[PATCH 06/18] ext4: convert to miscattr

From: Miklos Szeredi
Date: Wed Feb 03 2021 - 07:46:15 EST


Use the miscattr API to let the VFS handle locking, permission checking and
conversion.

Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Cc: "Theodore Ts'o" <tytso@xxxxxxx>
---
fs/ext4/ext4.h | 11 +--
fs/ext4/file.c | 2 +
fs/ext4/ioctl.c | 209 ++++++++++--------------------------------------
fs/ext4/namei.c | 2 +
4 files changed, 49 insertions(+), 175 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 2866d249f3d2..dc4f8c59f279 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -472,15 +472,6 @@ struct flex_groups {
EXT4_VERITY_FL | \
EXT4_INLINE_DATA_FL)

-/* Flags we can manipulate with through FS_IOC_FSSETXATTR */
-#define EXT4_FL_XFLAG_VISIBLE (EXT4_SYNC_FL | \
- EXT4_IMMUTABLE_FL | \
- EXT4_APPEND_FL | \
- EXT4_NODUMP_FL | \
- EXT4_NOATIME_FL | \
- EXT4_PROJINHERIT_FL | \
- EXT4_DAX_FL)
-
/* Flags that should be inherited by new inodes from their parent. */
#define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
@@ -2921,6 +2912,8 @@ extern int ext4_ind_remove_space(handle_t *handle, struct inode *inode,
/* ioctl.c */
extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
+int ext4_miscattr_set(struct dentry *dentry, struct miscattr *ma);
+int ext4_miscattr_get(struct dentry *dentry, struct miscattr *ma);
extern void ext4_reset_inode_seed(struct inode *inode);

/* migrate.c */
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 349b27f0dda0..cbc35bd1a7da 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -920,5 +920,7 @@ const struct inode_operations ext4_file_inode_operations = {
.get_acl = ext4_get_acl,
.set_acl = ext4_set_acl,
.fiemap = ext4_fiemap,
+ .miscattr_get = ext4_miscattr_get,
+ .miscattr_set = ext4_miscattr_set,
};

diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index d9665d2f82db..883f39340318 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -20,6 +20,7 @@
#include <linux/uaccess.h>
#include <linux/delay.h>
#include <linux/iversion.h>
+#include <linux/miscattr.h>
#include "ext4_jbd2.h"
#include "ext4.h"
#include <linux/fsmap.h>
@@ -341,11 +342,6 @@ static int ext4_ioctl_setflags(struct inode *inode,
goto flags_out;

oldflags = ei->i_flags;
-
- err = vfs_ioc_setflags_prepare(inode, oldflags, flags);
- if (err)
- goto flags_out;
-
/*
* The JOURNAL_DATA flag can only be changed by
* the relevant capability.
@@ -456,9 +452,8 @@ static int ext4_ioctl_setflags(struct inode *inode,
}

#ifdef CONFIG_QUOTA
-static int ext4_ioctl_setproject(struct file *filp, __u32 projid)
+static int ext4_ioctl_setproject(struct inode *inode, __u32 projid)
{
- struct inode *inode = file_inode(filp);
struct super_block *sb = inode->i_sb;
struct ext4_inode_info *ei = EXT4_I(inode);
int err, rc;
@@ -542,7 +537,7 @@ static int ext4_ioctl_setproject(struct file *filp, __u32 projid)
return err;
}
#else
-static int ext4_ioctl_setproject(struct file *filp, __u32 projid)
+static int ext4_ioctl_setproject(struct inode *inode, __u32 projid)
{
if (projid != EXT4_DEF_PROJID)
return -EOPNOTSUPP;
@@ -550,56 +545,6 @@ static int ext4_ioctl_setproject(struct file *filp, __u32 projid)
}
#endif

