* * * READ ME * * *
* * * Veritas File System 5.1 SP1 RP2 * * *
* * * P-patch 1 * * *
Patch Date: 2012-02-08
This document provides the following information:
* PATCH NAME
* OPERATING SYSTEMS SUPPORTED BY THE PATCH
* PACKAGES AFFECTED BY THE PATCH
* BASE PRODUCT VERSIONS FOR THE PATCH
* SUMMARY OF INCIDENTS FIXED BY THE PATCH
* DETAILS OF INCIDENTS FIXED BY THE PATCH
* INSTALLATION PRE-REQUISITES
* INSTALLING THE PATCH
* REMOVING THE PATCH
PATCH NAME
----------
Veritas File System 5.1 SP1 RP2 P-patch 1
OPERATING SYSTEMS SUPPORTED BY THE PATCH
----------------------------------------
AIX 5.3
AIX 6.1
AIX 7.1
PACKAGES AFFECTED BY THE PATCH
------------------------------
VRTSvxfs
BASE PRODUCT VERSIONS FOR THE PATCH
-----------------------------------
* Veritas Storage Foundation for Oracle RAC 5.1 SP1
* Veritas Storage Foundation Cluster File System 5.1 SP1
* Veritas Storage Foundation 5.1 SP1
* Veritas Storage Foundation High Availability 5.1 SP1
SUMMARY OF INCIDENTS FIXED BY THE PATCH
---------------------------------------
Patch ID: 5.1.112.100
Patch ID: 5.1.112.0
DETAILS OF INCIDENTS FIXED BY THE PATCH
---------------------------------------
This patch fixes the following Symantec incidents:
Patch ID: 5.1.112.100
* 2413811 (Tracking ID: 1590963)
SYMPTOM:
Maximum Number of subdirectories is limited to 32767
DESCRIPTION:
Currently, there limit on maximum numbers of subdirectories. This
limit is fixed to 32767. This value can be increased to 64K on Linux, HP and
Solaris platforms. Also there is a need to provide Flexibility to change the
value
of maximum numbers of subdirectories.
RESOLUTION:
Code is modified to add vx_maxlink tunable to control maximum number
of sub directories
* 2508171 (Tracking ID: 2246127)
SYMPTOM:
Mount command may take more time in case of large IAU file.
DESCRIPTION:
At time of mount, IAU file is read one block at time. The read block is processed
and then next block is read. In case there are huge number of files in filesystem,
IAU file for the filesystem becomes large. Reading of such large IAU file, one
block at time is taking time to complete mount command.
RESOLUTION:
Code is changed to read IAU file using multiple threads in parallel, also now
complete extent is read and then it is processed.
* 2521672 (Tracking ID: 2515380)
SYMPTOM:
The ff command hangs and later it exits after program exceeds memory
limit with following error.
# ff -F vxfs /dev/vx/dsk/bernddg/testvol
UX:vxfs ff: ERROR: V-3-24347: program limit of 30701385 exceeded for directory
data block list
UX:vxfs ff: ERROR: V-3-20177: /dev/vx/dsk/bernddg/testvol
DESCRIPTION:
'ff' command lists all files on device of vxfs file system. In 'ff' command we
do directory lookup. In a function we save the block addresses for a directory.
For that we traverse all the directory blocks.
Then we have function which keeps track of buffer in which we read directory
blocks and the extent up to which we have read directory blocks. This function
is called with offset and it return the offset up to which we have read the
directory blocks. The offset passed to this function has to be the offset within
the extent. But, we were wrongly passing logical offset which can be greater
than extent size. As a effect the offset returned gets wrapped to 0. The caller
thinks that we have not read anything and hence the loop.
RESOLUTION:
Remove call to function which maintains buffer offsets for reading data. That
call was incorrect and redundant. We actually call that function correctly from
one of the functions above.
* 2551576 (Tracking ID: 2526174)
SYMPTOM:
The vxfs_fcl_seektime function seeks to the first record in the FCL file that
has a timestamp greater than or equal to the specified time. FCL
vxfs_fcl_seektime()API can incorrectly return EINVAL(no records in FCL file
newer than specified time) error even though records after specified time are
present in FCL log.
DESCRIPTION:
Error EINVAL was returned when partial records exist in FCL log, because search
for FCL record was not continued till correct last offset. 'last offset' is
where search should stop. last offset is determined in binary search when record
newer than specified time is found. While doing binary search FCL partial
records are skipped. When record newer than specified time is found - length for
which partial records were found was not considered in last offset calculation.
Therefore last offset calculation was incorrect and hence FCL record search was
terminated earlier i.e. before record at specified time is found.
RESOLUTION:
if partial records are found during binary search, length of partial records is
now added to the last offset to get the correct last offset.
* 2561355 (Tracking ID: 2561334)
SYMPTOM:
System log file may contain following error message on multi-threaded
environment
with Dynamic Storage Tiers(DST).
UX:vxfs fsppadm: ERROR: V-3-26626: File Change Log IOTEMP and ACCESSTEMP index
creation failure for /vx/fsvm with message Argument list too long
DESCRIPTION:
In DST, while enforcing policy, SQL queries are generated and written to file
.__fsppadm_enforcesql present in lost+found. In multi threaded environment, 16
threads works in parallel on ILIST and geenrate SQL queries and write it to
file. This may lead to corruption of file, if multiple threads write to file
simultaneously.
RESOLUTION:
using flockfile() instead of adding new code to take lock on
.__fsppadm_enforcesq file descriptor before writing into it.
* 2561791 (Tracking ID: 2527765)
SYMPTOM:
On AIX, a VxFS directory cannot have more than 32K sub-directories. New
directory creation in directory already having 32K sub-directories fails. So
there is a need to support >32K sub-directories for VxFS on AIX.
DESCRIPTION:
on AIX there is a Operating System limitation which restricts the number of
links of a directory/file to 32K (MAXLINK). Therefore one cannot create
sub-directories greater than 32K.
RESOLUTION:
VxFS uses an internal 32 bit link count and hence VxFS internal structures are
capable of handling more than 32k sub-directories. None of the VxFS commands
use MAXLINK count hence there are no other dependencies. So a new tunable i.e.
'maxlink_enable' has been added to allow >32k sub-directories and removed
limitation of 32K sub-directories.
Known Limitations with this fix:
a] AIX Base command limitations:
Since the value of MAXLINK can go only up to 32k, certain AIX commands that have
the dependency on this value would fail to produce correct results. IBM has
completed the analysis of such commands and following are expected to produce
incorrect results when run with >32K directories.
AIX commands /usr/bin/istat, /usr/bin/li, /usr/bin/ls and /usr/bin/find commands
will report incorrect nlink count when there are >32k subdirectories.
b] VxFS limitations :
1) In case of CFS, ALL nodes of the cluster must run with same maxlink_enable value.
2) once this tunable is set then it cannot be disabled. By default it is disabled.
* 2564431 (Tracking ID: 2515459)
SYMPTOM:
Local mount hangs in vx_bc_binval_cookie like the following stack
delay
vx_bc_binval_cookie
vx_blkinval_cookie
vx_freeze_flush_cookie
vx_freeze_all
vx_freeze
vx_set_tunefs1
vx_set_tunefs
vx_aioctl_full
vx_aioctl_common
vx_aioctl
vx_ioctl
genunix:ioctl
unix:syscall_trap32
DESCRIPTION:
The hanging process for local mount is waiting for a buffer to be unlocked. But
that buffer can only be released if its associated cloned map writes get flushed.
But a necessary flush is missed.
RESOLUTION:
Add code to synchronize cloned map writes so that all the cloned maps will be
cleared and the buffers associated with them will be released.
* 2567091 (Tracking ID: 2527578)
SYMPTOM:
System crashes due to NULL pointer deference with the following stack -
simple_lock+000014 ()
vx_bhash_rele@AF161_63+00001C ()
vx_inode_deinit+0000D4 ()
vx_idrop+0002A4 ()
vx_detach_fset+000CC8 ()
vx_unmount+0001AC ()
vx_unmount_skey+000034 ()
vfs_unmount+000098 ()
kunmount+0000DC ()
uvmount+000208 ()
ovlya_addr_sc_flih_main+000130 ()
DESCRIPTION:
The crash happens as a result of accessing an address for which memory hasn't
been allocated. This address corresponds to a spinlock and therefore the crash
while locking the spinlock.
RESOLUTION:
Allocate and initialize the spinlock before locking.
* 2574396 (Tracking ID: 2433934)
SYMPTOM:
Performance degradation observed when CFS is used compared to standalone VxFS as
back-end NFS data servers.
