Re: [9fans] 9pfuse adventure

[sqweek <sqweek@gmail.com>]

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 Right. On 64-bit arches, linux forces the O_LARGEFILE (0x8000) flag
in sys_open(). FUSE passes the flags along in fuse_send_open(), which
makes its way to 9pfuse's _fuseopen(). _fuseopen() _tries_ to ignore
the O_LARGEFILE flag, but on 64-bit arches, the userspace fcntl header
<bits/fcntl.h> defines O_LARGEFILE as 0... even though the kernel
still treats it as 0x8000.
 Friggin mess. Patch attached.
-sqweek

On Fri, Mar 21, 2008 at 7:08 PM, John Soros <sorosj@gmail.com> wrote:
> Hi!
>  well, i have been having this error for quite a while with 9pfuse. on amd64 linux (archlinux), i couldn't even ls a mounted directory, now that i have a 32 bit system, ls works, but cp doesn't (i have no idea if it hasanything to do with the arch, though).
>  this is how i mount sources with p9p:
>  $ 9fs sources
>  $ 9 mount `namespace`/sources /tmp/sources
>  then ls in a directory in /tmp/sources works, but when i try to copy, attached is the output.
>  I'm open to testing whatever fixes you might suggest.
>  regs
>  John

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Index: main.c
===================================================================
RCS file: /cvs/plan9/src/cmd/9pfuse/main.c,v
retrieving revision 1.14
diff -u -r1.14 main.c
--- main.c	23 Nov 2007 21:28:33 -0000	1.14
+++ main.c	27 Mar 2008 02:47:39 -0000
@@ -24,11 +24,19 @@
 #endif
 
 #ifndef O_LARGEFILE
-#  if defined(__linux__)
-#    define O_LARGEFILE 0100000  /* Sigh */
-#  else
-#    define O_LARGEFILE 0
-#  endif
+#  define O_LARGEFILE 0
+#endif
+
+/* Work around glibc's broken <bits/fcntl.h> which defines
+ * O_LARGEFILE to 0 on 64 bit architectures.  But, on those same
+ * architectures, linux _forces_ O_LARGEFILE (which is always
+ * 0100000 in the kernel) at each file open. FUSE is all too
+ * happy to pass the flag onto us, where we'd have no idea what
+ * to do with it if we trusted glibc.
+ */
+#if defined(__linux__)
+#  undef O_LARGEFILE
+#  define O_LARGEFILE 0100000
 #endif
 
 #ifndef O_CLOEXEC