[PATCH v2 0/2] quota: Add mountpath based quota support

[PATCH v2 0/2] quota: Add mountpath based quota support

[Sascha Hauer]

Current quotactl syscall uses a path to a block device to specify the
filesystem to work on which makes it unsuitable for filesystems that
do not have a block device. This series adds a new syscall quotactl_path()
which replaces the path to the block device with a mountpath, but otherwise
behaves like original quotactl.

This is done to add quota support to UBIFS. UBIFS quota support has been
posted several times with different approaches to put the mountpath into
the existing quotactl() syscall until it has been suggested to make it a
new syscall instead, so here it is.

I'm not posting the full UBIFS quota series here as it remains unchanged
and I'd like to get feedback to the new syscall first. For those interested
the most recent series can be found here: https://lwn.net/Articles/810463/

Changes since (implicit) v1:
- Ignore second path argument to Q_QUOTAON. With this quotactl_path() can
  only do the Q_QUOTAON operation on filesystems which use hidden inodes
  for quota metadata storage
- Drop unnecessary quotactl_cmd_onoff() check

Sascha Hauer (2):
  quota: Add mountpath based quota support
  quota: wire up quotactl_path

 arch/alpha/kernel/syscalls/syscall.tbl      |  1 +
 arch/arm/tools/syscall.tbl                  |  1 +
 arch/arm64/include/asm/unistd.h             |  2 +-
 arch/arm64/include/asm/unistd32.h           |  2 +
 arch/ia64/kernel/syscalls/syscall.tbl       |  1 +
 arch/m68k/kernel/syscalls/syscall.tbl       |  1 +
 arch/microblaze/kernel/syscalls/syscall.tbl |  1 +
 arch/mips/kernel/syscalls/syscall_n32.tbl   |  1 +
 arch/mips/kernel/syscalls/syscall_n64.tbl   |  1 +
 arch/mips/kernel/syscalls/syscall_o32.tbl   |  1 +
 arch/parisc/kernel/syscalls/syscall.tbl     |  1 +
 arch/powerpc/kernel/syscalls/syscall.tbl    |  1 +
 arch/s390/kernel/syscalls/syscall.tbl       |  1 +
 arch/sh/kernel/syscalls/syscall.tbl         |  1 +
 arch/sparc/kernel/syscalls/syscall.tbl      |  1 +
 arch/x86/entry/syscalls/syscall_32.tbl      |  1 +
 arch/x86/entry/syscalls/syscall_64.tbl      |  1 +
 arch/xtensa/kernel/syscalls/syscall.tbl     |  1 +
 fs/quota/quota.c                            | 49 +++++++++++++++++++++
 include/linux/syscalls.h                    |  2 +
 include/uapi/asm-generic/unistd.h           |  4 +-
 kernel/sys_ni.c                             |  1 +
 22 files changed, 74 insertions(+), 2 deletions(-)

-- 
2.20.1

[PATCH 1/2] quota: Add mountpath based quota support

[Sascha Hauer]

Add syscall quotactl_path, a variant of quotactl which allows to specify
the mountpath instead of a path of to a block device.

The quotactl syscall expects a path to the mounted block device to
specify the filesystem to work on. This limits usage to filesystems
which actually have a block device. quotactl_path replaces the path
to the block device with a path where the filesystem is mounted at.

The global Q_SYNC command to sync all filesystems is not supported for
this new syscall, otherwise quotactl_path behaves like quotactl.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 fs/quota/quota.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/fs/quota/quota.c b/fs/quota/quota.c
index 6d16b2be5ac4..6f1df32abeea 100644
--- a/fs/quota/quota.c
+++ b/fs/quota/quota.c
@@ -17,6 +17,7 @@
 #include <linux/capability.h>
 #include <linux/quotaops.h>
 #include <linux/types.h>
+#include <linux/mount.h>
 #include <linux/writeback.h>
 #include <linux/nospec.h>
 #include "compat.h"
@@ -968,3 +969,51 @@ SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
 		path_put(pathp);
 	return ret;
 }
+
+SYSCALL_DEFINE4(quotactl_path, unsigned int, cmd, const char __user *,
+		mountpoint, qid_t, id, void __user *, addr)
+{
+	struct super_block *sb;
+	struct path mountpath;
+	unsigned int cmds = cmd >> SUBCMDSHIFT;
+	unsigned int type = cmd & SUBCMDMASK;
+	int ret;
+
+	if (type >= MAXQUOTAS)
+		return -EINVAL;
+
+	if (!mountpoint)
+		return -ENODEV;
+
+	ret = user_path_at(AT_FDCWD, mountpoint,
+			     LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT, &mountpath);
+	if (ret)
+		return ret;
+
+	sb = mountpath.dentry->d_inode->i_sb;
+
+	if (quotactl_cmd_write(cmds)) {
+		ret = mnt_want_write(mountpath.mnt);
+		if (ret)
+			goto out;
+	}
+
+	if (quotactl_cmd_onoff(cmds))
+		down_write(&sb->s_umount);
+	else
+		down_read(&sb->s_umount);
+
+	ret = do_quotactl(sb, type, cmds, id, addr, ERR_PTR(-EINVAL));
+
+	if (quotactl_cmd_onoff(cmds))
+		up_write(&sb->s_umount);
+	else
+		up_read(&sb->s_umount);
+
+	if (quotactl_cmd_write(cmds))
+		mnt_drop_write(mountpath.mnt);
+out:
+	path_put(&mountpath);
+
+	return ret;
+}
-- 
2.20.1

[PATCH 2/2] quota: wire up quotactl_path

[Sascha Hauer]