DESCRIPTION:
In CFS, if one thread holding read-write lock on inode in exclusive mode, other
threads are stuck for the same inode, even if they want to access inode in shared
mode, resulting in performance degradation.
RESOLUTION:
Code is changed to avoid taking read-write lock for inode in exclusive mode, where
it is not required.
* 2581351 (Tracking ID: 2588593)
SYMPTOM:
df(1M) shows wrong usage value for volume when large file is deleted.
DESCRIPTION:
We maintain all freed extent size in the in core global variable and transaction
subroutine specific data structures.
After deletion of a large file, we were missing to update this in core global
variable. df(1M) while reporting
usage data, read the freed space information from this global variable which
contains stale information.
RESOLUTION:
Code is modified to account the freed extent data into global vaiable used by
df(1M) so that correct usage for volume is
reported by df(1M).
* 2586283 (Tracking ID: 2603511)
SYMPTOM:
On Systems with Oracle 11.2.0.3 or higher installed, database operations can
fail with the following message is displayed in the system logs: "ODM ERROR
V-41-4-1-105-22 Invalid argument"
DESCRIPTION:
A change in and Oracle API in 11.2.0.3 , Oracle Disk Manager (ODM) is unable to
create a file due to a unrecognized f-mode.
RESOLUTION:
The code is modified to mask and take into consideration only the files which
are known to ODM instead of failing the creation of the file.
* 2587025 (Tracking ID: 2528819)
SYMPTOM:
AIX can fail to create new worker threads for VxFS. The following message is seen
in the system log-
"WARNING: msgcnt 175 mesg 097: V-2-97: vxfs failed to create new thread"
DESCRIPTION:
AIX is failing the thread creation because it cannot find a free slot in that
kproc and returning ENOMEM.
RESOLUTION:
Limit the maximum number of VxFS worker threads.
* 2587139 (Tracking ID: 2511432)
SYMPTOM:
Poor VxFS performance for application doing writes on a mmaped file which has
been written to before being mmaped and therefore has all the associated pages
already brought into memory as a result. Large page-ins are observed as soon as
the writes begin. Also large page-outs are observed periodically afterward.
DESCRIPTION:
Buffered writes to a file brings the associated page in memory. Such a page can
be written to. However mmaping this file now will mark the page read-only.
Any mmaped write writing to same page will encounter now a protection fault
thereby leading to page-in.
The VxFS background flushing mechanism periodically flushes the entire file
which leads to large page-outs. During these page-outs the writes happening else
where on the file slowdown owing to unavailability of various inode locks
currently held by the flushing thread.
RESOLUTION:
For preventing large page-ins we have removed the extra overhead of protection
fault by marking pages read-write in the mmap range wherever possible.
We have introduced a new tunable "vx_ctrl_flush" which can be tuned to control
the amount of flushing by background flushing thread and therefore the page-outs.
* 2602982 (Tracking ID: 2599590)
SYMPTOM:
Expansion of a 100% full file system may panic the machine with the following
stack trace.
bad_kern_reference()
$cold_vfault()
vm_hndlr()
bubbledown()
vx_logflush()
vx_log_sync1()
vx_log_sync()
vx_worklist_thread()
kthread_daemon_startup()
DESCRIPTION:
When 100% full file system is expanded intent log of the file system is
truncated and blocks freed up are used during the expansion. Due to a bug the
block map of the replica intent log inode was not getting updated thereby
causing the block maps of the two inodes to differ. This caused some of the in-
core structures of the intent log to go NULL. The machine panics while de-
referencing one of this structure.
RESOLUTION:
Updated the block map of the replica intent log inode correctly. 100% full file
system now can be expanded only If the last extent in the intent log contains
more than 32 blocks, otherwise fsadm will fail. To expand such a file-system,
some of the files should be deleted manually and resize be retried.
* 2603015 (Tracking ID: 2565400)
SYMPTOM:
Sequential buffered I/O reads are slow in performance.
DESCRIPTION:
Read-Aheads are not happening because the file-system's read-ahead size gets
incorrectly calculated.
RESOLUTION:
Fixed the incorrect typecast.
* 2603121 (Tracking ID: 2577079)
SYMPTOM:
Customer suspects high pinned memory usage by VxFS.
DESCRIPTION:
Customer is suspecting high pinned memory usage by VxFS. But from the dump
available vxfs usage doesn't seems to be high. Therefore adding separate counters
to help in finding pinned memory usage by VxFS.
RESOLUTION:
vx_info counters added to track total, inode cache, buffer cache, DNLC pinned
memory usage.
* 2624650 (Tracking ID: 2624262)
SYMPTOM:
Panic hit in vx_bc_do_brelse() function while executing dedup functionality with
following backtrace.
vx_bc_do_brelse()
vx_mixread_compare()
vx_dedup_extents()
enqueue_entity()
__alloc_pages_slowpath()
__get_free_pages()
vx_getpages()
vx_do_dedup()
vx_aioctl_dedup()
vx_aioctl_common()
vx_rwunlock()
vx_aioctl()
vx_ioctl()
vfs_ioctl()
do_vfs_ioctl()
sys_ioctl()
DESCRIPTION:
While executing function vx_mixread_compare() in dedup codepath, we hit error
due
to which an allocated data structure remained uninitialised.
The panic occurs due to writing to this uninitialised allocated data structure
in
the function vx_mixread_compare().
RESOLUTION:
Code is changed to free the memory allocated to the data structure when we are
going out due to error.
* 2626960 (Tracking ID: 2626390)
SYMPTOM:
Freeing a large number of pages at once can induce a small i/o latency.
DESCRIPTION:
By reading an entire file into memory and then removing the file all the pages
will be freed. Pages are freed in chunks. Currently the smallest configurable
chunk size for freeing pages is 64MB.
RESOLUTION:
Enhance the fine tuning of the chunk invalidation size, now allow smaller
chunks to be tuned. Example tuning below will set the chunk size for freeing
pages to 8Mb, the table shows the tuning values now available.
# vxtunefs -D chunk inval_size=6
chunk inval_size: 64 256 128 64 32 16 8 4 unit is Mb
Tuning value : 0 1 2 3 4 5 6 7
* 2630984 (Tracking ID: 2622899)
SYMPTOM:
Number of PDTs not set correctly by default.
# /opt/VRTS/bin/vxtunefs -D print
Filesystem parameters:
drefund enable = 0
drefund supported = 0
number of pdts = 1
default number of pdts = 16
Above vxtunefs output shows by default no. of PDTs should be 16 but it is
incorrectly set to 1.
DESCRIPTION:
VxFS configuration tunable are read from file /etc/vx/vxfssystem. If this file
is not present VxFS decides tunable values based on memory and number of cpus.
Values read from configuration file are stored in a structure and sent to
kernel. Because of a wrong initialization of structure, VxFS thinks that these
values have come from configuration file and ends up assigning wrong values to
tunable even the configuration file does not exist.
RESOLUTION:
To initialize the tunable structure properly. So that tunables are set to values
based on memory and number of cpus get assigned.
* 2631026 (Tracking ID: 2332314)
SYMPTOM:
Internal noise.fullfsck test with ODM enabled hit an assert fdd_odm_aiodone:3
DESCRIPTION:
In case of failed IO in fdd_write_clone_end() function, error was not set on
buffer which is causing the assert.
RESOLUTION:
Code is changed so we set the error on buffer in case of IO failures in
fdd_write_clone_end() function.
* 2631221 (Tracking ID: 2349744)
SYMPTOM:
A system can panic when performing buffered i/o using large i/o sizes.
The following is an example stacktrace showing where the system panics:
abend_trap+000000 ()
xm_bad_free+000264 ()
xmfree+0004AC ()
vx_memfree_cpu+00006C ()
vx_alloc+000124 ()
vx_worklist_enqueue+000034 ()
vx_sched_thread+00024C ()
vx_sched_thread0+000038 ()
vx_thread_base+000048 ()
threadentry+000054 ()
DESCRIPTION:
Prior to the VxFS5.1 release the maximum buffered i/o size was restricted to
128Kb on the AIX platform. To assist buffered i/o performance an enhancement
was introduced in release 5.1 to perform larger sized buffered i/o's. With this
enhancement VxFS can be asked to perform buffered i/o of sizes greater than
128K by tuning the vxfs tunables "read_pref_io" and "write_pref_io" to values
greater than 128K.
When performing buffered i/o using i/o sizes of multiple-megabytes the system
can panic in the routine xmfree() whilst freeing the memory from a heap
different from which it was allocated from.
RESOLUTION:
Freeing the memory from correct heap.
* 2631221 (Tracking ID: 2349744)
SYMPTOM:
A system can panic when performing buffered i/o using large i/o sizes.
