* [RFC] [PATCH 1/5] ACL support for ext2/3
@ 2002-10-10 5:10 tytso
2002-10-10 18:34 ` [Ext2-devel] " Christoph Hellwig
0 siblings, 1 reply; 3+ messages in thread
From: tytso @ 2002-10-10 5:10 UTC (permalink / raw)
To: linux-kernel; +Cc: ext2-devel
This patch (as well as the following one) implements core ACL support
which is needed for XFS as well as ext2/3 ACL support. Parts of this
were patch was posted by Nathan Scott 2 or 3 days ago. (Although
apparently XFS doesn't need the library functions provided by
fs/posix_acl.c.)
# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
#
# fs/Config.help | 13 +
# fs/Config.in | 2
# fs/Makefile | 3
# fs/posix_acl.c | 465 ++++++++++++++++++++++++++++++++++++++++++++++
# include/linux/fs.h | 5
# include/linux/posix_acl.h | 87 ++++++++
# 6 files changed, 574 insertions(+), 1 deletion(-)
#
# --------------------------------------------
# 02/10/05 tytso@think.thunk.org 1.669
# Ported 0.8.50 acl patch to 2.5.
# --------------------------------------------
#
diff -Nru a/fs/Config.help b/fs/Config.help
--- a/fs/Config.help Wed Oct 9 23:53:33 2002
+++ b/fs/Config.help Wed Oct 9 23:53:33 2002
@@ -1,3 +1,16 @@
+CONFIG_FS_POSIX_ACL
+ Posix Access Control Lists (ACLs) support permissions for users and
+ groups beyond the owner/group/world scheme.
+
+ To learn more about Access Control Lists, visit the Posix ACLs for
+ Linux website <http://acl.bestbits.at/>.
+
+ If you plan to use Access Control Lists, you may also need the
+ getfacl and setfacl utilities, along with some additional patches
+ from the website.
+
+ If you don't know what Access Control Lists are, say N.
+
CONFIG_QUOTA
If you say Y here, you will be able to set per user limits for disk
usage (also called disk quotas). Currently, it works for the
diff -Nru a/fs/Config.in b/fs/Config.in
--- a/fs/Config.in Wed Oct 9 23:53:33 2002
+++ b/fs/Config.in Wed Oct 9 23:53:33 2002
@@ -4,6 +4,8 @@
mainmenu_option next_comment
comment 'File systems'
+bool 'POSIX Access Control Lists' CONFIG_FS_POSIX_ACL
+
bool 'Quota support' CONFIG_QUOTA
dep_tristate ' Old quota format support' CONFIG_QFMT_V1 $CONFIG_QUOTA
dep_tristate ' Quota format v2 support' CONFIG_QFMT_V2 $CONFIG_QUOTA
diff -Nru a/fs/Makefile b/fs/Makefile
--- a/fs/Makefile Wed Oct 9 23:53:33 2002
+++ b/fs/Makefile Wed Oct 9 23:53:33 2002
@@ -6,7 +6,7 @@
#
export-objs := open.o dcache.o buffer.o bio.o inode.o dquot.o mpage.o aio.o \
- fcntl.o mbcache.o
+ fcntl.o mbcache.o posix_acl.o
obj-y := open.o read_write.o devices.o file_table.o buffer.o \
bio.o super.o block_dev.o char_dev.o stat.o exec.o pipe.o \
@@ -31,6 +31,7 @@
obj-$(CONFIG_BINFMT_ELF) += binfmt_elf.o
obj-$(CONFIG_FS_MBCACHE) += mbcache.o
+obj-$(CONFIG_FS_POSIX_ACL) += posix_acl.o
obj-$(CONFIG_QUOTA) += dquot.o
obj-$(CONFIG_QFMT_V1) += quota_v1.o
diff -Nru a/fs/posix_acl.c b/fs/posix_acl.c
--- /dev/null Wed Dec 31 16:00:00 1969
+++ b/fs/posix_acl.c Wed Oct 9 23:53:33 2002
@@ -0,0 +1,465 @@
+/*
+ * linux/fs/posix_acl.c
+ *
+ * Copyright (C) 2002 by Andreas Gruenbacher <a.gruenbacher@computer.org>
+ *
+ * Fixes from William Schumacher incorporated on 15 March 2001.
