of data block that is
being requested. They then use the VOP_BMAP function to calculate
the mapping from logical block number to physical block number from
which to access the data. This change expands the interface to also
pass the physical block number in cases where the VOP_MAP function
may no longer work, for example when a file is being truncated.

No functional change.

Reviewed by:  kib
Tested by:    Peter Holm
Sponsored by: Netflix
2019-12-03 23:07:09 +00:00
Kirk McKusick
90381b1ca9 When updating the user or group disk quotas for the return of inodes or
disk blocks, set the FORCE flag in the call to chkiq() or chkdq() since
the user is always allowed to return resources and hence there is no need
to check the user's credential .

Reported by:    Christopher Krah, Thomas Barabosch, and Jan-Niclas Hilgert of Fraunhofer FKIE
Reported as:    FS-1-UFS-1: Denial Of Service in mount (prison_priv_check)
Discussed with: kib
MFC:            1 week
Sponsored by:   Netflix
2019-07-31 22:44:58 +00:00
Alan Somers
65417f5e27 Remove "struct ucred*" argument from vtruncbuf
vtruncbuf takes a "struct ucred*" argument. AFAICT, it's been unused ever
since that function was first added in r34611. Remove it.  Also, remove some
"struct ucred" arguments from fuse and nfs functions that were only used by
vtruncbuf.

Reviewed by:	cem
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D20377
2019-05-24 20:27:50 +00:00
Kirk McKusick
3532718257 Give more complete information in INVARIANTS panic messages at end of
the ffs_truncate() function.

Sponsored by: Netflix
2019-03-11 23:53:56 +00:00
Kirk McKusick
8f829a5cf0 Continuing efforts to provide hardening of FFS. This change adds a
check hash to the filesystem inodes. Access attempts to files
associated with an inode with an invalid check hash will fail with
EINVAL (Invalid argument). Access is reestablished after an fsck
is run to find and validate the inodes with invalid check-hashes.
This check avoids a class of filesystem panics related to corrupted
inodes. The hash is done using crc32c.

Note this check-hash is for the inode itself and not any of its
indirect blocks. Check-hash validation may be extended to also
cover indirect block pointers, but that will be a separate (and
more costly) feature.

Check hashes are added only to UFS2 and not to UFS1 as UFS1 is
primarily used in embedded systems with small memories and low-powered
processors which need as light-weight a filesystem as possible.

Reviewed by:  kib
Tested by:    Peter Holm
Sponsored by: Netflix
2018-12-11 22:14:37 +00:00
Kirk McKusick
9fc5d538fc In preparation for adding inode check-hashes, clean up and
document the libufs interface for fetching and storing inodes.
The undocumented getino / putino interface has been replaced
with a new getinode / putinode interface.

Convert the utilities that had been using the undocumented
interface to use the new documented interface.

No functional change (as for now the libufs library does not
do inode check-hashes).

Reviewed by:  kib
Tested by:    Peter Holm
Sponsored by: Netflix
2018-11-13 21:40:56 +00:00
Mark Murray
19fa89e938 Remove the Yarrow PRNG algorithm option in accordance with due notice
given in random(4).

This includes updating of the relevant man pages, and no-longer-used
harvesting parameters.

Ensure that the pseudo-unit-test still does something useful, now also
with the "other" algorithm instead of Yarrow.

PR:		230870
Reviewed by:	cem
Approved by:	so(delphij,gtetlow)
Approved by:	re(marius)
Differential Revision:	https://reviews.freebsd.org/D16898
2018-08-26 12:51:46 +00:00
Kirk McKusick
7e038bc257 Replace the TRIM consolodation framework originally added in -r337396
driven by problems found with the algorithms being tested for TRIM
consolodation.

Reported by:  Peter Holm
Suggested by: kib
Reviewed by:  kib
Sponsored by: Netflix
2018-08-18 22:21:59 +00:00
Kirk McKusick
cc91864c26 Revert -r337396. It is being replaced with a revised interface that
resulted from testing and further reviews.
2018-08-18 21:21:06 +00:00
Kirk McKusick
68c49bcc40 Put in place the framework for consolodating contiguous blocks into
a smaller number of larger TRIM requests. The hope had been to have
the full TRIM consolodation in place for 12.0, but the algorithms
are still under development and need further testing. With this
framework in place it will be possible to easily add TRIM consolodation
once the optimal strategy has been found.