The following is an example stacktrace showing where the system panics:
abend_trap+000000 ()
xm_bad_free+000264 ()
xmfree+0004AC ()
vx_memfree_cpu+00006C ()
vx_alloc+000124 ()
vx_worklist_enqueue+000034 ()
vx_sched_thread+00024C ()
vx_sched_thread0+000038 ()
vx_thread_base+000048 ()
threadentry+000054 ()
DESCRIPTION:
Prior to the VxFS5.1 release the maximum buffered i/o size was restricted to
128Kb on the AIX platform. To assist buffered i/o performance an enhancement
was introduced in release 5.1 to perform larger sized buffered i/o's. With this
enhancement VxFS can be asked to perform buffered i/o of sizes greater than
128K by tuning the vxfs tunables "read_pref_io" and "write_pref_io" to values
greater than 128K.
When performing buffered i/o using i/o sizes of multiple-megabytes the system
can panic in the routine xmfree() whilst freeing the memory from a heap
different from which it was allocated from.
RESOLUTION:
Freeing the memory from correct heap.
* 2631315 (Tracking ID: 2631276)
SYMPTOM:
Lookup fails for the file which is in partitioned directory and is being
accessed
using its vxfs namespace extension name.
DESCRIPTION:
If file is present in the partitioned directory and is accessed using its vxfs
namespace extension name then its name is searched in
one of the hidden leaf directory. This leaf directory mostly doesn't contains
entry
for this file. Due this lookup fails.
RESOLUTION:
Code has been modified to call partitioned directory related lookup routine at
upper
level so that lookup doesn't fails even if
file is accessed using its extended namespace name.
* 2635583 (Tracking ID: 2271797)
SYMPTOM:
Internal Noise Testing with locally mounted VxFS filesystem hit an assert
"f:vx_getblk:1a"
DESCRIPTION:
The assert is hit due to overlay inode is being marked with the flag regarding bad
copy of inode present on disk.
RESOLUTION:
Code is changed to set the flag regarding bad copy of inode present on disk, only
if the inode is not overlay.
* 2642027 (Tracking ID: 2350956)
SYMPTOM:
Internal noise test on locally mounted filesystem exited with error message
"bin/testit : Failed to full fsck cleanly, exiting" and in the logs we get the
userspace assert
"bmaptops.c 369: ASSERT(devid == 0 || (start == VX_HOLE && devid ==
VX_DEVID_HOLE)) failed".
DESCRIPTION:
The function bmap_data4_set() gets called while entering bmap allocation
information for typed extents of type VX_TYPE_DATA_4 or VX_TYPE_IADDR_4. The
assert expects that, either devid should be zero or if extent start is a hole,
then devid should be VX_DEVID_HOLE. However, we never have extent descriptors to
represent holes in typed extents. The assertion is incorrect.
RESOLUTION:
The assert corrected to check that extent start is not a hole and either devid is
zero, or extent start is VX_OVERLAY with devid being VX_DEVID_HOLE.
* 2646557 (Tracking ID: 2529201)
SYMPTOM:
The fscdsconv limits specified in the cdslimitstab file were wrong.
Hence some of the cds related commands were failing.
DESCRIPTION:
The cdslimitstab file is used by the CDS/PDC commands to gather
information about the migration targets. Limits of vx_maxlink for 32k & 64k are
wrong. Below are limits mentioned in cdslimittab ::
OS_MAX_NLINKS=32767
VXFS_MAX_NLINKS=65565
2^64 -1 evaluates to 65535.
If we create 32768 directories in single directory then fscdsconv is throwing
error for nlink.
RESOLUTION:
The limit for VXFS_MAX_NLINKS is set correctly to 65535.
* 2654644 (Tracking ID: 2630954)
SYMPTOM:
During internal CFS stress reconfiguration testing, the fsck(1M)
command exits by hitting an assert.
DESCRIPTION:
When the dexh_getblk() function is executed, if the extent size is
greater than 256 Kbytes, the extent is divided into chunks of 256 Kbytes each.
When the extent of the hash inodes are read in the dexh_getblk() function, a
maximum of 256 Kbytes (MAXBUFSZ) is read at a time. Currently, the chunk size is
assigned as 256 Kbytes every time. But there is a bug when the last chunk in the
extent is less than 256 Kbytes because of which the length of the buffer is
assigned incorrectly and we get an aliased buffer in the buffer cache. Instead,
for the last chunk, the remaining size in the extent to be read should be
assigned as the chunk size.
RESOLUTION:
The code is modified so that the buffer size is calculated correctly.
* 2669195 (Tracking ID: 2326037)
SYMPTOM:
Internal Stress Test on cluster file system with clones failed while writing to
file with error ENOENT.
DESCRIPTION:
VxFS file-system trying to write to clone which is in process of removal. As clone
removal process works asynchronously, process starts to push changes from inode of
primary fset to inode of clone fset. But when actual write happens the inode of
clone fset is removed, hence error ENOENT is returned.
RESOLUTION:
Code is added to re-validate the inode being written.
Patch ID: 5.1.112.0
* 2169326 (Tracking ID: 2169324)
SYMPTOM:
On LM , When clone is mounted for a file system and some quota is
assigned to clone. And if quota exceeds then clone is removed and if files from
clones are being accessed then assert may hit in function vx_idelxwri_off()
through vx_trunc_tran()
DESCRIPTION:
During clone removable, we go through the all inodes of the
clone(s) being removed and hit the assert because there is difference between
on-disk and in-core sizes for the file , which is being modified by the
application.
RESOLUTION:
While truncating files, if VX_IEPTTRUNC op is set,
set the in-core file size to on_disk file size.
* 2243061 (Tracking ID: 1296491)
SYMPTOM:
Performing a nested mount on a CFS file system triggers a data page fault if a
forced unmount is also taking place on the CFS file system. The panic stack
trace involves the following kernel routines:
vx_glm_range_unlock
vx_mount
domount
mount
syscall
DESCRIPTION:
When the underlying cluster mounted file system is in the process of unmounting,
the nested mount dereferences a NULL vfs structure pointer, thereby causing a
system panic.
RESOLUTION:
The code has been modified to prevent the underlying cluster file system from a
forced unmount when a nested mount above the file system, is in progress. The
ENXIO error will be returned to the forced unmount attempt.
* 2243063 (Tracking ID: 1949445)
SYMPTOM:
Hang when file creates were being performed on large directory. stack of hung
thread is similar to below:
vxglm:vxg_grant_sleep+226
vxglm:vxg_cmn_lock+563
vxglm:vxg_api_lock+412
vxfs:vx_glm_lock+29
vxfs:vx_get_ownership+70
vxfs:vx_exh_coverblk+89
vxfs:vx_exh_split+142
vxfs:vx_dexh_setup+1874
vxfs:vx_dexh_create+385
vxfs:vx_dexh_init+832
vxfs:vx_do_create+713
DESCRIPTION:
For large directories, Large Directory Hash(LDH) is enabled to improve lookup on
such large directories. Hang was due to taking ownership of LDH inode twice in
same thread context i.e. while building hash for directory.
RESOLUTION:
Avoid taking ownership again if we already have the ownership of the LDH inode.
* 2247299 (Tracking ID: 2161379)
SYMPTOM:
In a CFS enviroment various filesytems operations hang with the following stack
trace
T1:
vx_event_wait+0x40
vx_async_waitmsg+0xc
vx_msg_send+0x19c
vx_iread_msg+0x27c
vx_rwlock_getdata+0x2e4
vx_glm_cbfunc+0x14c
vx_glmlist_thread+0x204
T2:
vx_ilock+0xc
vx_assume_iowner+0x100
vx_hlock_getdata+0x3c
vx_glm_cbfunc+0x104
vx_glmlist_thread+0x204
DESCRIPTION:
Due to improper handling of the ENOTOWNER error in the iread receive function.
We continously retry the operation while holding an Inode Lock blocking
all other threads and causing a deadlock
RESOLUTION:
The code is modified to release the inode lock on ENOTOWNER error and acquire it
again, thus resolving the deadlock
There are totally 4 vx_msg_get_owner() caller with ilocked=1:
vx_rwlock_getdata() : Need Fix
vx_glock_getdata() : Need Fix
vx_cfs_doextop_iau(): Not using the owner for message loop, no need to fix.
vx_iupdat_msg() : Already has 'unlock/delay/lock' on ENOTOWNER
condition!
* 2249658 (Tracking ID: 2220300)
SYMPTOM:
'vx_sched' hogs CPU resources.
