running time for a full fsck. It also reduces the random access time
for large files and speeds the traversal time for directory tree walks.
The key idea is to reserve a small area in each cylinder group
immediately following the inode blocks for the use of metadata,
specifically indirect blocks and directory contents. The new policy
is to preferentially place metadata in the metadata area and
everything else in the blocks that follow the metadata area.
The size of this area can be set when creating a filesystem using
newfs(8) or changed in an existing filesystem using tunefs(8).
Both utilities use the `-k held-for-metadata-blocks' option to
specify the amount of space to be held for metadata blocks in each
cylinder group. By default, newfs(8) sets this area to half of
minfree (typically 4% of the data area).
This work was inspired by a paper presented at Usenix's FAST '13:
www.usenix.org/conference/fast13/ffsck-fast-file-system-checker
Details of this implementation appears in the April 2013 of ;login:
www.usenix.org/publications/login/april-2013-volume-38-number-2.
A copy of the April 2013 ;login: paper can also be downloaded
from: www.mckusick.com/publications/faster_fsck.pdf.
Reviewed by: kib
Tested by: Peter Holm
MFC after: 4 weeks
cluster_write() and cluster_wbuild() functions. The flags to be
allowed are a subset of the GB_* flags for getblk().
Sponsored by: The FreeBSD Foundation
Tested by: pho
(implemented by ffs_reallocblks_ufs[12]) relocates the file's blocks
so as to cluster them together into a contiguous set of blocks on
the disk.
When the cluster crosses the boundary into the first indirect block,
the first indirect block is initially allocated in a position
immediately following the last direct block. Block reallocation
would usually destroy locality by moving the indirect block out of
the way to keep the data blocks contiguous. This change compensates
for this problem by noting that the first indirect block should be
left immediately following the last direct block. It then tries
to start a new cluster of contiguous blocks (referenced by the
indirect block) immediately following the indirect block.
We should also do this for other indirect block boundaries, but it
is only important for the first one.
Suggested by: Bruce Evans
MFC: 2 weeks
messages for a filesystem being out of space need to be moved so that
they do not print out until after a failed cleanup attempt.
Suggested by: Jeff Roberson
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
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
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>
vnode buffers locked at once. In particular, there are indirect buffers
among locked ones. The bdwrite() may start the flushing to keep dirty
buffer list at the bounds. If any buffer on the dirty list requires
translation from logical to physical block number, code may ends up
trying to lock an indirect buffer already locked in ffs_balloc_ufsX.
Prevent the bdflush() activity when several buffers are locked at once
by setting the TDP_INBDFUSH for the problematic code blocks.
Reported and tested by: pho, Josef Buchsteiner at Juniper
In collaboration with: kan
MFC after: 1 month
allocation, free the indirect blocks before clearing the disk pointers,
that could lead to the softupdate inconsistencies in the case of the
machine or disk crash at the wrong time.
Rearrange the recover code to do the ffs_blkfree() after the second
ffs_syncvnode(), that clears the pointers chain.
Proposed and reviewed by: tegge
Tested by: Peter Holm
MFC after: 3 weeks
the inode, do the rollback in case the allocation failed (due to
insufficient free space or quota limits). But, the code does leaves the
buffers corresponding to the inoirect blocks on the vnode bufobj list.
This causes several assertion failures (for instance, "ffs_truncate3"
in ffs_truncate()) to fail, and could result in the indirect block
aliasing problem, like writing the context of such blocks to random
disk location.
Remove the buffers from the bufobj properly.
Reported and tested by: Peter Holm
Reviewed by: tegge
MFC after: 3 weeks
The "business class upgrade" was implemented in UFS's VOP_LOCK
implementation ufs_lock() which is the wrong layer, so move it to
ffs_lock().
Also, as long as we have not abandonned advanced vfs-stacking we
should not preclude it from happening: instead of implementing a
copy locally, use the VOP_LOCK_APV(&ufs) to correctly arrive at
vop_stdlock() at the bottom.
I'm not sure why a credential was added to these in the first place, it is
not used anywhere and it doesn't make much sense:
The credentials for syncing a file (ability to write to the
file) should be checked at the system call level.
Credentials for syncing one or more filesystems ("none")
should be checked at the system call level as well.
If the filesystem implementation needs a particular credential
to carry out the syncing it would logically have to the
cached mount credential, or a credential cached along with
any delayed write data.
Discussed with: rwatson
license, per letter dated July 22, 1999 and irc message from Robert
Watson saying that clause 3 can be removed from those files with an
NAI copyright that also have only a University of California
copyrights.
Approved by: core, rwatson
get the same value from ip->i_ump->um_devvp.
