Commit Graph

490 Commits

Author SHA1 Message Date
Junio C Hamano
298a958224 Merge branch 'jk/list-objects-filter-cleanup'
A couple of bugfixes with code clean-up.

* jk/list-objects-filter-cleanup:
  list-objects-filter: convert filter_spec to a strbuf
  list-objects-filter: add and use initializers
  list-objects-filter: handle null default filter spec
  list-objects-filter: don't memset after releasing filter struct
2022-09-19 14:35:24 -07:00
Junio C Hamano
08d61c7061 Merge branch 'jk/plug-list-object-filter-leaks'
The code that manages list-object-filter structure, used in partial
clones, leaked the instances, which has been plugged.

* jk/plug-list-object-filter-leaks:
  prepare_repo_settings(): plug leak of config values
  list_objects_filter_options: plug leak of filter_spec strings
  transport: free filter options in disconnect_git()
  transport: deep-copy object-filter struct for fetch-pack
  list_objects_filter_copy(): deep-copy sparse_oid_name field
2022-09-14 12:56:40 -07:00
Jeff King
2a01bdedf8 list-objects-filter: add and use initializers
In 7e2619d8ff (list_objects_filter_options: plug leak of filter_spec
strings, 2022-09-08), we noted that the filter_spec string_list was
inconsistent in how it handled memory ownership of strings stored in the
list. The fix there was a bit of a band-aid to set the "strdup_strings"
variable right before adding anything.

That works OK, and it lets the users of the API continue to
zero-initialize the struct. But it makes the code a bit hard to follow
and accident-prone, as any other spots appending the filter_spec need to
think about whether to set the strdup_strings value, too (there's one
such spot in partial_clone_get_default_filter_spec(), which is probably
a possible memory leak).

So let's do that full cleanup now. We'll introduce a
LIST_OBJECTS_FILTER_INIT macro and matching function, and use them as
appropriate (though it is for the "_options" struct, this matches the
corresponding list_objects_filter_release() function).

This is harder than it seems! Many other structs, like
git_transport_data, embed the filter struct. So they need to initialize
it themselves even if the rest of the enclosing struct is OK with
zero-initialization. I found all of the relevant spots by grepping
manually for declarations of list_objects_filter_options. And then doing
so recursively for structs which embed it, and ones which embed those,
and so on.

I'm pretty sure I got everything, but there's no change that would alert
the compiler if any topics in flight added new declarations. To catch
this case, we now double-check in the parsing function that things were
initialized as expected and BUG() if appropriate.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-12 08:38:59 -07:00
Jeff King
dd49699d12 transport: free filter options in disconnect_git()
If a user of the transport API calls transport_set_option() with
TRANS_OPT_LIST_OBJECTS_FILTER, it doesn't pass a struct, but rather a
string with the filter-spec, which the transport code then stores in its
own list_objects_filter_options struct.

When the caller is done and we call transport_disconnect(), the contents
of that filter struct are then leaked. We should release it before
freeing the transport struct.

Another way to solve this would be for transport_set_option() to pass a
pointer to the struct. But that's awkward, because there's a generic
transport-option interface that always takes a string. Plus it opens up
questions of memory lifetimes; by storing its own filter-options struct,
the transport code remains self-contained.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-08 11:07:58 -07:00
Jeff King
3f0e86a158 transport: deep-copy object-filter struct for fetch-pack
When the transport code for the git protocol calls into fetch_pack(), it
has to fill out a fetch_pack_args struct that is mostly taken from the
transport options. We pass along any object-filter data by doing a
struct assignment of the list_objects_filter_options struct. But doing
so isn't safe; it contains allocated pointers in its filter_spec
string_list, which could lead to a double-free if one side mutates or
frees the string_list.

And indeed, the fetch-pack code does clear and rewrite the list via
expand_list_objects_filter_spec(), leaving the transport code with
dangling pointers.

This hasn't been a problem so far, though, because the transport code
doesn't look further at the filter struct. But it should, because in
some cases (when fetch-pack doesn't rewrite the list), it ends up
leaking the string_list.

So let's start by turning this shallow copy into a deep one, which
should let us fix the transport leak in a subsequent patch. Likewise,
we'll free the deep copy we made here when we're done with it (to avoid
leaking).

Note that it would also work to pass fetch-pack a pointer to our filter
struct, rather than a copy. But it's awkward for fetch-pack to take a
pointer in its arg struct; the actual git-fetch-pack command allocates a
fetch_pack_args struct on the stack and expects it to contain the filter
options. It could be rewritten to avoid this, but a deep copy serves our
purposes just as well.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-08 11:06:14 -07:00
Ævar Arnfjörð Bjarmason
5cf88fd8b0 git-compat-util.h: use "UNUSED", not "UNUSED(var)"
As reported in [1] the "UNUSED(var)" macro introduced in
2174b8c75de (Merge branch 'jk/unused-annotation' into next,
2022-08-24) breaks coccinelle's parsing of our sources in files where
it occurs.