DESCRIPTION:
vx_sched process calls vx_iflush_list() to perform the background flushing
processing. vx_iflush_list() calls vx_logwrite_flush() if the file has had
logged-writes performed upon it. vx_logwrite_flush() performs a old trick that
is ineffective when flushing in chunks. The trick is to flush the file
asynchronously, then flush the file again synchronously. This therefore flushes
the entire file twice, this is double the work when chunk flushing.
RESOLUTION:
vx_logwrite_flush() has been changed to flush the file once rather than twice.
So Removed asynchronous flush in vx_logwrite_flush().
* 2255786 (Tracking ID: 2253617)
SYMPTOM:
Fullfsck fails to run cleanly using "fsck -n".
DESCRIPTION:
In case of duplicate file name entries in one directory, fsck
compares the directory entry with the previous entries. If the filename
already exists further action is taken according to the user input [Yes/No]. As
we are using strncmp, it will compare first n characters, if it matches it will
return success and will consider it as a duplicate file name entry and fails to
run cleanly using "fsck -n"
RESOLUTION:
Checking the filename size and changing the length in strncmp to
name_len + 1 solves the issue.
* 2257904 (Tracking ID: 2251223)
SYMPTOM:
The 'df -h' command can take 10 seconds to run to completion and yet still
report an inaccurate free block count, shortly after removing a large number
of files.
DESCRIPTION:
When removing files, some file data blocks are released and counted in the
total free block count instantly. However blocks may not always be freed
immediately as VxFS can sometimes delay the releasing of blocks. Therefore
the displayed free block count, at any one time, is the summation of the
free blocks and the 'delayed' free blocks.
Once a file 'remove transaction' is done, its delayed free blocks will be
eliminated and the free block count increased accordingly. However, some
functions which process transactions, for example a metadata update, can also
alter the free block count, but ignore the current delayed free blocks. As a
result, if file 'remove transactions' have not finished updating their free
blocks and their delayed free blocks information, the free space count can
occasionally show greater than the real disk space. Therefore to obtain an
up-to-date and valid free block count for a file system a delay and retry
loop was delaying 1 second before each retry and looping 10 times before
giving up. Thus the 'df -h' command can sometimes take 10 seconds, but
even if the file system waits for 10 seconds there is no guarantee that the
output displayed will be accurate or valid.
RESOLUTION:
The delayed free block count is recalculated accurately when transactions
are created and when metadata is flushed to disk.
* 2275543 (Tracking ID: 1475345)
SYMPTOM:
write() system call hangs for over 10 seconds
DESCRIPTION:
While performing a transactions in case of logged write we used to
asynchronously flush one buffer at a time belonging to the transaction space.
Such Asynchronous flushing was causing intermediate delays in write operation
because of reduced transaction space.
RESOLUTION:
Flush all the dirty buffers on the file in one attempt through synchronous
flush, which will free up a large amount of transaction space. This will reduce
the delay during write system call.
* 2280386 (Tracking ID: 2061177)
SYMPTOM:
'fsadm -de' command erroring with 'bad file number' on filesystem(s) on
5.0MP3RP1.
DESCRIPTION:
<1>first, Our kernel fs doesn't have any problem. There is not corrupt layout in
their system. The metasave got from the customer is the proof (we can't
reproduce this problem and there is not corrupted inode in that metasave).
<2>second, As you know, fsadm is a application which has 2 parts: the
application part and the kernel part. The application part read layout from raw
disk to make strategy and the kernel part is to implement. So, For a buffer
write fs, there should be a problem that can't be avoided that is the sync
problem. In our customer's system, when they do fsadm -de, they also so huge of
write operation (they also have many check points and As you know more check
points more copy on write which means checkpoint will multi the write operation.
That why more checkpoints more problem).
RESOLUTION:
our solution is to add sync operation in fsadm before it read layout
from raw disk to avoid kernel and application un-sync.
* 2280552 (Tracking ID: 2246579)
SYMPTOM:
Filesystem corruptions and system panic when attempting to extend a 100%-full disk
layout version 5(DLV5) VxFS filesystem using fsadm(1M).
DESCRIPTION:
The behavior is caused by filesystem metadata that is relocated to the intent log
area inadvertently being destroyed when the intent log is cleared during the
resize operation.
RESOLUTION:
Refresh the incore intent log extent map by reading the bmap of the intent log
inode before clearing it.
* 2296277 (Tracking ID: 2296107)
SYMPTOM:
The fsppadm command (fsppadm query -a mountpoint ) displays ""Operation not
applicable" " while querying the mount point.
DESCRIPTION:
During fsppadm query process, fsppadm will try to open every file's named data
stream "" in the filesystem. but vxfs inernal file FCL: "changelog" doesn't
support this operation. "ENOSYS" is returned in this case. fsppadm will
translate "ENOSYS" into "Operation not applicable", and print the bogus error
message.
RESOLUTION:
Fix fsppadm's get_file_tags() to ignore the "ENOSYS" error.
* 2311490 (Tracking ID: 2074806)
SYMPTOM:
a dmapi program using dm_punch_hole may result in corrupted data
DESCRIPTION:
When the dm_punch_hole call is made on a file with allocated
extents is used immediatly after a previous write then data can be written
through stale pages. This causes data to be written to the wrong location
RESOLUTION:
dm_punch_hole will now invalidate all the pages within the hole its
creating.
* 2320044 (Tracking ID: 2419989)
SYMPTOM:
ncheck(1M) command with '-i' option does not limit the output to the specified
inodes.
DESCRIPTION:
Currently, ncheck(1M) command with '-i' option currently shows free space
information and other inodes that are not in the list provides by '-i' option.
RESOLUTION:
ncheck(1M) command is modified to print only those inodes that are specified by
'-i' option.
* 2320049 (Tracking ID: 2419991)
SYMPTOM:
There is no way to specify an inode that is unique to the file
system since we reuse inode numbers in multiple filesets. We therefore would
need to be able to specify a list of filesets similar to the '-i' option for
inodes, or add a new '-o' option where you can specify fileset+inode pairs.
DESCRIPTION:
When ncheck command is called with '-i' option in conjunction with
-oblock/device/sector option, it displays inodes having same inode number from
all
filesets. We don't have any command line option that helps us to specify a
unique
inode and fileset combination.
RESOLUTION:
Code is modified to add '-f' option in ncheck command using which one could
specify
the fset number on which one wants to filter the results. Further, if this
option
is used with '-i' option, we could uniquely specify the inode-fileset pair/s
that
that we want to display.
* 2329887 (Tracking ID: 2253938)
SYMPTOM:
In a Cluster File System (CFS) environment , the file read
performances gradually degrade up to 10% of the original
read performance and the fsadm(1M) -F vxfs -D -E
shows a large number (> 70%) of free blocks in
extents smaller than 64k.
For example,
% Free blocks in extents smaller than 64 blks: 73.04
% Free blocks in extents smaller than 8 blks: 5.33
DESCRIPTION:
In a CFS environment, the disk space is divided into
Allocation Units (AUs).The delegation for these AUs is
cached locally on the nodes.
When an extending write operation is performed on a file,
the file system tries to allocate the requested block from
an AU whose delegation is locally cached, rather than
finding the largest free extent available that matches the
requested size in the other AUs. This leads to a
fragmentation of the free space, thus leading to badly
fragmented files.
RESOLUTION:
The code is modified such that the time for which the
delegation of the AU is cached can be reduced using a
tuneable, thus allowing allocations from other AUs with
larger size free extents. Also, the fsadm(1M) command is
enhanced to de-fragment free space using the -C option.
* 2329893 (Tracking ID: 2316094)
SYMPTOM:
vxfsstat incorrectly reports "vxi_bcache_maxkbyte" greater than "vx_bc_bufhwm"
after reinitialization of buffer cache globals. reinitialization can happen in
case of dynamic reconfig operations.
vxfsstat's "vxi_bcache_maxkbyte" counter shows maximum memory available for
buffer cache buffers allocation. Maximum memory available for buffer allocation
depends on total memory available for Buffer cache(buffers + buffer headers)
i.e. "vx_bc_bufhwm" global. Therefore vxi_bcache_maxkbyte should never greater
than vx_bc_bufhwm.
DESCRIPTION:
"vxi_bcache_maxkbyte" is per-CPU counter i.e. part of global per-CPU 'vx_info'
counter structure. vxfsstat does sum of all per-cpu counters and reports result
of sum. During re-intitialation of buffer cache, this counter was not set to
zero properly before new value is assigned to it. Therefore total sum of this
per-CPU counter can be more than 'vx_bc_bufhwm'.
RESOLUTION:
During buffer cache re-initialization, "vxi_bcache_maxkbyte" is now correctly
set to zero such that final sum of this per-CPU counter is correct.
