[PATCH 05/29] xfs: factor out a helper for a single XFS_IOC_ATTRMULTI_BY_HANDLE op

Christoph Hellwig
2020-01-14T08:15:32Z

Add a new helper to handle a single attr multi ioctl operation that
can be shared between the native and compat ioctl implementation.

There is a slight change in heavior in that we don't break out of the
loop when copying in the attribute name fails. The previous behavior
was rather inconsistent here as it continued for any other kind of
error.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/xfs_ioctl.c | 97 +++++++++++++++++++++++---------------------
fs/xfs/xfs_ioctl.h | 18 ++------
fs/xfs/xfs_ioctl32.c | 50 +++--------------------
3 files changed, 59 insertions(+), 106 deletions(-)

diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index f4d5c865e29e..3dbbc1099375 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -347,7 +347,7 @@ xfs_attrlist_by_handle(
return error;
}

-int
+static int
xfs_attrmulti_attr_get(
struct inode *inode,
unsigned char *name,
@@ -379,7 +379,7 @@ xfs_attrmulti_attr_get(
return error;
}

-int
+static int
xfs_attrmulti_attr_set(
struct inode *inode,
unsigned char *name,
@@ -410,6 +410,51 @@ xfs_attrmulti_attr_set(
return error;
}

+int
+xfs_ioc_attrmulti_one(
+ struct file *parfilp,
+ struct inode *inode,
+ uint32_t opcode,
+ void __user *uname,
+ void __user *value,
+ uint32_t *len,
+ uint32_t flags)
+{
+ unsigned char *name;
+ int error;
+
+ if ((flags & ATTR_ROOT) && (flags & ATTR_SECURE))
+ return -EINVAL;
+ flags &= ~ATTR_KERNEL_FLAGS;
+
+ name = strndup_user(uname, MAXNAMELEN);
+ if (IS_ERR(name))
+ return PTR_ERR(name);
+
+ switch (opcode) {
+ case ATTR_OP_GET:
+ error = xfs_attrmulti_attr_get(inode, name, value, len, flags);
+ break;
+ case ATTR_OP_REMOVE:
+ value = NULL;
+ *len = 0;
+ /*FALLTHRU*/
+ case ATTR_OP_SET:
+ error = mnt_want_write_file(parfilp);
+ if (error)
+ break;
+ error = xfs_attrmulti_attr_set(inode, name, value, *len, flags);
+ mnt_drop_write_file(parfilp);
+ break;
+ default:
+ error = -EINVAL;
+ break;
+ }
+
+ kfree(name);
+ return error;
+}
+
STATIC int
xfs_attrmulti_by_handle(
struct file *parfilp,
@@ -420,7 +465,6 @@ xfs_attrmulti_by_handle(
xfs_fsop_attrmulti_handlereq_t am_hreq;
struct dentry *dentry;
unsigned int i, size;
- unsigned char *attr_name;

if (!capable(CAP_SYS_ADMIN))
return -EPERM;
@@ -448,49 +492,10 @@ xfs_attrmulti_by_handle(

error = 0;
for (i = 0; i < am_hreq.opcount; i++) {
- if ((ops[i].am_flags & ATTR_ROOT) &&
- (ops[i].am_flags & ATTR_SECURE)) {
- ops[i].am_error = -EINVAL;
- continue;
- }
- ops[i].am_flags &= ~ATTR_KERNEL_FLAGS;
-
- attr_name = strndup_user(ops[i].am_attrname, MAXNAMELEN);
- if (IS_ERR(attr_name)) {
- ops[i].am_error = PTR_ERR(attr_name);
- break;
- }
-
- switch (ops[i].am_opcode) {
- case ATTR_OP_GET:
- ops[i].am_error = xfs_attrmulti_attr_get(
- d_inode(dentry), attr_name,
- ops[i].am_attrvalue, &ops[i].am_length,
- ops[i].am_flags);
- break;
- case ATTR_OP_SET:
- ops[i].am_error = mnt_want_write_file(parfilp);
- if (ops[i].am_error)
- break;
- ops[i].am_error = xfs_attrmulti_attr_set(
- d_inode(dentry), attr_name,
- ops[i].am_attrvalue, ops[i].am_length,
- ops[i].am_flags);
- mnt_drop_write_file(parfilp);
- break;
- case ATTR_OP_REMOVE:
- ops[i].am_error = mnt_want_write_file(parfilp);
- if (ops[i].am_error)
- break;
- ops[i].am_error = xfs_attrmulti_attr_set(
- d_inode(dentry), attr_name, NULL, 0,
- ops[i].am_flags);
- mnt_drop_write_file(parfilp);
- break;
- default:
- ops[i].am_error = -EINVAL;
- }
- kfree(attr_name);
+ ops[i].am_error = xfs_ioc_attrmulti_one(parfilp,
+ d_inode(dentry), ops[i].am_opcode,
+ ops[i].am_attrname, ops[i].am_attrvalue,
+ &ops[i].am_length, ops[i].am_flags);
}

