Commit Graph

37 Commits

Author SHA1 Message Date
Ronnie Sahlberg
447ff1bf0a lockfile.c: make lock_file return a meaningful errno on failurei
Making errno when returning from lock_file() meaningful, which should
fix

 * an existing almost-bug in lock_ref_sha1_basic where it assumes
   errno==ENOENT is meaningful and could waste some work on retries

 * an existing bug in repack_without_refs where it prints
   strerror(errno) and picks advice based on errno, despite errno
   potentially being zero and potentially having been clobbered by
   that point

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
2014-07-14 11:54:41 -07:00
Ronnie Sahlberg
6af926e8bc lockfile.c: add a new public function unable_to_lock_message
Introducing a new unable_to_lock_message helper, which has nicer
semantics than unable_to_lock_error and cleans up lockfile.c a little.

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
2014-07-14 11:54:40 -07:00
Michael Haggerty
2fbd4f92fa lockfile: fix buffer overflow in path handling
The path of the file to be locked is held in lock_file::filename,
which is a fixed-length buffer of length PATH_MAX.  This buffer is
also (temporarily) used to hold the path of the lock file, which is
the path of the file being locked plus ".lock".  Because of this, the
path of the file being locked must be less than (PATH_MAX - 5)
characters long (5 chars are needed for ".lock" and one character for
the NUL terminator).

On entry into lock_file(), the path length was only verified to be
less than PATH_MAX characters, not less than (PATH_MAX - 5)
characters.

When and if resolve_symlink() is called, then that function is
correctly told to treat the buffer as (PATH_MAX - 5) characters long.
This part is correct.  However:

* If LOCK_NODEREF was specified, then resolve_symlink() is never
  called.

* If resolve_symlink() is called but the path is not a symlink, then
  the length check is never applied.

So it is possible for a path with length (PATH_MAX - 5 <= len <
PATH_MAX) to make it through the checks.  When ".lock" is strcat()ted
to such a path, the lock_file::filename buffer is overflowed.

Fix the problem by adding a check when entering lock_file() that the
original path is less than (PATH_MAX - 5) characters.

[jc: with independent development by Peff]

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-07 10:29:28 -07:00
Carlos Martín Nieto
e2a57aac8a Name make_*_path functions more accurately
Rename the make_*_path functions so it's clearer what they do, in
particlar make clear what the differnce between make_absolute_path and
make_nonrelative_path is by renaming them real_path and absolute_path
respectively. make_relative_path has an understandable name and is
renamed to relative_path to maintain the name convention.

The function calls have been replaced 1-to-1 in their usage.

Signed-off-by: Carlos Martín Nieto <cmn@elego.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-03-17 16:08:30 -07:00
Matthieu Moy
a8c37a0e01 lockfile: show absolute filename in unable_to_lock_message
When calling a git command from a subdirectory and a file locking fails,
the user will get a path relative to the root of the worktree, which is
invalid from the place where the command is ran. Make it easy for the
user to know which file it is.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-12 15:48:24 -08:00
Miklos Vajna
1b018fd9be git branch -D: give a better error message when lockfile creation fails
Previously the old error message just told the user that it was not
possible to delete the ref from the packed-refs file. Give instructions
on how to resolve the problem.

Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2009-09-29 08:14:47 -07:00
Junio C Hamano
36587681b4 Merge branch 'ar/unlink-err'
* ar/unlink-err:
  print unlink(2) errno in copy_or_link_directory
  replace direct calls to unlink(2) with unlink_or_warn
  Introduce an unlink(2) wrapper which gives warning if unlink failed
2009-05-18 09:01:06 -07:00
Felipe Contreras
4b25d091ba Fix a bunch of pointer declarations (codestyle)
Essentially; s/type* /type */ as per the coding guidelines.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-05-01 15:17:31 -07:00
Alex Riesen
691f1a28bf replace direct calls to unlink(2) with unlink_or_warn
This helps to notice when something's going wrong, especially on
systems which lock open files.

I used the following criteria when selecting the code for replacement:
- it was already printing a warning for the unlink failures
- it is in a function which already printing something or is
  called from such a function
- it is in a static function, returning void and the function is only
  called from a builtin main function (cmd_)
- it is in a function which handles emergency exit (signal handlers)
- it is in a function which is obvously cleaning up the lockfiles

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-04-29 18:37:41 -07:00
John Tapsell
bdfd739dac Make the 'lock file' exists error more informative
It looks like someone did 90% of the work, then forgot to actually use
the function in one place.