The only functional change with this patch is the elimination of TRIM
requests for blocks that are freed before they have been likely to
have been written.

Reviewed by: kib
Discussed with: Warner Losh and Chuck Silvers
Sponsored by: Netflix
2018-08-06 21:09:11 +00:00
Pedro F. Giffuni
51369649b0 sys: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:43:44 +00:00
Kirk McKusick
75e3597abb Continuing efforts to provide hardening of FFS, this change adds a
check hash to cylinder groups. If a check hash fails when a cylinder
group is read, no further allocations are attempted in that cylinder
group until it has been fixed by fsck. This avoids a class of
filesystem panics related to corrupted cylinder group maps. The
hash is done using crc32c.

Check hases are added only to UFS2 and not to UFS1 as UFS1 is primarily
used in embedded systems with small memories and low-powered processors
which need as light-weight a filesystem as possible.

Specifics of the changes:

sys/sys/buf.h:
    Add BX_FSPRIV to reserve a set of eight b_xflags that may be used
    by individual filesystems for their own purpose. Their specific
    definitions are found in the header files for each filesystem
    that uses them. Also add fields to struct buf as noted below.

sys/kern/vfs_bio.c:
    It is only necessary to compute a check hash for a cylinder
    group when it is actually read from disk. When calling bread,
    you do not know whether the buffer was found in the cache or
    read. So a new flag (GB_CKHASH) and a pointer to a function to
    perform the hash has been added to breadn_flags to say that the
    function should be called to calculate a hash if the data has
    been read. The check hash is placed in b_ckhash and the B_CKHASH
    flag is set to indicate that a read was done and a check hash
    calculated. Though a rather elaborate mechanism, it should
    also work for check hashing other metadata in the future. A
    kernel internal API change was to change breada into a static
    fucntion and add flags and a function pointer to a check-hash
    function.

sys/ufs/ffs/fs.h:
    Add flags for types of check hashes; stored in a new word in the
    superblock. Define corresponding BX_ flags for the different types
    of check hashes. Add a check hash word in the cylinder group.

sys/ufs/ffs/ffs_alloc.c:
    In ffs_getcg do the dance with breadn_flags to get a check hash and
    if one is provided, check it.

sys/ufs/ffs/ffs_vfsops.c:
    Copy across the BX_FFSTYPES flags in background writes.
    Update the check hash when writing out buffers that need them.

sys/ufs/ffs/ffs_snapshot.c:
    Recompute check hash when updating snapshot cylinder groups.

sys/libkern/crc32.c:
lib/libufs/Makefile:
lib/libufs/libufs.h:
lib/libufs/cgroup.c:
    Include libkern/crc32.c in libufs and use it to compute check
    hashes when updating cylinder groups.

Four utilities are affected:

sbin/newfs/mkfs.c:
    Add the check hashes when building the cylinder groups.

sbin/fsck_ffs/fsck.h:
sbin/fsck_ffs/fsutil.c:
    Verify and update check hashes when checking and writing cylinder groups.

sbin/fsck_ffs/pass5.c:
    Offer to add check hashes to existing filesystems.
    Precompute check hashes when rebuilding cylinder group
    (although this will be done when it is written in fsutil.c
    it is necessary to do it early before comparing with the old
    cylinder group)

sbin/dumpfs/dumpfs.c
    Print out the new check hash flag(s)

sbin/fsdb/Makefile:
    Needs to add libufs now used by pass5.c imported from fsck_ffs.

