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author | Junio C Hamano <gitster@pobox.com> | 2017-02-28 00:57:12 +0300 |
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committer | Junio C Hamano <gitster@pobox.com> | 2017-02-28 00:57:12 +0300 |
commit | 3ad8b5bf26362ac67c9020bf8c30eee54a84f56d (patch) | |
tree | 6355ea894d4920b87ce28f005dcc30603f56882c /sha1_file.c | |
parent | 538569bc8a212a45b7b3f124822b4c3e458752f5 (diff) | |
parent | 446397774ad3b9f2ae81bcfbe0628e99c3db7e49 (diff) |
Merge branch 'mh/ref-remove-empty-directory'
Deletion of a branch "foo/bar" could remove .git/refs/heads/foo
once there no longer is any other branch whose name begins with
"foo/", but we didn't do so so far. Now we do.
* mh/ref-remove-empty-directory: (23 commits)
files_transaction_commit(): clean up empty directories
try_remove_empty_parents(): teach to remove parents of reflogs, too
try_remove_empty_parents(): don't trash argument contents
try_remove_empty_parents(): rename parameter "name" -> "refname"
delete_ref_loose(): inline function
delete_ref_loose(): derive loose reference path from lock
log_ref_write_1(): inline function
log_ref_setup(): manage the name of the reflog file internally
log_ref_write_1(): don't depend on logfile argument
log_ref_setup(): pass the open file descriptor back to the caller
log_ref_setup(): improve robustness against races
log_ref_setup(): separate code for create vs non-create
log_ref_write(): inline function
rename_tmp_log(): improve error reporting
rename_tmp_log(): use raceproof_create_file()
lock_ref_sha1_basic(): use raceproof_create_file()
lock_ref_sha1_basic(): inline constant
raceproof_create_file(): new function
safe_create_leading_directories(): set errno on SCLD_EXISTS
safe_create_leading_directories_const(): preserve errno
...
Diffstat (limited to 'sha1_file.c')
-rw-r--r-- | sha1_file.c | 76 |
1 files changed, 75 insertions, 1 deletions
diff --git a/sha1_file.c b/sha1_file.c index ec957db5e1..6628f06da3 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -129,8 +129,10 @@ enum scld_error safe_create_leading_directories(char *path) *slash = '\0'; if (!stat(path, &st)) { /* path exists */ - if (!S_ISDIR(st.st_mode)) + if (!S_ISDIR(st.st_mode)) { + errno = ENOTDIR; ret = SCLD_EXISTS; + } } else if (mkdir(path, 0777)) { if (errno == EEXIST && !stat(path, &st) && S_ISDIR(st.st_mode)) @@ -158,13 +160,85 @@ enum scld_error safe_create_leading_directories(char *path) enum scld_error safe_create_leading_directories_const(const char *path) { + int save_errno; /* path points to cache entries, so xstrdup before messing with it */ char *buf = xstrdup(path); enum scld_error result = safe_create_leading_directories(buf); + + save_errno = errno; free(buf); + errno = save_errno; return result; } +int raceproof_create_file(const char *path, create_file_fn fn, void *cb) +{ + /* + * The number of times we will try to remove empty directories + * in the way of path. This is only 1 because if another + * process is racily creating directories that conflict with + * us, we don't want to fight against them. + */ + int remove_directories_remaining = 1; + + /* + * The number of times that we will try to create the + * directories containing path. We are willing to attempt this + * more than once, because another process could be trying to + * clean up empty directories at the same time as we are + * trying to create them. + */ + int create_directories_remaining = 3; + + /* A scratch copy of path, filled lazily if we need it: */ + struct strbuf path_copy = STRBUF_INIT; + + int ret, save_errno; + + /* Sanity check: */ + assert(*path); + +retry_fn: + ret = fn(path, cb); + save_errno = errno; + if (!ret) + goto out; + + if (errno == EISDIR && remove_directories_remaining-- > 0) { + /* + * A directory is in the way. Maybe it is empty; try + * to remove it: + */ + if (!path_copy.len) + strbuf_addstr(&path_copy, path); + + if (!remove_dir_recursively(&path_copy, REMOVE_DIR_EMPTY_ONLY)) + goto retry_fn; + } else if (errno == ENOENT && create_directories_remaining-- > 0) { + /* + * Maybe the containing directory didn't exist, or + * maybe it was just deleted by a process that is + * racing with us to clean up empty directories. Try + * to create it: + */ + enum scld_error scld_result; + + if (!path_copy.len) + strbuf_addstr(&path_copy, path); + + do { + scld_result = safe_create_leading_directories(path_copy.buf); + if (scld_result == SCLD_OK) + goto retry_fn; + } while (scld_result == SCLD_VANISHED && create_directories_remaining-- > 0); + } + +out: + strbuf_release(&path_copy); + errno = save_errno; + return ret; +} + static void fill_sha1_path(struct strbuf *buf, const unsigned char *sha1) { int i; |