This saves a pointer in the memory copies of inodes, which can
easily run into several hundred kilobytes.
The extra indirection is unmeasurable in benchmarks.
Approved by: mckusick
- Define one flag GB_LOCK_NOWAIT that tells getblk() to pass the LK_NOWAIT
flag to the initial BUF_LOCK(). This will eventually be used in cases
were we want to use a buffer only if it is not currently in use.
- Convert all consumers of the getblk() api to use this extra parameter.
Reviwed by: arch
Not objected to by: mckusick
a full filesystem. Previously, if the allocation failed, we had to
fsync the file before rolling back any partial allocation of indirect
blocks. Most block allocation requests only need to allocate a single
data block and if that allocation fails, there is nothing to unroll.
So, before doing the fsync, we check to see if any rollback will
really be necessary. If none is necessary, then we simply return.
This update eliminates the flurry of disk activity that got triggered
whenever a filesystem would run out of space.
Sponsored by: DARPA & NAI Labs.
of a file in chunks that are less then the filesystem block size, if the
data is not already cached the system will perform a read-before-write.
The problem is that it does this on a block-by-block basis, breaking up the
I/Os and making clustering impossible for the writes. Programs such
as INN using cyclic file buffers suffer greatly. This problem is only going
to get worse as we use larger and larger filesystem block sizes.
The solution is to extend the sequential heuristic so UFS[2] can perform
a far larger read and readahead when dealing with this case.
(note: maximum disk write bandwidth is 27MB/sec thru filesystem)
(note: filesystem blocksize in test is 8K (1K frag))
dd if=/dev/zero of=test.dat bs=1k count=2m conv=notrunc
Before: (note half of these are reads)
tty da0 da1 acd0 cpu
tin tout KB/t tps MB/s KB/t tps MB/s KB/t tps MB/s us ni sy in id
0 76 14.21 598 8.30 0.00 0 0.00 0.00 0 0.00 0 0 7 1 92
0 76 14.09 813 11.19 0.00 0 0.00 0.00 0 0.00 0 0 9 5 86
0 76 14.28 821 11.45 0.00 0 0.00 0.00 0 0.00 0 0 8 1 91
After: (note half of these are reads)
tty da0 da1 acd0 cpu
tin tout KB/t tps MB/s KB/t tps MB/s KB/t tps MB/s us ni sy in id
0 76 63.62 434 26.99 0.00 0 0.00 0.00 0 0.00 0 0 18 1 80
0 76 63.58 424 26.30 0.00 0 0.00 0.00 0 0.00 0 0 17 2 82
0 76 63.82 438 27.32 0.00 0 0.00 0.00 0 0.00 1 0 19 2 79
Reviewed by: mckusick
Approved by: re
X-MFC after: immediately (was heavily tested in -stable for 4 months)
As this code is not actually used by any of the existing
interfaces, it seems unlikely to break anything (famous
last words).
The internal kernel interface to manipulate these attributes
is invoked using two new IO_ flags: IO_NORMAL and IO_EXT.
These flags may be specified in the ioflags word of VOP_READ,
VOP_WRITE, and VOP_TRUNCATE. Specifying IO_NORMAL means that
you want to do I/O to the normal data part of the file and
IO_EXT means that you want to do I/O to the extended attributes
part of the file. IO_NORMAL and IO_EXT are mutually exclusive
for VOP_READ and VOP_WRITE, but may be specified individually
or together in the case of VOP_TRUNCATE. For example, when
removing a file, VOP_TRUNCATE is called with both IO_NORMAL
and IO_EXT set. For backward compatibility, if neither IO_NORMAL
nor IO_EXT is set, then IO_NORMAL is assumed.
Note that the BA_ and IO_ flags have been `merged' so that they
may both be used in the same flags word. This merger is possible
by assigning the IO_ flags to the low sixteen bits and the BA_
flags the high sixteen bits. This works because the high sixteen
bits of the IO_ word is reserved for read-ahead and help with
write clustering so will never be used for flags. This merge
lets us get away from code of the form:
if (ioflags & IO_SYNC)
flags |= BA_SYNC;
For the future, I have considered adding a new field to the
vattr structure, va_extsize. This addition could then be
exported through the stat structure to allow applications to
find out the size of the extended attribute storage and also
would provide a more standard interface for truncating them
(via VOP_SETATTR rather than VOP_TRUNCATE).
I am also contemplating adding a pathconf parameter (for
concreteness, lets call it _PC_MAX_EXTSIZE) which would
let an application determine the maximum size of the extended
atribute storage.