Reviewed by: kib
Tested by: Peter Holm (pho)
2017-09-22 12:45:15 +00:00
Warner Losh
fbbd9655e5 Renumber copyright clause 4
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by:	Jan Schaumann <jschauma@stevens.edu>
Pull Request:	https://github.com/freebsd/freebsd/pull/96
2017-02-28 23:42:47 +00:00
Ed Maste
1dc349ab95 prefix UFS symbols with UFS_ to reduce namespace pollution
Specifically:
  ROOTINO -> UFS_ROOTINO
  WINO -> UFS_WINO
  NXADDR -> UFS_NXADDR
  NDADDR -> UFS_NDADDR
  NIADDR -> UFS_NIADDR
  MAXSYMLINKLEN_UFS[12] -> UFS[12]_MAXSYMLINKLEN (for consistency)

Also prefix ext2's and nandfs's NDADDR and NIADDR with EXT2_ and NANDFS_

Reviewed by:	kib, mckusick
Obtained from:	NetBSD
MFC after:	1 month
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D9536
2017-02-15 19:50:26 +00:00
Konstantin Belousov
e1db68971e Reduce size of ufs inode.
Remove redunand i_dev and i_fs pointers, which are available as
ip->i_ump->um_dev and ip->i_ump->um_fs, and reorder members by size to
reduce padding.  To compensate added derefences, the most often i_ump
access to differentiate between UFS1 and UFS2 dinode layout is
removed, by addition of the new i_flag IN_UFS2.  Overall, this
actually reduces the amount of memory dereferences.

On 64bit machine, original struct inode size is 176, reduced to 152
bytes with the change.

Tested by:	pho (previous version)
Reviewed by:	mckusick
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2016-09-17 16:47:34 +00:00
Bruce Evans
0c01bcb9ff Sprinkle DOINGASYNC() checks so as to do delayed writes for async
mounts in almost all cases instead of in most cases.  Don't override
DOINGASYNC() by any condition except IO_SYNC.

Fix previous sprinking of DOINGASYNC() checks.  Don't override IO_SYNC
by DOINGASYNC().  In ffs_write() and ffs_extwrite(), there were
intentional overrides that just broke O_SYNC of data.  In
ffs_truncate(), there are 5 calls to ffs_update(), 4 with
apparently-unintentional overrides and 1 without; this had no effect
due to the main async mount hack descibed below.

Fix 1 place in ffs_truncate() where the caller's IO_ASYNC was overridden
for the soft updates case too (to do a delayed write instead of a sync
write).  This is supposed to be the only change that affects anything
except async mounts.

In ffs_update(), remove the 19 year old efficiency hack of ignoring
the waitfor flag for async mounts, so that fsync() almost works for
async mounts.  All callers are supposed to be fixed to not ask for a
sync update unless they are for fsync() or [I]O_SYNC operations.
fsync() now almost works for async mounts.  It used to sync the data
but not the most important metdata (the inode).  It still doesn't sync
associated directories.

This gave 10-20% fewer writes for my makeworld benchmark with async
mounted tmp and obj directories from an already small number.

Style fixes:
- in ffs_balloc.c, remove rotted quadruplicated comments about the
  simplest part of the DOING*() decisions and rearrange the nearly-
  quadruplicated code to be more nearly so.
- in ufs_vnops.c, use a consistent style with less negative logic and
  no manual "optimization" of || to | in DOING*() expressions.

Reviewed by:	kib (previous version)
2016-09-08 17:40:40 +00:00
Konstantin Belousov
f30ddc49e6 If IO_SYNC was passed to ffs_truncate(), request synchronous inode
update from the final ffs_update().

Noted by:	bde
MFC after:	1 week
2016-05-17 21:30:58 +00:00
Edward Tomasz Napierala
ae34b6ff96 Add four new RCTL resources - readbps, readiops, writebps and writeiops,
for limiting disk (actually filesystem) IO.

Note that in some cases these limits are not quite precise. It's ok,
as long as it's within some reasonable bounds.

Testing - and review of the code, in particular the VFS and VM parts - is
very welcome.

MFC after:	1 month
Relnotes:	yes
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D5080
2016-04-07 04:23:25 +00:00
Kirk McKusick
24b6748c42 The UFS filesystem requires that the last block of a file always be
allocated. When shortening the length of a file in which the new end
of the file contains a hole, the hole must have a block allocated.

