The ticket allocator is just a simple slab implementation internal to the
log. It requires the icloglock to be held when manipulating it and this
contributes to contention on that lock.
Just kill the entire allocator and use a memory zone instead. While there,
allow us to gracefully fail allocation with ENOMEM.
SGI-PV: 978729
SGI-Modid: xfs-linux-melb:xfs-kern:30771a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Rather than use the icloglock for protecting the iclog completion callback
chain, use a new per-iclog lock so that walking the callback chain doesn't
require holding a global lock.
This reduces contention on the icloglock during transaction commit and log
I/O completion by reducing the number of times we need to hold the global
icloglock during these operations.
SGI-PV: 978729
SGI-Modid: xfs-linux-melb:xfs-kern:30770a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
While investigating the extent corruption bug I ran into this bug in debug
only code. xfs_bmap_check_leaf_extents() loops through the leaf blocks of
the extent btree checking that every extent is entirely before the next
extent. It also compares the last extent in the previous block to the
first extent in the current block when the previous block has been
released and potentially unmapped. So take a copy of the last extent
instead of a pointer. Also move the last extent check out of the loop
because we only need to do it once.
SGI-PV: 976035
SGI-Modid: xfs-linux-melb:xfs-kern:30718a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Most VN_RELE calls either directly contain a XFS_ITOV or have the
corresponding xfs_inode already in scope. Use the IRELE helper instead of
VN_RELE to clarify the code. With a little more work we can kill VN_RELE
altogether and define IRELE in terms of iput directly.
SGI-PV: 976035
SGI-Modid: xfs-linux-melb:xfs-kern:30710a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
The three subcases of xfs_ioc_xattr don't share any semantics and almost
no code, so split it into three separate helpers.
SGI-PV: 976035
SGI-Modid: xfs-linux-melb:xfs-kern:30709a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
- rename rootvp to root for clarify
- remove useless vn_to_inode call
- check is_bad_inode before calling d_alloc_root
- use iput instead of VN_RELE in the error case
SGI-PV: 976035
SGI-Modid: xfs-linux-melb:xfs-kern:30708a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
When writing into preallocated regions there is a case where XFS can oops
or hang doing the unwritten extent conversion on I/O completion. It turns
out that the problem is related to the btree cursor being invalid.
When we do an insert into the tree, we may need to split blocks in the
tree. When we only split at the leaf level (i.e. level 0), everything
works just fine. However, if we have a multi-level split in the btreee,
the cursor passed to the insert function is no longer valid once the
insert is complete.
The leaf level split is handled correctly because all the operations at
level 0 are done using the original cursor, hence it is updated correctly.
However, when we need to update the next level up the tree, we don't use
that cursor - we use a cloned cursor that points to the index in the next
level up where we need to do the insert.
Hence if we need to split a second level, the changes to the tree are
reflected in the cloned cursor and not the original cursor. This
clone-and-move-up-a-level-on-split behaviour recurses all the way to the
top of the tree.
The complexity here is that these cloned cursors do not point to the
original index that was inserted - they point to the newly allocated block
(the right block) and the original cursor pointer to that level may still
point to the left block. Hence, without deep examination of the cloned
cursor and buffers, we cannot update the original cursor with the new path
from the cloned cursor.
In these cases the original cursor could be pointing to the wrong block(s)
and hence a subsequent modification to the tree using that cursor will
lead to corruption of the tree.
The crash case occurs when the tree changes height - we insert a new level
in the tree, and the cursor does not have a buffer in it's path for that
level. Hence any attempt to walk back up the cursor to the root block will
result in a null pointer dereference.
To make matters even more complex, the BMAP BT is rooted in an inode, so
we can have a change of height in the btree *without a root split*. That
is, if the root block in the inode is full when we split a leaf node, we
cannot fit the pointer to the new block in the root, so we allocate a new
block, migrate all the ptrs out of the inode into the new block and point
the inode root block at the newly allocated block. This changes the height
of the tree without a root split having occurred and hence invalidates the
path in the original cursor.
The patch below prevents xfs_bmbt_insert() from returning with an invalid
cursor by detecting the cases that invalidate the original cursor and
refresh it by do a lookup into the btree for the original index we were
inserting at.
Note that the INOBT, AGFBNO and AGFCNT btree implementations also have
this bug, but the cursor is currently always destroyed or revalidated
after an insert for those trees. Hence this patch only address the problem
in the BMBT code.