Sponsored by: DARPA & NAI Labs.
filesystem expands the inode to 256 bytes to make space for 64-bit
block pointers. It also adds a file-creation time field, an ability
to use jumbo blocks per inode to allow extent like pointer density,
and space for extended attributes (up to twice the filesystem block
size worth of attributes, e.g., on a 16K filesystem, there is space
for 32K of attributes). UFS2 fully supports and runs existing UFS1
filesystems. New filesystems built using newfs can be built in either
UFS1 or UFS2 format using the -O option. In this commit UFS1 is
the default format, so if you want to build UFS2 format filesystems,
you must specify -O 2. This default will be changed to UFS2 when
UFS2 proves itself to be stable. In this commit the boot code for
reading UFS2 filesystems is not compiled (see /sys/boot/common/ufsread.c)
as there is insufficient space in the boot block. Once the size of the
boot block is increased, this code can be defined.
Things to note: the definition of SBSIZE has changed to SBLOCKSIZE.
The header file <ufs/ufs/dinode.h> must be included before
<ufs/ffs/fs.h> so as to get the definitions of ufs2_daddr_t and
ufs_lbn_t.
Still TODO:
Verify that the first level bootstraps work for all the architectures.
Convert the utility ffsinfo to understand UFS2 and test growfs.
Add support for the extended attribute storage. Update soft updates
to ensure integrity of extended attribute storage. Switch the
current extended attribute interfaces to use the extended attribute
storage. Add the extent like functionality (framework is there,
but is currently never used).
Sponsored by: DARPA & NAI Labs.
Reviewed by: Poul-Henning Kamp <phk@freebsd.org>
been unlinked (e.g., with a zero link count). We have to expunge
all trace of these files from the snapshot so that they are neither
reclaimed prematurely by fsck nor saved unnecessarily by dump.
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.
Sorry john! (your next MFC will be a doosie!)
Reviewed by: peter@freebsd.org, dillon@freebsd.org
X-MFC after: ha ha ha ha
the gating of system calls that cause modifications to the underlying
filesystem. The gating can be enabled by any filesystem that needs
to consistently suspend operations by adding the vop_stdgetwritemount
to their set of vnops. Once gating is enabled, the function
vfs_write_suspend stops all new write operations to a filesystem,
allows any filesystem modifying system calls already in progress
to complete, then sync's the filesystem to disk and returns. The
function vfs_write_resume allows the suspended write operations to
begin again. Gating is not added by default for all filesystems as
for SMP systems it adds two extra locks to such critical kernel
paths as the write system call. Thus, gating should only be added
as needed.
Details on the use and current status of snapshots in FFS can be
found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness
is not included here. Unless and until you create a snapshot file,
these changes should have no effect on your system (famous last words).
<sys/bio.h>.
<sys/bio.h> is now a prerequisite for <sys/buf.h> but it shall
not be made a nested include according to bdes teachings on the
subject of nested includes.
Diskdrivers and similar stuff below specfs::strategy() should no
longer need to include <sys/buf.> unless they need caching of data.
Still a few bogus uses of struct buf to track down.
Repocopy by: peter
filesystem fills up. If the first indirect block exists and FFS is able
to allocate deeper indirect blocks, but is not able to allocate the
data block, FFS improperly unwinds the indirect blocks and leaves a
block pointer hanging to a freed block. This will cause a panic later
when the file is removed. The solution is to properly account for the
first block-pointer-to-an-indirect-block we had to create in a balloc
operation and then unwind it if a failure occurs.
Detective work by: Ian Dowse <iedowse@maths.tcd.ie>
Reviewed by: mckusick, Ian Dowse <iedowse@maths.tcd.ie>
Approved by: jkh
The problem occurs when an indirect block and a data block are
being allocated at the same time. For example when the 13th block
of the file is written, the filesystem needs to allocate the first
indirect block and a data block. If the indirect block allocation
succeeds, but the data block allocation fails, the error code
dellocates the indirect block as it has nothing at which to point.
Unfortunately, it does not deallocate the indirect block's associated
dependencies which then fail when they find the block unexpectedly
gone (ptr == 0 instead of its expected value). The fix is to fsync
the file before doing the block rollback, as the fsync will flush
out all of the dependencies. Once the rollback is done the file
must be fsync'ed again so that the soft updates code does not find
unexpected changes. This approach is much slower than writing the
code to back out the extraneous dependencies, but running out of
disk space is not expected to be a common occurence, so just getting
it right is the main criterion.
PR: kern/15063
Submitted by: Assar Westerlund <assar@stacken.kth.se>
been set for a mount point. Insert missing checks to ensure that all
write operations are done asynchronously when the MNT_ASYNC option
has been requested.
Submitted by: Craig A Soules <soules+@andrew.cmu.edu>
Reviewed by: Kirk McKusick <mckusick@mckusick.com>