* 2340741 (Tracking ID: 2282201)
SYMPTOM:
On a VxFS filesystem, vxdump(1m) operation running in parallel with
other filesystem Operations like create, delete etc. can fail with signal
SIGSEGV generating a core file.
DESCRIPTION:
vxdump caches the inodes to be dumped in a bit map before starting the dump of a
directory, however this value can change if there are creates and deletes
happening in the background leading to inconsistent bit map eventually
generating a core file.
RESOLUTION:
The code is updated to refresh the inode bit map before actually starting the
dump operation thus avoiding the core file generation.
* 2340799 (Tracking ID: 2059611)
SYMPTOM:
system panics because NULL tranp in vx_unlockmap().
DESCRIPTION:
vx_unlockmap is to unlock a map structure of file system. If the map is being
handled, we incremented the hold count. vx_unlockmap() attempts to check whether
this is an empty mlink doubly linked list while we have an async vx_mapiodone
routine which can change the link at unpredictable timing even though the hold
count is zero.
RESOLUTION:
evaluation order is changed inside vx_unlockmap(), such that
further evaluation can be skipped over when map hold count is zero.
* 2340817 (Tracking ID: 2192895)
SYMPTOM:
System panics when performing fcl commands at
unix:panicsys
unix:vpanic_common
unix:panic
genunix:vmem_xalloc
genunix:vmem_alloc
unix:segkmem_xalloc
unix:segkmem_alloc_vn
genunix:vmem_xalloc
genunix:vmem_alloc
genunix:kmem_alloc
vxfs:vx_getacl
vxfs:vx_getsecattr
genunix:fop_getsecattr
genunix:cacl
genunix:acl
unix:syscall_trap32
DESCRIPTION:
The acl count in inode can be corrupted due to race condition. For
example, setacl can change the acl count when getacl is processing the same
inode, which could cause a invalid use of acl count.
RESOLUTION:
Code is modified to add the protection for the vulnerable acl count to avoid
corruption.
* 2340825 (Tracking ID: 2290800)
SYMPTOM:
When using fsdb to look at the map of ILIST file ("mapall" command), fsdb can
wrongly report a large hole at the end of ILIST file.
DESCRIPTION:
while reading bmap of ILIST file, if hole at the end of indirect extents is
found, fsdb may incorrectly end up marking the hole as the last extent in the
bmap, causing the mapall command to show a large hole till the end of file.
RESOLUTION:
Code has been modified to read ILIST file's bmap correctly when holes at the end
of indirect extents found, instead of marking that hole as the last extent of
file.
* 2340831 (Tracking ID: 2272072)
SYMPTOM:
GAB panics the box because VCS engine "had" did not respond, the lbolt
wraps around.
DESCRIPTION:
The lbolt wraps around after 498 days machine uptime. In VxFS, we
flush VxFS meta data buffers based on their age. The age calculation happens
taking lbolt in account.
Due to lbolt wrapping the buffers were not flushed. So, a lot of metadata IO's
stopped and hence, the panic.
RESOLUTION:
In the function for handling flushing of dirty buffers, also handle
the condition if lbolt has wrapped. If it has then assign current lbolt time
to the last update time of dirtylist.
* 2340834 (Tracking ID: 2302426)
SYMPTOM:
System panics when multiple 'vxassist mirror' commands are running
concurrently with following stack strace:
0) panic+0x410
1) unaligned_hndlr+0x190
2) bubbleup+0x880 ( )
+------------- TRAP #1 ----------------------------
| Unaligned Reference Fault in KERNEL mode
| IIP=0xe000000000b03ce0:0
| IFA=0xe0000005aa53c114 <---
| p struct save_state 0x2c561031.0x9fffffff5ffc7400
+------------- TRAP #1 ----------------------------
LVL FUNC ( IN0, IN1, IN2, IN3, IN4, IN5, IN6, IN7 )
3) vx_copy_getemap_structs+0x70
4) vx_send_getemapmsg+0x240
5) vx_cfs_getemap+0x240
6) vx_get_freeexts_ioctl+0x990
7) vxportal_ioctl+0x4d0
8) spec_ioctl+0x100
9) vno_ioctl+0x390
10) ioctl+0x3c0
11) syscall+0x5a0
DESCRIPTION:
Panic is caused because of de-referencing an unaligned address in CFS message
structure.
RESOLUTION:
Used bcopy to ensure proper alignment of the addresses.
* 2340839 (Tracking ID: 2316793)
SYMPTOM:
Shortly after removing files in a file system commands like 'df', which use
'statfs()', can take 10 seconds to complete.
DESCRIPTION:
To obtain an up-to-date and valid free block count in a file system a delay and
retry loop was delaying 1 second before each retry and looping 10 times before
giving up. This unnecessarily excessive retying could cause a 10 second delay
per file system when executing the df command.
RESOLUTION:
The original 10 retries with a 1 second delay each, have been reduced to 1 retry
after a 20 millisecond delay, when waiting for an updated free block count.
* 2341007 (Tracking ID: 2300682)
SYMPTOM:
When a file is newly created, issuing "fsppadm query -a /mount_point" could show
incorrect IOTemp information.
DESCRIPTION:
fsppadm query outputs incorrect data when the file re-uses the inode number
which belonged to a removed file, but the database still contains this obsolete
record for the removed one.
fsppadm utility takes use of a database to save inodes' historical data. It
compares the nearest and the farthest records for an inode to compute IOTemp in
a time window. And it picks the generation of inode in the farthest record to
check the inode existence. However, if the farthest is missing, zero as the
generation is used mistakenly.
RESOLUTION:
If the nearest record for a given inode exists in database, we extract the
generation entry instead of that from the farthest one.
* 2360817 (Tracking ID: 2332460)
SYMPTOM:
Executing the VxFS 'vxedquota -p user1 user2' command to copy quota information
of one user to other users takes a long time to run to completion.
DESCRIPTION:
VxFS maintains quota information in two files - external quota files and
internal quota files. Whilst copying quota information of one user to another,
the required quota information is read from both the external and internal
files. However the quota information should only need to be read from the
external file in a situation where the read from the internal file has failed.
Reading from both files is therefore causing an unnecessary delay in the command
execution time.
RESOLUTION:
The unnecessary duplication of reading both the external and internal Quota
files to retrieve the same information has been removed.
* 2360819 (Tracking ID: 2337470)
SYMPTOM:
Cluster File System can unexpectedly and prematurely report a 'file system
out of inodes' error when attempting to create a new file. The error message
reported will be similar to the following:
vxfs: msgcnt 1 mesg 011: V-2-11: vx_noinode - /dev/vx/dsk/dg/vol file system out
of inodes
DESCRIPTION:
When allocating new inodes in a cluster file system, vxfs will search for an
available free inode in the 'Inode-Allocation-Units' [IAUs] that are currently
delegated to the local node. If none are available, it will then search the
IAUs that are not currently delegated to any node, or revoke an IAU delegated
to another node. It is also possible for gaps or HOLEs to be created in the IAU
structures as a side effect of the CFS delegation processing. However when
searching for an available free inode vxfs simply ignores any HOLEs it may find,
if the maximum size of the metadata structures has been reached (2^31) new IAUs
cannot be created, thus one of the HOLEs should then be populated and used for
new inode allocation. The problem occurred as HOLEs were being ignored,
consequently vxfs can prematurely report the "file system out of inodes" error
message even though there is plenty of free space in the vxfs file system to
create new inodes.
RESOLUTION:
New inodes will now be allocated from the gaps, or HOLEs, in the IAU structures
(created as a side effect of the CFS delegation processing). The HOLEs will be
populated rather than returning a 'file system out of inodes' error.
* 2360821 (Tracking ID: 1956458)
SYMPTOM:
When attempting to check information of checkpoints by
fsckptadm -C blockinfo ,
the command failed with error 6 (ENXIO), the file system is disabled and some
errors come out in message file:
vxfs: msgcnt 4 mesg 012: V-2-12: vx_iget - /dev/vx/dsk/sfsdg/three file system
invalid inode number 4495
vxfs: msgcnt 5 mesg 096: V-2-96: vx_setfsflags - /dev/vx/dsk/sfsdg/three file
system fullfsck flag set - vx_cfs_iread
DESCRIPTION:
VxFS takes use of ilist files in primary fileset and checkpoints to accommodate
inode information. A hole in a ilist file indicates that inodes in the hole
don't exist and are not allocated yet in the corresponding fileset or
checkpoint.
fsckptadm will check every inode in the primary fileset and the downstream
checkpoints. If the inode falls into a hole in a prior checkpoint,
i.e. the associated file was not generated at the time of the checkpoint
creation, fsckptadm exits with error.
