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authorPatrick McHardy <kaber@trash.net>2013-03-31 18:10:34 +0200
committerPatrick McHardy <kaber@trash.net>2013-03-31 18:10:34 +0200
commit70711d223510ba1773cfe1d7770a56141c815ff8 (patch)
tree4a71f38a3a554ddecaa31b7d8c6bc49b7d1705b4 /fs/xattr.c
parentd53b4ed072d9779cdf53582c46436dec06d0961f (diff)
parent19f949f52599ba7c3f67a5897ac6be14bfcb1200 (diff)
Merge tag 'v3.8' of /home/kaber/src/repos/linux
Linux 3.8 Signed-off-by: Patrick McHardy <kaber@trash.net> Conflicts: include/linux/Kbuild include/linux/netlink.h
Diffstat (limited to 'fs/xattr.c')
-rw-r--r--fs/xattr.c337
1 files changed, 283 insertions, 54 deletions
diff --git a/fs/xattr.c b/fs/xattr.c
index 1d7ac379045..3377dff1840 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -20,6 +20,7 @@
#include <linux/fsnotify.h>
#include <linux/audit.h>
#include <linux/vmalloc.h>
+#include <linux/posix_acl_xattr.h>
#include <asm/uaccess.h>
@@ -295,11 +296,13 @@ vfs_removexattr(struct dentry *dentry, const char *name)
if (error)
return error;
+ mutex_lock(&inode->i_mutex);
error = security_inode_removexattr(dentry, name);
- if (error)
+ if (error) {
+ mutex_unlock(&inode->i_mutex);
return error;
+ }
- mutex_lock(&inode->i_mutex);
error = inode->i_op->removexattr(dentry, name);
mutex_unlock(&inode->i_mutex);
@@ -347,6 +350,9 @@ setxattr(struct dentry *d, const char __user *name, const void __user *value,
error = -EFAULT;
goto out;
}
+ if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) ||
+ (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0))
+ posix_acl_fix_xattr_from_user(kvalue, size);
}
error = vfs_setxattr(d, kname, kvalue, size, flags);
@@ -364,8 +370,9 @@ SYSCALL_DEFINE5(setxattr, const char __user *, pathname,
{
struct path path;
int error;
-
- error = user_path(pathname, &path);
+ unsigned int lookup_flags = LOOKUP_FOLLOW;
+retry:
+ error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
if (error)
return error;
error = mnt_want_write(path.mnt);
@@ -374,6 +381,10 @@ SYSCALL_DEFINE5(setxattr, const char __user *, pathname,
mnt_drop_write(path.mnt);
}
path_put(&path);
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
return error;
}
@@ -383,8 +394,9 @@ SYSCALL_DEFINE5(lsetxattr, const char __user *, pathname,
{
struct path path;
int error;
-
- error = user_lpath(pathname, &path);
+ unsigned int lookup_flags = 0;
+retry:
+ error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
if (error)
return error;
error = mnt_want_write(path.mnt);
@@ -393,28 +405,30 @@ SYSCALL_DEFINE5(lsetxattr, const char __user *, pathname,
mnt_drop_write(path.mnt);
}
path_put(&path);
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
return error;
}
SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name,
const void __user *,value, size_t, size, int, flags)
{
- int fput_needed;
- struct file *f;
+ struct fd f = fdget(fd);
struct dentry *dentry;
int error = -EBADF;
- f = fget_light(fd, &fput_needed);
- if (!f)
+ if (!f.file)
return error;
- dentry = f->f_path.dentry;
- audit_inode(NULL, dentry);
- error = mnt_want_write_file(f);
+ dentry = f.file->f_path.dentry;
+ audit_inode(NULL, dentry, 0);
+ error = mnt_want_write_file(f.file);
if (!error) {
error = setxattr(dentry, name, value, size, flags);
- mnt_drop_write_file(f);
+ mnt_drop_write_file(f.file);
}
