make generic_acl slightly more generic

Now that we cache the ACL pointers in the generic inode all the generic_acl
cruft can go away and generic_acl.c can directly implement xattr handlers
dealing with the full Posix ACL semantics for in-memory filesystems.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

3 files changed, 10 insertions, 141 deletions

diff --git a/mm/Makefile b/mm/Makefile
index 82131d0f8d85..7a68d2ab5560 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -22,7 +22,6 @@ obj-$(CONFIG_HUGETLBFS)	+= hugetlb.o
 obj-$(CONFIG_NUMA)      += mempolicy.o
 obj-$(CONFIG_SPARSEMEM) += sparse.o
 obj-$(CONFIG_SPARSEMEM_VMEMMAP) += sparse-vmemmap.o
-obj-$(CONFIG_TMPFS_POSIX_ACL) += shmem_acl.o
 obj-$(CONFIG_SLOB) += slob.o
 obj-$(CONFIG_MMU_NOTIFIER) += mmu_notifier.o
 obj-$(CONFIG_KSM) += ksm.o
diff --git a/mm/shmem.c b/mm/shmem.c
index 3cd32c2ea0a0..f8485062f3ba 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -41,6 +41,7 @@ static struct vfsmount *shm_mnt;
 
 #include <linux/xattr.h>
 #include <linux/exportfs.h>
+#include <linux/posix_acl.h>
 #include <linux/generic_acl.h>
 #include <linux/mman.h>
 #include <linux/string.h>
@@ -809,7 +810,7 @@ static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
                 error = inode_setattr(inode, attr);
 #ifdef CONFIG_TMPFS_POSIX_ACL
         if (!error && (attr->ia_valid & ATTR_MODE))
-                error = generic_acl_chmod(inode, &shmem_acl_ops);
+                error = generic_acl_chmod(inode);
 #endif
         if (page)
                 page_cache_release(page);
@@ -1823,11 +1824,13 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
                                 return error;
                         }
                 }
-                error = shmem_acl_init(inode, dir);
+#ifdef CONFIG_TMPFS_POSIX_ACL
+                error = generic_acl_init(inode, dir);
                 if (error) {
                         iput(inode);
                         return error;
                 }
+#endif
                 if (dir->i_mode & S_ISGID) {
                         inode->i_gid = dir->i_gid;
                         if (S_ISDIR(mode))
@@ -2074,8 +2077,8 @@ static struct xattr_handler shmem_xattr_security_handler = {
 };
 
 static struct xattr_handler *shmem_xattr_handlers[] = {
-        &shmem_xattr_acl_access_handler,
-        &shmem_xattr_acl_default_handler,
+        &generic_acl_access_handler,
+        &generic_acl_default_handler,
         &shmem_xattr_security_handler,
         NULL
 };
@@ -2454,7 +2457,7 @@ static const struct inode_operations shmem_inode_operations = {
         .getxattr       = generic_getxattr,
         .listxattr      = generic_listxattr,
         .removexattr    = generic_removexattr,
-        .check_acl      = shmem_check_acl,
+        .check_acl      = generic_check_acl,
 #endif
 
 };
@@ -2477,7 +2480,7 @@ static const struct inode_operations shmem_dir_inode_operations = {
         .getxattr       = generic_getxattr,
         .listxattr      = generic_listxattr,
         .removexattr    = generic_removexattr,
-        .check_acl      = shmem_check_acl,
+        .check_acl      = generic_check_acl,
 #endif
 };
 
@@ -2488,7 +2491,7 @@ static const struct inode_operations shmem_special_inode_operations = {
         .getxattr       = generic_getxattr,
         .listxattr      = generic_listxattr,
         .removexattr    = generic_removexattr,
-        .check_acl      = shmem_check_acl,
+        .check_acl      = generic_check_acl,
 #endif
 };
 