Also the helper function did not use the correct variable.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-03-04 20:35:19 -08:00
Junio C Hamano
8c5b85ce87 Merge branch 'maint'
* maint:
  More friendly message when locking the index fails.
  Document git blame --reverse.
  Documentation: Note file formats send-email accepts
2009-02-19 23:44:07 -08:00
Matthieu Moy
e43a6fd3e9 More friendly message when locking the index fails.
Just saying that index.lock exists doesn't tell the user _what_ to do
to fix the problem. We should give an indication that it's normally
safe to delete index.lock after making sure git isn't running here.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-02-19 23:22:57 -08:00
Jeff King
57b235a4bc refactor signal handling for cleanup functions
The current code is very inconsistent about which signals
are caught for doing cleanup of temporary files and lock
files. Some callsites checked only SIGINT, while others
checked a variety of death-dealing signals.

This patch factors out those signals to a single function,
and then calls it everywhere. For some sites, that means
this is a simple clean up. For others, it is an improvement
in that they will now properly clean themselves up after a
larger variety of signals.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-21 22:46:53 -08:00
Jeff King
4a16d07272 chain kill signals for cleanup functions
If a piece of code wanted to do some cleanup before exiting
(e.g., cleaning up a lockfile or a tempfile), our usual
strategy was to install a signal handler that did something
like this:

  do_cleanup(); /* actual work */
  signal(signo, SIG_DFL); /* restore previous behavior */
  raise(signo); /* deliver signal, killing ourselves */

For a single handler, this works fine. However, if we want
to clean up two _different_ things, we run into a problem.
The most recently installed handler will run, but when it
removes itself as a handler, it doesn't put back the first
handler.

This patch introduces sigchain, a tiny library for handling
a stack of signal handlers. You sigchain_push each handler,
and use sigchain_pop to restore whoever was before you in
the stack.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-21 22:46:52 -08:00
Junio C Hamano
0693f9ddad Make sure lockfiles are unlocked when dying on SIGPIPE
We cleaned up lockfiles upon receiving the usual suspects HUP, TERM, QUIT
but a wicked user could kill us of asphyxiation by piping our output to a
pipe that does not read.  Protect ourselves by catching SIGPIPE and clean
up the lockfiles as well in such a case.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-12-21 01:56:20 -08:00
Junio C Hamano
acd3b9eca8 Enhance hold_lock_file_for_{update,append}() API
This changes the "die_on_error" boolean parameter to a mere "flags", and
changes the existing callers of hold_lock_file_for_update/append()
functions to pass LOCK_DIE_ON_ERROR.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-10-19 12:35:37 -07:00
Paolo Bonzini
ad5fa3cc0e rollback lock files on more signals than just SIGINT
Other signals are also common, for example SIGTERM and SIGHUP.
This patch modifies the lock file mechanism to catch more signals.
It also modifies http-push.c which was missing SIGTERM.

Signed-off-by: Paolo Bonzini <bonzini@gnu.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-31 14:33:59 -07:00
Junio C Hamano
b84c343c88 Merge branch 'db/clone-in-c'
* db/clone-in-c:
  Add test for cloning with "--reference" repo being a subset of source repo
  Add a test for another combination of --reference
  Test that --reference actually suppresses fetching referenced objects
  clone: fall back to copying if hardlinking fails
  builtin-clone.c: Need to closedir() in copy_or_link_directory()
  builtin-clone: fix initial checkout
  Build in clone
  Provide API access to init_db()
  Add a function to set a non-default work tree
  Allow for having for_each_ref() list extra refs
  Have a constant extern refspec for "--tags"
  Add a library function to add an alternate to the alternates file
  Add a lockfile function to append to a file
  Mark the list of refs to fetch as const

Conflicts:

	cache.h
	t/t5700-clone-reference.sh
2008-05-25 13:41:37 -07:00
Clemens Buchacher
a129293938 Reset the signal being handled
This did not cause any problems, because remove_lock_file_on_signal is
only registered for SIGINT.