Reported by: Maxim Sobolev
Reviewed by: kib
Tested by:   Peter Holm
2016-02-24 01:58:40 +00:00
Kirk McKusick
d2a28cb080 The bread() function was inconsistent about whether it would return
a buffer pointer in the event of an error (for some errors it would
return a buffer pointer and for other errors it would not return a
buffer pointer). The cluster_read() function was similarly inconsistent.

Clients of these functions were inconsistent in handling errors.
Some would assume that no buffer was returned after an error and
would thus lose buffers under certain error conditions. Others would
assume that brelse() should always be called after an error and
would thus panic the system under certain error conditions.

To correct both of these problems with minimal code churn, bread()
and cluster_write() now always free the buffer when returning an
error thus ensuring that buffers will never be lost. The brelse()
routine checks for being passed a NULL buffer pointer and silently
returns to avoid panics. Thus both approaches to handling error
returns from bread() and cluster_read() will work correctly.

Future code should be written assuming that bread() and cluster_read()
will never return a buffer with an error, so should not attempt to
brelse() the buffer when an error is returned.

Reviewed by: kib
2016-01-27 21:23:01 +00:00
Mark Murray
d1b06863fb Huge cleanup of random(4) code.
* GENERAL
- Update copyright.
- Make kernel options for RANDOM_YARROW and RANDOM_DUMMY. Set
  neither to ON, which means we want Fortuna
- If there is no 'device random' in the kernel, there will be NO
  random(4) device in the kernel, and the KERN_ARND sysctl will
  return nothing. With RANDOM_DUMMY there will be a random(4) that
  always blocks.
- Repair kern.arandom (KERN_ARND sysctl). The old version went
  through arc4random(9) and was a bit weird.
- Adjust arc4random stirring a bit - the existing code looks a little
  suspect.
- Fix the nasty pre- and post-read overloading by providing explictit
  functions to do these tasks.
- Redo read_random(9) so as to duplicate random(4)'s read internals.
  This makes it a first-class citizen rather than a hack.
- Move stuff out of locked regions when it does not need to be
  there.
- Trim RANDOM_DEBUG printfs. Some are excess to requirement, some
  behind boot verbose.
- Use SYSINIT to sequence the startup.
- Fix init/deinit sysctl stuff.
- Make relevant sysctls also tunables.
- Add different harvesting "styles" to allow for different requirements
  (direct, queue, fast).
- Add harvesting of FFS atime events. This needs to be checked for
  weighing down the FS code.
- Add harvesting of slab allocator events. This needs to be checked for
  weighing down the allocator code.
- Fix the random(9) manpage.
- Loadable modules are not present for now. These will be re-engineered
  when the dust settles.
- Use macros for locks.
- Fix comments.

* src/share/man/...
- Update the man pages.

* src/etc/...
- The startup/shutdown work is done in D2924.

* src/UPDATING
- Add UPDATING announcement.

* src/sys/dev/random/build.sh
- Add copyright.
- Add libz for unit tests.

* src/sys/dev/random/dummy.c
- Remove; no longer needed. Functionality incorporated into randomdev.*.

* live_entropy_sources.c live_entropy_sources.h
- Remove; content moved.
- move content to randomdev.[ch] and optimise.

* src/sys/dev/random/random_adaptors.c src/sys/dev/random/random_adaptors.h
- Remove; plugability is no longer used. Compile-time algorithm
  selection is the way to go.

* src/sys/dev/random/random_harvestq.c src/sys/dev/random/random_harvestq.h
- Add early (re)boot-time randomness caching.

* src/sys/dev/random/randomdev_soft.c src/sys/dev/random/randomdev_soft.h
- Remove; no longer needed.

* src/sys/dev/random/uint128.h
- Provide a fake uint128_t; if a real one ever arrived, we can use
  that instead. All that is needed here is N=0, N++, N==0, and some
  localised trickery is used to manufacture a 128-bit 0ULLL.