RESOLUTION:
Skip inodes in the downstream checkpoints, if these inodes are located in a
hole.
* 2368738 (Tracking ID: 2368737)
SYMPTOM:
If a file which has shared extents has corrupt indirect blocks, then in certain
cases the reference count tracking system can try to interpret this block and
panic the system. Since this is a asynchronous background operation, this
processing will retry repeatedly on every file system mount and hence can result
in panic every time the file system is mounted.
DESCRIPTION:
Reference count tracking system for shared extents updates reference count in a
lazy fashion. So in certain cases it asynchronously has to access shared
indirect blocks belonging to a file to account for reference count updates. But
due if this indirect block has been corrupted badly "a priori", then this
tracking mechanism can panic the system repeatedly on every mount.
RESOLUTION:
The reference count tracking system validates the read indirect extent from the
disk and in case it is not found valid sets VX_FULLFSCK flag in the superblock
marking it for full fsck and disables the file system on the current node.
* 2373565 (Tracking ID: 2283315)
SYMPTOM:
System may panic when "fsadm -e" is run on a file system containing file level
snapshots. The panic stack looks like:
crash_kexec()
__die at()
do_page_fault()
error_exit()
[exception RIP: vx_bmap_lookup+36]
vx_bmap_lookup()
vx_bmap()
vx_reorg_emap()
vx_extmap_reorg()
vx_reorg()
vx_aioctl_full()
vx_aioctl_common()
vx_aioctl()
vx_ioctl()
do_ioctl()
vfs_ioctl()
sys_ioctl()
tracesys
DESCRIPTION:
The panic happened because of a NULL inode pointer passed to vx_bmap_lookup()
function. During reorganizing extents of a file, block map (bmap) lookup
operation is done on a file to get the information about the extents of the
file. If this bmap lookup finds a hole at an offset in a file containing shared
extents, a local variable is not updated that makes the inode pointer NULL
during the next bmap lookup operation.
RESOLUTION:
Initialized the local variable such that inode pointer passed to
vx_bmap_lookup() will be non NULL.
* 2386483 (Tracking ID: 2374887)
SYMPTOM:
Access to a file system can hang when creating a named attribute
due to a read/write lock being held exclusively and indefinitely
causing a thread to loop in vx_tran_nattr_dircreate()
A typical stacktrace of a looping thread:
vx_itryhold_locked
vx_iget
vx_attr_iget
vx_attr_kgeti
vx_attr_getnonimmed
vx_acl_inherit
vx_aclop_creat
vx_attr_creatop
vx_new_attr
vx_attr_inheritbuf
vx_attr_inherit
vx_tran_nattr_dircreate
vx_nattr_copen
vx_nattr_open
vx_setea
vx_linux_setxattr
vfs_setxattr
link_path_walk
sys_setxattr
system_call
DESCRIPTION:
The initial creation of a named attribute for a regular file
or directory will result in the automatic creation of a
'named attribute directory'. Creations are initially attempted
in a single transaction. Should the single transaction fail
due to a read/write lock being held then a retry should split
the task into multiple transactions. An incorrect reset of a
tracking structure meant that all retries were performed using
a single transaction creating an endless retry loop.
RESOLUTION:
The tracking structure is no longer reset within the retry loop.
* 2402643 (Tracking ID: 2399178)
SYMPTOM:
Full fsck does large directory index validation during pass2c. However, if
the number of large directories are more then this pass takes a lot of time. There
is huge scope to improve the full fsck performance during this pass.
DESCRIPTION:
Pass2c consists of following basic operations:-
[1] Read the entries in the large directory
[2] Cross check hash values of those entries with the hash directory inode
contents residing on the attribute ilist.
This means this is another heavy IO intensive pass.
RESOLUTION:
1.Use directory block read-ahead during Step [1].
2.Wherever possible, access the file contents extent-wise rather than in fs
block size (while reading entries in the directory) or in hash block size (8k,
during dexh_getblk)
Using above mentioned enhancements, the buffer cache can be utilized in better way.
* 2405590 (Tracking ID: 2397976)
SYMPTOM:
A system can panic when performing buffered i/o using large i/o sizes.
The following is an example stacktrace showing where the system panics:
d_map_list_tce+000510
efc_mapdma_iocb+000498
efc_start+000518
efc_output+0005A4
efsc_start+0006A8
efsc_strategy+000D98
std_devstrat+000364
devstrat+000050
scsidisk_start+000D7C
scsidisk_iodone+00068C
internal_iodone_offl+000174
iodone_offl+000080
i_softmod+000274
flih_util+00024C
DESCRIPTION:
Prior to the VxFS5.1 release the maximum buffered i/o size was restricted to
128Kb on the AIX platform. To assist buffered i/o performance an enhancement
was introduced in release 5.1 to perform larger sized buffered i/o's. With this
enhancement VxFS can be asked to perform buffered i/o of sizes greater than
128K by tuning the vxfs tunables "read_pref_io" and "write_pref_io" to values
greater than 128K.
When performing buffered i/o using i/o sizes of multiple-megabytes the system
can panic in the routine d_map_list_tce() whilst performing DMA mappings.
RESOLUTION:
A 128Kb buffered i/o size limitation is being reintroduced to avoid the
possibility of system panic. Regardless of the "read_pref_io"
or "write_pref_io" tunable settings the maximum i/o size for buffered i/o will
be restricted to 128Kb.
* 2412029 (Tracking ID: 2384831)
SYMPTOM:
System panics with the following stack trace. This happens in some cases when
names streams are used in VxFS.
machine_kexec()
crash_kexec()
__die
do_page_fault()
error_exit()
[exception RIP: iput+75]
vx_softcnt_flush()
vx_ireuse_clean()
vx_ilist_chunkclean()
vx_inode_free_list()
vx_ifree_scan_list()
vx_workitem_process()
vx_worklist_process()
vx_worklist_thread()
vx_kthread_init()
kernel_thread()
DESCRIPTION:
VxFS internally creates a directory to keep the named streams pertaining to a
file. In some scenarios, an error code path is missing to release the hold on
that directory. Due to this unmount of the file system will not clean the inode
belonging to that directory. Later when VxFS reuses such a inode panic is seen.
RESOLUTION:
Release the hold on the named streams directory in case of an error.
* 2412177 (Tracking ID: 2371710)
SYMPTOM:
User quota file corruption occurs when DELICACHE feature is enabled, the current
usage of inodes of a user becomes negative after frequent file creations and
deletions. Checking quota info using command "vxquota -vu username", the number
of files is "-1" like:
# vxquota -vu testuser2
Disk quotas for testuser2 (uid 500):
Filesystem usage quota limit timeleft files quota limit
timeleft
/vol01 1127809 8239104 8239104 -1 0 0
DESCRIPTION:
This issue is introduced by the inode DELICACHE feature in 5.1SP1, it is a
performance enhancement to optimize the updates done to inode map during file
creations and deletions. The feature is enabled by default, and can be changed
by vxtunefs.
When DELICACHE is enabled and quota is set for vxfs, there will be an extra
quota update for the inodes on inactive list during removing process. Since
these inodes' quota has been updated already before put on delicache list, the
current number of user files gets decremented twice eventually.
RESOLUTION:
Add a flag to identify the inodes moved to inactive list from delicache list, so
that the flag can be used to prevent updating the quota again during removing
process.
* 2412179 (Tracking ID: 2387609)
SYMPTOM:
Quota usage gets set to ZERO when umount/mount the file system though files
owned by users exist. This issue may occur after some file creations and
deletions. Checking the quota usage using "vxrepquota" command and the output
would be like following:
# vxrepquota -uv /vx/sofs1/
/dev/vx/dsk/sfsdg/sofs1 (/vx/sofs1):
Block limits File limits
User used soft hard timeleft used soft hard timeleft
testuser1 -- 0 3670016 4194304 0 0 0
testuser2 -- 0 3670016 4194304 0 0 0
testuser3 -- 0 3670016 4194304 0 0 0
Additionally the quota usage may not be updated after inode/block usage reaches
ZERO.
DESCRIPTION:
The issue occurs when VxFS merges external per node quota files with internal
quota file. The block offset within external quota file could be calculated
wrongly in some scenario. When any hole found in per node quota file, the file
offset such that it points the next non-HOLE offset will be modified, but we
miss to change the block offset accordingly which points to the next available
quota record in a block.