Let's instead partially go with the approach suggested in [2] of
making this not take an argument. As noted in [1] "coccinelle" will
ignore such tokens in argument lists that it doesn't know about, and
it's less of a surprise to syntax highlighters.

This undoes the "help us notice when a parameter marked as unused is
actually use" part of 9b24034754 (git-compat-util: add UNUSED macro,
2022-08-19), a subsequent commit will further tweak the macro to
implement a replacement for that functionality.

1. https://lore.kernel.org/git/220825.86ilmg4mil.gmgdl@evledraar.gmail.com/
2. https://lore.kernel.org/git/220819.868rnk54ju.gmgdl@evledraar.gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-01 10:49:48 -07:00
Jeff King
f7d5741279 transport: mark bundle transport_options as unused
get_refs_from_bundle() is a virtual function which must match the
signature of other transports, but it doesn't look at its
transport_options at all. This isn't a bug, because not all transports
necessarily support all options. Let's mark it as unused to appease
-Wunused-parameter.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-19 12:18:55 -07:00
Derrick Stolee
f5adaa5cc3 transport.c: avoid "whitelist"
The word "whitelist" has cultural implications that are not inclusive.
Thankfully, it is not difficult to reword and avoid its use.

The GIT_ALLOW_PROTOCOL environment variable was referred to as a
"whitelist", but the word "allow" is already part of the variable.
Replace "whitelist" with "allow_list" in these cases to demonstrate that
we are processing a list of allowed protocols.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-07-19 12:45:31 -07:00
Junio C Hamano
07a454027b Merge branch 'fh/transport-push-leakfix'
Leakfix.

* fh/transport-push-leakfix:
  transport: free local and remote refs in transport_push()
  transport: unify return values and exit point from transport_push()
  transport: remove unnecessary indenting in transport_push()
2022-06-07 14:10:57 -07:00
Frantisek Hrbata
8c49d704ef transport: free local and remote refs in transport_push()
Fix memory leaks in transport_push(), where remote_refs and local_refs
are never freed.

116 bytes in 1 blocks are definitely lost in loss record 56 of 103
   at 0x484486F: malloc (vg_replace_malloc.c:381)
   by 0x4938D7E: strdup (strdup.c:42)
   by 0x628418: xstrdup (wrapper.c:39)
   by 0x4FD454: process_capabilities (connect.c:232)
   by 0x4FD454: get_remote_heads (connect.c:354)
   by 0x610A38: handshake (transport.c:333)
   by 0x612B02: transport_push (transport.c:1302)
   by 0x4803D6: push_with_options (push.c:357)
   by 0x4811D6: do_push (push.c:414)
   by 0x4811D6: cmd_push (push.c:650)
   by 0x405210: run_builtin (git.c:465)
   by 0x405210: handle_builtin (git.c:719)
   by 0x406363: run_argv (git.c:786)
   by 0x406363: cmd_main (git.c:917)
   by 0x404F17: main (common-main.c:56)

5,912 (388 direct, 5,524 indirect) bytes in 2 blocks are definitely lost in loss record 98 of 103
   at 0x4849464: calloc (vg_replace_malloc.c:1328)
   by 0x628705: xcalloc (wrapper.c:150)
   by 0x5C216D: alloc_ref_with_prefix (remote.c:975)
   by 0x5C232A: alloc_ref (remote.c:983)
   by 0x5C232A: one_local_ref (remote.c:2299)
   by 0x5C232A: one_local_ref (remote.c:2289)
   by 0x5BDB03: do_for_each_repo_ref_iterator (iterator.c:418)
   by 0x5B4C4F: do_for_each_ref (refs.c:1486)
   by 0x5B4C4F: refs_for_each_ref (refs.c:1492)
   by 0x5B4C4F: for_each_ref (refs.c:1497)
   by 0x5C6ADF: get_local_heads (remote.c:2310)
   by 0x612A85: transport_push (transport.c:1286)
   by 0x4803D6: push_with_options (push.c:357)
   by 0x4811D6: do_push (push.c:414)
   by 0x4811D6: cmd_push (push.c:650)
   by 0x405210: run_builtin (git.c:465)
   by 0x405210: handle_builtin (git.c:719)
   by 0x406363: run_argv (git.c:786)
   by 0x406363: cmd_main (git.c:917)

Signed-off-by: Frantisek Hrbata <frantisek@hrbata.com>
Reviewed-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-27 14:51:17 -07:00
Frantisek Hrbata
35919bf1ab transport: unify return values and exit point from transport_push()
It seems there is no reason to return 1 instead of -1 when push_refs()
is not set in transport vtable. Let's unify the error return values and
use the done label as a single exit point from transport_push().

Suggested-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Frantisek Hrbata <frantisek@hrbata.com>
Reviewed-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-27 14:51:16 -07:00
Frantisek Hrbata
6448182a83 transport: remove unnecessary indenting in transport_push()
Remove the big indented block for transport_push() check in transport vtable
and let's just return error immediately. Hopefully this makes the code
more readable.

