If rename() fails, call rollback_lock_file() to delete the lock file
(in case it is still present) and reset the filename field to the
empty string so that the lockfile object is left in a valid state.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If closing an open lockfile fails, then we cannot be sure of the
contents of the lockfile, so there is nothing sensible to do but
delete it. This change also insures that the lock_file object is left
in a defined state in this error path (namely, unlocked).
The only caller that is ultimately affected by this change is
try_merge_strategy() -> write_locked_index(), which can call
close_lock_file() via various execution paths. This caller uses a
static lock_file object which previously could have been reused after
a failed close_lock_file() even though it was still in locked state.
This change causes the lock_file object to be unlocked on failure,
thus fixing this error-handling path.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It was previously a bug to call commit_lock_file() with a lock_file
object that was not active (an illegal access would happen within the
function). It was presumably never done, but this would be an easy
programming error to overlook. So before continuing, do a consistency
check that the lock_file object really is locked.
Helped-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It does just what we need.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is a bit easier to read than the old version, which nested part
of the non-error code in an "if" block.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Ronnie Sahlberg <sahlberg@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Declare the return value to be const to make it clear that we aren't
giving callers permission to write over the string that it points at.
(The return value is the filename field of a struct lock_file, which
can be used by a signal handler at any time and therefore shouldn't be
tampered with.)
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It's bad manners. Especially since there could be a signal during the
call to unlink_or_warn(), in which case the signal handler will see
the wrong filename and delete the reference file, leaving the lockfile
behind.
So make our own copy to work with.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are a few places that use these values, so define constants for
them.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Document the valid states of lock_file objects, how they get into each
state, and how the state is encoded in the object's fields.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The purpose of this change is to make the state diagram for
lock_file objects simpler and deterministic.
If locking fails, lock_file() sometimes leaves the lock_file object
partly initialized, but sometimes not. It sometimes registers the
object in lock_file_list, but sometimes not. This makes the state
diagram for lock_file objects effectively indeterministic and hard
to reason about. A future patch will also change the filename field
into a strbuf, which needs more involved initialization, so it will
become even more important that the state of a lock_file object is
well-defined after a failed attempt to lock.
The ambiguity doesn't currently have any ill effects, because
lock_file objects cannot be removed from the lock_file_list anyway.
But to make it easier to document and reason about the code, make
this behavior consistent: *always* initialize the lock_file object
and *always* register it in lock_file_list the first time it is
used, regardless of whether an error occurs.
While we're at it, make sure that all of the lock_file fields are
initialized to values appropriate for an unlocked object; the caller
is only responsible for making sure that on_list is set to zero before
the first time it is used.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If there is an error copying the old contents to the lockfile, roll
back the lockfile before exiting so that the lockfile is not held
until process cleanup.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If the call to adjust_shared_perm() fails, lock_file returns -1, which
to the caller looks like any other failure to lock the file. So in
this case, roll back the lockfile before returning so that the lock
file is deleted immediately and the lockfile object is left in a
predictable state (namely, unlocked). Previously, the lockfile was
retained until process cleanup in this situation.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When rolling back the lockfile, call close_lock_file() so that the
lock_file's fd field gets set back to -1. This keeps the lock_file
object in a valid state, which is important because these objects are
allowed to be reused. It also makes it unnecessary to check whether
the file has already been closed, because close_lock_file() takes care
of that.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Eliminate a layer of nesting.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Ronnie Sahlberg <sahlberg@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It is only necessary to clear the lock_file's filename field if it was
not already clear.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Ronnie Sahlberg <sahlberg@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Suggested-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Document a couple more functions and the flags argument as used by
hold_lock_file_for_update() and hold_lock_file_for_append().
Reorganize the document to make it more accessible.
Helped-by: Jonathan Nieder <jrnieder@gmail.com>
Helped-by: Junio Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This function is used for other things besides the index, so rename it
accordingly.
Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Ronnie Sahlberg <sahlberg@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
setitmer(2) and related API elements can be configured from
Makefile but autoconf did not know about it.