if (copy_to_user(am_hreq.ops, ops, size))
diff --git a/fs/xfs/xfs_ioctl.h b/fs/xfs/xfs_ioctl.h
index 819504df00ae..bb50cb3dc61f 100644
--- a/fs/xfs/xfs_ioctl.h
+++ b/fs/xfs/xfs_ioctl.h
@@ -30,21 +30,9 @@ xfs_readlink_by_handle(
struct file *parfilp,
xfs_fsop_handlereq_t *hreq);

-extern int
-xfs_attrmulti_attr_get(
- struct inode *inode,
- unsigned char *name,
- unsigned char __user *ubuf,
- uint32_t *len,
- uint32_t flags);
-
-extern int
-xfs_attrmulti_attr_set(
- struct inode *inode,
- unsigned char *name,
- const unsigned char __user *ubuf,
- uint32_t len,
- uint32_t flags);
+int xfs_ioc_attrmulti_one(struct file *parfilp, struct inode *inode,
+ uint32_t opcode, void __user *uname, void __user *value,
+ uint32_t *len, uint32_t flags);

extern struct dentry *
xfs_handle_to_dentry(
diff --git a/fs/xfs/xfs_ioctl32.c b/fs/xfs/xfs_ioctl32.c
index e6a7f619a54c..ee428ddf51e5 100644
--- a/fs/xfs/xfs_ioctl32.c
+++ b/fs/xfs/xfs_ioctl32.c
@@ -416,7 +416,6 @@ xfs_compat_attrmulti_by_handle(
compat_xfs_fsop_attrmulti_handlereq_t am_hreq;
struct dentry *dentry;
unsigned int i, size;
- unsigned char *attr_name;

if (!capable(CAP_SYS_ADMIN))
return -EPERM;
@@ -445,50 +444,11 @@ xfs_compat_attrmulti_by_handle(

error = 0;
for (i = 0; i < am_hreq.opcount; i++) {
- if ((ops[i].am_flags & ATTR_ROOT) &&
- (ops[i].am_flags & ATTR_SECURE)) {
- ops[i].am_error = -EINVAL;
- continue;
- }
- ops[i].am_flags &= ~ATTR_KERNEL_FLAGS;
-
- attr_name = strndup_user(compat_ptr(ops[i].am_attrname),
- MAXNAMELEN);
- if (IS_ERR(attr_name)) {
- ops[i].am_error = PTR_ERR(attr_name);
- break;
- }
-
- switch (ops[i].am_opcode) {
- case ATTR_OP_GET:
- ops[i].am_error = xfs_attrmulti_attr_get(
- d_inode(dentry), attr_name,
- compat_ptr(ops[i].am_attrvalue),
- &ops[i].am_length, ops[i].am_flags);
- break;
- case ATTR_OP_SET:
- ops[i].am_error = mnt_want_write_file(parfilp);
- if (ops[i].am_error)
- break;
- ops[i].am_error = xfs_attrmulti_attr_set(
- d_inode(dentry), attr_name,
- compat_ptr(ops[i].am_attrvalue),
- ops[i].am_length, ops[i].am_flags);
- mnt_drop_write_file(parfilp);
- break;
- case ATTR_OP_REMOVE:
- ops[i].am_error = mnt_want_write_file(parfilp);
- if (ops[i].am_error)
- break;
- ops[i].am_error = xfs_attrmulti_attr_set(
- d_inode(dentry), attr_name, NULL, 0,
- ops[i].am_flags);
- mnt_drop_write_file(parfilp);
- break;
- default:
- ops[i].am_error = -EINVAL;
- }
- kfree(attr_name);
+ ops[i].am_error = xfs_ioc_attrmulti_one(parfilp,
+ d_inode(dentry), ops[i].am_opcode,
+ compat_ptr(ops[i].am_attrname),
+ compat_ptr(ops[i].am_attrvalue),
+ &ops[i].am_length, ops[i].am_flags);
}

if (copy_to_user(compat_ptr(am_hreq.ops), ops, size))
--
2.24.1