The patch titled
Subject: coda: stop using 'struct timespec' in user API
has been removed from the -mm tree. Its filename was
coda-stop-using-struct-timespec-in-user-api.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Arnd Bergmann <arnd@xxxxxxxx>
Subject: coda: stop using 'struct timespec' in user API
We exchange file timestamps with user space using psdev device read/write
operations with a fixed but architecture specific binary layout.
On 32-bit systems, this uses a 'timespec' structure that is defined by the
C library to contain two 32-bit values for seconds and nanoseconds. As we
get ready for the year 2038 overflow of the 32-bit signed seconds, the
kernel now uses 64-bit timestamps internally, and user space will do the
same change by changing the 'timespec' definition in the future.
Unfortunately, this breaks the layout of the coda_vattr structure, so we
need to redefine that in terms of something that does not change. I'm
introducing a new 'struct vtimespec' structure here that keeps the
existing layout, and the same change has to be done in the coda user space
copy of linux/coda.h before anyone can use that on a 32-bit architecture
with 64-bit time_t.
An open question is what should happen to actual times past y2038, as they
are now truncated to the last valid date when sent to user space, and
interpreted as pre-1970 times when a timestamp with the MSB set is read
back into the kernel. Alternatively, we could change the new
timespec64_to_coda()/coda_to_timespec64() functions to use a different
interpretation and extend the available range further to the future by
disallowing past timestamps. This would require more changes in the user
space side though.
Link: http://lkml.kernel.org/r/562b7324149461743e4fbe2fedbf7c242f7e274a.1558117389.git.jaharkes@xxxxxxxxxx
Link: https://patchwork.kernel.org/patch/10474735/
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Jan Harkes <jaharkes@xxxxxxxxxx>
Acked-by: Jan Harkes <jaharkes@xxxxxxxxxx>
Cc: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: Fabian Frederick <fabf@xxxxxxxxx>
Cc: Mikko Rapeli <mikko.rapeli@xxxxxx>
Cc: Sam Protsenko <semen.protsenko@xxxxxxxxxx>
Cc: Yann Droneaud <ydroneaud@xxxxxxxxxx>
Cc: Zhouyang Jia <jiazhouyang09@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/filesystems/coda.txt | 11 +++--
fs/coda/coda_linux.c | 50 ++++++++++++++++++++-------
include/uapi/linux/coda.h | 20 +++++++++-
3 files changed, 62 insertions(+), 19 deletions(-)
--- a/Documentation/filesystems/coda.txt~coda-stop-using-struct-timespec-in-user-api
+++ a/Documentation/filesystems/coda.txt
@@ -481,7 +481,10 @@ kernel support.
-
+ struct vtimespec {
+ long tv_sec; /* seconds */
+ long tv_nsec; /* nanoseconds */
+ };
struct coda_vattr {
enum coda_vtype va_type; /* vnode type (for create) */
@@ -493,9 +496,9 @@ kernel support.
long va_fileid; /* file id */
u_quad_t va_size; /* file size in bytes */
long va_blocksize; /* blocksize preferred for i/o */
- struct timespec va_atime; /* time of last access */
- struct timespec va_mtime; /* time of last modification */
- struct timespec va_ctime; /* time file changed */
+ struct vtimespec va_atime; /* time of last access */
+ struct vtimespec va_mtime; /* time of last modification */
+ struct vtimespec va_ctime; /* time file changed */
u_long va_gen; /* generation number of file */
u_long va_flags; /* flags defined for file */
dev_t va_rdev; /* device special file represents */
--- a/fs/coda/coda_linux.c~coda-stop-using-struct-timespec-in-user-api
+++ a/fs/coda/coda_linux.c
@@ -66,6 +66,32 @@ unsigned short coda_flags_to_cflags(unsi
return coda_flags;
}
+static struct timespec64 coda_to_timespec64(struct vtimespec ts)
+{
+ /*
+ * We interpret incoming timestamps as 'signed' to match traditional
+ * usage and support pre-1970 timestamps, but this breaks in y2038
+ * on 32-bit machines.