Signed-off-by: Clemens Buchacher <drizzd@aon.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-25 13:06:55 -07:00
Daniel Barkalow
ea3cd5c7c6 Add a lockfile function to append to a file
This takes care of copying the original contents into the replacement
file after the lock is held, so that concurrent additions can't miss
each other's changes.

[jc: munged to drop mmap in favor of copy_file.]

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-04 17:41:44 -07:00
Brandon Casey
d6cf61bfd4 close_lock_file(): new function in the lockfile API
The lockfile API is a handy way to obtain a file that is cleaned
up if you die().  But sometimes you would need this sequence to
work:

 1. hold_lock_file_for_update() to get a file descriptor for
    writing;

 2. write the contents out, without being able to decide if the
    results should be committed or rolled back;

 3. do something else that makes the decision --- and this
    "something else" needs the lockfile not to have an open file
    descriptor for writing (e.g. Windows do not want a open file
    to be renamed);

 4. call commit_lock_file() or rollback_lock_file() as
    appropriately.

This adds close_lock_file() you can call between step 2 and 3 in
the above sequence.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-01-16 15:35:03 -08:00
Steffen Prohaska
ecf4831d89 Use is_absolute_path() in diff-lib.c, lockfile.c, setup.c, trace.c
Using the helper function to test for absolute paths makes porting easier.

Signed-off-by: Steffen Prohaska <prohaska@zib.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-11-26 12:32:05 -08:00
Johannes Schindelin
4723ee992c Close files opened by lock_file() before unlinking.
This is needed on Windows since open files cannot be unlinked.

Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-11-14 15:18:39 -08:00
Bradford C. Smith
5d5a7a6738 fully resolve symlinks when creating lockfiles
Make the code for resolving symlinks in lockfile.c more robust as
follows:

1. Handle relative symlinks
2. recursively resolve symlink chains up to 5

[jc: removed lstat/stat calls to do things stupid way]

Signed-off-by: Bradford C. Smith <bradford.carl.smith@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-07-27 00:02:05 -07:00
Junio C Hamano
d58e8d34b0 When locking in a symlinked repository, try to lock the original.
In a working tree prepared in new-workdir (in contrib/), some files in .git/
directory are symbolic links to the original repository.  The usual sequence of
lock-write-rename would break the symbolic link.

Ideally we should resolve relative symbolic link with maxdepth, but I do not
want to risk too elaborate patch before 1.5.3 release, so this is a minimum
and trivially obvious fix.  new-workdir creates its symbolic links absolute,
and does not link from a symlinked workdir, so this fix should suffice for now.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-07-25 16:22:55 -07:00
Sven Verdoolaege
9a4cbdca34 lockfile.c: schedule remove_lock_file only once.
Removing a lockfile once should be enough.

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-07-13 08:55:15 -07:00
Junio C Hamano
a6080a0a44 War on whitespace
This uses "git-apply --whitespace=strip" to fix whitespace errors that have
crept in to our source files over time.  There are a few files that need
to have trailing whitespaces (most notably, test vectors).  The results
still passes the test, and build result in Documentation/ area is unchanged.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-06-07 00:04:01 -07:00
Junio C Hamano
5e635e3960 lockfile: record the primary process.
The usual process flow is the main process opens and holds the lock to
the index, does its thing, perhaps spawning children during the course,
and then writes the resulting index out by releaseing the lock.

However, the lockfile interface uses atexit(3) to clean it up, without
regard to who actually created the lock.  This typically leads to a
confusing behaviour of lock being released too early when the child
exits, and then the parent process when it calls commit_lockfile()
finds that it cannot unlock it.

This fixes the problem by recording who created and holds the lock, and
upon atexit(3) handler, child simply ignores the lockfile the parent
created.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-21 11:55:23 -07:00
Junio C Hamano
5e7f56ac33 git-read-tree --index-output=<file>
This corrects the interface mistake of the previous one, and
gives a command line parameter to the only plumbing command that
currently needs it: "git-read-tree".

We can add the calls to set_alternate_index_output() to other
plumbing commands that update the index if/when needed.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-03 23:44:32 -07:00
Junio C Hamano
30ca07a249 _GIT_INDEX_OUTPUT: allow plumbing to output to an alternative index file.
When defined, this allows plumbing commands that update the
index (add, apply, checkout-index, merge-recursive, mv,
read-tree, rm, update-index, and write-tree) to write their
resulting index to an alternative index file while holding a
lock to the original index file.  With this, git-commit that
jumps the index does not have to make an extra copy of the index
file, and more importantly, it can do the update while holding
the lock on the index.