Wire up the quotactl_path syscall added in the previous patch.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 arch/alpha/kernel/syscalls/syscall.tbl      | 1 +
 arch/arm/tools/syscall.tbl                  | 1 +
 arch/arm64/include/asm/unistd.h             | 2 +-
 arch/arm64/include/asm/unistd32.h           | 2 ++
 arch/ia64/kernel/syscalls/syscall.tbl       | 1 +
 arch/m68k/kernel/syscalls/syscall.tbl       | 1 +
 arch/microblaze/kernel/syscalls/syscall.tbl | 1 +
 arch/mips/kernel/syscalls/syscall_n32.tbl   | 1 +
 arch/mips/kernel/syscalls/syscall_n64.tbl   | 1 +
 arch/mips/kernel/syscalls/syscall_o32.tbl   | 1 +
 arch/parisc/kernel/syscalls/syscall.tbl     | 1 +
 arch/powerpc/kernel/syscalls/syscall.tbl    | 1 +
 arch/s390/kernel/syscalls/syscall.tbl       | 1 +
 arch/sh/kernel/syscalls/syscall.tbl         | 1 +
 arch/sparc/kernel/syscalls/syscall.tbl      | 1 +
 arch/x86/entry/syscalls/syscall_32.tbl      | 1 +
 arch/x86/entry/syscalls/syscall_64.tbl      | 1 +
 arch/xtensa/kernel/syscalls/syscall.tbl     | 1 +
 include/linux/syscalls.h                    | 2 ++
 include/uapi/asm-generic/unistd.h           | 4 +++-
 kernel/sys_ni.c                             | 1 +
 21 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl
index a6617067dbe6..3fe90880c821 100644
--- a/arch/alpha/kernel/syscalls/syscall.tbl
+++ b/arch/alpha/kernel/syscalls/syscall.tbl
@@ -481,3 +481,4 @@
 549	common	faccessat2			sys_faccessat2
 550	common	process_madvise			sys_process_madvise
 551	common	epoll_pwait2			sys_epoll_pwait2
+552	common	quotactl_path			sys_quotactl_path
diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl
index 20e1170e2e0a..a62509df217f 100644
--- a/arch/arm/tools/syscall.tbl
+++ b/arch/arm/tools/syscall.tbl
@@ -455,3 +455,4 @@
 439	common	faccessat2			sys_faccessat2
 440	common	process_madvise			sys_process_madvise
 441	common	epoll_pwait2			sys_epoll_pwait2
+442	common	quotactl_path			sys_quotactl_path
diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h
index 86a9d7b3eabe..949788f5ba40 100644
--- a/arch/arm64/include/asm/unistd.h
+++ b/arch/arm64/include/asm/unistd.h
@@ -38,7 +38,7 @@
 #define __ARM_NR_compat_set_tls		(__ARM_NR_COMPAT_BASE + 5)
 #define __ARM_NR_COMPAT_END		(__ARM_NR_COMPAT_BASE + 0x800)
 
-#define __NR_compat_syscalls		442
+#define __NR_compat_syscalls		443
 #endif
 
 #define __ARCH_WANT_SYS_CLONE
diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
index cccfbbefbf95..734c254ca1b6 100644
--- a/arch/arm64/include/asm/unistd32.h
+++ b/arch/arm64/include/asm/unistd32.h
@@ -891,6 +891,8 @@ __SYSCALL(__NR_faccessat2, sys_faccessat2)
 __SYSCALL(__NR_process_madvise, sys_process_madvise)
 #define __NR_epoll_pwait2 441
 __SYSCALL(__NR_epoll_pwait2, compat_sys_epoll_pwait2)
+#define __NR_quotactl_path 442
+__SYSCALL(__NR_quotactl_path, sys_quotactl_path)
 