VxFS updates per node quota records only when global internal quota file shows
either of some bytes or inode usage, otherwise it doesn't copy the usage from
global quota file to per node quota file. But for the case where quota usage in
external quota files has gone down to zero and both bytes and inode usage in
global file becomes zero, per node quota records would be not updated and left
with incorrect usage. It should also check bytes or inodes usage in per node
quota record. It should skip coping records only when bytes and inodes usage in
both global quota file and per node quota file is zero.
RESOLUTION:
Corrected the way to calculate the block offset when any hole is found in per
node quota file.
Added code to also check blocks or inodes usage in per node quota record while
updating user quota usage.
* 2412181 (Tracking ID: 2372093)
SYMPTOM:
New fsadm command options, to defragment a given percentage
of the available freespace in a file system, have been introduced
as part of an initiative to help improve Cluster File System [CFS]
performance - the new additional command usage is as follows:
fsadm -C -U
We have since found that this new freespace defragmentation
operation can sometimes hang (whilst it also continues to consume
some cpu) in specific circumstances when executed on a Cluster
mounted File System [CFS]
DESCRIPTION:
The hang can occur when file system metadata is being relocated.
In our example case the hang occurs whilst relocating inodes whose
corresponding files are being actively updated via a different
node (from which the fsadm command is being executed) in the cluster.
During the relocation an error code path is taken due to an
unexpected mismatch between temporary replica metadata, the code
path then results in a deadlock, or hang.
RESOLUTION:
As there is no overriding need to relocate structural metadata for
the purposes of defragmenting the available freespace, we have
chosen to simply leave all structural metadata where it is when
performing this operation thus avoiding its relocation. The changes
required for this solution are therefore very low risk.
* 2412187 (Tracking ID: 2401196)
SYMPTOM:
System panic in vx_ireuse_clean during Dynamic Reconfiguration on VRTSvxfs
5.1SP1 onwards.
DESCRIPTION:
while Dynamic Reconfiguration(DR) we move inodes to temporary DR inode lists so
that DR can go ahead and deinit the various inode lists. In this case we were
not taking care of the newly added delicache list(added in 5.1SP1) and were
wrongly and unknowingly moving the inode from delicache list to the freelist.
That way we end up having the the inode belonging to a local FS with VX_IREMOVE
set on the freelist, which breaks our assumption that such inode should belong
to CFS and causes panic because of dereferencing NULL CFS inode related fields
of the local inode.
RESOLUTION:
Added case to take care of inodes on delicache list during DR so that they
remain on their own list and don't get moved to freelist.
* 2418819 (Tracking ID: 2283893)
SYMPTOM:
In a Cluster File System (CFS) environment , the file read
performances gradually degrade up to 10% of the original
read performance and the fsadm(1M) -F vxfs -D -E
shows a large number (> 70%) of free blocks in
extents smaller than 64k.
For example,
% Free blocks in extents smaller than 64 blks: 73.04
% Free blocks in extents smaller than 8 blks: 5.33
DESCRIPTION:
In a CFS environment, the disk space is divided into
Allocation Units (AUs).The delegation for these AUs is
cached locally on the nodes.
When an extending write operation is performed on a file,
the file system tries to allocate the requested block from
an AU whose delegation is locally cached, rather than
finding the largest free extent available that matches the
requested size in the other AUs. This leads to a
fragmentation of the free space, thus leading to badly
fragmented files.
RESOLUTION:
The code is modified such that the time for which the
delegation of the AU is cached can be reduced using a
tuneable, thus allowing allocations from other AUs with
larger size free extents. Also, the fsadm(1M) command is
enhanced to de-fragment free space using the -C option.
* 2420060 (Tracking ID: 2403126)
SYMPTOM:
Hang is seen in the cluster when one of the nodes in the cluster leaves or
rebooted. One of the nodes in the cluster will contain the following stack trace.
e_sleep_thread()
vx_event_wait()
vx_async_waitmsg()
vx_msg_send()
vx_send_rbdele_resp()
vx_recv_rbdele+00029C ()
vx_recvdele+000100 ()
vx_msg_recvreq+000158 ()
vx_msg_process_thread+0001AC ()
vx_thread_base+00002C ()
threadentry+000014 (??, ??, ??, ??)
DESCRIPTION:
Whenever a node in the cluster leaves, reconfiguration happens and all the
resources that are held by the leaving nodes are consolidated. This is done on
one node of the cluster called primary node. Each node sends a message to the
primary node about the resources it is currently holding. During this
reconfiguration, in a corner case, VxFS is incorrectly calculating the message
length which is larger than what GAB(Veritas Group Membership and Atomic
Broadcast) layer can handle. As a result the message is getting lost. The sender
thinks that the message is sent and waits for acknowledgement. The message is
actually dropped at sender and never sent. The master node which is waiting for
this message will wait forever and the reconfiguration never completes leading
to hang.
RESOLUTION:
The message length calculation is done properly now and GAB can handle the messages.
* 2425429 (Tracking ID: 2422574)
SYMPTOM:
On CFS, after turning the quota on, when any node is rebooted and rejoins the
cluster, it fails to mount the filesystem.
DESCRIPTION:
At the time of mounting the filesystem after rebooting the node, mntlock was
already set, which didn't allow the remount of filesystem, if quota is on.
RESOLUTION:
Code is changed so that the mntlock flag is masked in quota operation as it's
already set on the mount.
* 2426039 (Tracking ID: 2412604)
SYMPTOM:
Once the time limit expires after exceeding the soft-limit of user quota size on
VxFS filesystem, writes are still permissible over that soft-limit.
DESCRIPTION:
After exceeding the soft-limit, in the initial setup of the soft-limit the timer
didn't use to start.
RESOLUTION:
Start the timer during the initial setting of quota limits if current usage has
already crossed the soft quota limits.
* 2427269 (Tracking ID: 2399228)
SYMPTOM:
Occasionally Oracle Archive logs can be created smaller than they should be,
in the reported case the resultant Oracle Archive logs were incorrectly sized
as 512 bytes.
DESCRIPTION:
The fcntl [file control] command F_FREESP [Free storage space] can be
utilised to change the size of a regular file. If the file size is reduced we
call it a "truncate", and space allocated in the truncated area will be
returned to the file system freespace pool. If the file size is increased using
F_FREESP we call it a "truncate-up", although the file size changes no space is
allocated in the extended area of the file.
Oracle archive logs utilize the F_FREESP fcntl command to perform a truncate-up
of a new file before a smaller write of 512 bytes [at the the start of the
file] is then performed. A timing window was found with F_FREESP which meant
that 'truncate-up' file size was lost, or rather overwritten, by the subsequent
write of the data, thus causing the file to appear with a size of just 512
bytes.
RESOLUTION:
A timing window has been closed whereby the flush of the allocating [512byte]
write was triggered after the new F_FREESP file size has been updated in the
inode.
* 2427281 (Tracking ID: 2413172)
SYMPTOM:
vxfs_fcl_seektime() API seeks to the first record in the File change log(FCL)
file after specified time. This API can incorrectly return EINVAL(FCL record not
found)error while reading first block of FCL file.
DESCRIPTION:
To seek to the first record after the given time, first a binary search is
performed to get the largest block offset where fcl record time is less than the
given time. Then a linear search from this offset is performed to find the first
record which has time value greater than specified time.
FCL records are read in buffers. There can be scenarios where FCL records read
in one buffer are less than buffer size, e.g. reading first block of FCL file.
In such scenarios, buffer read can continue even when all data in current buffer
has been read. This is due to wrong check which decides if all records in one
buffer has been read.
Thus reading buffer beyond boundary was causing search to terminate without
finding record for given time and hence EINVAL error was returned.
Actually, VxFS should detect that it is partially filled buffer and the search
should continue reading the next buffer.
RESOLUTION:
Check which decides if all records in buffer have been read is corrected such
that buffer is read within its boundaries.
* 2478237 (Tracking ID: 2384861)
SYMPTOM:
The following asserts are seen during internal stress and regression runs
f:vx_do_filesnap:1b
f:vx_inactive:2a
f:xted_check_rwdata:31
f:vx_do_unshare:1
DESCRIPTION:
These asserts validate some assumption in various function also there were some
miscellaneous issues which were seen during internal testing.
RESOLUTION:
The code has been modified to fix the internal reported issues which other
miscellaneous changes.
* 2478325 (Tracking ID: 2251015)
SYMPTOM:
Command fsck(1M) will take longer time to complete.
DESCRIPTION:
Command fsck(1M), in extreme case like 2TB file system with a 1KB block size, 130+
checkpoints, and 100-250 million inodes per file set takes 15+ hours
to complete intent log replay because it has to read a few GB of IAU headers and
summaries one synchronous block at a time.