- fput_light(f, fput_needed);
+ fdput(f);
return error;
}
@@ -427,6 +441,7 @@ getxattr(struct dentry *d, const char __user *name, void __user *value,
{
ssize_t error;
void *kvalue = NULL;
+ void *vvalue = NULL;
char kname[XATTR_NAME_MAX + 1];
error = strncpy_from_user(kname, name, sizeof(kname));
@@ -438,13 +453,20 @@ getxattr(struct dentry *d, const char __user *name, void __user *value,
if (size) {
if (size > XATTR_SIZE_MAX)
size = XATTR_SIZE_MAX;
- kvalue = kzalloc(size, GFP_KERNEL);
- if (!kvalue)
- return -ENOMEM;
+ kvalue = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
+ if (!kvalue) {
+ vvalue = vmalloc(size);
+ if (!vvalue)
+ return -ENOMEM;
+ kvalue = vvalue;
+ }
}
error = vfs_getxattr(d, kname, kvalue, size);
if (error > 0) {
+ if ((strcmp(kname, XATTR_NAME_POSIX_ACL_ACCESS) == 0) ||
+ (strcmp(kname, XATTR_NAME_POSIX_ACL_DEFAULT) == 0))
+ posix_acl_fix_xattr_to_user(kvalue, size);
if (size && copy_to_user(value, kvalue, error))
error = -EFAULT;
} else if (error == -ERANGE && size >= XATTR_SIZE_MAX) {
@@ -452,7 +474,10 @@ getxattr(struct dentry *d, const char __user *name, void __user *value,
than XATTR_SIZE_MAX bytes. Not possible. */
error = -E2BIG;
}
- kfree(kvalue);
+ if (vvalue)
+ vfree(vvalue);
+ else
+ kfree(kvalue);
return error;
}
@@ -461,12 +486,17 @@ SYSCALL_DEFINE4(getxattr, const char __user *, pathname,
{
struct path path;
ssize_t error;
-
- error = user_path(pathname, &path);
+ unsigned int lookup_flags = LOOKUP_FOLLOW;
+retry:
+ error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
if (error)
return error;
error = getxattr(path.dentry, name, value, size);
path_put(&path);
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
return error;
}
@@ -475,28 +505,31 @@ SYSCALL_DEFINE4(lgetxattr, const char __user *, pathname,
{
struct path path;
ssize_t error;
-
- error = user_lpath(pathname, &path);
+ unsigned int lookup_flags = 0;
+retry:
+ error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
if (error)
return error;
error = getxattr(path.dentry, name, value, size);
path_put(&path);
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
return error;
}
SYSCALL_DEFINE4(fgetxattr, int, fd, const char __user *, name,
void __user *, value, size_t, size)
{
- int fput_needed;
- struct file *f;
+ struct fd f = fdget(fd);
ssize_t error = -EBADF;
- f = fget_light(fd, &fput_needed);
- if (!f)
+ if (!f.file)
return error;
- audit_inode(NULL, f->f_path.dentry);
- error = getxattr(f->f_path.dentry, name, value, size);
- fput_light(f, fput_needed);
+ audit_inode(NULL, f.file->f_path.dentry, 0);
+ error = getxattr(f.file->f_path.dentry, name, value, size);
+ fdput(f);
return error;
}
@@ -543,12 +576,17 @@ SYSCALL_DEFINE3(listxattr, const char __user *, pathname, char __user *, list,
{
struct path path;
ssize_t error;
-
- error = user_path(pathname, &path);
+ unsigned int lookup_flags = LOOKUP_FOLLOW;
+retry:
+ error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
if (error)
return error;
error = listxattr(path.dentry, list, size);
path_put(&path);
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
return error;
}
@@ -557,27 +595,30 @@ SYSCALL_DEFINE3(llistxattr, const char __user *, pathname, char __user *, list,
{
struct path path;
ssize_t error;
-
- error = user_lpath(pathname, &path);
+ unsigned int lookup_flags = 0;
+retry:
+ error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
if (error)
return error;
error = listxattr(path.dentry, list, size);
path_put(&path);
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
return error;
}
SYSCALL_DEFINE3(flistxattr, int, fd, char __user *, list, size_t, size)
{
- int fput_needed;
- struct file *f;
+ struct fd f = fdget(fd);
ssize_t error = -EBADF;
- f = fget_light(fd, &fput_needed);
- if (!f)
+ if (!f.file)
return error;
- audit_inode(NULL, f->f_path.dentry);
- error = listxattr(f->f_path.dentry, list, size);
- fput_light(f, fput_needed);
+ audit_inode(NULL, f.file->f_path.dentry, 0);
+ error = listxattr(f.file->f_path.dentry, list, size);
+ fdput(f);
return error;
}
@@ -604,8 +645,9 @@ SYSCALL_DEFINE2(removexattr, const char __user *, pathname,
{
struct path path;
int error;
-
- error = user_path(pathname, &path);
+ unsigned int lookup_flags = LOOKUP_FOLLOW;
+retry:
+ error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
if (error)
return error;
error = mnt_want_write(path.mnt);
@@ -614,6 +656,10 @@ SYSCALL_DEFINE2(removexattr, const char __user *, pathname,
mnt_drop_write(path.mnt);
}
path_put(&path);
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
return error;
}
@@ -622,8 +668,9 @@ SYSCALL_DEFINE2(lremovexattr, const char __user *, pathname,
{
struct path path;
int error;
-
- error = user_lpath(pathname, &path);
+ unsigned int lookup_flags = 0;
+retry:
+ error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
if (error)
return error;
error = mnt_want_write(path.mnt);
@@ -632,27 +679,29 @@ SYSCALL_DEFINE2(lremovexattr, const char __user *, pathname,
mnt_drop_write(path.mnt);
}
path_put(&path);
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
return error;
}
SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name)
{
- int fput_needed;
- struct file *f;
+ struct fd f = fdget(fd);
struct dentry *dentry;
int error = -EBADF;
- f = fget_light(fd, &fput_needed);
- if (!f)
+ if (!f.file)
return error;
- dentry = f->f_path.dentry;
- audit_inode(NULL, dentry);
- error = mnt_want_write_file(f);
+ dentry = f.file->f_path.dentry;
+ audit_inode(NULL, dentry, 0);
+ error = mnt_want_write_file(f.file);
if (!error) {
error = removexattr(dentry, name);
- mnt_drop_write_file(f);
+ mnt_drop_write_file(f.file);
}
- fput_light(f, fput_needed);
+ fdput(f);
return error;
}
@@ -783,3 +832,183 @@ EXPORT_SYMBOL(generic_getxattr);
EXPORT_SYMBOL(generic_listxattr);
EXPORT_SYMBOL(generic_setxattr);
EXPORT_SYMBOL(generic_removexattr);
+
+/*
+ * Allocate new xattr and copy in the value; but leave the name to callers.
+ */
+struct simple_xattr *simple_xattr_alloc(const void *value, size_t size)
+{
+ struct simple_xattr *new_xattr;
+ size_t len;
+
+ /* wrap around? */
+ len = sizeof(*new_xattr) + size;
+ if (len <= sizeof(*new_xattr))
+ return NULL;
+
+ new_xattr = kmalloc(len, GFP_KERNEL);
+ if (!new_xattr)
+ return NULL;
+
+ new_xattr->size = size;
+ memcpy(new_xattr->value, value, size);
+ return new_xattr;
+}
+
+/*
+ * xattr GET operation for in-memory/pseudo filesystems
+ */
+int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
+ void *buffer, size_t size)
+{
+ struct simple_xattr *xattr;
+ int ret = -ENODATA;
+
+ spin_lock(&xattrs->lock);
+ list_for_each_entry(xattr, &xattrs->head, list) {
+ if (strcmp(name, xattr->name))