 /*
  * Please add new compat syscalls above this comment and update
diff --git a/arch/ia64/kernel/syscalls/syscall.tbl b/arch/ia64/kernel/syscalls/syscall.tbl
index bfc00f2bd437..4758a22a4d80 100644
--- a/arch/ia64/kernel/syscalls/syscall.tbl
+++ b/arch/ia64/kernel/syscalls/syscall.tbl
@@ -362,3 +362,4 @@
 439	common	faccessat2			sys_faccessat2
 440	common	process_madvise			sys_process_madvise
 441	common	epoll_pwait2			sys_epoll_pwait2
+442	common	quotactl_path			sys_quotactl_path
diff --git a/arch/m68k/kernel/syscalls/syscall.tbl b/arch/m68k/kernel/syscalls/syscall.tbl
index 7fe4e45c864c..b9072d2f1fdc 100644
--- a/arch/m68k/kernel/syscalls/syscall.tbl
+++ b/arch/m68k/kernel/syscalls/syscall.tbl
@@ -441,3 +441,4 @@
 439	common	faccessat2			sys_faccessat2
 440	common	process_madvise			sys_process_madvise
 441	common	epoll_pwait2			sys_epoll_pwait2
+442	common	quotactl_path			sys_quotactl_path
diff --git a/arch/microblaze/kernel/syscalls/syscall.tbl b/arch/microblaze/kernel/syscalls/syscall.tbl
index a522adf194ab..95e0cb59e8c1 100644
--- a/arch/microblaze/kernel/syscalls/syscall.tbl
+++ b/arch/microblaze/kernel/syscalls/syscall.tbl
@@ -447,3 +447,4 @@
 439	common	faccessat2			sys_faccessat2
 440	common	process_madvise			sys_process_madvise
 441	common	epoll_pwait2			sys_epoll_pwait2
+442	common	quotactl_path			sys_quotactl_path
diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl
index 0f03ad223f33..027fe0351e66 100644
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
@@ -380,3 +380,4 @@
 439	n32	faccessat2			sys_faccessat2
 440	n32	process_madvise			sys_process_madvise
 441	n32	epoll_pwait2			compat_sys_epoll_pwait2
+442	n32	quotactl_path			sys_quotactl_path
diff --git a/arch/mips/kernel/syscalls/syscall_n64.tbl b/arch/mips/kernel/syscalls/syscall_n64.tbl
index 91649690b52f..f4bddccab043 100644
--- a/arch/mips/kernel/syscalls/syscall_n64.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n64.tbl
@@ -356,3 +356,4 @@
 439	n64	faccessat2			sys_faccessat2
 440	n64	process_madvise			sys_process_madvise
 441	n64	epoll_pwait2			sys_epoll_pwait2
+442	n64	quotactl_path			sys_quotactl_path
diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl
index 4bad0c40aed6..bc2f3ad1de87 100644
--- a/arch/mips/kernel/syscalls/syscall_o32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_o32.tbl
@@ -429,3 +429,4 @@
 439	o32	faccessat2			sys_faccessat2
 440	o32	process_madvise			sys_process_madvise
 441	o32	epoll_pwait2			sys_epoll_pwait2		compat_sys_epoll_pwait2
+442	o32	quotactl_path			sys_quotactl_path
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl
index 6bcc31966b44..80a4b6dbae77 100644
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl
@@ -439,3 +439,4 @@
 439	common	faccessat2			sys_faccessat2
 440	common	process_madvise			sys_process_madvise
 441	common	epoll_pwait2			sys_epoll_pwait2		compat_sys_epoll_pwait2
+442	common	quotactl_path			sys_quotactl_path
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
index f744eb5cba88..29a706828330 100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -531,3 +531,4 @@
 439	common	faccessat2			sys_faccessat2
 440	common	process_madvise			sys_process_madvise
 441	common	epoll_pwait2			sys_epoll_pwait2		compat_sys_epoll_pwait2
+442	common	quotactl_path			sys_quotactl_path
diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
index d443423495e5..6ed53d992736 100644
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl
@@ -444,3 +444,4 @@
 439  common	faccessat2		sys_faccessat2			sys_faccessat2
 440  common	process_madvise		sys_process_madvise		sys_process_madvise
 441  common	epoll_pwait2		sys_epoll_pwait2		compat_sys_epoll_pwait2
+442  common	quotactl_path		sys_quotactl_path
diff --git a/arch/sh/kernel/syscalls/syscall.tbl b/arch/sh/kernel/syscalls/syscall.tbl
index 9df40ac0ebc0..f8488ad641b6 100644
--- a/arch/sh/kernel/syscalls/syscall.tbl
+++ b/arch/sh/kernel/syscalls/syscall.tbl
@@ -444,3 +444,4 @@
 439	common	faccessat2			sys_faccessat2
 440	common	process_madvise			sys_process_madvise
 441	common	epoll_pwait2			sys_epoll_pwait2
+442	common	quotactl_path			sys_quotactl_path
diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl
index 40d8c7cd8298..211d7269246b 100644
--- a/arch/sparc/kernel/syscalls/syscall.tbl
+++ b/arch/sparc/kernel/syscalls/syscall.tbl
@@ -487,3 +487,4 @@
 439	common	faccessat2			sys_faccessat2
 440	common	process_madvise			sys_process_madvise
 441	common	epoll_pwait2			sys_epoll_pwait2		compat_sys_epoll_pwait2
+442	common	quotactl_path			sys_quotactl_path
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 874aeacde2dd..deb7650cfc88 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -446,3 +446,4 @@
 439	i386	faccessat2		sys_faccessat2
 440	i386	process_madvise		sys_process_madvise
 441	i386	epoll_pwait2		sys_epoll_pwait2		compat_sys_epoll_pwait2
+442	common	quotactl_path		sys_quotactl_path
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index 78672124d28b..cdbfb67852e6 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -363,6 +363,7 @@
 439	common	faccessat2		sys_faccessat2
 440	common	process_madvise		sys_process_madvise
 441	common	epoll_pwait2		sys_epoll_pwait2
+442	common	quotactl_path		sys_quotactl_path
 
 #
 # Due to a historical design error, certain syscalls are numbered differently
diff --git a/arch/xtensa/kernel/syscalls/syscall.tbl b/arch/xtensa/kernel/syscalls/syscall.tbl
index 46116a28eeed..b434eda5653a 100644
--- a/arch/xtensa/kernel/syscalls/syscall.tbl
+++ b/arch/xtensa/kernel/syscalls/syscall.tbl
@@ -412,3 +412,4 @@
 439	common	faccessat2			sys_faccessat2
 440	common	process_madvise			sys_process_madvise
 441	common	epoll_pwait2			sys_epoll_pwait2
+442	common	quotactl_path			sys_quotactl_path
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 7688bc983de5..2e1bf7c2165f 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -482,6 +482,8 @@ asmlinkage long sys_pipe2(int __user *fildes, int flags);
 /* fs/quota.c */
 asmlinkage long sys_quotactl(unsigned int cmd, const char __user *special,
 				qid_t id, void __user *addr);
+asmlinkage long sys_quotactl_path(unsigned int cmd, const char __user *mountpoint,
+				  qid_t id, void __user *addr);
 
 /* fs/readdir.c */
 asmlinkage long sys_getdents64(unsigned int fd,
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index 728752917785..dad876b86488 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -861,9 +861,11 @@ __SYSCALL(__NR_faccessat2, sys_faccessat2)
 __SYSCALL(__NR_process_madvise, sys_process_madvise)
 #define __NR_epoll_pwait2 441
 __SC_COMP(__NR_epoll_pwait2, sys_epoll_pwait2, compat_sys_epoll_pwait2)
+#define __NR_quotactl_path 442
+__SYSCALL(__NR_quotactl_path, sys_quotactl_path)
 
 #undef __NR_syscalls
-#define __NR_syscalls 442
+#define __NR_syscalls 443
 
 /*
  * 32 bit systems traditionally used different
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 19aa806890d5..d24431782414 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -99,6 +99,7 @@ COND_SYSCALL(flock);
 
 /* fs/quota.c */
 COND_SYSCALL(quotactl);
+COND_SYSCALL(quotactl_path);
 
 /* fs/readdir.c */
 
-- 
2.20.1

[PATCH] quotactl.2: Add documentation for quotactl_path()

[Sascha Hauer]

