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90 Commits

Author SHA1 Message Date
Tom Lane
0cf3363c01 Fix inadequate buffer locking in FSM and VM page re-initialization.
When reading an existing FSM or VM page that was found to be corrupt by the
buffer manager, the code applied PageInit() to reinitialize the page, but
did so without any locking.  There is thus a hazard that two backends might
concurrently do PageInit, which in itself would still be OK, but the slower
one might then zero over subsequent data changes applied by the faster one.
Even that is unlikely to be fatal; but it's not desirable, so add locking
to prevent it.

This does not add any locking overhead in the normal code path where the
page is OK.  It's not immediately obvious that that's safe, but I believe
it is, for reasons explained in the added comments.

Problem noted by R P Asim.  It's been like this for a long time, so
back-patch to all supported branches.

Discussion: https://postgr.es/m/CANXE4Te4G0TGq6cr0-TvwP0H4BNiK_-hB5gHe8mF+nz0mcYfMQ@mail.gmail.com
2018-07-13 11:53:17 -04:00
Heikki Linnakangas
1c02ee314b Fix WAL-logging of FSM and VM truncation.
When a relation is truncated, it is important that the FSM is truncated as
well. Otherwise, after recovery, the FSM can return a page that has been
truncated away, leading to errors like:

ERROR:  could not read block 28991 in file "base/16390/572026": read only 0
of 8192 bytes

We were using MarkBufferDirtyHint() to dirty the buffer holding the last
remaining page of the FSM, but during recovery, that might in fact not
dirty the page, and the FSM update might be lost.

To fix, use the stronger MarkBufferDirty() function. MarkBufferDirty()
requires us to do WAL-logging ourselves, to protect from a torn page, if
checksumming is enabled.

Also fix an oversight in visibilitymap_truncate: it also needs to WAL-log
when checksumming is enabled.

Analysis by Pavan Deolasee.

Discussion: <CABOikdNr5vKucqyZH9s1Mh0XebLs_jRhKv6eJfNnD2wxTn=_9A@mail.gmail.com>

Backpatch to 9.3, where we got data checksums.
2016-10-19 15:00:34 +03:00
Bruce Momjian
04e15c69d2 Remove tabs after spaces in C comments
This was not changed in HEAD, but will be done later as part of a
pgindent run.  Future pgindent runs will also do this.

Report by Tom Lane

Backpatch through all supported branches, but not HEAD
2014-05-06 11:26:28 -04:00
Jeff Davis
20723ce801 Add buffer_std flag to MarkBufferDirtyHint().
MarkBufferDirtyHint() writes WAL, and should know if it's got a
standard buffer or not. Currently, the only callers where buffer_std
is false are related to the FSM.

In passing, rename XLOG_HINT to XLOG_FPI, which is more descriptive.

Back-patch to 9.3.
2013-06-17 08:04:18 -07:00
Simon Riggs
96ef3b8ff1 Allow I/O reliability checks using 16-bit checksums
Checksums are set immediately prior to flush out of shared buffers
and checked when pages are read in again. Hint bit setting will
require full page write when block is dirtied, which causes various
infrastructure changes. Extensive comments, docs and README.

WARNING message thrown if checksum fails on non-all zeroes page;
ERROR thrown but can be disabled with ignore_checksum_failure = on.

Feature enabled by an initdb option, since transition from option off
to option on is long and complex and has not yet been implemented.
Default is not to use checksums.

Checksum used is WAL CRC-32 truncated to 16-bits.

Simon Riggs, Jeff Davis, Greg Smith
Wide input and assistance from many community members. Thank you.
2013-03-22 13:54:07 +00:00
Bruce Momjian
bd61a623ac Update copyrights for 2013
Fully update git head, and update back branches in ./COPYRIGHT and
legal.sgml files.
2013-01-01 17:15:01 -05:00
Alvaro Herrera
c219d9b0a5 Split tuple struct defs from htup.h to htup_details.h
This reduces unnecessary exposure of other headers through htup.h, which
is very widely included by many files.