diff --git a/mm/shmem_acl.c b/mm/shmem_acl.c
deleted file mode 100644
index f8d5330ec0d7..000000000000
--- a/mm/shmem_acl.c
+++ /dev/null
@@ -1,133 +0,0 @@
-/*
- * mm/shmem_acl.c
- *
- * (C) 2005 Andreas Gruenbacher <agruen@suse.de>
- *
- * This file is released under the GPL.
- */
-
-#include <linux/fs.h>
-#include <linux/shmem_fs.h>
-#include <linux/xattr.h>
-#include <linux/generic_acl.h>
-
-/**
- * shmem_get_acl  -   generic_acl_operations->getacl() operation
- */
-static struct posix_acl *
-shmem_get_acl(struct inode *inode, int type)
-{
-        struct posix_acl *acl = NULL;
-
-        spin_lock(&inode->i_lock);
-        switch(type) {
-                case ACL_TYPE_ACCESS:
-                        acl = posix_acl_dup(inode->i_acl);
-                        break;
-
-                case ACL_TYPE_DEFAULT:
-                        acl = posix_acl_dup(inode->i_default_acl);
-                        break;
-        }
-        spin_unlock(&inode->i_lock);
-
-        return acl;
-}
-
-/**
- * shmem_set_acl  -   generic_acl_operations->setacl() operation
- */
-static void
-shmem_set_acl(struct inode *inode, int type, struct posix_acl *acl)
-{
-        struct posix_acl *free = NULL;
-
-        spin_lock(&inode->i_lock);
-        switch(type) {
-                case ACL_TYPE_ACCESS:
-                        free = inode->i_acl;
-                        inode->i_acl = posix_acl_dup(acl);
-                        break;
-
-                case ACL_TYPE_DEFAULT:
-                        free = inode->i_default_acl;
-                        inode->i_default_acl = posix_acl_dup(acl);
-                        break;
-        }
-        spin_unlock(&inode->i_lock);
-        posix_acl_release(free);
-}
-
-struct generic_acl_operations shmem_acl_ops = {
-        .getacl = shmem_get_acl,
-        .setacl = shmem_set_acl,
-};
-
-static size_t
-shmem_xattr_list_acl(struct dentry *dentry, char *list, size_t list_size,
-                const char *name, size_t name_len, int type)
-{
-        return generic_acl_list(dentry->d_inode, &shmem_acl_ops,
-                                type, list, list_size);
-}
-
-static int
-shmem_xattr_get_acl(struct dentry *dentry, const char *name, void *buffer,
-                     size_t size, int type)
-{
-        if (strcmp(name, "") != 0)
-                return -EINVAL;
-        return generic_acl_get(dentry->d_inode, &shmem_acl_ops, type,
-                               buffer, size);
-}
-
-static int
-shmem_xattr_set_acl(struct dentry *dentry, const char *name, const void *value,
-                     size_t size, int flags, int type)
-{
-        if (strcmp(name, "") != 0)
-                return -EINVAL;
-        return generic_acl_set(dentry->d_inode, &shmem_acl_ops, type,
-                               value, size);
-}
-
-struct xattr_handler shmem_xattr_acl_access_handler = {
-        .prefix = POSIX_ACL_XATTR_ACCESS,
-        .flags  = ACL_TYPE_ACCESS,
-        .list   = shmem_xattr_list_acl,
-        .get    = shmem_xattr_get_acl,
-        .set    = shmem_xattr_set_acl,
-};
-
-struct xattr_handler shmem_xattr_acl_default_handler = {
-        .prefix = POSIX_ACL_XATTR_DEFAULT,
-        .flags  = ACL_TYPE_DEFAULT,
-        .list   = shmem_xattr_list_acl,
-        .get    = shmem_xattr_get_acl,
-        .set    = shmem_xattr_set_acl,
-};
-
-/**
- * shmem_acl_init  -  Inizialize the acl(s) of a new inode
- */
-int
-shmem_acl_init(struct inode *inode, struct inode *dir)
-{
-        return generic_acl_init(inode, dir, &shmem_acl_ops);
-}
-
-/**
- * shmem_check_acl  -  check_acl() callback for generic_permission()
- */
-int
-shmem_check_acl(struct inode *inode, int mask)
-{
-        struct posix_acl *acl = shmem_get_acl(inode, ACL_TYPE_ACCESS);
-
-        if (acl) {
-                int error = posix_acl_permission(inode, acl, mask);
-                posix_acl_release(acl);
-                return error;
-        }
-        return -EAGAIN;
-}