Support for POSIX range locks using fcntl. (#423)

Support for POSIX range locks using fcntl.
hpc · Jun 15, 2022 · b4d1d25 · b4d1d25
1 parent 202b69f
commit b4d1d25
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Showing 2 changed files with 26 additions and 0 deletions.
diff --git a/src/aiori-POSIX.c b/src/aiori-POSIX.c
@@ -27,6 +27,7 @@
 #endif                          /* __linux__ */
 
 #include <errno.h>
+#include <unistd.h>
 #include <fcntl.h>              /* IO operations */
 #include <sys/stat.h>
 #include <assert.h>
@@ -131,6 +132,7 @@ option_help * POSIX_options(aiori_mod_opt_t ** init_backend_options, aiori_mod_o
 
   option_help h [] = {
     {0, "posix.odirect", "Direct I/O Mode", OPTION_FLAG, 'd', & o->direct_io},
+    {0, "posix.rangelocks", "Use range locks (read locks for read ops)", OPTION_FLAG, 'd', & o->range_locks},
 #ifdef HAVE_BEEGFS_BEEGFS_H
     {0, "posix.beegfs.NumTargets", "", OPTION_OPTIONAL_ARGUMENT, 'd', & o->beegfs_numTargets},
     {0, "posix.beegfs.ChunkSize", "", OPTION_OPTIONAL_ARGUMENT, 'd', & o->beegfs_chunkSize},
@@ -691,6 +693,18 @@ static IOR_offset_t POSIX_Xfer(int access, aiori_fd_t *file, IOR_size_t * buffer
         if (lseek64(fd, offset, SEEK_SET) == -1)
                 ERRF("lseek64(%d, %lld, SEEK_SET) failed", fd, offset);
         off_t mem_offset = 0;
+
+        if(o->range_locks){
+          struct flock lck = {
+          .l_whence = SEEK_SET,
+          .l_start  = offset,
+          .l_len    = remaining,
+          .l_type = access == WRITE ? F_WRLCK : F_RDLCK,
+          }; 
+          if(fcntl(fd, F_SETLKW, &lck) != 0){
+              WARN("Error with F_SETLKW");
+          }
+        }        
         while (remaining > 0) {
                 /* write/read file */
                 if (access == WRITE) {  /* WRITE */
@@ -757,6 +771,17 @@ static IOR_offset_t POSIX_Xfer(int access, aiori_fd_t *file, IOR_size_t * buffer
                 mem_offset += rc;
                 xferRetries++;
         }
+        if(o->range_locks){
+          struct flock lck = {
+          .l_whence = SEEK_SET,
+          .l_start  = offset,
+          .l_len    = length,
+          .l_type = F_UNLCK,
+          }; 
+          if(fcntl(fd, F_SETLK, &lck) != 0){
+              WARN("Error with F_UNLCK");
+          }
+        }        
 #ifdef HAVE_GPFS_FCNTL_H
         if (o->gpfs_hint_access) {
             gpfs_access_end(fd, length, offset, access);

diff --git a/src/aiori-POSIX.h b/src/aiori-POSIX.h
@@ -26,6 +26,7 @@ typedef struct{
   int beegfs_numTargets;           /* number storage targets to use */
   int beegfs_chunkSize;            /* srtipe pattern for new files */
   int gpuDirect;
+  int range_locks;                 /* use POSIX range locks for writes */
 } posix_options_t;
 
 void POSIX_Sync(aiori_mod_opt_t * param);