+ * (Reported by Charles Bertsch, <CBertsch@microtest.com>).
+ */
+
+/*
+ * This file contains generic functions for manipulating
+ * POSIX 1003.1e draft standard 17 ACLs.
+ */
+
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <asm/atomic.h>
+#include <linux/fs.h>
+#include <linux/posix_acl.h>
+#include <linux/module.h>
+
+#include <linux/smp_lock.h>
+#include <linux/errno.h>
+
+MODULE_AUTHOR("Andreas Gruenbacher <a.gruenbacher@computer.org>");
+MODULE_DESCRIPTION("Generic Posix Access Control List (ACL) Manipulation");
+MODULE_LICENSE("GPL");
+
+EXPORT_SYMBOL(posix_acl_alloc);
+EXPORT_SYMBOL(posix_acl_clone);
+EXPORT_SYMBOL(posix_acl_valid);
+EXPORT_SYMBOL(posix_acl_equiv_mode);
+EXPORT_SYMBOL(posix_acl_from_mode);
+EXPORT_SYMBOL(posix_acl_create_masq);
+EXPORT_SYMBOL(posix_acl_chmod_masq);
+EXPORT_SYMBOL(posix_acl_masq_nfs_mode);
+EXPORT_SYMBOL(posix_acl_permission);
+
+EXPORT_SYMBOL(get_posix_acl);
+EXPORT_SYMBOL(set_posix_acl);
+
+/*
+ * Allocate a new ACL with the specified number of entries.
+ */
+struct posix_acl *
+posix_acl_alloc(int count, int flags)
+{
+ const size_t size = sizeof(struct posix_acl) +
+ count * sizeof(struct posix_acl_entry);
+ struct posix_acl *acl = kmalloc(size, flags);
+ if (acl) {
+ atomic_set(&acl->a_refcount, 1);
+ acl->a_count = count;
+ }
+ return acl;
+}
+
+/*
+ * Clone an ACL.
+ */
+struct posix_acl *
+posix_acl_clone(const struct posix_acl *acl, int flags)
+{
+ struct posix_acl *clone = NULL;
+
+ if (acl) {
+ int size = sizeof(struct posix_acl) + acl->a_count *
+ sizeof(struct posix_acl_entry);
+ clone = kmalloc(size, flags);
+ if (clone) {
+ memcpy(clone, acl, size);
+ atomic_set(&clone->a_refcount, 1);
+ }
+ }
+ return clone;
+}
+
+/*
+ * Check if an acl is valid. Returns 0 if it is, or -E... otherwise.
+ */
+int
+posix_acl_valid(const struct posix_acl *acl)
+{
+ const struct posix_acl_entry *pa, *pe;
+ int state = ACL_USER_OBJ;
+ unsigned int id = 0; /* keep gcc happy */
+ int needs_mask = 0;
+
+ FOREACH_ACL_ENTRY(pa, acl, pe) {
+ if (pa->e_perm & ~(ACL_READ|ACL_WRITE|ACL_EXECUTE))
+ return -EINVAL;
+ switch (pa->e_tag) {
+ case ACL_USER_OBJ:
+ if (state == ACL_USER_OBJ) {
+ id = 0;
+ state = ACL_USER;
+ break;
+ }
+ return -EINVAL;
+
+ case ACL_USER:
+ if (state != ACL_USER)
+ return -EINVAL;
+ if (pa->e_id == ACL_UNDEFINED_ID ||
+ pa->e_id < id)
+ return -EINVAL;
+ id = pa->e_id + 1;
+ needs_mask = 1;
+ break;
+
+ case ACL_GROUP_OBJ:
+ if (state == ACL_USER) {
+ id = 0;
+ state = ACL_GROUP;
+ break;
+ }
+ return -EINVAL;
+
+ case ACL_GROUP:
+ if (state != ACL_GROUP)
+ return -EINVAL;
+ if (pa->e_id == ACL_UNDEFINED_ID ||
+ pa->e_id < id)
+ return -EINVAL;
+ id = pa->e_id + 1;
+ needs_mask = 1;
+ break;
+
+ case ACL_MASK:
+ if (state != ACL_GROUP)
+ return -EINVAL;
+ state = ACL_OTHER;
+ break;
+
+ case ACL_OTHER:
+ if (state == ACL_OTHER ||
+ (state == ACL_GROUP && !needs_mask)) {
+ state = 0;
+ break;
+ }
+ return -EINVAL;
+
+ default:
+ return -EINVAL;
+ }
+ }
+ if (state == 0)
+ return 0;
+ return -EINVAL;
+}
+
+/*
+ * Returns 0 if the acl can be exactly represented in the traditional
+ * file mode permission bits, or else 1. Returns -E... on error.