I have chosen to move the function prototypes to the new file as well,
because that means htup.h no longer needs to include tupdesc.h.  In
itself this doesn't have much effect in indirect inclusion of tupdesc.h
throughout the tree, because it's also required by execnodes.h; but it's
something to explore in the future, and it seemed best to do the htup.h
change now while I'm busy with it.
2012-08-30 16:52:35 -04:00
Bruce Momjian
e126958c2e Update copyright notices for year 2012. 2012-01-01 18:01:58 -05:00
Bruce Momjian
6416a82a62 Remove unnecessary #include references, per pgrminclude script. 2011-09-01 10:04:27 -04:00
Bruce Momjian
5d950e3b0c Stamp copyrights for year 2011. 2011-01-01 13:18:15 -05:00
Magnus Hagander
9f2e211386 Remove cvs keywords from all files. 2010-09-20 22:08:53 +02:00
Robert Haas
d37781fa82 Tidy up a few calls to smrgextend().
In the new API introduced by my patch to include the backend ID in
temprel filenames, the last argument to smrgextend() became skipFsync
rather than isTemp, but these calls didn't get the memo.  It's not
really a problem to pass rel->rd_istemp rather than just plain false,
because smgrextend() now automatically skips the fsync for temprels
anyway, but this seems cleaner and saves some minute number of cycles.
2010-08-19 02:58:37 +00:00
Robert Haas
debcec7dc3 Include the backend ID in the relpath of temporary relations.
This allows us to reliably remove all leftover temporary relation
files on cluster startup without reference to system catalogs or WAL;
therefore, we no longer include temporary relations in XLOG_XACT_COMMIT
and XLOG_XACT_ABORT WAL records.

Since these changes require including a backend ID in each
SharedInvalSmgrMsg, the size of the SharedInvalidationMessage.id
field has been reduced from two bytes to one, and the maximum number
of connections has been reduced from INT_MAX / 4 to 2^23-1.  It would
be possible to remove these restrictions by increasing the size of
SharedInvalidationMessage by 4 bytes, but right now that doesn't seem
like a good trade-off.

Review by Jaime Casanova and Tom Lane.
2010-08-13 20:10:54 +00:00
Bruce Momjian
65e806cba1 pgindent run for 9.0 2010-02-26 02:01:40 +00:00
Tom Lane
cbe9d6beb4 Fix up rickety handling of relation-truncation interlocks.
Move rd_targblock, rd_fsm_nblocks, and rd_vm_nblocks from relcache to the smgr
relation entries, so that they will get reset to InvalidBlockNumber whenever
an smgr-level flush happens.  Because we now send smgr invalidation messages
immediately (not at end of transaction) when a relation truncation occurs,
this ensures that other backends will reset their values before they next
access the relation.  We no longer need the unreliable assumption that a
VACUUM that's doing a truncation will hold its AccessExclusive lock until
commit --- in fact, we can intentionally release that lock as soon as we've
completed the truncation.  This patch therefore reverts (most of) Alvaro's
patch of 2009-11-10, as well as my marginal hacking on it yesterday.  We can
also get rid of assorted no-longer-needed relcache flushes, which are far more
expensive than an smgr flush because they kill a lot more state.

In passing this patch fixes smgr_redo's failure to perform visibility-map
truncation, and cleans up some rather dubious assumptions in freespace.c and
visibilitymap.c about when rd_fsm_nblocks and rd_vm_nblocks can be out of
date.
2010-02-09 21:43:30 +00:00
Tom Lane
16e5859cd2 Allow free space map vacuuming to be interrupted. 2010-02-09 00:28:57 +00:00
Bruce Momjian
0239800893 Update copyright for the year 2010. 2010-01-02 16:58:17 +00:00
Bruce Momjian
d747140279 8.4 pgindent run, with new combined Linux/FreeBSD/MinGW typedef list
provided by Andrew.
2009-06-11 14:49:15 +00:00
Heikki Linnakangas
b2a667b9ee Add a new option to RestoreBkpBlocks() to indicate if a cleanup lock should
be used instead of the normal exclusive lock, and make WAL redo functions
responsible for calling RestoreBkpBlocks(). They know better what kind of a
lock they need.