SGI-PV: 979339
SGI-Modid: xfs-linux-melb:xfs-kern:30701a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
At ENOSPC, we can get a filesystem shutdown due to a cancelling a dirty
transaction in xfs_mkdir or xfs_create. This is due to the initial
allocation attempt not taking into account inode alignment and hence we
can prepare the AGF freelist for allocation when it's not actually
possible to do an allocation. This results in inode allocation returning
ENOSPC with a dirty transaction, and hence we shut down the filesystem.
Because the first allocation is an exact allocation attempt, we must tell
the allocator that the alignment does not affect the allocation attempt.
i.e. we will accept any extent alignment as long as the extent starts at
the block we want. Unfortunately, this means that if the longest free
extent is less than the length + alignment necessary for fallback
allocation attempts but is long enough to attempt a non-aligned
allocation, we will modify the free list.
If we then have the exact allocation fail, all other allocation attempts
will also fail due to the alignment constraint being taken into account.
Hence the initial attempt needs to set the "alignment slop" field so that
alignment, while not required, must be taken into account when determining
if there is enough space left in the AG to do the allocation.
That means if the exact allocation fails, we will not dirty the freelist
if there is not enough space available fo a subsequent allocation to
succeed. Hence we get an ENOSPC error back to userspace without shutting
down the filesystem.
SGI-PV: 978886
SGI-Modid: xfs-linux-melb:xfs-kern:30699a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Replace the xfs_ail_entry_t with a struct list_head and clean the
surrounding code up. Also fixes a livelock in xfs_trans_first_push_ail()
by terminating the loop at the head of the list correctly.
SGI-PV: 978682
SGI-Modid: xfs-linux-melb:xfs-kern:30636a
Signed-off-by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
When xfs_mountfs is called by xfs_mount xfs_readsb was called 35 lines
above unconditionally, so there is no need to try to read the superblock
if it's not present. If any other port doesn't have the superblock read at
this point it should just call it directly from it's xfs_mount equivalent.
SGI-PV: 976035
SGI-Modid: xfs-linux-melb:xfs-kern:30603a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Donald Douwsma <donaldd@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
It's completely unused so we might aswell kill it. Note that there is
another t_sema in struct xlog_ticket, which is used and actually an sv_t
despite the name. That one is left untouched by this patch.
SGI-PV: 971186
SGI-Modid: xfs-linux-melb:xfs-kern:30591a
Signed-off-by: Niv Sardi <xaiki@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Now that the ktrace_enter() code is using atomics, the non-power-of-2
buffer sizes - which require modulus operations to get the index - are
showing up as using substantial CPU in the profiles.
Force the buffer sizes to be rounded up to the nearest power of two and
use masking rather than modulus operations to convert the index counter to
the buffer index. This reduces ktrace_enter overhead to 8% of a CPU time,
and again almost halves the trace intensive test runtime.
SGI-PV: 977546
SGI-Modid: xfs-linux-melb:xfs-kern:30538a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
ktrace_enter() is consuming vast amounts of CPU time due to the use of a
single global lock for protecting buffer index increments. Change it to
use per-buffer atomic counters - this reduces ktrace_enter() overhead
during a trace intensive test on a 4p machine from 58% of all CPU time to
12% and halves test runtime.
SGI-PV: 977546
SGI-Modid: xfs-linux-melb:xfs-kern:30537a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
XFS changes the c/mtime of an inode when truncating it to the same size.
The c/mtime is only supposed to change if the size is changed. Not to be
confused with ftruncate, where the c/mtime is supposed to be changed even
if the size is not changed.
The Linux VFS encodes this semantic difference in the flags it sends down
to ->setattr, which XFS currently ignores. We need to make XFS pay
attention to the VFS flags and hence Do The Right Thing.
SGI-PV: 977547
SGI-Modid: xfs-linux-melb:xfs-kern:30536a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
As Dave pointed out after the export ops changes we now always encode the
parent into the filehandle for regular files, but it's not actually needed
when the filesystem is export with no_subtree_check. This one-liner fixes
xfs_fs_encode_fh to skip encoding the parent unless nessecary.
SGI-PV: 976035
SGI-Modid: xfs-linux-melb:xfs-kern:30535a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
We can just use xfs_ilock/xfs_iunlock instead and get rid of the ugly
bhv_vrwlock_t.
SGI-PV: 976035
SGI-Modid: xfs-linux-melb:xfs-kern:30533a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Instead of of xfs_get_dir_entry use a macro to get the xfs_inode from the
dentry in the callers and grab the reference manually.
Only grab the reference once as it's fine to keep it over the dmapi calls.