Expand the quotactl.2 manpage with a description for quotactl_path()
that takes a mountpoint path instead of a path to a block device.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 man2/quotactl.2      | 31 ++++++++++++++++++++++++++++---
 man2/quotactl_path.2 |  1 +
 2 files changed, 29 insertions(+), 3 deletions(-)
 create mode 100644 man2/quotactl_path.2

diff --git a/man2/quotactl.2 b/man2/quotactl.2
index 7869c64ea..76505c668 100644
--- a/man2/quotactl.2
+++ b/man2/quotactl.2
@@ -34,6 +34,8 @@ quotactl \- manipulate disk quotas
 .PP
 .BI "int quotactl(int " cmd ", const char *" special ", int " id \
 ", caddr_t " addr );
+.BI "int quotactl_path(int " cmd ", const char *" mountpoint ", int " id \
+", caddr_t " addr );
 .fi
 .SH DESCRIPTION
 The quota system can be used to set per-user, per-group, and per-project limits
@@ -48,7 +50,11 @@ after this, the soft limit counts as a hard limit.
 .PP
 The
 .BR quotactl ()
-call manipulates disk quotas.
+and
+.BR quotactl_path ()
+calls manipulate disk quotas. The difference between both functions is the way
+how the filesystem being manipulated is specified, see description of the arguments
+below.
 The
 .I cmd
 argument indicates a command to be applied to the user or
@@ -75,10 +81,19 @@ value is described below.
 .PP
 The
 .I special
-argument is a pointer to a null-terminated string containing the pathname
+argument to
+.BR quotactl ()
+is a pointer to a null-terminated string containing the pathname
 of the (mounted) block special device for the filesystem being manipulated.
 .PP
 The
+.I mountpoint
+argument to
+.BR quotactl_path ()
+is a pointer to a null-terminated string containing the pathname
+of the mountpoint for the filesystem being manipulated.
+.PP
+The
 .I addr
 argument is the address of an optional, command-specific, data structure
 that is copied in or out of the system.
@@ -133,7 +148,17 @@ flag in the
 .I dqi_flags
 field returned by the
 .B Q_GETINFO
-operation.
+operation. The
+.BR quotactl_path ()
+variant of this syscall generally ignores the
+.IR addr
+and
+.IR id
+arguments, so the
+.B Q_QUOTAON
+operation of
+.BR quotactl_path ()
+is only suitable for work with hidden system inodes.
 .IP
 This operation requires privilege
 .RB ( CAP_SYS_ADMIN ).
diff --git a/man2/quotactl_path.2 b/man2/quotactl_path.2
new file mode 100644
index 000000000..5f63187c6
--- /dev/null
+++ b/man2/quotactl_path.2
@@ -0,0 +1 @@
+.so man2/quotactl.2
-- 
2.20.1

Re: [PATCH 1/2] quota: Add mountpath based quota support

[Christoph Hellwig]

> +	if (!mountpoint)
> +		return -ENODEV;
> +
> +	ret = user_path_at(AT_FDCWD, mountpoint,
> +			     LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT, &mountpath);

user_path_at handles an empty path, although you'll get EFAULT instead.
Do we care about the -ENODEV here?

Otherwise this looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH 2/2] quota: wire up quotactl_path

[Christoph Hellwig]

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH 2/2] quota: wire up quotactl_path

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 15914 bytes --]

Hi Sascha,

I love your patch! Perhaps something to improve:

[auto build test WARNING on arm64/for-next/core]
[also build test WARNING on tip/x86/asm m68k/for-next hp-parisc/for-next powerpc/next s390/features linus/master v5.11-rc7]
[cannot apply to sparc-next/master sparc/master xtensa/for_next next-20210211]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Sascha-Hauer/quota-Add-mountpath-based-quota-support/20210211-233912
base:   https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
config: x86_64-randconfig-a013-20210209 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project c9439ca36342fb6013187d0a69aef92736951476)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # https://github.com/0day-ci/linux/commit/0fa8489f958d6ec34215930a8d1a2d4b6644fea3
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Sascha-Hauer/quota-Add-mountpath-based-quota-support/20210211-233912
        git checkout 0fa8489f958d6ec34215930a8d1a2d4b6644fea3
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   In file included from arch/x86/entry/syscall_32.c:13:
   ./arch/x86/include/generated/asm/syscalls_32.h:830:18: error: expected parameter declarator
   __SYSCALL_COMMON(442, sys_quotactl_path)
                    ^
   ./arch/x86/include/generated/asm/syscalls_32.h:830:18: error: expected ')'
   ./arch/x86/include/generated/asm/syscalls_32.h:830:17: note: to match this '('
   __SYSCALL_COMMON(442, sys_quotactl_path)
                   ^
>> ./arch/x86/include/generated/asm/syscalls_32.h:830:1: warning: declaration specifier missing, defaulting to 'int'
   __SYSCALL_COMMON(442, sys_quotactl_path)
   ^
   int
   ./arch/x86/include/generated/asm/syscalls_32.h:830:17: error: this function declaration is not a prototype [-Werror,-Wstrict-prototypes]
   __SYSCALL_COMMON(442, sys_quotactl_path)
                   ^
                                          void
   ./arch/x86/include/generated/asm/syscalls_32.h:830:41: error: expected ';' after top level declarator
   __SYSCALL_COMMON(442, sys_quotactl_path)
                                           ^
                                           ;
   In file included from arch/x86/entry/syscall_32.c:24:
   ./arch/x86/include/generated/asm/syscalls_32.h:830:23: error: use of undeclared identifier 'sys_quotactl_path'
   __SYSCALL_COMMON(442, sys_quotactl_path)
                         ^
   1 warning and 5 errors generated.
--
   kernel/sys_ni.c:88:1: warning: no previous prototype for function '__x64_sys_flock' [-Wmissing-prototypes]
   COND_SYSCALL(flock);
   ^
   arch/x86/include/asm/syscall_wrapper.h:256:2: note: expanded from macro 'COND_SYSCALL'
           __X64_COND_SYSCALL(name)                                        \
           ^
   arch/x86/include/asm/syscall_wrapper.h:100:2: note: expanded from macro '__X64_COND_SYSCALL'
           __COND_SYSCALL(x64, sys_##name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:83:14: note: expanded from macro '__COND_SYSCALL'
           __weak long __##abi##_##name(const struct pt_regs *__unused)    \
                       ^
   <scratch space>:225:1: note: expanded from here
   __x64_sys_flock
   ^
   kernel/sys_ni.c:88:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   arch/x86/include/asm/syscall_wrapper.h:256:2: note: expanded from macro 'COND_SYSCALL'
           __X64_COND_SYSCALL(name)                                        \
           ^
   arch/x86/include/asm/syscall_wrapper.h:100:2: note: expanded from macro '__X64_COND_SYSCALL'
           __COND_SYSCALL(x64, sys_##name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:83:9: note: expanded from macro '__COND_SYSCALL'
           __weak long __##abi##_##name(const struct pt_regs *__unused)    \
                  ^
   kernel/sys_ni.c:88:1: warning: no previous prototype for function '__ia32_sys_flock' [-Wmissing-prototypes]
   COND_SYSCALL(flock);
   ^
   arch/x86/include/asm/syscall_wrapper.h:257:2: note: expanded from macro 'COND_SYSCALL'
           __IA32_COND_SYSCALL(name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:120:2: note: expanded from macro '__IA32_COND_SYSCALL'
           __COND_SYSCALL(ia32, sys_##name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:83:14: note: expanded from macro '__COND_SYSCALL'
           __weak long __##abi##_##name(const struct pt_regs *__unused)    \
                       ^
   <scratch space>:229:1: note: expanded from here
   __ia32_sys_flock
   ^
   kernel/sys_ni.c:88:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   arch/x86/include/asm/syscall_wrapper.h:257:2: note: expanded from macro 'COND_SYSCALL'
           __IA32_COND_SYSCALL(name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:120:2: note: expanded from macro '__IA32_COND_SYSCALL'
           __COND_SYSCALL(ia32, sys_##name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:83:9: note: expanded from macro '__COND_SYSCALL'
           __weak long __##abi##_##name(const struct pt_regs *__unused)    \
                  ^
   kernel/sys_ni.c:101:1: warning: no previous prototype for function '__x64_sys_quotactl' [-Wmissing-prototypes]
   COND_SYSCALL(quotactl);
   ^
   arch/x86/include/asm/syscall_wrapper.h:256:2: note: expanded from macro 'COND_SYSCALL'
           __X64_COND_SYSCALL(name)                                        \
           ^
   arch/x86/include/asm/syscall_wrapper.h:100:2: note: expanded from macro '__X64_COND_SYSCALL'
           __COND_SYSCALL(x64, sys_##name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:83:14: note: expanded from macro '__COND_SYSCALL'
           __weak long __##abi##_##name(const struct pt_regs *__unused)    \
                       ^
   <scratch space>:233:1: note: expanded from here
   __x64_sys_quotactl
   ^
   kernel/sys_ni.c:101:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   arch/x86/include/asm/syscall_wrapper.h:256:2: note: expanded from macro 'COND_SYSCALL'
           __X64_COND_SYSCALL(name)                                        \
           ^
   arch/x86/include/asm/syscall_wrapper.h:100:2: note: expanded from macro '__X64_COND_SYSCALL'
           __COND_SYSCALL(x64, sys_##name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:83:9: note: expanded from macro '__COND_SYSCALL'
           __weak long __##abi##_##name(const struct pt_regs *__unused)    \
                  ^
   kernel/sys_ni.c:101:1: warning: no previous prototype for function '__ia32_sys_quotactl' [-Wmissing-prototypes]
   COND_SYSCALL(quotactl);
   ^
   arch/x86/include/asm/syscall_wrapper.h:257:2: note: expanded from macro 'COND_SYSCALL'
           __IA32_COND_SYSCALL(name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:120:2: note: expanded from macro '__IA32_COND_SYSCALL'
           __COND_SYSCALL(ia32, sys_##name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:83:14: note: expanded from macro '__COND_SYSCALL'
           __weak long __##abi##_##name(const struct pt_regs *__unused)    \
                       ^
   <scratch space>:237:1: note: expanded from here
   __ia32_sys_quotactl
   ^
   kernel/sys_ni.c:101:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   arch/x86/include/asm/syscall_wrapper.h:257:2: note: expanded from macro 'COND_SYSCALL'
           __IA32_COND_SYSCALL(name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:120:2: note: expanded from macro '__IA32_COND_SYSCALL'
           __COND_SYSCALL(ia32, sys_##name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:83:9: note: expanded from macro '__COND_SYSCALL'
           __weak long __##abi##_##name(const struct pt_regs *__unused)    \
                  ^
>> kernel/sys_ni.c:102:1: warning: no previous prototype for function '__x64_sys_quotactl_path' [-Wmissing-prototypes]
   COND_SYSCALL(quotactl_path);
   ^
   arch/x86/include/asm/syscall_wrapper.h:256:2: note: expanded from macro 'COND_SYSCALL'
           __X64_COND_SYSCALL(name)                                        \
           ^
   arch/x86/include/asm/syscall_wrapper.h:100:2: note: expanded from macro '__X64_COND_SYSCALL'
           __COND_SYSCALL(x64, sys_##name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:83:14: note: expanded from macro '__COND_SYSCALL'
           __weak long __##abi##_##name(const struct pt_regs *__unused)    \
                       ^
   <scratch space>:241:1: note: expanded from here
   __x64_sys_quotactl_path
   ^
   kernel/sys_ni.c:102:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   arch/x86/include/asm/syscall_wrapper.h:256:2: note: expanded from macro 'COND_SYSCALL'
           __X64_COND_SYSCALL(name)                                        \
           ^
   arch/x86/include/asm/syscall_wrapper.h:100:2: note: expanded from macro '__X64_COND_SYSCALL'
           __COND_SYSCALL(x64, sys_##name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:83:9: note: expanded from macro '__COND_SYSCALL'
           __weak long __##abi##_##name(const struct pt_regs *__unused)    \
                  ^
>> kernel/sys_ni.c:102:1: warning: no previous prototype for function '__ia32_sys_quotactl_path' [-Wmissing-prototypes]
   COND_SYSCALL(quotactl_path);
   ^
   arch/x86/include/asm/syscall_wrapper.h:257:2: note: expanded from macro 'COND_SYSCALL'
           __IA32_COND_SYSCALL(name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:120:2: note: expanded from macro '__IA32_COND_SYSCALL'
           __COND_SYSCALL(ia32, sys_##name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:83:14: note: expanded from macro '__COND_SYSCALL'
           __weak long __##abi##_##name(const struct pt_regs *__unused)    \
                       ^
   <scratch space>:245:1: note: expanded from here
   __ia32_sys_quotactl_path
   ^
   kernel/sys_ni.c:102:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   arch/x86/include/asm/syscall_wrapper.h:257:2: note: expanded from macro 'COND_SYSCALL'
           __IA32_COND_SYSCALL(name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:120:2: note: expanded from macro '__IA32_COND_SYSCALL'
           __COND_SYSCALL(ia32, sys_##name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:83:9: note: expanded from macro '__COND_SYSCALL'
           __weak long __##abi##_##name(const struct pt_regs *__unused)    \
                  ^
   kernel/sys_ni.c:113:1: warning: no previous prototype for function '__x64_sys_signalfd4' [-Wmissing-prototypes]
   COND_SYSCALL(signalfd4);
   ^
   arch/x86/include/asm/syscall_wrapper.h:256:2: note: expanded from macro 'COND_SYSCALL'
           __X64_COND_SYSCALL(name)                                        \
           ^
   arch/x86/include/asm/syscall_wrapper.h:100:2: note: expanded from macro '__X64_COND_SYSCALL'
           __COND_SYSCALL(x64, sys_##name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:83:14: note: expanded from macro '__COND_SYSCALL'
           __weak long __##abi##_##name(const struct pt_regs *__unused)    \
                       ^
   <scratch space>:249:1: note: expanded from here
   __x64_sys_signalfd4
   ^
   kernel/sys_ni.c:113:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   arch/x86/include/asm/syscall_wrapper.h:256:2: note: expanded from macro 'COND_SYSCALL'
           __X64_COND_SYSCALL(name)                                        \
           ^
   arch/x86/include/asm/syscall_wrapper.h:100:2: note: expanded from macro '__X64_COND_SYSCALL'
           __COND_SYSCALL(x64, sys_##name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:83:9: note: expanded from macro '__COND_SYSCALL'
           __weak long __##abi##_##name(const struct pt_regs *__unused)    \
                  ^
   kernel/sys_ni.c:113:1: warning: no previous prototype for function '__ia32_sys_signalfd4' [-Wmissing-prototypes]
   COND_SYSCALL(signalfd4);
   ^
   arch/x86/include/asm/syscall_wrapper.h:257:2: note: expanded from macro 'COND_SYSCALL'
           __IA32_COND_SYSCALL(name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:120:2: note: expanded from macro '__IA32_COND_SYSCALL'
           __COND_SYSCALL(ia32, sys_##name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:83:14: note: expanded from macro '__COND_SYSCALL'
           __weak long __##abi##_##name(const struct pt_regs *__unused)    \
                       ^
   <scratch space>:253:1: note: expanded from here
   __ia32_sys_signalfd4
   ^
   kernel/sys_ni.c:113:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   arch/x86/include/asm/syscall_wrapper.h:257:2: note: expanded from macro 'COND_SYSCALL'
           __IA32_COND_SYSCALL(name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:120:2: note: expanded from macro '__IA32_COND_SYSCALL'
           __COND_SYSCALL(ia32, sys_##name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:83:9: note: expanded from macro '__COND_SYSCALL'
           __weak long __##abi##_##name(const struct pt_regs *__unused)    \
                  ^
   kernel/sys_ni.c:114:1: warning: no previous prototype for function '__ia32_compat_sys_signalfd4' [-Wmissing-prototypes]
   COND_SYSCALL_COMPAT(signalfd4);
   ^
   arch/x86/include/asm/syscall_wrapper.h:218:2: note: expanded from macro 'COND_SYSCALL_COMPAT'
           __IA32_COMPAT_COND_SYSCALL(name)                                \
           ^
   arch/x86/include/asm/syscall_wrapper.h:148:2: note: expanded from macro '__IA32_COMPAT_COND_SYSCALL'
           __COND_SYSCALL(ia32, compat_sys_##name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:83:14: note: expanded from macro '__COND_SYSCALL'
           __weak long __##abi##_##name(const struct pt_regs *__unused)    \
                       ^
   <scratch space>:257:1: note: expanded from here
   __ia32_compat_sys_signalfd4
   ^
   kernel/sys_ni.c:114:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   arch/x86/include/asm/syscall_wrapper.h:218:2: note: expanded from macro 'COND_SYSCALL_COMPAT'
           __IA32_COMPAT_COND_SYSCALL(name)                                \
           ^
   arch/x86/include/asm/syscall_wrapper.h:148:2: note: expanded from macro '__IA32_COMPAT_COND_SYSCALL'
           __COND_SYSCALL(ia32, compat_sys_##name)
           ^
   arch/x86/include/asm/syscall_wrapper.h:83:9: note: expanded from macro '__COND_SYSCALL'
           __weak long __##abi##_##name(const struct pt_regs *__unused)    \
                  ^
   kernel/sys_ni.c:123:1: warning: no previous prototype for function '__x64_sys_timerfd_create' [-Wmissing-prototypes]