RESOLUTION:
Changing the fsck code, to do read ahead on the IAU file reduces the fsck
log-replay time.
* 2480949 (Tracking ID: 2480935)
SYMPTOM:
System log file may contain following error message on multi-threaded environment
with Dynamic Storage Tiers(DST).
UX:vxfs fsppadm: ERROR: V-3-26626: File Change Log IOTEMP and ACCESSTEMP index
creation failure for /vx/fsvm with message Argument list too long
DESCRIPTION:
In DST, while enforcing policy, SQL queries are generated and written to file
.__fsppadm_enforcesql present in lost+found. In multi threaded environment, 16
threads works in parallel on ILIST and geenrate SQL queries and write it to
file. This may lead to corruption of file, if multiple threads write to file
simultaneously.
RESOLUTION:
Mutex is used to serialize writing of threads on SQL file.
* 2482337 (Tracking ID: 2431674)
SYMPTOM:
panic in vx_common_msgprint() via vx_inactive()
DESCRIPTION:
The problem is that the call VX_CMN_ERR( ) , uses a "llx" format
character which vx_common_msgprint() doesn't understand. It gives up trying to
process that format, but continues on without consuming the corresponding
parameter.
Everything else in the parameter list is effectively shifted by 8 bytes, and
when we
get to processing the string argument, it's game over.
RESOLUTION:
Changed the format to "llu", which vx_common_msgprint() understands.
* 2486597 (Tracking ID: 2486589)
SYMPTOM:
Multiple threads may wait on a mutex owned by a thread that is in function
vx_ireuse_steal() with following stack trace on machine with severe inode pressure.
vx_ireuse_steal()
vx_ireuse()
vx_iget()
DESCRIPTION:
Several thread are waiting to get inodes from VxFS. The current number of inodes
reached max number of inodes (vxfs_ninode) that can be created in memory. So no
new allocations can be possible, which results in thread wait.
RESOLUTION:
Code is modified so that in such situation, threads return ENOINODE instead of
retrying to get inodes.
* 2487976 (Tracking ID: 2483514)
SYMPTOM:
System panic in following stack:
pvthread+19E500 STACK:
[0001BF00]abend_trap+000000 ()
[000A29E4]tod_lock_write+000084 (??)
[000A34A0]tstop+0000C0 (??)
[04C2F04C].vx_untimeout+000078 ()
[04C29078].vx_timed_sleep+000090 ()
[04D2A72C].vx_open_modes+000574 ()
[04D2F80C].vx_open1+0001FC ()
[04D2FE80].vx_open+00007C ()
[04C39514].vx_open_skey+000044 ()
[0057D75C]vnop_open+0004BC (??, ??, ??, ??, ??)
[00615D24]openpnp+0005E4 (??, ??, ??, ??, ??, ??)
[006162E0]openpath+000100 (??, ??, ??, ??, ??, ??, ??)
[006167B4]copen+000294 (??, ??, ??, ??, ??)
[006156BC]kopen+00001C (??, ??, ??)
DESCRIPTION:
When a file is opened with O_DELAY flag and some process already has that file
opened in conflicting mode with O_NSHARE flag, the first process waits in loop
till the file is available instead exiting. This is achieved by associating a
timer with the waiting process. The waiting process will wakeup after the timer
expires and see if it can open the file, if not it starts a fresh timer and
sleeps again. AIX provides tstart/tstop kernel services to implement this
timer.
Associated with every timer we have a callback function which is executed when
the timer gets expired and after that the process sleeping for timer is awaken.
The callback routine is to add the expired timer to a global freelist. All the
expired timers on this global freelist are freed at the beginning of next
timeout
operation that happens with next open retry or each fresh open with O_DELAY.
The
callback function is executed just before the process sleeping for timer is
awaken, so there is a possibility of having timer on freelist but the process
waiting for that timer is still sleeping. Hence the timer can be freed up while
process is still sleeping. During this window if the process is aborted, we try
to stop a timer which might be already freed and this race results in panic.
RESOLUTION:
Avoid freeing up the expired timer on the freelist if the process associated
with
it is still sleeping. Once the process wakes up, it will set a flag on timer
structure to signal that this timer is safe to be freed up.
* 2494464 (Tracking ID: 2247387)
SYMPTOM:
Internal local mount noise.fullfsck.N4 test hit an assert vx_ino_update:2
With stack trace looking as below
panic: f:vx_ino_update:2
Stack Trace:
IP Function Name
0xe0000000023d5780 ted_call_demon+0xc0
0xe0000000023d6030 ted_assert+0x130
0xe000000000d66f80 vx_ino_update+0x230
0xe000000000d727e0 vx_iupdat_local+0x13b0
0xe000000000d638b0 vx_iupdat+0x230
0xe000000000f20880 vx_tflush_inode+0x210
0xe000000000f1fc80 __vx_fsq_flush___vx_tran.c__4096000_0686__+0xed0
0xe000000000f15160 vx_tranflush+0xe0
0xe000000000d2e600 vx_tranflush_threaded+0xc0
0xe000000000d16000 vx_workitem_process+0x240
0xe000000000d15ca0 vx_worklist_thread+0x7f0
0xe000000001471270 kthread_daemon_startup+0x90
End of Stack Trace
DESCRIPTION:
INOILPUSH flag is not set when inode is getting updated, which caused above
assert. The problem was creation and deletion of clone resets the INOILPUSH flag
and function vx_write1_fast() does not set the flag after updating the inode and
file.
RESOLUTION:
Code is modified so that if INOILPUSH flag is not set while function
vx_write1_fast(), then the flag is set in the function.
* 2508164 (Tracking ID: 2481984)
SYMPTOM:
Access to the file system got hang.
DESCRIPTION:
In function 'vx_setqrec', it will call 'vx_dqget'. when 'vx_dqget' return
errors, it will try to unlock DQ structure using 'VX_DQ_CLUSTER_UNLOCK'. But, in
this situation, DQ structure doesn't hold the lock. hence, this hang happens.
RESOLUTION:
'dq_inval' would be set in 'vx_dqget' in case of any error happens in
'vx_dqget'. Skip unlocking DQ structure in the error code path of 'vx_setqrec',
if 'dq_inval' is set.
* 2523084 (Tracking ID: 2515101)
SYMPTOM:
The "svmon -O vxfs=on" option can be used to collect VxFS file system details,
with this enabled subsequently executing the "svmon -S" command can generate a
system panic in the svm_getvxinode_gnode routine when trying to collect
information from the VxFS segment control blocks.
16)> f
pvthread+838900 STACK:
[F100000090704A38]perfvmmstat:svm_getvxinode_gnode+000038
DESCRIPTION:
VxFS will create and delete AIX Virtual Memory Management [VMM] structures
called Segment Control Blocks [SCB] via VMM interfaces. VxFS was leaking SCBs
via one specific code path. The "svmon -S" command will parse a global list of
SCB structures, including any SCB structures leaked by VxFS. If svmon is also
collecting information about VxFS file systems the gnode element of the SCB
will be dereferenced, for a leaked SCB the gnode will be stale and thus now
contain unrelated content, reading and dereferencing this content can generate
the panic.
RESOLUTION:
A very simple and low risk change now prevents Segment Control Blocks from
being leaked by VxFS, the SCBs will now be correctly removed by VxFS.
* 2529356 (Tracking ID: 2340953)
SYMPTOM:
During internal stress test, f:vx_iget:1a assert is seen.
DESCRIPTION:
While renaming certain file, we check if the target directory is in the path of
the source file to be renamed. while using function vx_iget() to reach till root
inode, one of parent directory incode number was 0 and hence the assert.
RESOLUTION:
Code is changed so that during renames, parent directory is first assigned correct
inode number before using vx_iget() function to retrieve root inode.
INSTALLING THE PATCH
--------------------
If the currently installed VRTSvxfs is below 5.1.112.0, you must upgrade VRTSvxfs to
5.1.112.0 level before installing this patch.
AIX maintenance levels and APARs can be downloaded from the
IBM Web site:
http://techsupport.services.ibm.com
Install the VRTSvxfs.bff patch if VRTSvxfs is
already installed at fileset level 5.1.112.0
A system reboot is required after installing this patch.
To apply the patch, first unmount all VxFS file systems,
then enter these commands:
# mount | grep vxfs
# cd
# installp -aXd VRTSvxfs.bff VRTSvxfs
# reboot
REMOVING THE PATCH
------------------
If you need to remove the patch, first unmount all VxFS
file systems, then enter these commands:
# mount | grep vxfs
# installp -r VRTSvxfs
# reboot
SPECIAL INSTRUCTIONS
--------------------
NONE
OTHERS
------
NONE