+ continue;
+
+ ret = xattr->size;
+ if (buffer) {
+ if (size < xattr->size)
+ ret = -ERANGE;
+ else
+ memcpy(buffer, xattr->value, xattr->size);
+ }
+ break;
+ }
+ spin_unlock(&xattrs->lock);
+ return ret;
+}
+
+static int __simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
+ const void *value, size_t size, int flags)
+{
+ struct simple_xattr *xattr;
+ struct simple_xattr *new_xattr = NULL;
+ int err = 0;
+
+ /* value == NULL means remove */
+ if (value) {
+ new_xattr = simple_xattr_alloc(value, size);
+ if (!new_xattr)
+ return -ENOMEM;
+
+ new_xattr->name = kstrdup(name, GFP_KERNEL);
+ if (!new_xattr->name) {
+ kfree(new_xattr);
+ return -ENOMEM;
+ }
+ }
+
+ spin_lock(&xattrs->lock);
+ list_for_each_entry(xattr, &xattrs->head, list) {
+ if (!strcmp(name, xattr->name)) {
+ if (flags & XATTR_CREATE) {
+ xattr = new_xattr;
+ err = -EEXIST;
+ } else if (new_xattr) {
+ list_replace(&xattr->list, &new_xattr->list);
+ } else {
+ list_del(&xattr->list);
+ }
+ goto out;
+ }
+ }
+ if (flags & XATTR_REPLACE) {
+ xattr = new_xattr;
+ err = -ENODATA;
+ } else {
+ list_add(&new_xattr->list, &xattrs->head);
+ xattr = NULL;
+ }
+out:
+ spin_unlock(&xattrs->lock);
+ if (xattr) {
+ kfree(xattr->name);
+ kfree(xattr);
+ }
+ return err;
+
+}
+
+/**
+ * simple_xattr_set - xattr SET operation for in-memory/pseudo filesystems
+ * @xattrs: target simple_xattr list
+ * @name: name of the new extended attribute
+ * @value: value of the new xattr. If %NULL, will remove the attribute
+ * @size: size of the new xattr
+ * @flags: %XATTR_{CREATE|REPLACE}
+ *
+ * %XATTR_CREATE is set, the xattr shouldn't exist already; otherwise fails
+ * with -EEXIST. If %XATTR_REPLACE is set, the xattr should exist;
+ * otherwise, fails with -ENODATA.
+ *
+ * Returns 0 on success, -errno on failure.
+ */
+int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
+ const void *value, size_t size, int flags)
+{
+ if (size == 0)
+ value = ""; /* empty EA, do not remove */
+ return __simple_xattr_set(xattrs, name, value, size, flags);
+}
+
+/*
+ * xattr REMOVE operation for in-memory/pseudo filesystems
+ */
+int simple_xattr_remove(struct simple_xattrs *xattrs, const char *name)
+{
+ return __simple_xattr_set(xattrs, name, NULL, 0, XATTR_REPLACE);
+}
+
+static bool xattr_is_trusted(const char *name)
+{
+ return !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN);
+}
+
+/*
+ * xattr LIST operation for in-memory/pseudo filesystems
+ */
+ssize_t simple_xattr_list(struct simple_xattrs *xattrs, char *buffer,
+ size_t size)
+{
+ bool trusted = capable(CAP_SYS_ADMIN);
+ struct simple_xattr *xattr;
+ size_t used = 0;
+
+ spin_lock(&xattrs->lock);
+ list_for_each_entry(xattr, &xattrs->head, list) {
+ size_t len;
+
+ /* skip "trusted." attributes for unprivileged callers */
+ if (!trusted && xattr_is_trusted(xattr->name))
+ continue;
+
+ len = strlen(xattr->name) + 1;
+ used += len;
+ if (buffer) {
+ if (size < used) {
+ used = -ERANGE;
+ break;
+ }
+ memcpy(buffer, xattr->name, len);
+ buffer += len;
+ }
+ }
+ spin_unlock(&xattrs->lock);
+
+ return used;
+}
+
+/*
+ * Adds an extended attribute to the list
+ */
+void simple_xattr_list_add(struct simple_xattrs *xattrs,
+ struct simple_xattr *new_xattr)
+{
+ spin_lock(&xattrs->lock);
+ list_add(&new_xattr->list, &xattrs->head);
+ spin_unlock(&xattrs->lock);
+}