However, I think the interface to let an environment variable
specify the output is a mistake, as shown in the documentation.
If a curious user has the environment variable set to something
other than the file GIT_INDEX_FILE points at, almost everything
will break.  This should instead be a command line parameter to
tell these plumbing commands to write the result in the named
file, to prevent stupid mistakes.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-04-03 23:44:32 -07:00
Steven Grimm
f9e8a43a00 Print a more accurate error message when we fail to create a lock file.
Signed-off-by: Steven Grimm <koreth@midwinter.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-06 10:42:49 -08:00
Junio C Hamano
e27e609bbf Merge branch 'maint'
* maint:
  pack-check.c::verify_packfile(): don't run SHA-1 update on huge data
  Fix infinite loop when deleting multiple packed refs.
2007-01-04 22:28:21 -08:00
Junio C Hamano
1084b845d9 Fix infinite loop when deleting multiple packed refs.
It was stupid to link the same element twice to lock_file_list
and end up in a loop, so we certainly need a fix.

But it is not like we are taking a lock on multiple files in
this case.  It is just that we leave the linked element on the
list even after commit_lock_file() successfully removes the
cruft.

We cannot remove the list element in commit_lock_file(); if we
are interrupted in the middle of list manipulation, the call to
remove_lock_file_on_signal() will happen with a broken list
structure pointed by lock_file_list, which would cause the cruft
to remain, so not removing the list element is the right thing
to do.  Instead we should be reusing the element already on the
list.

There is already a code for that in lock_file() function in
lockfile.c.  The code checks lk->next and the element is linked
only when it is not already on the list -- which is incorrect
for the last element on the list (which has NULL in its next
field), but if you read the check as "is this element already on
the list?" it actually makes sense.  We do not want to link it
on the list again, nor we would want to set up signal/atexit
over and over.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-03 01:22:35 -08:00
Junio C Hamano
85023577a8 simplify inclusion of system header files.
This is a mechanical clean-up of the way *.c files include
system header files.

 (1) sources under compat/, platform sha-1 implementations, and
     xdelta code are exempt from the following rules;

 (2) the first #include must be "git-compat-util.h" or one of
     our own header file that includes it first (e.g. config.h,
     builtin.h, pkt-line.h);

 (3) system headers that are included in "git-compat-util.h"
     need not be included in individual C source files.

 (4) "git-compat-util.h" does not have to include subsystem
     specific header files (e.g. expat.h).

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-20 09:51:35 -08:00
Junio C Hamano
40aaae88ad Better error message when we are unable to lock the index file
Most of the callers except the one in refs.c use the function to
update the index file.  Among the index writers, everybody
except write-tree dies if they cannot open it for writing.

This gives the function an extra argument, to tell it to die
when it cannot create a new file as the lockfile.

The only caller that does not have to die is write-tree, because
updating the index for the cache-tree part is optional and not
being able to do so does not affect the correctness.  I think we
do not have to be so careful and make the failure into die() the
same way as other callers, but that would be a different patch.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-08-12 17:08:25 -07:00
Junio C Hamano
138086a725 shared repository - add a few missing calls to adjust_shared_perm().
There were a few calls to adjust_shared_perm() that were
missing:

 - init-db creates refs, refs/heads, and refs/tags before
   reading from templates that could specify sharedrepository in
   the config file;

 - updating config file created it under user's umask without
   adjusting;

 - updating refs created it under user's umask without
   adjusting;

 - switching branches created .git/HEAD under user's umask
   without adjusting.

This moves adjust_shared_perm() from sha1_file.c to path.c,
since a few SIMPLE_PROGRAM need to call repository configuration
functions which in turn need to call adjust_shared_perm().
sha1_file.c needs to link with SHA1 computation library which
is usually not linked to SIMPLE_PROGRAM.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-09 22:15:50 -07:00
Junio C Hamano
021b6e4549 Make index file locking code reusable to others.
The framework to create lockfiles that are removed at exit is
first used to reliably write the index file, but it is
applicable to other things, so stop calling it "cache_file".

This also rewords a few remaining error message that called the
index file "cache file".

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-06 14:30:58 -07:00