Re: [PATCH] ceph: Fix file open flags on ppc64
From: Alexander Graf
Date: Fri Apr 21 2017 - 09:59:30 EST
On 21.04.17 04:22, Yan, Zheng wrote:
On 20 Apr 2017, at 20:40, Alexander Graf <agraf@xxxxxxx> wrote:
The file open flags (O_foo) are platform specific and should never go
out to an interface that is not local to the system.
Unfortunately these flags have leaked out onto the wire in the cephfs
implementation. That lead to bogus flags getting transmitted on ppc64.
This patch converts the kernel view of flags to the ceph view of file
open flags. On x86 systems, the new function should get optimized out
by smart compilers. On systems where the flags differ, it should adapt
them accordingly.
Fixes: 124e68e74 ("ceph: file operations")
Signed-off-by: Alexander Graf <agraf@xxxxxxx>
---
fs/ceph/file.c | 45 +++++++++++++++++++++++++++++++++++++++++++-
include/linux/ceph/ceph_fs.h | 24 +++++++++++++++++++++++
2 files changed, 68 insertions(+), 1 deletion(-)
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 26cc954..0ed6392 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -103,6 +103,49 @@ static size_t dio_get_pagev_size(const struct iov_iter *it)
return ERR_PTR(ret);
}
+static u32 ceph_flags_sys2wire(u32 flags)
+{
+ u32 wire_flags = 0;
+
+ switch (flags & O_ACCMODE) {
+ case O_RDONLY:
+ wire_flags |= CEPH_O_RDONLY;
+ break;
+ case O_WRONLY:
+ wire_flags |= CEPH_O_WRONLY;
+ break;
+ case O_RDWR:
+ wire_flags |= CEPH_O_RDWR;
+ break;
+ }
+ flags &= ~O_ACCMODE;
+
+#define ceph_sys2wire(a) if (flags & a) { wire_flags |= CEPH_##a; flags &= ~a; }
+
+ ceph_sys2wire(O_CREAT);
+ ceph_sys2wire(O_NOCTTY);
+ ceph_sys2wire(O_TRUNC);
+ ceph_sys2wire(O_APPEND);
+ ceph_sys2wire(O_NONBLOCK);
+ ceph_sys2wire(O_DSYNC);
+ ceph_sys2wire(FASYNC);
+ ceph_sys2wire(O_DIRECT);
+ ceph_sys2wire(O_LARGEFILE);
+ ceph_sys2wire(O_DIRECTORY);
+ ceph_sys2wire(O_NOFOLLOW);
+ ceph_sys2wire(O_NOATIME);
+ ceph_sys2wire(O_CLOEXEC);
+ ceph_sys2wire(__O_SYNC);
+ ceph_sys2wire(O_PATH);
+ ceph_sys2wire(__O_TMPFILE);
+
+#undef ceph_sys2wire
+
+ WARN_ONCE(flags, "Found unknown open flags: %x", flags);
+
+ return wire_flags;
+}
+
/*
* Prepare an open request. Preallocate ceph_cap to avoid an
* inopportune ENOMEM later.
@@ -123,7 +166,7 @@ static size_t dio_get_pagev_size(const struct iov_iter *it)
if (IS_ERR(req))
goto out;
req->r_fmode = ceph_flags_to_mode(flags);
- req->r_args.open.flags = cpu_to_le32(flags);
+ req->r_args.open.flags = ceph_flags_sys2wire(cpu_to_le32(flags));
cpu_to_le32(ceph_flags_sys2wire(flags)) ?
Jeff also pointed to it. Definitely, yes. My thinko.
req->r_args.open.mode = cpu_to_le32(create_mode);
out:
return req;
diff --git a/include/linux/ceph/ceph_fs.h b/include/linux/ceph/ceph_fs.h
index f4b2ee1..d254b48 100644
--- a/include/linux/ceph/ceph_fs.h
+++ b/include/linux/ceph/ceph_fs.h
@@ -366,6 +366,30 @@ enum {
#define CEPH_READDIR_FRAG_COMPLETE (1<<8)
#define CEPH_READDIR_HASH_ORDER (1<<9)
+/*
+ * open request flags
+ */
+#define CEPH_O_RDONLY 00000000
+#define CEPH_O_WRONLY 00000001
+#define CEPH_O_RDWR 00000002
+#define CEPH_O_CREAT 00000100
+#define CEPH_O_EXCL 00000200
+#define CEPH_O_NOCTTY 00000400
+#define CEPH_O_TRUNC 00001000
+#define CEPH_O_APPEND 00002000
+#define CEPH_O_NONBLOCK 00004000
+#define CEPH_O_DSYNC 00010000
+#define CEPH_FASYNC 00020000
+#define CEPH_O_DIRECT 00040000
+#define CEPH_O_LARGEFILE 00100000
+#define CEPH_O_DIRECTORY 00200000
+#define CEPH_O_NOFOLLOW 00400000
+#define CEPH_O_NOATIME 01000000
+#define CEPH_O_CLOEXEC 02000000
+#define CEPH___O_SYNC 04000000
+#define CEPH_O_PATH 010000000
+#define CEPH___O_TMPFILE 020000000
+
RDONLY, WRONLY, RDWR, CREAT, EXCL, TRUNC, DIRECTORY, NOFOLLOW are used by mds, no need to define the rest.
So currently the function checks for any bits it doesn't know about. Do
we want to drop that check then?
Alex