+ */
+ struct timespec64 ts64 = {
+ .tv_sec = ts.tv_sec,
+ .tv_nsec = ts.tv_nsec,
+ };
+
+ return ts64;
+}
+
+static struct vtimespec timespec64_to_coda(struct timespec64 ts64)
+{
+ /* clamp the timestamps to the maximum range rather than wrapping */
+ struct vtimespec ts = {
+ .tv_sec = lower_32_bits(clamp_t(time64_t, ts64.tv_sec,
+ LONG_MIN, LONG_MAX)),
+ .tv_nsec = ts64.tv_nsec,
+ };
+
+ return ts;
+}
/* utility functions below */
void coda_vattr_to_iattr(struct inode *inode, struct coda_vattr *attr)
@@ -105,11 +131,11 @@ void coda_vattr_to_iattr(struct inode *i
if (attr->va_size != -1)
inode->i_blocks = (attr->va_size + 511) >> 9;
if (attr->va_atime.tv_sec != -1)
- inode->i_atime = timespec_to_timespec64(attr->va_atime);
+ inode->i_atime = coda_to_timespec64(attr->va_atime);
if (attr->va_mtime.tv_sec != -1)
- inode->i_mtime = timespec_to_timespec64(attr->va_mtime);
+ inode->i_mtime = coda_to_timespec64(attr->va_mtime);
if (attr->va_ctime.tv_sec != -1)
- inode->i_ctime = timespec_to_timespec64(attr->va_ctime);
+ inode->i_ctime = coda_to_timespec64(attr->va_ctime);
}
@@ -130,12 +156,12 @@ void coda_iattr_to_vattr(struct iattr *i
vattr->va_uid = (vuid_t) -1;
vattr->va_gid = (vgid_t) -1;
vattr->va_size = (off_t) -1;
- vattr->va_atime.tv_sec = (time_t) -1;
- vattr->va_atime.tv_nsec = (time_t) -1;
- vattr->va_mtime.tv_sec = (time_t) -1;
- vattr->va_mtime.tv_nsec = (time_t) -1;
- vattr->va_ctime.tv_sec = (time_t) -1;
- vattr->va_ctime.tv_nsec = (time_t) -1;
+ vattr->va_atime.tv_sec = (long) -1;
+ vattr->va_atime.tv_nsec = (long) -1;
+ vattr->va_mtime.tv_sec = (long) -1;
+ vattr->va_mtime.tv_nsec = (long) -1;
+ vattr->va_ctime.tv_sec = (long) -1;
+ vattr->va_ctime.tv_nsec = (long) -1;
vattr->va_type = C_VNON;
vattr->va_fileid = -1;
vattr->va_gen = -1;
@@ -175,13 +201,13 @@ void coda_iattr_to_vattr(struct iattr *i
vattr->va_size = iattr->ia_size;
}
if ( valid & ATTR_ATIME ) {
- vattr->va_atime = timespec64_to_timespec(iattr->ia_atime);
+ vattr->va_atime = timespec64_to_coda(iattr->ia_atime);
}
if ( valid & ATTR_MTIME ) {
- vattr->va_mtime = timespec64_to_timespec(iattr->ia_mtime);
+ vattr->va_mtime = timespec64_to_coda(iattr->ia_mtime);
}
if ( valid & ATTR_CTIME ) {
- vattr->va_ctime = timespec64_to_timespec(iattr->ia_ctime);
+ vattr->va_ctime = timespec64_to_coda(iattr->ia_ctime);
}
}
--- a/include/uapi/linux/coda.h~coda-stop-using-struct-timespec-in-user-api
+++ a/include/uapi/linux/coda.h
@@ -211,6 +211,20 @@ struct CodaFid {
*/
enum coda_vtype { C_VNON, C_VREG, C_VDIR, C_VBLK, C_VCHR, C_VLNK, C_VSOCK, C_VFIFO, C_VBAD };
+#ifdef __linux__
+/*
+ * This matches the traditional Linux 'timespec' structure binary layout,
+ * before using 64-bit time_t everywhere. Overflows in y2038 on 32-bit
+ * architectures.
+ */
+struct vtimespec {
+ long tv_sec; /* seconds */
+ long tv_nsec; /* nanoseconds */
+};
+#else
+#define vtimespec timespec
+#endif
+
struct coda_vattr {
long va_type; /* vnode type (for create) */
u_short va_mode; /* files access mode and type */
@@ -220,9 +234,9 @@ struct coda_vattr {
long va_fileid; /* file id */
u_quad_t va_size; /* file size in bytes */
long va_blocksize; /* blocksize preferred for i/o */
- struct timespec va_atime; /* time of last access */
- struct timespec va_mtime; /* time of last modification */
- struct timespec va_ctime; /* time file changed */
+ struct vtimespec va_atime; /* time of last access */
+ struct vtimespec va_mtime; /* time of last modification */
+ struct vtimespec va_ctime; /* time file changed */
u_long va_gen; /* generation number of file */
u_long va_flags; /* flags defined for file */
cdev_t va_rdev; /* device special file represents */
_
Patches currently in -mm which might be from arnd@xxxxxxxx are
mm-sparse-fix-memory-leak-of-sparsemap_buf-in-aliged-memory-fix.patch
proc-sysctl-add-shared-variables-for-range-check-fix-3.patch