+ */
+int
+posix_acl_equiv_mode(const struct posix_acl *acl, mode_t *mode_p)
+{
+ const struct posix_acl_entry *pa, *pe;
+ mode_t mode = 0;
+ int not_equiv = 0;
+
+ FOREACH_ACL_ENTRY(pa, acl, pe) {
+ switch (pa->e_tag) {
+ case ACL_USER_OBJ:
+ mode |= (pa->e_perm & S_IRWXO) << 6;
+ break;
+ case ACL_GROUP_OBJ:
+ mode |= (pa->e_perm & S_IRWXO) << 3;
+ break;
+ case ACL_OTHER:
+ mode |= pa->e_perm & S_IRWXO;
+ break;
+ case ACL_MASK:
+ mode = (mode & ~S_IRWXG) |
+ ((pa->e_perm & S_IRWXO) << 3);
+ not_equiv = 1;
+ break;
+ case ACL_USER:
+ case ACL_GROUP:
+ not_equiv = 1;
+ break;
+ default:
+ return -EINVAL;
+ }
+ }
+ if (mode_p)
+ *mode_p = (*mode_p & ~S_IRWXUGO) | mode;
+ return not_equiv;
+}
+
+/*
+ * Create an ACL representing the file mode permission bits of an inode.
+ */
+struct posix_acl *
+posix_acl_from_mode(mode_t mode, int flags)
+{
+ struct posix_acl *acl = posix_acl_alloc(3, flags);
+ if (!acl)
+ return ERR_PTR(-ENOMEM);
+
+ acl->a_entries[0].e_tag = ACL_USER_OBJ;
+ acl->a_entries[0].e_id = ACL_UNDEFINED_ID;
+ acl->a_entries[0].e_perm = (mode & S_IRWXU) >> 6;
+
+ acl->a_entries[1].e_tag = ACL_GROUP_OBJ;
+ acl->a_entries[1].e_id = ACL_UNDEFINED_ID;
+ acl->a_entries[1].e_perm = (mode & S_IRWXG) >> 3;
+
+ acl->a_entries[2].e_tag = ACL_OTHER;
+ acl->a_entries[2].e_id = ACL_UNDEFINED_ID;
+ acl->a_entries[2].e_perm = (mode & S_IRWXO);
+ return acl;
+}
+
+/*
+ * Return 0 if current is granted want access to the inode
+ * by the acl. Returns -E... otherwise.