* jt/itimer-autoconf:
autoconf: check for setitimer()
autoconf: check for struct itimerval
git-compat-util.h: add missing semicolon after struct itimerval
"git merge-recursive" had a small bug that could have made it
mishandle "one side deleted, the other side did not touch it" in a
rare corner case, where the other side actually did touch to cause
the blob object names to be different but both blobs before and
after the change normalize to the same (e.g. correcting mistake to
check in a blob with CRLF line endings by replacing it with another
blob that records the same contents with LF line endings).
* sb/merge-recursive-copy-paste-fix:
merge-recursive: remove stale commented debugging code
merge-recursive: fix copy-paste mistake
We used to get confused when a process called us with SIGPIPE
ignored; we do want to die with SIGPIPE when the output is not
read by default, and do ignore the signal when appropriate.
* pr/use-default-sigpipe-setting:
mingw.h: add dummy functions for sigset_t operations
unblock and unignore SIGPIPE
"git fsck" failed to report that it found corrupt objects via its
exit status in some cases.
* jk/fsck-exit-code-fix:
fsck: return non-zero status on missing ref tips
fsck: exit with non-zero status upon error from fsck_obj()
"git config --add section.var val" used to lose existing
section.var whose value was an empty string.
* ta/config-add-to-empty-or-true-fix:
config: avoid a funny sentinel value "a^"
make config --add behave correctly for empty and NULL values
Reachability check (used in "git prune" and friends) did not add a
detached HEAD as a starting point to traverse objects still in use.
* mk/reachable-protect-detached-head:
reachable.c: add HEAD to reachability starting commits
An attempt to remove the entire tree in the "git fast-import" input
stream caused it to misbehave.
* mb/fast-import-delete-root:
fast-import: fix segfault in store_tree()
t9300: test filedelete command
When receiving an invalid pack stream that records the same object
twice, multiple threads got confused due to a race.
* jk/index-pack-threading-races:
index-pack: fix race condition with duplicate bases
"git push" over HTTP transport had an artificial limit on number of
refs that can be pushed imposed by the command line length.
* jk/send-pack-many-refspecs:
send-pack: take refspecs over stdin
* so/rebase-doc:
Documentation/git-rebase.txt: <upstream> must be given to specify <branch>
Documentation/git-rebase.txt: -f forces a rebase that would otherwise be a no-op
Some MUAs mangled a line in a message that begins with "From " to
">From " when writing to a mailbox file and feeding such an input
to "git am" used to lose such a line.
* jk/mbox-from-line:
mailinfo: work around -Wstring-plus-int warning
mailinfo: make ">From" in-body header check more robust
"rev-parse --verify --quiet $name" is meant to quietly exit with a
non-zero status when $name is not a valid object name, but still
gave error messages in some cases.
* da/rev-parse-verify-quiet:
stash: prefer --quiet over shell redirection of the standard error stream
refs: make rev-parse --quiet actually quiet
t1503: use test_must_be_empty
Documentation: a note about stdout for git rev-parse --verify --quiet
The pretty-format specifier "%d", which expanded to " (tagname)"
for a tagged commit, gained a cousin "%D" that just gives the
"tagname" without frills.
* hj/pretty-naked-decoration:
pretty: add %D format specifier
* 'maint' of git://github.com/git-l10n/git-po:
l10n: de.po: use comma before "um"
l10n: de.po: change Email to E-Mail
po/TEAMS: add new member to German translation team
pre- and post-receive hooks are no longer required to read all
their inputs.
* jc/ignore-sigpipe-while-running-hooks:
receive-pack: allow hooks to ignore its standard input stream
Code cleanup.
* jk/prune-packed-server-info:
repack: call prune_packed_objects() and update_server_info() directly
server-info: clean up after writing info/packs
make update-server-info more robust
prune-packed: fix minor memory leak
Using "hash-object --literally", test one of the new breakages
js/fsck-tag-validation topic teaches "fsck" to catch is caught.
* jc/hash-object-fsck-tag:
t1450: make sure fsck detects a malformed tagger line
