Hi,
I think I've found problem root cause.
As I'm working on "Online Capacity Expansion", my tests uses mounted arrays - this is in conflict with open_dev_ext()
and fails this function. Evrything is ok This means that reshape operation cannot be performed online (or this is valid on my system only?).
I do not know why on begin (in main() of mdadm.c) this function can succeed and later not (later system blocks array ?).
More, when I've made some open_dev_exe()+close() earlier, it works later also (please look used code below/treat patch as demo/).
Summarizing problem is related to mounted arrays only.
BR
Adam
>From cf545d2ffb906096da89aff7b1a5c5830221cc4a Mon Sep 17 00:00:00 2001
From: Adam Kwolek <adam.kwolek@xxxxxxxxx>
Date: Fri, 14 Jan 2011 11:11:19 +0100
Subject: [PATCH] ADK: open workaround 2
Signed-off-by: Adam Kwolek <adam.kwolek@xxxxxxxxx>
---
Grow.c | 17 +++++++++++++++++
mdadm.c | 11 +++++++++++
2 files changed, 28 insertions(+), 0 deletions(-)
diff --git a/Grow.c b/Grow.c
index 763287b..3b37f97 100644
--- a/Grow.c
+++ b/Grow.c
@@ -1285,6 +1285,10 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
struct mdinfo info;
struct mdinfo *sra;
+//adk
+ int fd_test = open_dev_excl(126);
+ if (fd_test >= 0)
+ close(fd_test);
if (ioctl(fd, GET_ARRAY_INFO, &array) < 0) {
fprintf(stderr, Name ": %s is not an active md array - aborting\n",
@@ -1319,6 +1323,10 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
" beyond %d\n", st->max_devs);
return 1;
}
+//adk
+ fd_test = open_dev_excl(126);
+ if (fd_test >= 0)
+ close(fd_test);
/* in the external case we need to check that the requested reshape is
* supported, and perform an initial check that the container holds the
@@ -1394,6 +1402,10 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
" be reshaped\n", devname);
return 1;
}
+//adk
+ fd_test = open_dev_excl(126);
+ if (fd_test >= 0)
+ close(fd_test);
/* ========= set size =============== */
if (size >= 0 && (size == 0 || size != array.size)) {
@@ -1462,6 +1474,10 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
goto release;
}
}
+//adk
+ fd_test = open_dev_excl(126);
+ if (fd_test >= 0)
+ close(fd_test);
info.array = array;
sysfs_init(&info, fd, NoMdDev);
@@ -1545,6 +1561,7 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
* number of devices (On-Line Capacity Expansion) must be
* performed at the level of the container
*/
+
rv = reshape_container(container, fd, devname, st, &info,
force, backup_file, quiet);
frozen = 0;
diff --git a/mdadm.c b/mdadm.c
index 2ffe94f..bc9d34e 100644
--- a/mdadm.c
+++ b/mdadm.c
@@ -127,6 +127,7 @@ int main(int argc, char *argv[])
ident.name[0] = 0;
ident.container = NULL;
ident.member = NULL;
+//adk - can open
while ((option_index = -1) ,
(opt=getopt_long(argc, argv,
@@ -134,6 +135,11 @@ int main(int argc, char *argv[])
&option_index)) != -1) {
int newmode = mode;
/* firstly, some mode-independent options */
+//adk
+ int fd_test = open_dev_excl(126);
+ if (fd_test >= 0)
+ close(fd_test);
+
switch(opt) {
case HelpOptions:
print_help = 2;
@@ -1115,6 +1121,11 @@ int main(int argc, char *argv[])
exit(2);
}
if (mode == MANAGE || mode == GROW) {
+//adk
+ int fd_test = open_dev_excl(126);
+ if (fd_test >= 0)
+ close(fd_test);
+
mdfd = open_mddev(devlist->devname, 1);
if (mdfd < 0)
exit(1);
--
1.6.0.2
> -----Original Message-----
> From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid-
> owner@xxxxxxxxxxxxxxx] On Behalf Of Kwolek, Adam
> Sent: Friday, January 14, 2011 8:32 AM
> To: Williams, Dan J
> Cc: neilb@xxxxxxx; linux-raid@xxxxxxxxxxxxxxx; Neubauer, Wojciech;
> Ciechanowski, Ed
> Subject: RE: open_dev_excl in reshape_container() fails
>
>
>
> > -----Original Message-----
> > From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid-
> > owner@xxxxxxxxxxxxxxx] On Behalf Of Dan Williams
> > Sent: Thursday, January 13, 2011 6:28 PM
> > To: Kwolek, Adam
> > Cc: neilb@xxxxxxx; linux-raid@xxxxxxxxxxxxxxx; Neubauer, Wojciech;
> > Ciechanowski, Ed
> > Subject: Re: open_dev_excl in reshape_container() fails
> >
> > 2011/1/13 Kwolek, Adam <adam.kwolek@xxxxxxxxx>:
> > > Hi,
> > >
> > > I've got a problem using open_dev_excl() in reshape_container(), it
> > fails. This functions goes down
> > > and calls open() with flags O_DIRECT| O_RDWR| O_EXCL.
> > > It fails in reshape_container(), ealier in Grow_reshape() exactly
> the
> > same test call to open_dev_excl() succeed.
> > > Between test open and open in reshape_container() there is no other
> > open() performed (or other i/o operation that can cause problem).
> > > It not depends on mdmon action because it is the same for raid5 and
> > raid0.
> > > Function open_dev() works, and I'm using it as workaround.
> > >
> > > In man pages for open() is told that O_EXCL flag should be used
> with
> > O_CREAT flag only.
> > > I've read in manual for open() also: "If O_EXCL is set and O_CREAT
> is
> > not set, the result is undefined"
> >
> > Right, it is undefined with respect to Posix, but for Linux O_EXCL on
> > a block device without O_CREAT is defined to bd_claim the block
> > device.
> >
> > http://www.kernel.org/doc/man-pages/online/pages/man2/open.2.html
> >
> > The second call to open_dev_excl is a bug, by definition you can't
> > exclusive open twice. Can you reuse the fd established in
> > Grow_reshape?
> >
> > --
> > Dan
>
> There is no second open. My test call to open_dev_excl() is closed at
> once ;),
> and it is used to detect where I can successfully open device and if
> there is any duplicated open.
> There is no other open that can block open_dev_excl() in
> reshape_container() (when monitor is absent also),
> or I was unable to find it.
> Handle cannot be reused, because in Grow_reshape() container is opened
> and in reshape_container() all arrays
> Are opened one by one.
>
> BR
> Adam
>
> > --
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