-/* Transfer internal flags to xflags */
-static inline __u32 ext4_iflags_to_xflags(unsigned long iflags)
-{
- __u32 xflags = 0;
-
- if (iflags & EXT4_SYNC_FL)
- xflags |= FS_XFLAG_SYNC;
- if (iflags & EXT4_IMMUTABLE_FL)
- xflags |= FS_XFLAG_IMMUTABLE;
- if (iflags & EXT4_APPEND_FL)
- xflags |= FS_XFLAG_APPEND;
- if (iflags & EXT4_NODUMP_FL)
- xflags |= FS_XFLAG_NODUMP;
- if (iflags & EXT4_NOATIME_FL)
- xflags |= FS_XFLAG_NOATIME;
- if (iflags & EXT4_PROJINHERIT_FL)
- xflags |= FS_XFLAG_PROJINHERIT;
- if (iflags & EXT4_DAX_FL)
- xflags |= FS_XFLAG_DAX;
- return xflags;
-}
-
-#define EXT4_SUPPORTED_FS_XFLAGS (FS_XFLAG_SYNC | FS_XFLAG_IMMUTABLE | \
- FS_XFLAG_APPEND | FS_XFLAG_NODUMP | \
- FS_XFLAG_NOATIME | FS_XFLAG_PROJINHERIT | \
- FS_XFLAG_DAX)
-
-/* Transfer xflags flags to internal */
-static inline unsigned long ext4_xflags_to_iflags(__u32 xflags)
-{
- unsigned long iflags = 0;
-
- if (xflags & FS_XFLAG_SYNC)
- iflags |= EXT4_SYNC_FL;
- if (xflags & FS_XFLAG_IMMUTABLE)
- iflags |= EXT4_IMMUTABLE_FL;
- if (xflags & FS_XFLAG_APPEND)
- iflags |= EXT4_APPEND_FL;
- if (xflags & FS_XFLAG_NODUMP)
- iflags |= EXT4_NODUMP_FL;
- if (xflags & FS_XFLAG_NOATIME)
- iflags |= EXT4_NOATIME_FL;
- if (xflags & FS_XFLAG_PROJINHERIT)
- iflags |= EXT4_PROJINHERIT_FL;
- if (xflags & FS_XFLAG_DAX)
- iflags |= EXT4_DAX_FL;
-
- return iflags;
-}
-
static int ext4_shutdown(struct super_block *sb, unsigned long arg)
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
@@ -767,15 +712,51 @@ static long ext4_ioctl_group_add(struct file *file,
return err;
}

-static void ext4_fill_fsxattr(struct inode *inode, struct fsxattr *fa)
+int ext4_miscattr_get(struct dentry *dentry, struct miscattr *ma)
{
+ struct inode *inode = d_inode(dentry);
struct ext4_inode_info *ei = EXT4_I(inode);
+ u32 flags = ei->i_flags & EXT4_FL_USER_VISIBLE;

- simple_fill_fsxattr(fa, ext4_iflags_to_xflags(ei->i_flags &
- EXT4_FL_USER_VISIBLE));
+ if (S_ISREG(inode->i_mode))
+ flags &= ~FS_PROJINHERIT_FL;

+ miscattr_fill_flags(ma, flags);
if (ext4_has_feature_project(inode->i_sb))
- fa->fsx_projid = from_kprojid(&init_user_ns, ei->i_projid);
+ ma->fsx_projid = from_kprojid(&init_user_ns, ei->i_projid);
+
+ return 0;
+}
+
+int ext4_miscattr_set(struct dentry *dentry, struct miscattr *ma)
+{
+ struct inode *inode = d_inode(dentry);
+ u32 flags = ma->flags;
+ int err = -EOPNOTSUPP;
+
+ ext4_fc_start_update(inode);
+ if (flags & ~EXT4_FL_USER_VISIBLE)
+ goto out;
+
+ /*
+ * chattr(1) grabs flags via GETFLAGS, modifies the result and
+ * passes that to SETFLAGS. So we cannot easily make SETFLAGS
+ * more restrictive than just silently masking off visible but
+ * not settable flags as we always did.
+ */
+ flags &= EXT4_FL_USER_MODIFIABLE;
+ if (ext4_mask_flags(inode->i_mode, flags) != flags)
+ goto out;
+ err = ext4_ioctl_check_immutable(inode, ma->fsx_projid, flags);
+ if (err)
+ goto out;
+ err = ext4_ioctl_setflags(inode, flags);
+ if (err)
+ goto out;
+ err = ext4_ioctl_setproject(inode, ma->fsx_projid);
+out:
+ ext4_fc_stop_update(inode);
+ return err;
}

/* So that the fiemap access checks can't overflow on 32 bit machines. */
@@ -813,54 +794,12 @@ static long __ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(filp);
struct super_block *sb = inode->i_sb;
- struct ext4_inode_info *ei = EXT4_I(inode);
- unsigned int flags;

ext4_debug("cmd = %u, arg = %lu\n", cmd, arg);