(And even that reference is actually superflous in Linux but I'll leave
that for another patch)
SGI-PV: 976035
SGI-Modid: xfs-linux-melb:xfs-kern:30531a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Cleanup the unneeded intermediate vnode step in the flushing helpers and
go directly from the xfs_inode to the struct address_space.
SGI-PV: 976035
SGI-Modid: xfs-linux-melb:xfs-kern:30530a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
- use proper goto based unwinding instead of the current mess of
multiple conditionals
- rename ip to inode because that's the normal convention for Linux
inodes while ip is the convention for xfs_inodes
- remove unlikely checks for the default_acl - branches marked unlikely
might lead to extreme branch bredictor slowdons if taken and for some
workloads a default acl is quite common
- properly indent the switch statements
- remove xfs_has_fs_struct as nfsd has a fs_struct in any semi-recent
kernel
SGI-PV: 976035
SGI-Modid: xfs-linux-melb:xfs-kern:30529a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Now that we update the log tail LSN less frequently on transaction
completion, we pass the contention straight to the global log state lock
(l_iclog_lock) during transaction completion.
We currently have to take this lock to decrement the iclog reference
count. there is a reference count on each iclog, so we need to take ţhe
global lock for all refcount changes.
When large numbers of processes are all doing small trnasctions, the iclog
reference counts will be quite high, and the state change that absolutely
requires the l_iclog_lock is the except rather than the norm.
Change the reference counting on the iclogs to use atomic_inc/dec so that
we can use atomic_dec_and_lock during transaction completion and avoid the
need for grabbing the l_iclog_lock for every reference count decrement
except the one that matters - the last.
SGI-PV: 975671
SGI-Modid: xfs-linux-melb:xfs-kern:30505a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
When hundreds of processors attempt to commit transactions at the same
time, they can contend on the AIL lock when updating the tail LSN held in
the in-core log structure.
At the moment, the tail LSN is only needed when actually writing out an
iclog, so it really does not need to be updated on every single
transaction completion - only those that result in switching iclogs and
flushing them to disk.
The result is that we reduce the number of times we need to grab the AIL
lock and the log grant lock by up to two orders of magnitude on large
processor count machines. The problem has previously been hidden by AIL
lock contention walking the AIL list which was recently solved and
uncovered this issue.
SGI-PV: 975671
SGI-Modid: xfs-linux-melb:xfs-kern:30504a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Remove open coded checks for the whether the inode is clean and replace
them with an inlined function.
SGI-PV: 977461
SGI-Modid: xfs-linux-melb:xfs-kern:30503a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Remove the xfs_icluster structure and replace with a radix tree lookup.
We don't need to keep a list of inodes in each cluster around anymore as
we can look them up quickly when we need to. The only time we need to do
this now is during inode writeback.
Factor the inode cluster writeback code out of xfs_iflush and convert it
to use radix_tree_gang_lookup() instead of walking a list of inodes built
when we first read in the inodes.
This remove 3 pointers from each xfs_inode structure and the xfs_icluster
structure per inode cluster. Hence we reduce the cache footprint of the
xfs_inodes by between 5-10% depending on cluster sparseness.
To be truly efficient we need a radix_tree_gang_lookup_range() call to
stop searching once we are past the end of the cluster instead of trying
to find a full cluster's worth of inodes.
Before (ia64):
$ cat /sys/slab/xfs_inode/object_size 536
After:
$ cat /sys/slab/xfs_inode/object_size 512
SGI-PV: 977460
SGI-Modid: xfs-linux-melb:xfs-kern:30502a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
When pdflush is writing back inodes, it can get stuck on inode cluster
buffers that are currently under I/O. This occurs when we write data to
multiple inodes in the same inode cluster at the same time.
Effectively, delayed allocation marks the inode dirty during the data
writeback. Hence if the inode cluster was flushed during the writeback of
the first inode, the writeback of the second inode will block waiting for
the inode cluster write to complete before writing it again for the newly
dirtied inode.
Basically, we want to avoid this from happening so we don't block pdflush
and slow down all of writeback. Hence we introduce a non-blocking async
inode flush flag that pdflush uses. If this flag is set, we use
non-blocking operations (e.g. try locks) whereever we can to avoid
blocking or extra I/O being issued.
SGI-PV: 970925
SGI-Modid: xfs-linux-melb:xfs-kern:30501a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
The only difference between the functions is one passes an inode for the
lookup, the other passes an inode number. However, they don't do the same
validity checking or set all the same state on the buffer that is returned
yet they should.