* src/sys/dev/random/unit_test.c src/sys/dev/random/unit_test.h
- Improve unit tests; previously the testing human needed clairvoyance;
  now the test will do a basic check of compressibility. Clairvoyant
  talent is still a good idea.
- This is still a long way off a proper unit test.

* src/sys/dev/random/fortuna.c src/sys/dev/random/fortuna.h
- Improve messy union to just uint128_t.
- Remove unneeded 'static struct fortuna_start_cache'.
- Tighten up up arithmetic.
- Provide a method to allow eternal junk to be introduced; harden
  it against blatant by compress/hashing.
- Assert that locks are held correctly.
- Fix the nasty pre- and post-read overloading by providing explictit
  functions to do these tasks.
- Turn into self-sufficient module (no longer requires randomdev_soft.[ch])

* src/sys/dev/random/yarrow.c src/sys/dev/random/yarrow.h
- Improve messy union to just uint128_t.
- Remove unneeded 'staic struct start_cache'.
- Tighten up up arithmetic.
- Provide a method to allow eternal junk to be introduced; harden
  it against blatant by compress/hashing.
- Assert that locks are held correctly.
- Fix the nasty pre- and post-read overloading by providing explictit
  functions to do these tasks.
- Turn into self-sufficient module (no longer requires randomdev_soft.[ch])
- Fix some magic numbers elsewhere used as FAST and SLOW.

Differential Revision: https://reviews.freebsd.org/D2025
Reviewed by: vsevolod,delphij,rwatson,trasz,jmg
Approved by: so (delphij)
2015-06-30 17:00:45 +00:00
Jeff Roberson
22a722605d - Convert the bufobj lock to rwlock.
- Use a shared bufobj lock in getblk() and inmem().
 - Convert softdep's lk to rwlock to match the bufobj lock.
 - Move INFREECNT to b_flags and protect it with the buf lock.
 - Remove unnecessary locking around bremfree() and BKGRDINPROG.

Sponsored by:	EMC / Isilon Storage Division
Discussed with:	mckusick, kib, mdf
2013-05-31 00:43:41 +00:00
Kirk McKusick
fe85d98a5b For UFS2 i_blocks is unsigned. The current "sanity" check that it
has gone below zero after the blocks in its inode are freed is a
no-op which the compiler fails to warn about because of the use of
the DIP macro. Change the sanity check to compare the number of
blocks being freed against the value i_blocks. If the number of
blocks being freed exceeds i_blocks, just set i_blocks to zero.

Reported by: Pedro Giffuni (pfg@)
MFC after:   2 weeks
2013-02-03 17:16:32 +00:00
Edward Tomasz Napierala
c52fd858ae Remove unused thread argument from vtruncbuf().
Reviewed by:	kib
2012-04-23 13:21:28 +00:00
Kirk McKusick
6c09f4a27c A refinement of change 232351 to avoid a race with a forcible unmount.
While we have a snapshot vnode unlocked to avoid a deadlock with another
inode in the same inode block being updated, the filesystem containing
it may be forcibly unmounted. When that happens the snapshot vnode is
revoked. We need to check for that condition and fail appropriately.

This change will be included along with 232351 when it is MFC'ed to 9.

Spotted by:  kib
Reviewed by: kib
2012-03-28 21:21:19 +00:00
Kirk McKusick
75a5838904 Add a third flags argument to ffs_syncvnode to avoid a possible conflict
with MNT_WAIT flags that passed in its second argument. This will be
MFC'ed together with r232351.

Discussed with: kib
2012-03-25 00:02:37 +00:00
Konstantin Belousov
92ccae0399 Remove superfluous brackets.
Submitted by:	alc
MFC after:	2 weeks
2012-03-11 21:25:42 +00:00
Konstantin Belousov
dd522d76dc Do schedule delayed writes for async mounts.
While there, make some style adjustments, like missed () around
return values.

Submitted by:	bde
Reviewed by:	mckusick
Tested by:	pho
MFC after:	2 weeks
2012-03-11 20:26:19 +00:00
Konstantin Belousov
2fd2c0b1e3 Do not fall back to slow synchronous i/o when low on memory or buffers.
The bawrite() schedules the write to happen immediately, and its use
frees the current thread to do more cleanups.