switch (cmd) {
case FS_IOC_GETFSMAP:
return ext4_ioc_getfsmap(sb, (void __user *)arg);
- case FS_IOC_GETFLAGS:
- flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
- if (S_ISREG(inode->i_mode))
- flags &= ~EXT4_PROJINHERIT_FL;
- return put_user(flags, (int __user *) arg);
- case FS_IOC_SETFLAGS: {
- int err;
-
- if (!inode_owner_or_capable(inode))
- return -EACCES;
-
- if (get_user(flags, (int __user *) arg))
- return -EFAULT;
-
- if (flags & ~EXT4_FL_USER_VISIBLE)
- return -EOPNOTSUPP;
- /*
- * chattr(1) grabs flags via GETFLAGS, modifies the result and
- * passes that to SETFLAGS. So we cannot easily make SETFLAGS
- * more restrictive than just silently masking off visible but
- * not settable flags as we always did.
- */
- flags &= EXT4_FL_USER_MODIFIABLE;
- if (ext4_mask_flags(inode->i_mode, flags) != flags)
- return -EOPNOTSUPP;
-
- err = mnt_want_write_file(filp);
- if (err)
- return err;
-
- inode_lock(inode);
- err = ext4_ioctl_check_immutable(inode,
- from_kprojid(&init_user_ns, ei->i_projid),
- flags);
- if (!err)
- err = ext4_ioctl_setflags(inode, flags);
- inode_unlock(inode);
- mnt_drop_write_file(filp);
- return err;
- }
case EXT4_IOC_GETVERSION:
case EXT4_IOC_GETVERSION_OLD:
return put_user(inode->i_generation, (int __user *) arg);
@@ -1242,60 +1181,6 @@ static long __ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
case EXT4_IOC_GET_ES_CACHE:
return ext4_ioctl_get_es_cache(filp, arg);

- case FS_IOC_FSGETXATTR:
- {
- struct fsxattr fa;
-
- ext4_fill_fsxattr(inode, &fa);
-
- if (copy_to_user((struct fsxattr __user *)arg,
- &fa, sizeof(fa)))
- return -EFAULT;
- return 0;
- }
- case FS_IOC_FSSETXATTR:
- {
- struct fsxattr fa, old_fa;
- int err;
-
- if (copy_from_user(&fa, (struct fsxattr __user *)arg,
- sizeof(fa)))
- return -EFAULT;
-
- /* Make sure caller has proper permission */
- if (!inode_owner_or_capable(inode))
- return -EACCES;
-
- if (fa.fsx_xflags & ~EXT4_SUPPORTED_FS_XFLAGS)
- return -EOPNOTSUPP;
-
- flags = ext4_xflags_to_iflags(fa.fsx_xflags);
- if (ext4_mask_flags(inode->i_mode, flags) != flags)
- return -EOPNOTSUPP;
-
- err = mnt_want_write_file(filp);
- if (err)
- return err;
-
- inode_lock(inode);
- ext4_fill_fsxattr(inode, &old_fa);
- err = vfs_ioc_fssetxattr_check(inode, &old_fa, &fa);
- if (err)
- goto out;
- flags = (ei->i_flags & ~EXT4_FL_XFLAG_VISIBLE) |
- (flags & EXT4_FL_XFLAG_VISIBLE);
- err = ext4_ioctl_check_immutable(inode, fa.fsx_projid, flags);
- if (err)
- goto out;
- err = ext4_ioctl_setflags(inode, flags);
- if (err)
- goto out;
- err = ext4_ioctl_setproject(filp, fa.fsx_projid);
-out:
- inode_unlock(inode);
- mnt_drop_write_file(filp);
- return err;
- }
case EXT4_IOC_SHUTDOWN:
return ext4_shutdown(sb, arg);

@@ -1330,12 +1215,6 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
/* These are just misnamed, they actually get/put from/to user an int */
switch (cmd) {
- case FS_IOC32_GETFLAGS:
- cmd = FS_IOC_GETFLAGS;
- break;
- case FS_IOC32_SETFLAGS:
- cmd = FS_IOC_SETFLAGS;
- break;
case EXT4_IOC32_GETVERSION:
cmd = EXT4_IOC_GETVERSION;
break;
@@ -1394,8 +1273,6 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case EXT4_IOC_CLEAR_ES_CACHE:
case EXT4_IOC_GETSTATE:
case EXT4_IOC_GET_ES_CACHE:
- case FS_IOC_FSGETXATTR:
- case FS_IOC_FSSETXATTR:
break;
default:
return -ENOIOCTLCMD;
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index cf652ba3e74d..76dc27834322 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -4130,6 +4130,8 @@ const struct inode_operations ext4_dir_inode_operations = {
.get_acl = ext4_get_acl,
.set_acl = ext4_set_acl,
.fiemap = ext4_fiemap,
+ .miscattr_get = ext4_miscattr_get,
+ .miscattr_set = ext4_miscattr_set,
};

const struct inode_operations ext4_special_inode_operations = {
--
2.26.2