+ */
+int
+posix_acl_permission(struct inode *inode, const struct posix_acl *acl, int want)
+{
+ const struct posix_acl_entry *pa, *pe, *mask_obj;
+ int found = 0;
+
+ FOREACH_ACL_ENTRY(pa, acl, pe) {
+ switch(pa->e_tag) {
+ case ACL_USER_OBJ:
+ /* (May have been checked already) */
+ if (inode->i_uid == current->fsuid)
+ goto check_perm;
+ break;
+ case ACL_USER:
+ if (pa->e_id == current->fsuid)
+ goto mask;
+ break;
+ case ACL_GROUP_OBJ:
+ if (in_group_p(inode->i_gid)) {
+ found = 1;
+ if ((pa->e_perm & want) == want)
+ goto mask;
+ }
+ break;
+ case ACL_GROUP:
+ if (in_group_p(pa->e_id)) {
+ found = 1;
+ if ((pa->e_perm & want) == want)
+ goto mask;
+ }
+ break;
+ case ACL_MASK:
+ break;
+ case ACL_OTHER:
+ if (found)
+ return -EACCES;
+ else
+ goto check_perm;
+ default:
+ return -EIO;
+ }
+ }
+ return -EIO;
+
+mask:
+ for (mask_obj = pa+1; mask_obj != pe; mask_obj++) {
+ if (mask_obj->e_tag == ACL_MASK) {
+ if ((pa->e_perm & mask_obj->e_perm & want) == want)
+ return 0;
+ return -EACCES;
+ }
+ }
+
+check_perm:
+ if ((pa->e_perm & want) == want)
+ return 0;
+ return -EACCES;
+}
+
+/*
+ * Modify acl when creating a new inode. The caller must ensure the acl is
+ * only referenced once.
+ *
+ * mode_p initially must contain the mode parameter to the open() / creat()
+ * system calls. All permissions that are not granted by the acl are removed.
+ * The permissions in the acl are changed to reflect the mode_p parameter.
+ */
+int
+posix_acl_create_masq(struct posix_acl *acl, mode_t *mode_p)
+{
+ struct posix_acl_entry *pa, *pe;
+ struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
+ mode_t mode = *mode_p;
+ int not_equiv = 0;
+
+ /* assert(atomic_read(acl->a_refcount) == 1); */
+
+ FOREACH_ACL_ENTRY(pa, acl, pe) {
+ switch(pa->e_tag) {
+ case ACL_USER_OBJ:
+ pa->e_perm &= (mode >> 6) | ~S_IRWXO;
+ mode &= (pa->e_perm << 6) | ~S_IRWXU;
+ break;
+
+ case ACL_USER:
+ case ACL_GROUP:
+ not_equiv = 1;
+ break;
+
+ case ACL_GROUP_OBJ:
+ group_obj = pa;
+ break;
+
+ case ACL_OTHER:
+ pa->e_perm &= mode | ~S_IRWXO;
+ mode &= pa->e_perm | ~S_IRWXO;
+ break;
+
+ case ACL_MASK:
+ mask_obj = pa;
+ not_equiv = 1;
+ break;
+
+ default:
+ return -EIO;
+ }
+ }
+
+ if (mask_obj) {
+ mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
+ mode &= (mask_obj->e_perm << 3) | ~S_IRWXG;
+ } else {
+ if (!group_obj)
+ return -EIO;
+ group_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
+ mode &= (group_obj->e_perm << 3) | ~S_IRWXG;
+ }
+
+ *mode_p = (*mode_p & ~S_IRWXUGO) | mode;
+ return not_equiv;
+}
+
+/*
+ * Modify the ACL for the chmod syscall.
+ */
+int
+posix_acl_chmod_masq(struct posix_acl *acl, mode_t mode)
+{
+ struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
+ struct posix_acl_entry *pa, *pe;
+
+ /* assert(atomic_read(acl->a_refcount) == 1); */
+
+ FOREACH_ACL_ENTRY(pa, acl, pe) {
+ switch(pa->e_tag) {
+ case ACL_USER_OBJ:
+ pa->e_perm = (mode & S_IRWXU) >> 6;
+ break;
+
+ case ACL_USER:
+ case ACL_GROUP:
+ break;
+
+ case ACL_GROUP_OBJ:
+ group_obj = pa;
+ break;
+
+ case ACL_MASK:
+ mask_obj = pa;
+ break;
+
+ case ACL_OTHER:
+ pa->e_perm = (mode & S_IRWXO);
+ break;
+
+ default:
+ return -EIO;
+ }
+ }
+
+ if (mask_obj) {
+ mask_obj->e_perm = (mode & S_IRWXG) >> 3;
+ } else {
+ if (!group_obj)
+ return -EIO;
+ group_obj->e_perm = (mode & S_IRWXG) >> 3;
+ }
+
+ return 0;
+}
+
+/*
+ * Adjust the mode parameter so that NFSv2 grants nobody permissions
+ * that may not be granted by the ACL. This is necessary because NFSv2
+ * may compute access permissions on the client side, and may serve cached
+ * data whenever it assumes access would be granted. Since ACLs may also
+ * be used to deny access to specific users, the minimal permissions
+ * for secure operation over NFSv2 are very restrictive. Permissions
+ * granted to users via Access Control Lists will not be effective over
+ * NFSv2.
