diff options
| -rw-r--r-- | AUTHORS | 1 | ||||
| -rw-r--r-- | lib/lockfile.c | 21 | ||||
| -rw-r--r-- | tests/lockfile.at | 7 |
3 files changed, 21 insertions, 8 deletions
@@ -175,6 +175,7 @@ YAMAMOTO Takashi yamamoto@valinux.co.jp Yongqiang Liu liuyq7809@gmail.com kk yap yapkke@stanford.edu likunyun kunyunli@hotmail.com +rahim entezari rahim.entezari@gmail.com 冯全树(Crab) fqs888@126.com 胡靖飞 hujingfei914@msn.com diff --git a/lib/lockfile.c b/lib/lockfile.c index db84aebb4..3708aec0d 100644 --- a/lib/lockfile.c +++ b/lib/lockfile.c @@ -55,7 +55,8 @@ struct lockfile { static struct hmap lock_table = HMAP_INITIALIZER(&lock_table); static void lockfile_unhash(struct lockfile *); -static int lockfile_try_lock(const char *name, struct lockfile **lockfilep); +static int lockfile_try_lock(const char *name, pid_t *pidp, + struct lockfile **lockfilep); /* Returns the name of the lockfile that would be created for locking a file * named 'filename_'. The caller is responsible for freeing the returned name, @@ -98,21 +99,27 @@ lockfile_lock(const char *file, struct lockfile **lockfilep) * stylized ways such that any number of readers may access a file while it * is being written. */ char *lock_name; + pid_t pid; int error; COVERAGE_INC(lockfile_lock); lock_name = lockfile_name(file); - error = lockfile_try_lock(lock_name, lockfilep); + error = lockfile_try_lock(lock_name, &pid, lockfilep); if (error) { COVERAGE_INC(lockfile_error); if (error == EACCES) { error = EAGAIN; } - VLOG_WARN("%s: failed to lock file: %s", - lock_name, strerror(error)); + if (pid) { + VLOG_WARN("%s: cannot lock file because it is already locked by " + "pid %ld", lock_name, (long int) pid); + } else { + VLOG_WARN("%s: failed to lock file: %s", + lock_name, strerror(error)); + } } free(lock_name); @@ -201,7 +208,7 @@ lockfile_register(const char *name, dev_t device, ino_t inode, int fd) } static int -lockfile_try_lock(const char *name, struct lockfile **lockfilep) +lockfile_try_lock(const char *name, pid_t *pidp, struct lockfile **lockfilep) { struct flock l; struct stat s; @@ -209,6 +216,7 @@ lockfile_try_lock(const char *name, struct lockfile **lockfilep) int fd; *lockfilep = NULL; + *pidp = 0; /* Check whether we've already got a lock on that file. */ if (!stat(name, &s)) { @@ -250,6 +258,9 @@ lockfile_try_lock(const char *name, struct lockfile **lockfilep) if (!error) { *lockfilep = lockfile_register(name, s.st_dev, s.st_ino, fd); } else { + if (!fcntl(fd, F_GETLK, &l) && l.l_type != F_UNLCK) { + *pidp = l.l_pid; + } close(fd); } return error; diff --git a/tests/lockfile.at b/tests/lockfile.at index 50999e47e..2644d3fa0 100644 --- a/tests/lockfile.at +++ b/tests/lockfile.at @@ -5,7 +5,8 @@ m4_define([CHECK_LOCKFILE], AT_KEYWORDS([lockfile]) AT_CHECK([test-lockfile $1], [0], [$1: success (m4_if( [$2], [1], [$2 child], [$2 children])) -], [$3]) +], [stderr]) + AT_CHECK([sed 's/pid [[0-9]]*/pid <pid>/' stderr], [0], [$3]) AT_CLEANUP]) CHECK_LOCKFILE([lock_and_unlock], [0]) @@ -23,13 +24,13 @@ lockfile|WARN|.file.~lock~: failed to lock file: Resource deadlock avoided CHECK_LOCKFILE([lock_blocks_other_process], [1], [lockfile|WARN|.file.~lock~: child does not inherit lock -lockfile|WARN|.file.~lock~: failed to lock file: Resource temporarily unavailable +lockfile|WARN|.file.~lock~: cannot lock file because it is already locked by pid <pid> ]) CHECK_LOCKFILE([lock_twice_blocks_other_process], [1], [lockfile|WARN|.file.~lock~: failed to lock file: Resource deadlock avoided lockfile|WARN|.file.~lock~: child does not inherit lock -lockfile|WARN|.file.~lock~: failed to lock file: Resource temporarily unavailable +lockfile|WARN|.file.~lock~: cannot lock file because it is already locked by pid <pid> ]) CHECK_LOCKFILE([lock_and_unlock_allows_other_process], [1]) |