Factor the functions into a common implementation.
SGI-PV: 970925
SGI-Modid: xfs-linux-melb:xfs-kern:30500a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Remove the xfs_refcache, it was only needed while we were still
building for 2.4 kernels.
SGI-PV: 971186
SGI-Modid: xfs-linux-melb:xfs-kern:30472a
Signed-off-by: Donald Douwsma <donaldd@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
On a forced shutdown, xfs_finish_reclaim() will skip flushing the inode.
If the inode flush lock is not already held and there is an outstanding
xfs_iflush_done() then we might free the inode prematurely. By acquiring
and releasing the flush lock we will synchronise with xfs_iflush_done().
SGI-PV: 909874
SGI-Modid: xfs-linux-melb:xfs-kern:30468a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <dgc@sgi.com>
* Use ide_default_irq() instead of ide_init_default_irq() in
ide_generic host driver (so the correct IRQ is always set
regardless of CONFIG_PCI / CONFIG_BLK_DEV_IDEPCI).
* Remove no longer needed ide_init_default_irq() macro.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* Make CONFIG_IDE_GENERIC depended on CONFIG_IDE_ARCH_OBSOLETE_DEFAULTS.
* Move default IDE ports setup from init_ide_data() to ide_generic.
* Use ide_init_port_hw() in ide_generic.
* Remove no longer needed CONFIG_IDE_ARCH_OBSOLETE_DEFAULTS.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
ide_init_default_irq() is always zero for CONFIG_PCI=y so hwif->irq
check in ide_hwif_configure() can be safely removed.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Do explicit port setup in legacy VLB host drivers instead of depending
on init_ide_data(). This way hwif->io_ports[] and hwif->irq are always
correctly set regardless of CONFIG_PCI / CONFIG_BLK_DEV_IDEPCI.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
These host drivers indirectly depend on CONFIG_IDE_ARCH_OBSOLETE_DEFAULTS=y
which is defined only on alpha, x86, ia64, m32r, mips and ppc32.
Moreover:
- on ia64 there is no ISA
- m32r is too new for VLB
- on ppc32 ISA is available only on PPC_CHRP (no default IDE ports)
and PPC_PREP (marked as BROKEN)
[ the common sense tells me that VLB was only used on x86 but there
are urban legends that one of these host drivers was needed on some
other arch - thus the extra care ]
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Do explicit port setup instead of depending on init_ide_data().
This way hwif->io_ports[] and hwif->irq are always correctly set
regardless of CONFIG_PCI / CONFIG_BLK_DEV_IDEPCI.
While at it fix printk().
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
CONFIG_BLK_DEV_4DRIVES deserves its own host driver:
* Add drivers/ide/legacy/ide-4drives.c and move "4drives" support there.
* Add ide-4drives.o in the link order after all other legacy host
drivers enabled by "ide0=" options (they all are mutually exclusive).
* Make ide-4drives host driver probe itself for IDE devices instead of
indirectly depending on ide_generic host driver.
* Add "probe" module parameter to ide-4drives and update documentation.
v2:
* s/paramater/parameter/ in ide.txt. (Noticed by Randy Dunlap)
v3:
* s/ide_4drives.probe/ide-4drives.probe/ in help entry.
(Noticed by Sergei Shtylyov)
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
On PPC32 ide_init_default_irq() is non-zero only for PPLUS and PPC_PREP
(the latter marked as BROKEN currently) so this ifdef can be removed.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
It is always == '((base) + 0x206)' if CONFIG_IDE_ARCH_OBSOLETE_DEFAULTS=y
and it is not needed otherwise (arm, blackfin, parisc, ppc64, sh, sparc[64]).
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* Use CONFIG_IDE_ARCH_OBSOLETE_DEFAULTS instead of
CONFIG_IDE_ARCH_OBSOLETE_INIT in init_ide_data().
* Remove no longer needed CONFIG_IDE_ARCH_OBSOLETE_INIT.
There should be no functional changes caused by this patch.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* Add CONFIG_IDE_ARCH_OBSOLETE_DEFAULTS to drivers/ide/Kconfig and use
it instead of defining IDE_ARCH_OBSOLETE_DEFAULTS in <arch/ide.h>.
v2:
* Define ide_default_irq() in ide-probe.c/ns87415.c if not already defined
and drop defining ide_default_irq() for CONFIG_IDE_ARCH_OBSOLETE_DEFAULTS=n.
[ Thanks to Stephen Rothwell and David Miller for noticing the problem. ]
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
David Chinner