Revision fd45e4784164d1017521086524e3442318c67370 authored by Dave Chinner on 02 January 2010, 02:38:56 UTC, committed by Alex Elder on 10 January 2010, 18:22:02 UTC
When we search for and find a busy extent during allocation we
force the log out to ensure the extent free transaction is on
disk before the allocation transaction. The current implementation
has a subtle bug in it--it does not handle multiple overlapping
ranges.

That is, if we free lots of little extents into a single
contiguous extent, then allocate the contiguous extent, the busy
search code stops searching at the first extent it finds that
overlaps the allocated range. It then uses the commit LSN of the
transaction to force the log out to.

Unfortunately, the other busy ranges might have more recent
commit LSNs than the first busy extent that is found, and this
results in xfs_alloc_search_busy() returning before all the
extent free transactions are on disk for the range being
allocated. This can lead to potential metadata corruption or
stale data exposure after a crash because log replay won't replay
all the extent free transactions that cover the allocation range.

Modified-by: Alex Elder <aelder@sgi.com>

(Dropped the "found" argument from the xfs_alloc_busysearch trace
event.)

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
1 parent 44e08c4
Raw File
setlocalversion
#!/bin/sh
#
# This scripts adds local version information from the version
# control systems git, mercurial (hg) and subversion (svn).
#
# If something goes wrong, send a mail the kernel build mailinglist
# (see MAINTAINERS) and CC Nico Schottelius
# <nico-linuxsetlocalversion -at- schottelius.org>.
#
#

usage() {
	echo "Usage: $0 [srctree]" >&2
	exit 1
}

cd "${1:-.}" || usage

# Check for git and a git repo.
if head=`git rev-parse --verify --short HEAD 2>/dev/null`; then

	# If we are at a tagged commit (like "v2.6.30-rc6"), we ignore it,
	# because this version is defined in the top level Makefile.
	if [ -z "`git describe --exact-match 2>/dev/null`" ]; then

		# If we are past a tagged commit (like "v2.6.30-rc5-302-g72357d5"),
		# we pretty print it.
		if atag="`git describe 2>/dev/null`"; then
			echo "$atag" | awk -F- '{printf("-%05d-%s", $(NF-1),$(NF))}'

		# If we don't have a tag at all we print -g{commitish}.
		else
			printf '%s%s' -g $head
		fi
	fi

	# Is this git on svn?
	if git config --get svn-remote.svn.url >/dev/null; then
	        printf -- '-svn%s' "`git svn find-rev $head`"
	fi

	# Update index only on r/w media
	[ -w . ] && git update-index --refresh --unmerged > /dev/null

	# Check for uncommitted changes
	if git diff-index --name-only HEAD | grep -v "^scripts/package" \
	    | read dummy; then
		printf '%s' -dirty
	fi

	# All done with git
	exit
fi

# Check for mercurial and a mercurial repo.
if hgid=`hg id 2>/dev/null`; then
	tag=`printf '%s' "$hgid" | cut -d' ' -f2`

	# Do we have an untagged version?
	if [ -z "$tag" -o "$tag" = tip ]; then
		id=`printf '%s' "$hgid" | sed 's/[+ ].*//'`
		printf '%s%s' -hg "$id"
	fi

	# Are there uncommitted changes?
	# These are represented by + after the changeset id.
	case "$hgid" in
		*+|*+\ *) printf '%s' -dirty ;;
	esac

	# All done with mercurial
	exit
fi

# Check for svn and a svn repo.
if rev=`svn info 2>/dev/null | grep '^Last Changed Rev'`; then
	rev=`echo $rev | awk '{print $NF}'`
	printf -- '-svn%s' "$rev"

	# All done with svn
	exit
fi
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