vim +/__x64_sys_quotactl_path +102 kernel/sys_ni.c

    99	
   100	/* fs/quota.c */
   101	COND_SYSCALL(quotactl);
 > 102	COND_SYSCALL(quotactl_path);
   103	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

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Re: [PATCH 2/2] quota: wire up quotactl_path

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 3275 bytes --]

Hi Sascha,

I love your patch! Yet something to improve:

[auto build test ERROR on arm64/for-next/core]
[also build test ERROR on tip/x86/asm m68k/for-next hp-parisc/for-next powerpc/next s390/features linus/master v5.11-rc7]
[cannot apply to sparc-next/master sparc/master xtensa/for_next next-20210211]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Sascha-Hauer/quota-Add-mountpath-based-quota-support/20210211-233912
base:   https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
config: x86_64-randconfig-a013-20210209 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project c9439ca36342fb6013187d0a69aef92736951476)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # https://github.com/0day-ci/linux/commit/0fa8489f958d6ec34215930a8d1a2d4b6644fea3
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Sascha-Hauer/quota-Add-mountpath-based-quota-support/20210211-233912
        git checkout 0fa8489f958d6ec34215930a8d1a2d4b6644fea3
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   In file included from arch/x86/entry/syscall_32.c:13:
>> ./arch/x86/include/generated/asm/syscalls_32.h:830:18: error: expected parameter declarator
   __SYSCALL_COMMON(442, sys_quotactl_path)
                    ^
>> ./arch/x86/include/generated/asm/syscalls_32.h:830:18: error: expected ')'
   ./arch/x86/include/generated/asm/syscalls_32.h:830:17: note: to match this '('
   __SYSCALL_COMMON(442, sys_quotactl_path)
                   ^
   ./arch/x86/include/generated/asm/syscalls_32.h:830:1: warning: declaration specifier missing, defaulting to 'int'
   __SYSCALL_COMMON(442, sys_quotactl_path)
   ^
   int
>> ./arch/x86/include/generated/asm/syscalls_32.h:830:17: error: this function declaration is not a prototype [-Werror,-Wstrict-prototypes]
   __SYSCALL_COMMON(442, sys_quotactl_path)
                   ^
                                          void
>> ./arch/x86/include/generated/asm/syscalls_32.h:830:41: error: expected ';' after top level declarator
   __SYSCALL_COMMON(442, sys_quotactl_path)
                                           ^
                                           ;
   In file included from arch/x86/entry/syscall_32.c:24:
>> ./arch/x86/include/generated/asm/syscalls_32.h:830:23: error: use of undeclared identifier 'sys_quotactl_path'
   __SYSCALL_COMMON(442, sys_quotactl_path)
                         ^
   1 warning and 5 errors generated.