Submitted by:	bde
Reviewed by:	mckusick
Tested by:	pho
MFC after:	2 weeks
2012-03-11 20:23:46 +00:00
Kirk McKusick
35338e6091 This change avoids a kernel deadlock on "snaplk" when using
snapshots on UFS filesystems running with journaled soft updates.
This is the first of several bugs that need to be fixed before
removing the restriction added in -r230250 to prevent the use
of snapshots on filesystems running with journaled soft updates.

The deadlock occurs when holding the snapshot lock (snaplk)
and then trying to flush an inode via ffs_update(). We become
blocked by another process trying to flush a different inode
contained in the same inode block that we need. It holds the
inode block for which we are waiting locked. When it tries to
write the inode block, it gets blocked waiting for the our
snaplk when it calls ffs_copyonwrite() to see if the inode
block needs to be copied in our snapshot.

The most obvious place that this deadlock arises is in the
ffs_copyonwrite() routine when it updates critical metadata
in a snapshot and tries to write it out before proceeding.
The fix here is to write the data and indirect block pointer
for the snapshot, but to skip the call to ffs_update() to
write the snapshot inode. To ensure that we will never have
to update a pointer in the inode itself, the ffs_snapshot()
routine that creates the snapshot has to ensure that all the
direct blocks are allocated as part of the creation of the
snapshot.

A less obvious place that this deadlock occurs is when we hold
the snaplk because we are deleting a snapshot. In the course of
doing the deletion, we need to allocate various soft update
dependency structures and allocate some journal space. If we
hit a resource limit while doing this we decrease the resources
in use by flushing out an existing dirty file to get it to give
up the soft dependency resources that it holds. The flush can
cause an ffs_update() to be done on the inode for the file that
we have selected to flush resulting in the same deadlock as
described above when the inode that we have chosen to flush
resides in the same inode block as the snapshot inode that we hold.
The fix is to defer cleaning up any time that the inode on which
we are operating is a snapshot.

Help and review by:    Jeff Roberson
Tested by:             Peter Holm
MFC (to 9 only) after: 2 weeks
2012-03-01 18:45:25 +00:00
Martin Matuska
82378711f9 Generalize ffs_pages_remove() into vn_pages_remove().
Remove mapped pages for all dataset vnodes in zfs_rezget() using
new vn_pages_remove() to fix mmapped files changed by
zfs rollback or zfs receive -F.

PR:		kern/160035, kern/156933
Reviewed by:	kib, pjd
Approved by:	re (kib)
MFC after:	1 week
2011-08-25 08:17:39 +00:00
Kirk McKusick
927a12ae16 Add an FFS specific mount option to allow a filesystem checker
(typically fsck_ffs) to register that it wishes to use FFS specific
sysctl's to update the filesystem. This ensures that two checkers
cannot run on a given filesystem at the same time and that no other
process accidentally or maliciously uses the filesystem updating
sysctls inappropriately. This functionality is needed by the
journaling soft-updates recovery code.
2011-07-15 16:20:33 +00:00
Alan Cox
6bbee8e28a Add a new option, OBJPR_NOTMAPPED, to vm_object_page_remove(). Passing this
option to vm_object_page_remove() asserts that the specified range of pages
is not mapped, or more precisely that none of these pages have any managed
mappings.  Thus, vm_object_page_remove() need not call pmap_remove_all() on
the pages.

This change not only saves time by eliminating pointless calls to
pmap_remove_all(), but it also eliminates an inconsistency in the use of
pmap_remove_all() versus related functions, like pmap_remove_write().  It
eliminates harmless but pointless calls to pmap_remove_all() that were being
performed on PG_UNMANAGED pages.

Update all of the existing assertions on pmap_remove_all() to reflect this
change.

Reviewed by:	kib
2011-06-29 16:40:41 +00:00
Kirk McKusick
43a3cc7796 Ensure that filesystem metadata contained within persistent snapshots
is always kept consistent.