At the moment, this just moves things around with no functional change, but
makes the hot standby patch that's under review cleaner.
2009-01-20 18:59:37 +00:00
Bruce Momjian
511db38ace Update copyright for 2009. 2009-01-01 17:24:05 +00:00
Heikki Linnakangas
011fa3662e Small comment fixes. 2008-12-03 12:22:53 +00:00
Heikki Linnakangas
4d6ee26171 Don't force creation of the FSM on searches. It will still be created
as soon as the first page fills up, and is marked as (almost) full,
though.
2008-11-27 13:32:26 +00:00
Heikki Linnakangas
9858a8c81c Rely on relcache invalidation to update the cached size of the FSM. 2008-11-26 17:08:58 +00:00
Heikki Linnakangas
3396000684 Rethink the way FSM truncation works. Instead of WAL-logging FSM
truncations in FSM code, call FreeSpaceMapTruncateRel from smgr_redo. To
make that cleaner from modularity point of view, move the WAL-logging one
level up to RelationTruncate, and move RelationTruncate and all the
related WAL-logging to new src/backend/catalog/storage.c file. Introduce
new RelationCreateStorage and RelationDropStorage functions that are used
instead of calling smgrcreate/smgrscheduleunlink directly. Move the
pending rel deletion stuff from smgrcreate/smgrscheduleunlink to the new
functions. This leaves smgr.c as a thin wrapper around md.c; all the
transactional stuff is now in storage.c.

This will make it easier to add new forks with similar truncation logic,
like the visibility map.
2008-11-19 10:34:52 +00:00
Heikki Linnakangas
e9816533e3 Update FSM on WAL replay. This is a bit limited; the FSM is only updated
on non-full-page-image WAL records, and quite arbitrarily, only if there's
less than 20% free space on the page after the insert/update (not on HOT
updates, though). The 20% cutoff should avoid most of the overhead, when
replaying a bulk insertion, for example, while ensuring that pages that
are full are marked as full in the FSM.

This is mostly to avoid the nasty worst case scenario, where you replay
from a PITR archive, and the FSM information in the base backup is really
out of date. If there was a lot of pages that the outdated FSM claims to
have free space, but don't actually have any, the first unlucky inserter
after the recovery would traverse through all those pages, just to find
out that they're full. We didn't have this problem with the old FSM
implementation, because we simply threw the FSM information away on a
non-clean shutdown.
2008-10-31 19:40:27 +00:00
Heikki Linnakangas
19c8dc839b Unite ReadBufferWithFork, ReadBufferWithStrategy, and ZeroOrReadBuffer
functions into one ReadBufferExtended function, that takes the strategy
and mode as argument. There's three modes, RBM_NORMAL which is the default
used by plain ReadBuffer(), RBM_ZERO, which replaces ZeroOrReadBuffer, and
a new mode RBM_ZERO_ON_ERROR, which allows callers to read corrupt pages
without throwing an error. The FSM needs the new mode to recover from
corrupt pages, which could happend if we crash after extending an FSM file,
and the new page is "torn".

Add fork number to some error messages in bufmgr.c, that still lacked it.
2008-10-31 15:05:00 +00:00
Tom Lane
68827a7ada Suppress an uninitialized-variable warning (not all versions of gcc
complain here, but some do)
2008-10-01 14:59:23 +00:00
Heikki Linnakangas
f06ef2bede Fix WAL redo of FSM truncation. We can't call smgrtruncate() during WAL
replay, because it tries to XLogInsert().
2008-10-01 08:12:14 +00:00
Tom Lane
6ca1b1cd95 Fix compiler warning (unportable sprintf usage) 2008-09-30 14:15:58 +00:00
Heikki Linnakangas
15c121b3ed Rewrite the FSM. Instead of relying on a fixed-size shared memory segment, the
free space information is stored in a dedicated FSM relation fork, with each
relation (except for hash indexes; they don't use FSM).

This eliminates the max_fsm_relations and max_fsm_pages GUC options; remove any
trace of them from the backend, initdb, and documentation.

Rewrite contrib/pg_freespacemap to match the new FSM implementation. Also
introduce a new variant of the get_raw_page(regclass, int4, int4) function in
contrib/pageinspect that let's you to return pages from any relation fork, and
a new fsm_page_contents() function to inspect the new FSM pages.
2008-09-30 10:52:14 +00:00
Tom Lane
3fcc7e8e18 Reduce memory consumption during VACUUM of large relations, by using
FSMPageData (6 bytes) instead of PageFreeSpaceInfo (8 or 16 bytes)
for the temporary array of page-free-space information.