Signed-off-by: Frantisek Hrbata <frantisek@hrbata.com>
Reviewed-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-27 14:51:16 -07:00
Junio C Hamano
538dc459a0 Merge branch 'ep/maint-equals-null-cocci'
Introduce and apply coccinelle rule to discourage an explicit
comparison between a pointer and NULL, and applies the clean-up to
the maintenance track.

* ep/maint-equals-null-cocci:
  tree-wide: apply equals-null.cocci
  tree-wide: apply equals-null.cocci
  contrib/coccinnelle: add equals-null.cocci
2022-05-20 15:26:59 -07:00
Junio C Hamano
2b0a58d164 Merge branch 'ep/maint-equals-null-cocci' for maint-2.35
* ep/maint-equals-null-cocci:
  tree-wide: apply equals-null.cocci
  contrib/coccinnelle: add equals-null.cocci
2022-05-02 10:06:04 -07:00
Junio C Hamano
afe8a9070b tree-wide: apply equals-null.cocci
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-02 09:50:37 -07:00
Junio C Hamano
0f5e885173 Merge branch 'rc/fetch-refetch'
"git fetch --refetch" learned to fetch everything without telling
the other side what we already have, which is useful when you
cannot trust what you have in the local object store.

* rc/fetch-refetch:
  docs: mention --refetch fetch option
  fetch: after refetch, encourage auto gc repacking
  t5615-partial-clone: add test for fetch --refetch
  fetch: add --refetch option
  builtin/fetch-pack: add --refetch option
  fetch-pack: add refetch
  fetch-negotiator: add specific noop initializer
2022-04-04 10:56:23 -07:00
Robert Coup
3c7bab06e1 fetch: add --refetch option
Teach fetch and transports the --refetch option to force a full fetch
without negotiating common commits with the remote. Use when applying a
new partial clone filter to refetch all matching objects.

Signed-off-by: Robert Coup <robert@coup.net.nz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-28 10:25:52 -07:00
Ævar Arnfjörð Bjarmason
0f0d118c65 transport: stop needlessly copying bundle header references
Amend the logic added in fddf2ebe38 (transport: teach all vtables to
allow fetch first, 2019-08-21) and save ourselves pointless work in
fetch_refs_from_bundle().

The fetch_refs_from_bundle() caller doesn't care about the "struct
ref *result" return value of get_refs_from_bundle(), and doesn't need
any of the work we were doing in looping over the
"data->header.references" in get_refs_from_bundle().

So this change saves us work, and also fixes a memory leak that we had
when called from fetch_refs_from_bundle(). The other caller of
get_refs_from_bundle() is the "get_refs_list" member we set up for the
"struct transport_vtable bundle_vtable". That caller does care about
the "struct ref *result" return value.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-04 13:24:18 -08:00
Ævar Arnfjörð Bjarmason
f36d4f8316 ls-remote & transport API: release "struct transport_ls_refs_options"
Fix a memory leak in codepaths that use the "struct
transport_ls_refs_options" API. Since the introduction of the struct
in 39835409d1 (connect, transport: encapsulate arg in struct,
2021-02-05) the caller has been responsible for freeing it.

That commit in turn migrated code originally added in
402c47d939 (clone: send ref-prefixes when using protocol v2,
2018-07-20) and b4be74105f (ls-remote: pass ref prefixes when
requesting a remote's refs, 2018-03-15). Only some of those codepaths
were releasing the allocated resources of the struct, now all of them
will.

Mark the "t/t5511-refspec.sh" test as passing when git is compiled
with SANITIZE=leak. They'll now be listed as running under the
"GIT_TEST_PASSING_SANITIZE_LEAK=true" test mode (the "linux-leaks" CI
target). Previously 24/47 tests would fail.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-06 18:02:34 -08:00
Junio C Hamano
12f82b0dd7 Merge branch 'ps/lockfile-cleanup-fix'
Some lockfile code called free() in signal-death code path, which
has been corrected.

* ps/lockfile-cleanup-fix:
  fetch: fix deadlock when cleaning up lockfiles in async signals
2022-01-12 15:11:43 -08:00
Patrick Steinhardt
58d4d7f1c5 fetch: fix deadlock when cleaning up lockfiles in async signals
When fetching packfiles, we write a bunch of lockfiles for the packfiles
we're writing into the repository. In order to not leave behind any
cruft in case we exit or receive a signal, we register both an exit
handler as well as signal handlers for common signals like SIGINT. These
handlers will then unlink the locks and free the data structure tracking
them. We have observed a deadlock in this logic though:

    (gdb) bt
    #0  __lll_lock_wait_private () at ../sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:95
    #1  0x00007f4932bea2cd in _int_free (av=0x7f4932f2eb20 <main_arena>, p=0x3e3e4200, have_lock=0) at malloc.c:3969
    #2  0x00007f4932bee58c in __GI___libc_free (mem=<optimized out>) at malloc.c:2975
    #3  0x0000000000662ab1 in string_list_clear ()
    #4  0x000000000044f5bc in unlock_pack_on_signal ()
    #5  <signal handler called>
    #6  _int_free (av=0x7f4932f2eb20 <main_arena>, p=<optimized out>, have_lock=0) at malloc.c:4024
    #7  0x00007f4932bee58c in __GI___libc_free (mem=<optimized out>) at malloc.c:2975
    #8  0x000000000065afd5 in strbuf_release ()
    #9  0x000000000066ddb9 in delete_tempfile ()
    #10 0x0000000000610d0b in files_transaction_cleanup.isra ()
    #11 0x0000000000611718 in files_transaction_abort ()
    #12 0x000000000060d2ef in ref_transaction_abort ()
    #13 0x000000000060d441 in ref_transaction_prepare ()
    #14 0x000000000060e0b5 in ref_transaction_commit ()
    #15 0x00000000004511c2 in fetch_and_consume_refs ()
    #16 0x000000000045279a in cmd_fetch ()
    #17 0x0000000000407c48 in handle_builtin ()
    #18 0x0000000000408df2 in cmd_main ()
    #19 0x00000000004078b5 in main ()

The process was killed with a signal, which caused the signal handler to
kick in and try free the data structures after we have unlinked the
locks. It then deadlocks while calling free(3P).

The root cause of this is that it is not allowed to call certain
functions in async-signal handlers, as specified by signal-safety(7).
Next to most I/O functions, this list of disallowed functions also
includes memory-handling functions like malloc(3P) and free(3P) because
they may not be reentrant. As a result, if we execute such functions in
the signal handler, then they may operate on inconistent state and fail
in unexpected ways.

Fix this bug by not calling non-async-signal-safe functions when running
in the signal handler. We're about to re-raise the signal anyway and
will thus exit, so it's not much of a problem to keep the string list of
lockfiles untouched. Note that it's fine though to call unlink(2), so
we'll still clean up the lockfiles correctly.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Reviewed-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-07 13:49:19 -08:00
Ævar Arnfjörð Bjarmason
7f14609e29 run-command API users: use strvec_push(), not argv construction
Change a pattern of hardcoding an "argv" array size, populating it and
assigning to the "argv" member of "struct child_process" to instead
use "strvec_push()" to add data to the "args" member.

As noted in the preceding commit this moves us further towards being
able to remove the "argv" member in a subsequent commit

These callers could have used strvec_pushl(), but moving to
strvec_push() makes the diff easier to read, and keeps the arguments
aligned as before.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-11-25 22:15:07 -08:00
Ævar Arnfjörð Bjarmason
5e3aba33da hook.[ch]: move find_hook() from run-command.c to hook.c
Move the find_hook() function from run-command.c to a new hook.c
library. This change establishes a stub library that's pretty
pointless right now, but will see much wider use with Emily Shaffer's
upcoming "configuration-based hooks" series.

Eventually all the hook related code will live in hook.[ch]. Let's
start that process by moving the simple find_hook() function over
as-is.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-27 09:44:54 -07:00
Junio C Hamano
5331af2352 Merge branch 'ab/serve-cleanup'
Code clean-up around "git serve".

* ab/serve-cleanup:
  upload-pack: document and rename --advertise-refs
  serve.[ch]: remove "serve_options", split up --advertise-refs code
  {upload,receive}-pack tests: add --advertise-refs tests
  serve.c: move version line to advertise_capabilities()
  serve: move transfer.advertiseSID check into session_id_advertise()
  serve.[ch]: don't pass "struct strvec *keys" to commands
  serve: use designated initializers
  transport: use designated initializers
  transport: rename "fetch" in transport_vtable to "fetch_refs"
  serve: mark has_capability() as static
2021-09-20 15:20:43 -07:00
Ævar Arnfjörð Bjarmason
7366096de9 bundle API: change "flags" to be "extra_index_pack_args"
Since the "flags" parameter was added in be042aff24 (Teach progress
eye-candy to fetch_refs_from_bundle(), 2011-09-18) there's never been
more than the one flag: BUNDLE_VERBOSE.

Let's have the only caller who cares about that pass "-v" itself
instead through new "extra_index_pack_args" parameter. The flexibility
of being able to pass arbitrary arguments to "unbundle" will be used
in a subsequent commit.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-07 10:59:23 -07:00
Ævar Arnfjörð Bjarmason
1fd88224a3 transport: use designated initializers
Change the assignments to the various transport_vtables to use
designated initializers, this makes the code easier to read and
maintain.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-05 08:59:37 -07:00
Ævar Arnfjörð Bjarmason
9b1cdd334d transport: rename "fetch" in transport_vtable to "fetch_refs"
Rename the "fetch" member of the transport_vtable to "fetch_refs" for
consistency with the existing "push_refs". Neither of them just push
"refs" but refs and objects, but having the two match makes the code
more readable than having it be inconsistent, especially since
"fetch_refs" is a lot easier to grep for than "fetch".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-05 08:59:36 -07:00
Junio C Hamano
bd4232fac3 Merge branch 'ab/struct-init'
Code cleanup around struct_type_init() functions.