+ *
+ * Privilege escalation can only happen for read operations, as writes are
+ * always carried out on the NFS server, where the proper access checks are
+ * implemented.
+ */
+int
+posix_acl_masq_nfs_mode(struct posix_acl *acl, mode_t *mode_p)
+{
+ struct posix_acl_entry *pa, *pe; int min_perm = S_IRWXO;
+
+ FOREACH_ACL_ENTRY(pa, acl, pe) {
+ switch(pa->e_tag) {
+ case ACL_USER_OBJ:
+ break;
+
+ case ACL_USER:
+ case ACL_GROUP_OBJ:
+ case ACL_GROUP:
+ case ACL_MASK:
+ case ACL_OTHER:
+ min_perm &= pa->e_perm;
+ break;
+
+ default:
+ return -EIO;
+ }
+ }
+ *mode_p = (*mode_p & ~(S_IRWXG|S_IRWXO)) | (min_perm << 3) | min_perm;
+
+ return 0;
+}
+
+/*
+ * Get the POSIX ACL of an inode.
+ */
+struct posix_acl *
+get_posix_acl(struct inode *inode, int type)
+{
+ struct posix_acl *acl;
+
+ if (!inode->i_op->get_posix_acl)
+ return ERR_PTR(-EOPNOTSUPP);
+ down(&inode->i_sem);
+ acl = inode->i_op->get_posix_acl(inode, type);
+ up(&inode->i_sem);
+
+ return acl;
+}
+
+/*
+ * Set the POSIX ACL of an inode.
+ */
+int
+set_posix_acl(struct inode *inode, int type, struct posix_acl *acl)
+{
+ int error;
+
+ if (!inode->i_op->set_posix_acl)
+ return -EOPNOTSUPP;
+ down(&inode->i_sem);
+ error = inode->i_op->set_posix_acl(inode, type, acl);
+ up(&inode->i_sem);
+
+ return error;
+}
diff -Nru a/include/linux/fs.h b/include/linux/fs.h
--- a/include/linux/fs.h Wed Oct 9 23:53:33 2002
+++ b/include/linux/fs.h Wed Oct 9 23:53:33 2002
@@ -770,6 +770,9 @@
unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
};
+/* posix_acl.h */
+struct posix_acl;
+
struct inode_operations {
int (*create) (struct inode *,struct dentry *,int);
struct dentry * (*lookup) (struct inode *,struct dentry *);
@@ -791,6 +794,8 @@
ssize_t (*getxattr) (struct dentry *, const char *, void *, size_t);
ssize_t (*listxattr) (struct dentry *, char *, size_t);
int (*removexattr) (struct dentry *, const char *);
+ struct posix_acl *(*get_posix_acl) (struct inode *, int);
+ int (*set_posix_acl) (struct inode *, int, struct posix_acl *);
};
struct seq_file;
diff -Nru a/include/linux/posix_acl.h b/include/linux/posix_acl.h
--- /dev/null Wed Dec 31 16:00:00 1969
+++ b/include/linux/posix_acl.h Wed Oct 9 23:53:33 2002
@@ -0,0 +1,87 @@
+/*
+ File: linux/posix_acl.h
+
+ (C) 2002 Andreas Gruenbacher, <a.gruenbacher@computer.org>
+*/
+
+
+#ifndef __LINUX_POSIX_ACL_H
+#define __LINUX_POSIX_ACL_H
+
+#include <linux/slab.h>
+
+#define ACL_UNDEFINED_ID (-1)
+
+/* a_type field in acl_user_posix_entry_t */
+#define ACL_TYPE_ACCESS (0x8000)
+#define ACL_TYPE_DEFAULT (0x4000)
+
+/* e_tag entry in struct posix_acl_entry */
+#define ACL_USER_OBJ (0x01)
+#define ACL_USER (0x02)
+#define ACL_GROUP_OBJ (0x04)
+#define ACL_GROUP (0x08)
+#define ACL_MASK (0x10)
+#define ACL_OTHER (0x20)
+
+/* permissions in the e_perm field */
+#define ACL_READ (0x04)
+#define ACL_WRITE (0x02)
+#define ACL_EXECUTE (0x01)
+//#define ACL_ADD (0x08)
+//#define ACL_DELETE (0x10)
+
+struct posix_acl_entry {
+ short e_tag;
+ unsigned short e_perm;
+ unsigned int e_id;
+};
+
+struct posix_acl {
+ atomic_t a_refcount;
+ unsigned int a_count;
+ struct posix_acl_entry a_entries[0];
+};
+
+#define FOREACH_ACL_ENTRY(pa, acl, pe) \
+ for(pa=(acl)->a_entries, pe=pa+(acl)->a_count; pa<pe; pa++)
+
+
+/*
+ * Duplicate an ACL handle.