Itagaki Takahiro
2008-03-10 02:04:10 +00:00
Bruce Momjian
9098ab9e32 Update copyrights in source tree to 2008. 2008-01-01 19:46:01 +00:00
Bruce Momjian
29dccf5fe0 Update CVS HEAD for 2007 copyright. Back branches are typically not
back-stamped for this.
2007-01-05 22:20:05 +00:00
Peter Eisentraut
409600942b KB -> kB 2006-11-24 09:20:12 +00:00
Bruce Momjian
f99a569a2e pgindent run for 8.2. 2006-10-04 00:30:14 +00:00
Tom Lane
9e936693a9 Fix free space map to correctly track the total amount of FSM space needed
even when a single relation requires more than max_fsm_pages pages.  Also,
make VACUUM emit a warning in this case, since it likely means that VACUUM
FULL or other drastic corrective measure is needed.  Per reports from Jeff
Frost and others of unexpected changes in the claimed max_fsm_pages need.
2006-09-21 20:31:22 +00:00
Bruce Momjian
e0522505bd Remove 576 references of include files that were not needed. 2006-07-14 14:52:27 +00:00
Tom Lane
ae643747b1 Fix a passel of recently-committed violations of the rule 'thou shalt
have no other gods before c.h'.  Also remove some demonstrably redundant
#include lines, mostly of <errno.h> which was added to c.h years ago.
2006-07-14 05:28:29 +00:00
Bruce Momjian
f2f5b05655 Update copyright for 2006. Update scripts. 2006-03-05 15:59:11 +00:00
Bruce Momjian
d5dd3d451e Add contrib/pg_freespacemap to display free space map information.
Mark Kirkwood
2006-02-12 03:55:53 +00:00
Peter Eisentraut
07bb9f086b Message corrections 2005-10-29 00:31:52 +00:00
Bruce Momjian
1dc3498251 Standard pgindent run for 8.1. 2005-10-15 02:49:52 +00:00
Tom Lane
0007490e09 Convert the arithmetic for shared memory size calculation from 'int'
to 'Size' (that is, size_t), and install overflow detection checks in it.
This allows us to remove the former arbitrary restrictions on NBuffers
etc.  It won't make any difference in a 32-bit machine, but in a 64-bit
machine you could theoretically have terabytes of shared buffers.
(How efficiently we could manage 'em remains to be seen.)  Similarly,
num_temp_buffers, work_mem, and maintenance_work_mem can be set above
2Gb on a 64-bit machine.  Original patch from Koichi Suzuki, additional
work by moi.
2005-08-20 23:26:37 +00:00
Bruce Momjian
28d0515d18 Fix FSM warning to mention increasing max_fsm_pages. Was incorrectly
max_fsm_relations.
2005-08-17 03:50:59 +00:00
Tom Lane
eb5949d190 Arrange for the postmaster (and standalone backends, initdb, etc) to
chdir into PGDATA and subsequently use relative paths instead of absolute
paths to access all files under PGDATA.  This seems to give a small
performance improvement, and it should make the system more robust
against naive DBAs doing things like moving a database directory that
has a live postmaster in it.  Per recent discussion.
2005-07-04 04:51:52 +00:00
Tom Lane
e92a88272e Modify hash_search() API to prevent future occurrences of the error
spotted by Qingqing Zhou.  The HASH_ENTER action now automatically
fails with elog(ERROR) on out-of-memory --- which incidentally lets
us eliminate duplicate error checks in quite a bunch of places.  If
you really need the old return-NULL-on-out-of-memory behavior, you
can ask for HASH_ENTER_NULL.  But there is now an Assert in that path
checking that you aren't hoping to get that behavior in a palloc-based
hash table.
Along the way, remove the old HASH_FIND_SAVE/HASH_REMOVE_SAVED actions,
which were not being used anywhere anymore, and were surely too ugly
and unsafe to want to see revived again.
2005-05-29 04:23:07 +00:00
Bruce Momjian
3b0a5e50d7 Update VACUUM VERBOSE FSM message, per Tom. 2005-04-24 03:51:49 +00:00
Bruce Momjian
714d5a4c37 Update VACUUM VERBOSE update, per Alvaro. 2005-04-23 21:16:34 +00:00
Bruce Momjian
9ba6587f8b Update working of VACUUM VERBOSE. 2005-04-23 21:10:20 +00:00
Bruce Momjian
52e08c35f7 Make VACUUM VERBOSE FSM output all output in a single INFO output
statement.
2005-04-23 20:56:01 +00:00