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

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Re: [PATCH 1/2] quota: Add mountpath based quota support

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 3017 bytes --]

Hi Sascha,

I love your patch! Yet something to improve:

[auto build test ERROR on arm64/for-next/core]
[also build test ERROR on tip/x86/asm m68k/for-next hp-parisc/for-next powerpc/next s390/features linus/master v5.11-rc7 next-20210211]
[cannot apply to sparc/master]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Sascha-Hauer/quota-Add-mountpath-based-quota-support/20210211-233912
base:   https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/core
config: x86_64-randconfig-a012-20210209 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project c9439ca36342fb6013187d0a69aef92736951476)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # https://github.com/0day-ci/linux/commit/4b7a3df11dd2ca215a6e9b24d81c98d6951476b6
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Sascha-Hauer/quota-Add-mountpath-based-quota-support/20210211-233912
        git checkout 4b7a3df11dd2ca215a6e9b24d81c98d6951476b6
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

>> fs/quota/quota.c:995:6: error: implicit declaration of function 'quotactl_cmd_write' [-Werror,-Wimplicit-function-declaration]
           if (quotactl_cmd_write(cmds)) {
               ^
   fs/quota/quota.c:995:6: note: did you mean 'quotactl_cmd_onoff'?
   fs/quota/quota.c:857:13: note: 'quotactl_cmd_onoff' declared here
   static bool quotactl_cmd_onoff(int cmd)
               ^
   1 error generated.


vim +/quotactl_cmd_write +995 fs/quota/quota.c

   972	
   973	SYSCALL_DEFINE4(quotactl_path, unsigned int, cmd, const char __user *,
   974			mountpoint, qid_t, id, void __user *, addr)
   975	{
   976		struct super_block *sb;
   977		struct path mountpath;
   978		unsigned int cmds = cmd >> SUBCMDSHIFT;
   979		unsigned int type = cmd & SUBCMDMASK;
   980		int ret;
   981	
   982		if (type >= MAXQUOTAS)
   983			return -EINVAL;
   984	
   985		if (!mountpoint)
   986			return -ENODEV;
   987	
   988		ret = user_path_at(AT_FDCWD, mountpoint,
   989				     LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT, &mountpath);
   990		if (ret)
   991			return ret;
   992	
   993		sb = mountpath.dentry->d_inode->i_sb;
   994	
 > 995		if (quotactl_cmd_write(cmds)) {

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
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Re: [PATCH 1/2] quota: Add mountpath based quota support

[Sascha Hauer]

On Thu, Feb 11, 2021 at 03:38:13PM +0000, Christoph Hellwig wrote:
> > +	if (!mountpoint)
> > +		return -ENODEV;
> > +
> > +	ret = user_path_at(AT_FDCWD, mountpoint,
> > +			     LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT, &mountpath);
> 
> user_path_at handles an empty path, although you'll get EFAULT instead.
> Do we care about the -ENODEV here?

The quotactl manpage documents EFAULT as error code for invalid addr or
special argument, so we really should return -EFAULT here.

Existing quotactl gets this wrong as well:

	if (!special) {
		if (cmds == Q_SYNC)
			return quota_sync_all(type);
		return -ENODEV;
	}

Should we fix this or is there userspace code that is confused by a changed
return value?

Sascha

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Re: [PATCH 1/2] quota: Add mountpath based quota support

[Jan Kara]

On Fri 12-02-21 09:38:35, Sascha Hauer wrote:
> On Thu, Feb 11, 2021 at 03:38:13PM +0000, Christoph Hellwig wrote:
> > > +	if (!mountpoint)
> > > +		return -ENODEV;
> > > +
> > > +	ret = user_path_at(AT_FDCWD, mountpoint,
> > > +			     LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT, &mountpath);
> > 
> > user_path_at handles an empty path, although you'll get EFAULT instead.
> > Do we care about the -ENODEV here?
> 
> The quotactl manpage documents EFAULT as error code for invalid addr or
> special argument, so we really should return -EFAULT here.
> 
> Existing quotactl gets this wrong as well:
> 
> 	if (!special) {
> 		if (cmds == Q_SYNC)
> 			return quota_sync_all(type);
> 		return -ENODEV;
> 	}
> 
> Should we fix this or is there userspace code that is confused by a changed
> return value?

I'd leave the original quotactl(2) as is. There's no strong reason to risk
breaking some userspace. For the new syscall, I agree we can just
standardize the return value, there ENODEV makes even less sense since
there's no device in that call.

