Merge pull request #2730 in HDFFV/hdf5 from ~DEROBINS/hdf5_der:file_locking_squash_2 to develop

* commit '47ad0ac7237b464e939fe54dd129a151944d9706':
  Renames BEST-EFFORT to BEST_EFFORT for file locking env var
  Updated the file locking Fortran property list wrappers and added a test.
  Fixed missing parens in VFDs
  Minor change to header comments in file locking C++ changes.
  Squash merge of file locking fixes

1 files changed, 40 insertions, 8 deletions

diff --git a/src/H5FDlog.c b/src/H5FDlog.c
index 78b7742..c0506e9 100644
--- a/src/H5FDlog.c
+++ b/src/H5FDlog.c
@@ -40,6 +40,9 @@
 /* The driver identification number, initialized at runtime */
 static hid_t H5FD_LOG_g = 0;
 
+/* Whether to ignore file locks when disabled (env var value) */
+static htri_t ignore_disabled_file_locks_s = FAIL;
+
 /* Driver-specific file access properties */
 typedef struct H5FD_log_fapl_t {
     char *logfile;              /* Allocated log file name */
@@ -80,6 +83,7 @@ typedef struct H5FD_log_t {
     haddr_t         eof;    /* end of file; current file size   */
     haddr_t         pos;    /* current file I/O position        */
     H5FD_file_op_t  op;     /* last operation                   */
+    hbool_t         ignore_disabled_file_locks;
     char            filename[H5FD_MAX_FILENAME_LEN];    /* Copy of file name from open operation */
 #ifndef H5_HAVE_WIN32_API
     /* On most systems the combination of device and i-node number uniquely
@@ -234,10 +238,20 @@ H5FL_DEFINE_STATIC(H5FD_log_t);
 static herr_t
 H5FD__init_package(void)
 {
+    char    *lock_env_var   = NULL;     /* Environment variable pointer */
     herr_t ret_value = SUCCEED;
 
     FUNC_ENTER_STATIC
 
+    /* Check the use disabled file locks environment variable */
+    lock_env_var = HDgetenv("HDF5_USE_FILE_LOCKING");
+    if(lock_env_var && !HDstrcmp(lock_env_var, "BEST_EFFORT"))
+        ignore_disabled_file_locks_s = TRUE;    /* Override: Ignore disabled locks */
+    else if(lock_env_var && (!HDstrcmp(lock_env_var, "TRUE") || !HDstrcmp(lock_env_var, "1")))
+        ignore_disabled_file_locks_s = FALSE;   /* Override: Don't ignore disabled locks */
+    else
+        ignore_disabled_file_locks_s = FAIL;    /* Environment variable not set, or not set correctly */
+
     if(H5FD_log_init() < 0)
         HGOTO_ERROR(H5E_VFL, H5E_CANTINIT, FAIL, "unable to initialize log VFD")
 
@@ -625,6 +639,16 @@ H5FD_log_open(const char *name, unsigned flags, hid_t fapl_id, haddr_t maxaddr)
         } /* end if */
     } /* end if */
 
+    /* Check the file locking flags in the fapl */
+    if(ignore_disabled_file_locks_s != FAIL)
+        /* The environment variable was set, so use that preferentially */
+        file->ignore_disabled_file_locks = ignore_disabled_file_locks_s;
+    else {
+        /* Use the value in the property list */
+        if(H5P_get(plist, H5F_ACS_IGNORE_DISABLED_FILE_LOCKS_NAME, &file->ignore_disabled_file_locks) < 0)
+            HGOTO_ERROR(H5E_VFL, H5E_CANTGET, NULL, "can't get ignore disabled file locks property")
+    }
+
     /* Check for non-default FAPL */
     if(H5P_FILE_ACCESS_DEFAULT != fapl_id) {
         /* This step is for h5repart tool only. If user wants to change file driver from
@@ -1671,11 +1695,15 @@ H5FD_log_lock(H5FD_t *_file, hbool_t rw)
 
     /* Place a non-blocking lock on the file */
     if(HDflock(file->fd, lock_flags | LOCK_NB) < 0) {
-        if(ENOSYS == errno)
-            HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "file locking disabled on this file system (use HDF5_USE_FILE_LOCKING environment variable to override)")
+        if(file->ignore_disabled_file_locks && ENOSYS == errno) {
+            /* When errno is set to ENOSYS, the file system does not support
+             * locking, so ignore it.
+             */
+            errno = 0;
+        }
         else
-            HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "unable to lock file")
-    } /* end if */
+            HSYS_GOTO_ERROR(H5E_VFL, H5E_CANTLOCKFILE, FAIL, "unable to lock file")
+    }
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -1704,11 +1732,15 @@ H5FD_log_unlock(H5FD_t *_file)
     HDassert(file);
 
     if(HDflock(file->fd, LOCK_UN) < 0) {
-        if(ENOSYS == errno)
-            HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "file locking disabled on this file system (use HDF5_USE_FILE_LOCKING environment variable to override)")
+        if(file->ignore_disabled_file_locks && ENOSYS == errno) {
+            /* When errno is set to ENOSYS, the file system does not support
+             * locking, so ignore it.
+             */
+            errno = 0;
+        }
         else
-            HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL, "unable to unlock file")
-    } /* end if */
+            HSYS_GOTO_ERROR(H5E_VFL, H5E_CANTUNLOCKFILE, FAIL, "unable to unlock file")
+    }
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)