* ab/struct-init:
  string-list.h users: change to use *_{nodup,dup}()
  string-list.[ch]: add a string_list_init_{nodup,dup}()
  dir.[ch]: replace dir_init() with DIR_INIT
  *.c *_init(): define in terms of corresponding *_INIT macro
  *.h: move some *_INIT to designated initializers
2021-07-16 17:42:53 -07:00
Ævar Arnfjörð Bjarmason
10b635b773 bundle: remove "ref_list" in favor of string-list.c API
Move away from the "struct ref_list" in bundle.c in favor of the
almost identical string-list.c API.

That API fits this use-case perfectly, but did not exist in its
current form when this code was added in 2e0afafebd (Add git-bundle:
move objects and references by archive, 2007-02-22), with hindsight we
could have used the path-list API, which later got renamed to
string-list. See 8fd2cb4069 (Extract helper bits from
c-merge-recursive work, 2006-07-25)

We need to change "name" to "string" and "oid" to "util" to make this
conversion, but other than that the APIs are pretty much identical for
what bundle.c made use of.

Let's also replace the memset(..,0,...) pattern with a more idiomatic
"INIT" macro, and finally add a *_release() function so to free the
allocated memory.

Before this the add_to_ref_list() would leak memory, now e.g. "bundle
list-heads" reports no memory leaks at all under valgrind.

In the bundle_header_init() function we're using a clever trick to
memcpy() what we'd get from the corresponding
BUNDLE_HEADER_INIT. There is a concurrent series to make use of that
pattern more generally, see [1].

1. https://lore.kernel.org/git/cover-0.5-00000000000-20210701T104855Z-avarab@gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-06 12:10:17 -07:00
Ævar Arnfjörð Bjarmason
15e7c7dca6 bundle.c: use a temporary variable for OIDs and names
In preparation for moving away from accessing the OID and name via the
"oid" and "name" slots in a subsequent commit, change the code that
accesses it to use named variables. This makes the subsequent change
smaller.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-06 12:10:16 -07:00
Ævar Arnfjörð Bjarmason
bc40dfb10a string-list.h users: change to use *_{nodup,dup}()
Change all in-tree users of the string_list_init(LIST, BOOL) API to
use string_list_init_{nodup,dup}(LIST) instead.

As noted in the preceding commit let's leave the now-unused
string_list_init() wrapper in-place for any in-flight users, it can be
removed at some later date.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-01 12:32:22 -07:00
Jeff King
ae1a7eefff fetch-pack: signal v2 server that we are done making requests
When fetching with the v0 protocol over ssh (or a local upload-pack with
pipes), the server closes the connection as soon as it is finished
sending the pack. So even though the client may still be operating on
the data via index-pack (e.g., resolving deltas, checking connectivity,
etc), the server has released all resources.

With the v2 protocol, however, the server considers the ssh session only
as a transport, with individual requests coming over it. After sending
the pack, it goes back to its main loop, waiting for another request to
come from the client. As a result, the ssh session hangs around until
the client process ends, which may be much later (because resolving
deltas, etc, may consume a lot of CPU).

This is bad for two reasons:

  - it's consuming resources on the server to leave open a connection
    that won't see any more use

  - if something bad happens to the ssh connection in the meantime (say,
    it gets killed by the network because it's idle, as happened in a
    real-world report), then ssh will exit non-zero, and we'll propagate
    the error up the stack.

The server is correct here not to hang up after serving the pack. The v2
protocol's design is meant to allow multiple requests like this, and
hanging up would be the wrong thing for a hypothetical client which was
planning to make more requests (though in practice, the git.git client
never would, and I doubt any other implementations would either).

The right thing is instead for the client to signal to the server that
it's not interested in making more requests. We can do that by closing
the pipe descriptor we use to write to ssh. This will propagate to the
server upload-pack as an EOF when it tries to read the next request (and
then it will close its half, and the whole connection will go away).

It's important to do this "half duplex" shutdown, because we have to do
it _before_ we actually receive the pack. This is an artifact of the way
fetch-pack and index-pack (or unpack-objects) interact. We hand the
connection off to index-pack (really, a sideband demuxer which feeds
it), and then wait until it returns. And it doesn't do that until it has
resolved all of the deltas in the pack, even though it was done reading
from the server long before.

So just closing the connection fully after index-pack returns would be
too late; we'd have held it open much longer than was necessary. And
teaching index-pack to close the connection is awkward. It's not even
seeing the whole conversation (the sideband demuxer is, but it doesn't
actually know what's in the packets, or when the end comes).

Note that this close() is happening deep within the transport code. It's
possible that a caller would want to perform other operations over the
same ssh transport after receiving the pack. But as of the current code,
none of the callers do, and there haven't been discussions of any plans
to change this. If we need to support that later, we can probably do so
by passing down a flag for "you're the last request on the transport;
it's OK to close" instead of the code just assuming that's true.