								Honza

-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

Re: [PATCH v2 0/2] quota: Add mountpath based quota support

[Jan Kara]

On Thu 11-02-21 16:30:21, Sascha Hauer wrote:
> Current quotactl syscall uses a path to a block device to specify the
> filesystem to work on which makes it unsuitable for filesystems that
> do not have a block device. This series adds a new syscall quotactl_path()
> which replaces the path to the block device with a mountpath, but otherwise
> behaves like original quotactl.
> 
> This is done to add quota support to UBIFS. UBIFS quota support has been
> posted several times with different approaches to put the mountpath into
> the existing quotactl() syscall until it has been suggested to make it a
> new syscall instead, so here it is.
> 
> I'm not posting the full UBIFS quota series here as it remains unchanged
> and I'd like to get feedback to the new syscall first. For those interested
> the most recent series can be found here: https://lwn.net/Articles/810463/
> 
> Changes since (implicit) v1:
> - Ignore second path argument to Q_QUOTAON. With this quotactl_path() can
>   only do the Q_QUOTAON operation on filesystems which use hidden inodes
>   for quota metadata storage
> - Drop unnecessary quotactl_cmd_onoff() check

Thanks modulo the 0-day complains and the small nit discussed the patches
and manpage update look good to me.

								Honza

> 
> Sascha Hauer (2):
>   quota: Add mountpath based quota support
>   quota: wire up quotactl_path
> 
>  arch/alpha/kernel/syscalls/syscall.tbl      |  1 +
>  arch/arm/tools/syscall.tbl                  |  1 +
>  arch/arm64/include/asm/unistd.h             |  2 +-
>  arch/arm64/include/asm/unistd32.h           |  2 +
>  arch/ia64/kernel/syscalls/syscall.tbl       |  1 +
>  arch/m68k/kernel/syscalls/syscall.tbl       |  1 +
>  arch/microblaze/kernel/syscalls/syscall.tbl |  1 +
>  arch/mips/kernel/syscalls/syscall_n32.tbl   |  1 +
>  arch/mips/kernel/syscalls/syscall_n64.tbl   |  1 +
>  arch/mips/kernel/syscalls/syscall_o32.tbl   |  1 +
>  arch/parisc/kernel/syscalls/syscall.tbl     |  1 +
>  arch/powerpc/kernel/syscalls/syscall.tbl    |  1 +
>  arch/s390/kernel/syscalls/syscall.tbl       |  1 +
>  arch/sh/kernel/syscalls/syscall.tbl         |  1 +
>  arch/sparc/kernel/syscalls/syscall.tbl      |  1 +
>  arch/x86/entry/syscalls/syscall_32.tbl      |  1 +
>  arch/x86/entry/syscalls/syscall_64.tbl      |  1 +
>  arch/xtensa/kernel/syscalls/syscall.tbl     |  1 +
>  fs/quota/quota.c                            | 49 +++++++++++++++++++++
>  include/linux/syscalls.h                    |  2 +
>  include/uapi/asm-generic/unistd.h           |  4 +-
>  kernel/sys_ni.c                             |  1 +
>  22 files changed, 74 insertions(+), 2 deletions(-)
> 
> -- 
> 2.20.1
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

Re: [PATCH 1/2] quota: Add mountpath based quota support

[Sascha Hauer]

On Fri, Feb 12, 2021 at 11:05:05AM +0100, Jan Kara wrote:
> On Fri 12-02-21 09:38:35, Sascha Hauer wrote:
> > On Thu, Feb 11, 2021 at 03:38:13PM +0000, Christoph Hellwig wrote:
> > > > +	if (!mountpoint)
> > > > +		return -ENODEV;
> > > > +
> > > > +	ret = user_path_at(AT_FDCWD, mountpoint,
> > > > +			     LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT, &mountpath);
> > > 
> > > user_path_at handles an empty path, although you'll get EFAULT instead.
> > > Do we care about the -ENODEV here?
> > 
> > The quotactl manpage documents EFAULT as error code for invalid addr or
> > special argument, so we really should return -EFAULT here.
> > 
> > Existing quotactl gets this wrong as well:
> > 
> > 	if (!special) {
> > 		if (cmds == Q_SYNC)
> > 			return quota_sync_all(type);
> > 		return -ENODEV;
> > 	}
> > 
> > Should we fix this or is there userspace code that is confused by a changed
> > return value?
> 
> I'd leave the original quotactl(2) as is. There's no strong reason to risk
> breaking some userspace. For the new syscall, I agree we can just
> standardize the return value, there ENODEV makes even less sense since
> there's no device in that call.

Ok, will do. Who can pick this series up? Anyone else I need to Cc next
round?

Sascha

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Re: [PATCH 1/2] quota: Add mountpath based quota support

[Jan Kara]

On Fri 12-02-21 11:29:00, Sascha Hauer wrote:
> On Fri, Feb 12, 2021 at 11:05:05AM +0100, Jan Kara wrote:
> > On Fri 12-02-21 09:38:35, Sascha Hauer wrote:
> > > On Thu, Feb 11, 2021 at 03:38:13PM +0000, Christoph Hellwig wrote:
> > > > > +	if (!mountpoint)
> > > > > +		return -ENODEV;
> > > > > +
> > > > > +	ret = user_path_at(AT_FDCWD, mountpoint,
> > > > > +			     LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT, &mountpath);
> > > > 
> > > > user_path_at handles an empty path, although you'll get EFAULT instead.
> > > > Do we care about the -ENODEV here?
> > > 
> > > The quotactl manpage documents EFAULT as error code for invalid addr or
> > > special argument, so we really should return -EFAULT here.
> > > 
> > > Existing quotactl gets this wrong as well:
> > > 
> > > 	if (!special) {
> > > 		if (cmds == Q_SYNC)
> > > 			return quota_sync_all(type);
> > > 		return -ENODEV;
> > > 	}
> > > 
> > > Should we fix this or is there userspace code that is confused by a changed
> > > return value?
> > 
> > I'd leave the original quotactl(2) as is. There's no strong reason to risk
> > breaking some userspace. For the new syscall, I agree we can just
> > standardize the return value, there ENODEV makes even less sense since
> > there's no device in that call.
> 
> Ok, will do. Who can pick this series up? Anyone else I need to Cc next
> round?

I guess I can pick up both kernel patches (the manpage patch needs to be
submitted to the manpage list) but please CC linux-api@vger as well so that
interested people are aware of the new syscall.

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

Re: [PATCH 1/2] quota: Add mountpath based quota support

[Al Viro]

On Thu, Feb 11, 2021 at 04:30:22PM +0100, Sascha Hauer wrote:

> +	sb = mountpath.dentry->d_inode->i_sb;

Minor nit: mountpath.mnt->mnt_sb, please.