+ */
+static inline struct posix_acl *
+posix_acl_dup(struct posix_acl *acl)
+{
+ if (acl)
+ atomic_inc(&acl->a_refcount);
+ return acl;
+}
+
+/*
+ * Free an ACL handle.
+ */
+static inline void
+posix_acl_release(struct posix_acl *acl)
+{
+ if (acl && atomic_dec_and_test(&acl->a_refcount))
+ kfree(acl);
+}
+
+
+/* posix_acl.c */
+
+extern struct posix_acl *posix_acl_alloc(int, int);
+extern struct posix_acl *posix_acl_clone(const struct posix_acl *, int);
+extern int posix_acl_valid(const struct posix_acl *);
+extern int posix_acl_permission(struct inode *, const struct posix_acl *, int);
+extern struct posix_acl *posix_acl_from_mode(mode_t, int);
+extern int posix_acl_equiv_mode(const struct posix_acl *, mode_t *);
+extern int posix_acl_create_masq(struct posix_acl *, mode_t *);
+extern int posix_acl_chmod_masq(struct posix_acl *, mode_t);
+extern int posix_acl_masq_nfs_mode(struct posix_acl *, mode_t *);
+
+extern struct posix_acl *get_posix_acl(struct inode *, int);
+extern int set_posix_acl(struct inode *, int, struct posix_acl *);
+
+#endif /* __LINUX_POSIX_ACL_H */
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [Ext2-devel] [RFC] [PATCH 1/5] ACL support for ext2/3
2002-10-10 5:10 [RFC] [PATCH 1/5] ACL support for ext2/3 tytso
@ 2002-10-10 18:34 ` Christoph Hellwig
2002-10-10 18:53 ` Andreas Gruenbacher
0 siblings, 1 reply; 3+ messages in thread
From: Christoph Hellwig @ 2002-10-10 18:34 UTC (permalink / raw)
To: tytso; +Cc: linux-kernel, ext2-devel
> +#include <linux/version.h>
shouldn't be needed
> +#include <linux/kernel.h>
> +#include <linux/slab.h>
> +#include <asm/atomic.h>
> +#include <linux/fs.h>
> +#include <linux/posix_acl.h>
> +#include <linux/module.h>
> +
> +#include <linux/smp_lock.h>
not needed
> +MODULE_AUTHOR("Andreas Gruenbacher <a.gruenbacher@computer.org>");
> +MODULE_DESCRIPTION("Generic Posix Access Control List (ACL) Manipulation");
> +MODULE_LICENSE("GPL");
looks pretty pointless as this can't be a module.. :)
> +struct posix_acl *
> +get_posix_acl(struct inode *inode, int type)
> +{
> + struct posix_acl *acl;
> +
> + if (!inode->i_op->get_posix_acl)
> + return ERR_PTR(-EOPNOTSUPP);
> + down(&inode->i_sem);
> + acl = inode->i_op->get_posix_acl(inode, type);
> + up(&inode->i_sem);
> +
> + return acl;
> +}
> +
> +/*
> + * Set the POSIX ACL of an inode.
