From: Sascha Hauer <s.hauer@pengutronix.de>
To: linux-fsdevel@vger.kernel.org
Cc: Richard Weinberger <richard@nod.at>,
Sascha Hauer <s.hauer@pengutronix.de>,
linux-mtd@lists.infradead.org, kernel@pengutronix.de,
Jan Kara <jack@suse.com>
Subject: [PATCH 1/8] quota: Allow to pass mount path to quotactl
Date: Fri, 24 Jan 2020 14:13:16 +0100 [thread overview]
Message-ID: <20200124131323.23885-2-s.hauer@pengutronix.de> (raw)
In-Reply-To: <20200124131323.23885-1-s.hauer@pengutronix.de>
This patch introduces the Q_PATH flag to the quotactl cmd argument.
When given, the path given in the special argument to quotactl will
be the mount path where the filesystem is mounted, instead of a path
to the block device.
This is necessary for filesystems which do not have a block device as
backing store. Particularly this is done for upcoming UBIFS support.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
fs/quota/quota.c | 53 +++++++++++++++++++++++++++-----------
include/uapi/linux/quota.h | 1 +
2 files changed, 39 insertions(+), 15 deletions(-)
diff --git a/fs/quota/quota.c b/fs/quota/quota.c
index 5444d3c4d93f..9ef51d02d5a5 100644
--- a/fs/quota/quota.c
+++ b/fs/quota/quota.c
@@ -19,6 +19,7 @@
#include <linux/types.h>
#include <linux/writeback.h>
#include <linux/nospec.h>
+#include <linux/mount.h>
static int check_quotactl_permission(struct super_block *sb, int type, int cmd,
qid_t id)
@@ -821,15 +822,20 @@ int kernel_quotactl(unsigned int cmd, const char __user *special,
{
uint cmds, type;
struct super_block *sb = NULL;
- struct path path, *pathp = NULL;
+ struct path file_path, *file_pathp = NULL, sb_path;
int ret;
+ bool q_path;
cmds = cmd >> SUBCMDSHIFT;
type = cmd & SUBCMDMASK;
+
if (type >= MAXQUOTAS)
return -EINVAL;
+ q_path = cmds & Q_PATH;
+ cmds &= ~Q_PATH;
+
/*
* As a special case Q_SYNC can be called without a specific device.
* It will iterate all superblocks that have quota enabled and call
@@ -847,28 +853,45 @@ int kernel_quotactl(unsigned int cmd, const char __user *special,
* resolution (think about autofs) and thus deadlocks could arise.
*/
if (cmds == Q_QUOTAON) {
- ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
+ ret = user_path_at(AT_FDCWD, addr,
+ LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT,
+ &file_path);
if (ret)
- pathp = ERR_PTR(ret);
+ file_pathp = ERR_PTR(ret);
else
- pathp = &path;
+ file_pathp = &file_path;
}
- sb = quotactl_block(special, cmds);
- if (IS_ERR(sb)) {
- ret = PTR_ERR(sb);
- goto out;
+ if (q_path) {
+ ret = user_path_at(AT_FDCWD, special,
+ LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT,
+ &sb_path);
+ if (ret)
+ goto out;
+
+ sb = sb_path.mnt->mnt_sb;
+ } else {
+ sb = quotactl_block(special, cmds);
+ if (IS_ERR(sb)) {
+ ret = PTR_ERR(sb);
+ goto out;
+ }
}
- ret = do_quotactl(sb, type, cmds, id, addr, pathp);
+ ret = do_quotactl(sb, type, cmds, id, addr, file_pathp);
+
+ if (q_path) {
+ path_put(&sb_path);
+ } else {
+ if (!quotactl_cmd_onoff(cmds))
+ drop_super(sb);
+ else
+ drop_super_exclusive(sb);
+ }
- if (!quotactl_cmd_onoff(cmds))
- drop_super(sb);
- else
- drop_super_exclusive(sb);
out:
- if (pathp && !IS_ERR(pathp))
- path_put(pathp);
+ if (file_pathp && !IS_ERR(file_pathp))
+ path_put(file_pathp);
return ret;
}
diff --git a/include/uapi/linux/quota.h b/include/uapi/linux/quota.h
index f17c9636a859..e1787c0df601 100644
--- a/include/uapi/linux/quota.h
+++ b/include/uapi/linux/quota.h
@@ -71,6 +71,7 @@
#define Q_GETQUOTA 0x800007 /* get user quota structure */
#define Q_SETQUOTA 0x800008 /* set user quota structure */
#define Q_GETNEXTQUOTA 0x800009 /* get disk limits and usage >= ID */
+#define Q_PATH 0x400000 /* quotactl special arg contains mount path */
/* Quota format type IDs */
#define QFMT_VFS_OLD 1
--
2.25.0
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next prev parent reply other threads:[~2020-01-24 13:15 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-24 13:13 [PATCH v4 0/8] Add quota support to UBIFS Sascha Hauer
2020-01-24 13:13 ` Sascha Hauer [this message]
2020-01-27 10:45 ` [PATCH 1/8] quota: Allow to pass mount path to quotactl Jan Kara
2020-01-28 10:06 ` Sascha Hauer
2020-01-28 11:41 ` Jan Kara
2020-01-29 1:29 ` Al Viro
2020-01-29 16:14 ` Jan Kara
2020-02-04 10:35 ` Sascha Hauer
2020-02-18 9:22 ` Jan Kara
2020-01-24 13:13 ` [PATCH 2/8] ubifs: move checks and preparation into setflags() Sascha Hauer
2020-01-24 13:13 ` [PATCH 3/8] ubifs: Add support for FS_IOC_FS[SG]ETXATTR ioctls Sascha Hauer
2020-01-24 13:13 ` [PATCH 4/8] ubifs: do not ubifs_inode() on potentially NULL pointer Sascha Hauer
2020-01-24 13:13 ` [PATCH 5/8] ubifs: Factor out ubifs_set_feature_flag() Sascha Hauer
2020-01-24 13:13 ` [PATCH 6/8] ubifs: Add support for project id Sascha Hauer
2020-01-24 13:13 ` [PATCH 7/8] ubifs: export get_znode Sascha Hauer
2020-01-24 13:13 ` [PATCH 8/8] ubifs: Add quota support Sascha Hauer
2020-01-26 18:30 ` kbuild test robot
2020-01-26 18:30 ` [RFC PATCH] ubifs: tnc_next() can be static kbuild test robot
2021-01-22 15:15 [PATCH v5 0/8] Add quota support to UBIFS Sascha Hauer
2021-01-22 15:15 ` [PATCH 1/8] quota: Allow to pass mount path to quotactl Sascha Hauer
2021-01-22 17:16 ` Christoph Hellwig
2021-01-25 8:38 ` Sascha Hauer
2021-01-25 15:45 ` Jan Kara
2021-01-25 20:42 ` Christoph Hellwig
2021-01-26 13:17 ` Jan Kara
2021-01-26 13:34 ` Christoph Hellwig
2021-01-26 16:18 ` Jan Kara
2021-01-27 14:05 ` Sascha Hauer
2021-01-27 14:19 ` Jan Kara
2021-01-26 10:45 ` Sascha Hauer
2021-01-27 14:46 ` Jan Kara
2021-01-27 16:25 ` Christoph Hellwig
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