The description above all discusses v2 ssh, so it's worth thinking about
how this interacts with other protocols:

  - in v0 protocols, we could do the same half-duplex shutdown (it just
    goes into the v0 do_fetch_pack() instead). This does work, but since
    it doesn't have the same persistence problem in the first place,
    there's little reason to change it at this point.

  - local fetches against git-upload-pack on the same machine will
    behave the same as ssh (they are talking over two pipes, and see EOF
    on their input pipe)

  - fetches against git-daemon will run this same code, and close one of
    the descriptors. In practice, this won't do anything, since there
    our two descriptors are dups of each other, and not part of a
    half-duplex pair. The right thing would probably be to call
    shutdown(SHUT_WR) on it. I didn't bother with that here. It doesn't
    face the same error-code problem (since it's just a TCP connection),
    so it's really only an optimization problem. And git:// is not that
    widely used these days, and has less impact on server resources than
    an ssh termination.

  - v2 http doesn't suffer from this problem in the first place, as our
    pipes terminate at a local git-remote-https, which is passing data
    along as individual requests via curl. Probably curl is keeping the
    TCP/TLS connection open for more requests, and we might be able to
    tell it manually "hey, we are done making requests now". But I think
    that's much less important. It again doesn't suffer from the
    error-code problem, and HTTP keepalive is pretty well understood
    (importantly, the timeouts can be set low, because clients like curl
    know how to reconnect for subsequent requests if necessary). So it's
    probably not worth figuring out how to tell curl that we're done
    (though if we do, this patch is probably the first step anyway;
    fetch-pack closes the pipe back to remote-https, which would be the
    signal that it should tell curl we're done).

The code is pretty straightforward. We close the pipe at the right
moment, and set it to -1 to mark it as invalid. I modified the later
cleanup code to avoid calling close(-1). That's not strictly necessary,
since close(-1) is a noop, but hopefully makes things a bit more obvious
to a reader.

I suspect that trying to call more transport functions after the close()
(e.g., calling transport_fetch_refs() again) would fail, as it's not
smart enough to realize we need to re-open the ssh connection. But
that's already true when v0 is in use. And no current callers want to do
that (and again, the solution is probably a flag in the transport code
to keep things open, which can be added later).

There's no test here, as the situation it covers is inherently racy (the
question is when upload-pack exits, compared to when index-pack finishes
resolving deltas and exits). The rather gross shell snippet below does
recreate the problematic situation; when run on a sufficiently-large
repository (git.git works fine), it kills an "idle" upload-pack while
the client is resolving deltas, leading to a failed clone.

    (
	    git clone --no-local --progress . foo.git 2>&1
	    echo >&2 "clone exit code=$?"
    ) |
    tr '\r' '\n' |
    while read line
    do
	    case "$done,$line" in
	    ,Resolving*)
		    echo "hit resolving deltas; killing upload-pack"
		    killall -9 git-upload-pack
		    done=t
		    ;;
	    esac
    done

Reported-by: Greg Pflaum <greg.pflaum@pnp-hcl.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-20 07:38:40 +09:00
Junio C Hamano
644f4a2046 Merge branch 'jt/push-negotiation'
"git push" learns to discover common ancestor with the receiving
end over protocol v2.

* jt/push-negotiation:
  send-pack: support push negotiation
  fetch: teach independent negotiation (no packfile)
  fetch-pack: refactor command and capability write
  fetch-pack: refactor add_haves()
  fetch-pack: refactor process_acks()
2021-05-16 21:05:22 +09:00
Jonathan Tan
9c1e657a8f fetch: teach independent negotiation (no packfile)
Currently, the packfile negotiation step within a Git fetch cannot be
done independent of sending the packfile, even though there is at least
one application wherein this is useful. Therefore, make it possible for
this negotiation step to be done independently. A subsequent commit will
use this for one such application - push negotiation.

This feature is for protocol v2 only. (An implementation for protocol v0
would require a separate implementation in the fetch, transport, and
transport helper code.)

In the protocol, the main hindrance towards independent negotiation is
that the server can unilaterally decide to send the packfile. This is
solved by a "wait-for-done" argument: the server will then wait for the
client to say "done". In practice, the client will never say it; instead
it will cease requests once it is satisfied.

In the client, the main change lies in the transport and transport
helper code. fetch_refs_via_pack() performs everything needed - protocol
version and capability checks, and the negotiation itself.

There are 2 code paths that do not go through fetch_refs_via_pack() that
needed to be individually excluded: the bundle transport (excluded
through requiring smart_options, which the bundle transport doesn't
support) and transport helpers that do not support takeover. If or when
we support independent negotiation for protocol v0, we will need to
modify these 2 code paths to support it. But for now, report failure if
independent negotiation is requested in these cases.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-05 10:41:29 +09:00
Junio C Hamano
a819e2b3ef Merge branch 'ow/push-quiet-set-upstream'
"git push --quiet --set-upstream" was not quiet when setting the
upstream branch configuration, which has been corrected.