> + */
> +int
> +set_posix_acl(struct inode *inode, int type, struct posix_acl *acl)
> +{
> + int error;
> +
> + if (!inode->i_op->set_posix_acl)
> + return -EOPNOTSUPP;
> + down(&inode->i_sem);
> + error = inode->i_op->set_posix_acl(inode, type, acl);
> + up(&inode->i_sem);
> +
> + return error;
> +}
> diff -Nru a/include/linux/fs.h b/include/linux/fs.h
> --- a/include/linux/fs.h Wed Oct 9 23:53:33 2002
> +++ b/include/linux/fs.h Wed Oct 9 23:53:33 2002
> @@ -770,6 +770,9 @@
> unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
> };
>
> +/* posix_acl.h */
> +struct posix_acl;
> +
> struct inode_operations {
> int (*create) (struct inode *,struct dentry *,int);
> struct dentry * (*lookup) (struct inode *,struct dentry *);
> @@ -791,6 +794,8 @@
> ssize_t (*getxattr) (struct dentry *, const char *, void *, size_t);
> ssize_t (*listxattr) (struct dentry *, char *, size_t);
> int (*removexattr) (struct dentry *, const char *);
> + struct posix_acl *(*get_posix_acl) (struct inode *, int);
> + int (*set_posix_acl) (struct inode *, int, struct posix_acl *);
Either you make all setting/retrieving of ACLs go through this interface or
just rip it. We don't need more than one way to fiddle with ACLs.
Also they should take dentries..
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [Ext2-devel] [RFC] [PATCH 1/5] ACL support for ext2/3
2002-10-10 18:34 ` [Ext2-devel] " Christoph Hellwig
@ 2002-10-10 18:53 ` Andreas Gruenbacher
0 siblings, 0 replies; 3+ messages in thread
From: Andreas Gruenbacher @ 2002-10-10 18:53 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: linux-kernel, ext2-devel, tytso
On Thursday 10 October 2002 20:34, Christoph Hellwig wrote:
> [...]
> > diff -Nru a/include/linux/fs.h b/include/linux/fs.h
> > --- a/include/linux/fs.h Wed Oct 9 23:53:33 2002
> > +++ b/include/linux/fs.h Wed Oct 9 23:53:33 2002
> > @@ -770,6 +770,9 @@
> > unsigned long (*get_unmapped_area)(struct file *, unsigned long,
> > unsigned long, unsigned long, unsigned long); };
> >
> > +/* posix_acl.h */
> > +struct posix_acl;
> > +
> > struct inode_operations {
> > int (*create) (struct inode *,struct dentry *,int);
> > struct dentry * (*lookup) (struct inode *,struct dentry *);
> > @@ -791,6 +794,8 @@
> > ssize_t (*getxattr) (struct dentry *, const char *, void *, size_t);
> > ssize_t (*listxattr) (struct dentry *, char *, size_t);
> > int (*removexattr) (struct dentry *, const char *);
> > + struct posix_acl *(*get_posix_acl) (struct inode *, int);
> > + int (*set_posix_acl) (struct inode *, int, struct posix_acl *);
>
> Either you make all setting/retrieving of ACLs go through this interface or
> just rip it. We don't need more than one way to fiddle with ACLs.
This is an open design problem. Going through the xattr interface is too slow
for the nfs_permission_mode hack (which if enabled masks off permissions
before sending them to old clients to be on the safe side). On the other
hand, always going through the inode operations is also quirky as we would
need to dispatch xattr names and decode values both in the VFS and in the FS.
A clean solution to this would be very welcome.
> Also they should take dentries.
They will once permission() also takes dentries. Before that they can't.
--Andreas.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2002-10-10 18:48 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2002-10-10 5:10 [RFC] [PATCH 1/5] ACL support for ext2/3 tytso
2002-10-10 18:34 ` [Ext2-devel] " Christoph Hellwig
2002-10-10 18:53 ` Andreas Gruenbacher
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