Suggested by:	Jeff Roberson
2011-06-15 23:19:09 +00:00
Jeff Roberson
280e091a99 Implement fully asynchronous partial truncation with softupdates journaling
to resolve errors which can cause corruption on recovery with the old
synchronous mechanism.

 - Append partial truncation freework structures to indirdeps while
   truncation is proceeding.  These prevent new block pointers from
   becoming valid until truncation completes and serialize truncations.
 - On completion of a partial truncate journal work waits for zeroed
   pointers to hit indirects.
 - softdep_journal_freeblocks() handles last frag allocation and last
   block zeroing.
 - vtruncbuf/ffs_page_remove moved into softdep_*_freeblocks() so it
   is only implemented in one place.
 - Block allocation failure handling moved up one level so it does not
   proceed with buf locks held.  This permits us to do more extensive
   reclaims when filesystem space is exhausted.
 - softdep_sync_metadata() is broken into two parts, the first executes
   once at the start of ffs_syncvnode() and flushes truncations and
   inode dependencies.  The second is called on each locked buf.  This
   eliminates excessive looping and rollbacks.
 - Improve the mechanism in process_worklist_item() that handles
   acquiring vnode locks for handle_workitem_remove() so that it works
   more generally and does not loop excessively over the same worklist
   items on each call.
 - Don't corrupt directories by zeroing the tail in fsck.  This is only
   done for regular files.
 - Push a fsync complete record for files that need it so the checker
   knows a truncation in the journal is no longer valid.

Discussed with:	mckusick, kib (ffs_pages_remove and ffs_truncate parts)
Tested by:	pho
2011-06-10 22:48:35 +00:00
Konstantin Belousov
fae5c47dd4 Add function lbn_offset to calculate offset of the indirect block of
given level.

Reviewed by:	jeff
Tested by:	pho
2010-11-11 11:35:42 +00:00
Jeff Roberson
9f9c8c59ae - Handle the truncation of an inode with an effective link count of 0 in
the context of the process that reduced the effective count.  Previously
   all truncation as a result of unlink happened in the softdep flush
   thread.  This had the effect of being impossible to rate limit properly
   with the journal code.  Now the process issuing unlinks is suspended
   when the journal files.  This has a side-effect of improving rm
   performance by allowing more concurrent work.
 - Handle two cases in inactive, one for effnlink == 0 and another when
   nlink finally reaches 0.
 - Eliminate the SPACECOUNTED related code since the truncation is no
   longer delayed.

Discussed with:	mckusick
2010-07-06 07:11:04 +00:00
Jeff Roberson
113db2dddb - Merge soft-updates journaling from projects/suj/head into head. This
brings in support for an optional intent log which eliminates the need
   for background fsck on unclean shutdown.

Sponsored by:   iXsystems, Yahoo!, and Juniper.
With help from: McKusick and Peter Holm
2010-04-24 07:05:35 +00:00
Robert Watson
ec7e66e84c Following a fair amount of real world experience with ACLs and
extended attributes since FreeBSD 5, make the following semantic
changes:

- Don't update the inode modification time (mtime) when extended
  attributes (and hence also ACLs) are added, modified, or removed.
- Don't update the inode access tie (atime) when extended attributes
  (and hence also ACLs) are queried.

This means that rsync (and related tools) won't improperly think
that the data in the file has changed when only the ACL has changed.

Note that ffs_reallocblks() has not been changed to not update on an
IO_EXT transaction, but currently EAs don't use the cluster write
routines so this shouldn't be a problem.  If EAs grow support for
clustering, then VOP_REALLOCBLKS() will need to grow a flag argument
to carry down IO_EXT to UFS.

MFC after:	1 week
PR:             ports/125739
Reported by:    Alexander Zagrebin <alexz@visp.ru>
Tested by:      pluknet <pluknet@gmail.com>,
                Greg Byshenk <freebsd@byshenk.net>
Discussed with: kib, kientzle, timur, Alexander Bokovoy <ab@samba.org>
2009-01-27 21:48:47 +00:00