* ow/push-quiet-set-upstream:
  transport: respect verbosity when setting upstream
2021-04-30 13:50:25 +09:00
Øystein Walle
f3cce896a8 transport: respect verbosity when setting upstream
A command such as `git push -qu origin feature` will print "Branch
'feature' set up to track remote branch 'feature' from 'origin'." even
when --quiet is passed. In this case it's because install_branch_config() is
always called with BRANCH_CONFIG_VERBOSE.

struct transport keeps track of the desired verbosity. Fix the above
issue by passing BRANCH_CONFIG_VERBOSE conditionally based on that.

Signed-off-by: Øystein Walle <oystwa@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-15 12:52:49 -07:00
Junio C Hamano
22eee7f455 Merge branch 'll/clone-reject-shallow'
"git clone --reject-shallow" option fails the clone as soon as we
notice that we are cloning from a shallow repository.

* ll/clone-reject-shallow:
  builtin/clone.c: add --reject-shallow option
2021-04-08 13:23:25 -07:00
Junio C Hamano
642a40019c Merge branch 'ah/plugleaks'
Plug or annotate remaining leaks that trigger while running the
very basic set of tests.

* ah/plugleaks:
  transport: also free remote_refs in transport_disconnect()
  parse-options: don't leak alias help messages
  parse-options: convert bitfield values to use binary shift
  init-db: silence template_dir leak when converting to absolute path
  init: remove git_init_db_config() while fixing leaks
  worktree: fix leak in dwim_branch()
  clone: free or UNLEAK further pointers when finished
  reset: free instead of leaking unneeded ref
  symbolic-ref: don't leak shortened refname in check_symref()
2021-04-07 16:54:08 -07:00
Li Linchao
4fe788b1b0 builtin/clone.c: add --reject-shallow option
In some scenarios, users may want more history than the repository
offered for cloning, which happens to be a shallow repository, can
give them. But because users don't know it is a shallow repository
until they download it to local, we may want to refuse to clone
this kind of repository, without creating any unnecessary files.

The '--depth=x' option cannot be used as a solution; the source may
be deep enough to give us 'x' commits when cloned, but the user may
later need to deepen the history to arbitrary depth.

Teach '--reject-shallow' option to "git clone" to abort as soon as
we find out that we are cloning from a shallow repository.

Signed-off-by: Li Linchao <lilinchao@oschina.cn>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-01 12:58:58 -07:00
Andrzej Hunt
68ffe095a2 transport: also free remote_refs in transport_disconnect()
transport_get_remote_refs() can populate the transport struct's
remote_refs. transport_disconnect() is already responsible for most of
transport's cleanup - therefore we also take care of freeing remote_refs
there.

There are 2 locations where transport_disconnect() is called before
we're done using the returned remote_refs. This patch changes those
callsites to only call transport_disconnect() after the returned refs
are no longer being used - which is necessary to safely be able to
free remote_refs during transport_disconnect().

This commit fixes the following leak which was found while running
t0000, but is expected to also fix the same pattern of leak in all
locations that use transport_get_remote_refs():

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
    #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
    #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
    #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
    #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
    #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
    #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
    #8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
    #9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
    #10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    #12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    #13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    #14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    #15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-21 14:39:10 -07:00
René Scharfe
ca56dadb4b use CALLOC_ARRAY
Add and apply a semantic patch for converting code that open-codes
CALLOC_ARRAY to use it instead.  It shortens the code and infers the
element size automatically.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-13 16:00:09 -08:00
Jonathan Tan
39835409d1 connect, transport: encapsulate arg in struct
In a future patch we plan to return the name of an unborn current branch
from deep in the callchain to a caller via a new pointer parameter that
points at a variable in the caller when the caller calls
get_remote_refs() and transport_get_remote_refs().

In preparation for that, encapsulate the existing ref_prefixes
parameter into a struct. The aforementioned unborn current branch will
go into this new struct in the future patch.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-05 13:49:54 -08:00
Josh Steadmon
23bf486aca transport: log received server session ID
When a client receives a session-id capability from a protocol v0, v1,
or v2 server, log the received session ID via a trace2 data event.

Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-11 18:26:53 -08:00
Srinidhi Kaushik
3b990aa645 push: parse and set flag for "--force-if-includes"
The previous commit added the necessary machinery to implement the
"--force-if-includes" protection, when "--force-with-lease" is used
without giving exact object the remote still ought to have. Surface
the feature by adding a command line option and a configuration
variable to enable it.

 - Add a flag: "TRANSPORT_PUSH_FORCE_IF_INCLUDES" to indicate that the
   new option was passed from the command line of via configuration
   settings; update command line and configuration parsers to set the
   new flag accordingly.

 - Introduce a new configuration option "push.useForceIfIncludes", which
   is equivalent to setting "--force-if-includes" in the command line.

