Hi,
Since a --direct-io feature was requested a few times the past decade with
little response and the actual patch is quite trivial, I patched both
v3.0.9 and master branch and included the patches here.
If this functionality is acceptable I don't mind spending the additional
effort to update the documentation, etc.
Beware that the underlying filesystem needs Direct I/O support, therefore
for this to work on NFS, one needs the kernel CONFIG_NFS_DIRECTIO enabled
(probably default these days anyway). This is the reason why --direct-io
is not enabled by default and should be used with care. I don't know what
the behavior is if the local or remote side do not support O_DIRECT.
In my tests it provides a much more stable copy process (on NFS) with
improved performance, but I didn't do any prolonged repeated tests yet (I
only used it during a large copy that was ongoing so I prefer not to
juggle with numbers here). Please test yourself and report back.
Kind regards,
--
-- dag wieers, d...@wieers.com, http://dag.wieers.com/
-- dagit linux solutions, i...@dagit.net, http://dagit.net/
[Any errors in spelling, tact or fact are transmission errors]
diff --git a/options.c b/options.c
index 088202e..4f2a3f5 100644
--- a/options.c
+++ b/options.c
@@ -122,6 +122,7 @@ int blocking_io = -1;
int checksum_seed = 0;
int inplace = 0;
int delay_updates = 0;
+int direct_io = 0;
long block_size = 0; /* "long" because popt can't set an int32. */
char number_separator;
char *skip_compress = NULL;
@@ -746,6 +747,7 @@ void usage(enum logcode F)
rprintf(F," --partial keep partially transferred files\n");
rprintf(F," --partial-dir=DIR put a partially transferred file into DIR\n");
rprintf(F," --delay-updates put all updated files into place at transfer's end\n");
+ rprintf(F," --direct-io don't use buffer cache for files being transfered\n");
rprintf(F," -m, --prune-empty-dirs prune empty directory chains from the file-list\n");
rprintf(F," --numeric-ids don't map uid/gid values by user/group name\n");
rprintf(F," --usermap=STRING custom username mapping\n");
@@ -977,6 +979,7 @@ static struct poptOption long_options[] = {
{"partial-dir", 0, POPT_ARG_STRING, &partial_dir, 0, 0, 0 },
{"delay-updates", 0, POPT_ARG_VAL, &delay_updates, 1, 0, 0 },
{"no-delay-updates", 0, POPT_ARG_VAL, &delay_updates, 0, 0, 0 },
+ {"direct-io", 'n', POPT_ARG_NONE, &direct_io, 0, 0, 0 },
{"prune-empty-dirs",'m', POPT_ARG_VAL, &prune_empty_dirs, 1, 0, 0 },
{"no-prune-empty-dirs",0,POPT_ARG_VAL, &prune_empty_dirs, 0, 0, 0 },
{"no-m", 0, POPT_ARG_VAL, &prune_empty_dirs, 0, 0, 0 },
@@ -2654,6 +2657,9 @@ void server_options(char **args, int *argc_p)
} else if (keep_partial && am_sender)
args[ac++] = "--partial";
+ if (direct_io)
+ args[ac++] = "--direct-io";
+
if (ignore_errors)
args[ac++] = "--ignore-errors";
diff --git a/syscall.c b/syscall.c
index fd23d15..9d432c0 100644
--- a/syscall.c
+++ b/syscall.c
@@ -34,6 +34,7 @@
#endif
extern int dry_run;
+extern int direct_io;
extern int am_root;
extern int am_sender;
extern int read_only;
@@ -69,7 +70,11 @@ int do_symlink(const char *lnk, const char *fname)
* and write the lnk into it. */
if (am_root < 0) {
int ok, len = strlen(lnk);
- int fd = open(fname, O_WRONLY|O_CREAT|O_TRUNC, S_IWUSR|S_IRUSR);
+ int flags = O_WRONLY|O_CREAT|O_TRUNC;
+
+ if (direct_io) flags |= O_DIRECT;
+
+ int fd = open(fname, flags, S_IWUSR|S_IRUSR);
if (fd < 0)
return -1;
ok = write(fd, lnk, len) == len;
@@ -190,6 +195,8 @@ int do_open(const char *pathname, int flags, mode_t mode)
RETURN_ERROR_IF_RO_OR_LO;
}
+ if (direct_io) flags |= O_DIRECT;
+
return open(pathname, flags | O_BINARY, mode);
}
@@ -461,6 +468,8 @@ int do_open_nofollow(const char *pathname, int flags)
#endif
}
+ if (direct_io) flags |= O_DIRECT;
+
#ifdef O_NOFOLLOW
fd = open(pathname, flags|O_NOFOLLOW);
#else
--- options.c.orig 2013-02-14 13:36:19.000000000 +0100
+++ options.c 2013-02-14 13:36:33.000000000 +0100
@@ -120,6 +120,7 @@
int checksum_seed = 0;
int inplace = 0;
int delay_updates = 0;
+int direct_io = 0;
long block_size = 0; /* "long" because popt can't set an int32. */
char *skip_compress = NULL;
@@ -381,6 +382,7 @@
rprintf(F," --partial keep partially transferred files\n");
rprintf(F," --partial-dir=DIR put a partially transferred file into DIR\n");
rprintf(F," --delay-updates put all updated files into place at transfer's end\n");
+ rprintf(F," --direct-io don't use buffer cache for files being transferedd\n");
rprintf(F," -m, --prune-empty-dirs prune empty directory chains from the file-list\n");
rprintf(F," --numeric-ids don't map uid/gid values by user/group name\n");
rprintf(F," --timeout=SECONDS set I/O timeout in seconds\n");
@@ -593,6 +595,7 @@
{"partial-dir", 0, POPT_ARG_STRING, &partial_dir, 0, 0, 0 },
{"delay-updates", 0, POPT_ARG_VAL, &delay_updates, 1, 0, 0 },
{"no-delay-updates", 0, POPT_ARG_VAL, &delay_updates, 0, 0, 0 },
+ {"direct-io", 'n', POPT_ARG_NONE, &direct_io, 0, 0, 0 },
{"prune-empty-dirs",'m', POPT_ARG_VAL, &prune_empty_dirs, 1, 0, 0 },
{"no-prune-empty-dirs",0,POPT_ARG_VAL, &prune_empty_dirs, 0, 0, 0 },
{"no-m", 0, POPT_ARG_VAL, &prune_empty_dirs, 0, 0, 0 },
@@ -2002,6 +2005,9 @@
} else if (keep_partial && am_sender)
args[ac++] = "--partial";
+ if (direct_io)
+ args[ac++] = "--direct-io";
+
if (ignore_errors)
args[ac++] = "--ignore-errors";
--- syscall.c.direct-io 2011-02-21 20:32:51.000000000 +0100
+++ syscall.c 2013-02-14 13:39:40.000000000 +0100
@@ -30,6 +30,7 @@
#endif
extern int dry_run;
+extern int direct_io;
extern int am_root;
extern int read_only;
extern int list_only;
@@ -143,6 +144,8 @@
RETURN_ERROR_IF_RO_OR_LO;
}
+ if (direct_io) flags |= O_DIRECT;
+
return open(pathname, flags | O_BINARY, mode);
}
--
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