 - Update "remote-curl" to recognize and pass this option to "send-pack"
   when enabled.

 - Update "advise" to catch the reject reason "REJECT_REF_NEEDS_UPDATE",
   set when the ref status is "REF_STATUS_REJECT_REMOTE_UPDATED" and
   (optionally) print a help message when the push fails.

 - The new option is a "no-op" in the following scenarios:
    * When used without "--force-with-lease".
    * When used with "--force-with-lease", and if the expected commit
      on the remote side is specified as an argument.

Signed-off-by: Srinidhi Kaushik <shrinidhi.kaushik@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-03 09:59:19 -07:00
Srinidhi Kaushik
99a1f9ae10 push: add reflog check for "--force-if-includes"
Add a check to verify if the remote-tracking ref of the local branch
is reachable from one of its "reflog" entries.

The check iterates through the local ref's reflog to see if there
is an entry for the remote-tracking ref and collecting any commits
that are seen, into a list; the iteration stops if an entry in the
reflog matches the remote ref or if the entry timestamp is older
the latest entry of the remote ref's "reflog". If there wasn't an
entry found for the remote ref, "in_merge_bases_many()" is called
to check if it is reachable from the list of collected commits.

When a local branch that is based on a remote ref, has been rewound
and is to be force pushed on the remote, "--force-if-includes" runs
a check that ensures any updates to the remote-tracking ref that may
have happened (by push from another repository) in-between the time
of the last update to the local branch (via "git-pull", for instance)
and right before the time of push, have been integrated locally
before allowing a forced update.

If the new option is passed without specifying "--force-with-lease",
or specified along with "--force-with-lease=<refname>:<expect>" it
is a "no-op".

Signed-off-by: Srinidhi Kaushik <shrinidhi.kaushik@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-10-03 09:59:18 -07:00
Junio C Hamano
6c430a647c Merge branch 'jx/proc-receive-hook'
"git receive-pack" that accepts requests by "git push" learned to
outsource most of the ref updates to the new "proc-receive" hook.

* jx/proc-receive-hook:
  doc: add documentation for the proc-receive hook
  transport: parse report options for tracking refs
  t5411: test updates of remote-tracking branches
  receive-pack: new config receive.procReceiveRefs
  doc: add document for capability report-status-v2
  New capability "report-status-v2" for git-push
  receive-pack: feed report options to post-receive
  receive-pack: add new proc-receive hook
  t5411: add basic test cases for proc-receive hook
  transport: not report a non-head push as a branch
2020-09-25 15:25:39 -07:00
Junio C Hamano
b4100f366c Merge branch 'jt/lazy-fetch'
Updates to on-demand fetching code in lazily cloned repositories.

* jt/lazy-fetch:
  fetch: no FETCH_HEAD display if --no-write-fetch-head
  fetch-pack: remove no_dependents code
  promisor-remote: lazy-fetch objects in subprocess
  fetch-pack: do not lazy-fetch during ref iteration
  fetch: only populate existing_refs if needed
  fetch: avoid reading submodule config until needed
  fetch: allow refspecs specified through stdin
  negotiator/noop: add noop fetch negotiator
2020-09-03 12:37:04 -07:00
Jiang Xin
1702ae6f61 transport: parse report options for tracking refs
When pushing a pseudo reference (such as "refs/for/master/topic"), may
create or update one or more references.  The real names of the
references will be stored in the report options.  Parse report options
to create or update remote-tracking branches properly.

Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-27 12:48:47 -07:00
Jiang Xin
63518a574a New capability "report-status-v2" for git-push
The new introduced "proc-receive" hook may handle a command for a
pseudo-reference with a zero-old as its old-oid, while the hook may
create or update a reference with different name, different new-oid,
and different old-oid (the reference may exist already with a non-zero
old-oid).  Current "report-status" protocol cannot report the status for
such reference rewrite.

Add new capability "report-status-v2" and new report protocol which is
not backward compatible for report of git-push.

If a user pushes to a pseudo-reference "refs/for/master/topic", and
"receive-pack" creates two new references "refs/changes/23/123/1" and
"refs/changes/24/124/1", for client without the knowledge of
"report-status-v2", "receive-pack" will only send "ok/ng" directives in
the report, such as:

    ok ref/for/master/topic

But for client which has the knowledge of "report-status-v2",
"receive-pack" will use "option" directives to report more attributes
for the reference given by the above "ok/ng" directive.

    ok refs/for/master/topic
    option refname refs/changes/23/123/1
    option new-oid <new-oid>
    ok refs/for/master/topic
    option refname refs/changes/24/124/1
    option new-oid <new-oid>

The client will report two new created references to the end user.

Suggested-by: Junio C Hamano <gitster@pobox.com>
Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-27 12:47:47 -07:00
Jiang Xin
917c612512 transport: not report a non-head push as a branch
When pushing a new reference (not a head or tag), report it as a new
reference instead of a new branch.

Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-27 12:47:47 -07:00