Re: [Cluster-devel] [PATCH 16/18] gfs2: use generic posix ACL infrastructure

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,

On Wed, 2013-12-11 at 02:42 -0800, Christoph Hellwig wrote:
> plain text document attachment
> (0016-gfs2-use-generic-posix-ACL-infrastructure.patch)
> This contains some major refactoring for the create path so that
> inodes are created with the right mode to start with instead of
> fixing it up later.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>

A really nice clean up - this is a very useful step forward in
simplifying the create path. Thanks for sorting this out,

Steve.

> ---
>  fs/gfs2/acl.c   |  234 +++++++------------------------------------------------
>  fs/gfs2/acl.h   |    4 +-
>  fs/gfs2/inode.c |   33 ++++++--
>  fs/gfs2/xattr.c |    4 +-
>  4 files changed, 62 insertions(+), 213 deletions(-)
> 
> diff --git a/fs/gfs2/acl.c b/fs/gfs2/acl.c
> index e82e4ac..ba94566 100644
> --- a/fs/gfs2/acl.c
> +++ b/fs/gfs2/acl.c
> @@ -49,10 +49,6 @@ struct posix_acl *gfs2_get_acl(struct inode *inode, int type)
>  	if (!ip->i_eattr)
>  		return NULL;
>  
> -	acl = get_cached_acl(&ip->i_inode, type);
> -	if (acl != ACL_NOT_CACHED)
> -		return acl;
> -
>  	name = gfs2_acl_name(type);
>  	if (name == NULL)
>  		return ERR_PTR(-EINVAL);
> @@ -80,7 +76,7 @@ static int gfs2_set_mode(struct inode *inode, umode_t mode)
>  	return error;
>  }
>  
> -static int gfs2_acl_set(struct inode *inode, int type, struct posix_acl *acl)
> +int gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
>  {
>  	int error;
>  	int len;
> @@ -88,219 +84,49 @@ static int gfs2_acl_set(struct inode *inode, int type, struct posix_acl *acl)
>  	const char *name = gfs2_acl_name(type);
>  
>  	BUG_ON(name == NULL);
> -	len = posix_acl_to_xattr(&init_user_ns, acl, NULL, 0);
> -	if (len == 0)
> -		return 0;
> -	data = kmalloc(len, GFP_NOFS);
> -	if (data == NULL)
> -		return -ENOMEM;
> -	error = posix_acl_to_xattr(&init_user_ns, acl, data, len);
> -	if (error < 0)
> -		goto out;
> -	error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS);
> -	if (!error)
> -		set_cached_acl(inode, type, acl);
> -out:
> -	kfree(data);
> -	return error;
> -}
> -
> -int gfs2_acl_create(struct gfs2_inode *dip, struct inode *inode)
> -{
> -	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
> -	struct posix_acl *acl;
> -	umode_t mode = inode->i_mode;
> -	int error = 0;
> -
> -	if (!sdp->sd_args.ar_posix_acl)
> -		return 0;
> -	if (S_ISLNK(inode->i_mode))
> -		return 0;
> -
> -	acl = gfs2_get_acl(&dip->i_inode, ACL_TYPE_DEFAULT);
> -	if (IS_ERR(acl))
> -		return PTR_ERR(acl);
> -	if (!acl) {
> -		mode &= ~current_umask();
> -		return gfs2_set_mode(inode, mode);
> -	}
> -
> -	if (S_ISDIR(inode->i_mode)) {
> -		error = gfs2_acl_set(inode, ACL_TYPE_DEFAULT, acl);
> -		if (error)
> -			goto out;
> -	}
> -
> -	error = __posix_acl_create(&acl, GFP_NOFS, &mode);
> -	if (error < 0)
> -		return error;
>  
> -	if (error == 0)
> -		goto munge;
> -
> -	error = gfs2_acl_set(inode, ACL_TYPE_ACCESS, acl);
> -	if (error)
> -		goto out;
> -munge:
> -	error = gfs2_set_mode(inode, mode);
> -out:
> -	posix_acl_release(acl);
> -	return error;
> -}
> -
> -int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr)
> -{
> -	struct inode *inode = &ip->i_inode;
> -	struct posix_acl *acl;
> -	char *data;
> -	unsigned int len;
> -	int error;
> -
> -	acl = gfs2_get_acl(&ip->i_inode, ACL_TYPE_ACCESS);
> -	if (IS_ERR(acl))
> -		return PTR_ERR(acl);
> -	if (!acl)
> -		return gfs2_setattr_simple(inode, attr);
> -
> -	error = __posix_acl_chmod(&acl, GFP_NOFS, attr->ia_mode);
> -	if (error)
> -		return error;
> -
> -	len = posix_acl_to_xattr(&init_user_ns, acl, NULL, 0);
> -	data = kmalloc(len, GFP_NOFS);
> -	error = -ENOMEM;
> -	if (data == NULL)
> -		goto out;
> -	posix_acl_to_xattr(&init_user_ns, acl, data, len);
> -	error = gfs2_xattr_acl_chmod(ip, attr, data);
> -	kfree(data);
> -	set_cached_acl(&ip->i_inode, ACL_TYPE_ACCESS, acl);
> -
> -out:
> -	posix_acl_release(acl);
> -	return error;
> -}
> -
> -static int gfs2_acl_type(const char *name)
> -{
> -	if (strcmp(name, GFS2_POSIX_ACL_ACCESS) == 0)
> -		return ACL_TYPE_ACCESS;
> -	if (strcmp(name, GFS2_POSIX_ACL_DEFAULT) == 0)
> -		return ACL_TYPE_DEFAULT;
> -	return -EINVAL;
> -}
> -
> -static int gfs2_xattr_system_get(struct dentry *dentry, const char *name,
> -				 void *buffer, size_t size, int xtype)
> -{
> -	struct inode *inode = dentry->d_inode;
> -	struct gfs2_sbd *sdp = GFS2_SB(inode);
> -	struct posix_acl *acl;
> -	int type;
> -	int error;
> -
> -	if (!sdp->sd_args.ar_posix_acl)
> -		return -EOPNOTSUPP;
> -
> -	type = gfs2_acl_type(name);
> -	if (type < 0)
> -		return type;
> -
> -	acl = gfs2_get_acl(inode, type);
> -	if (IS_ERR(acl))
> -		return PTR_ERR(acl);
> -	if (acl == NULL)
> -		return -ENODATA;
> -
> -	error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
> -	posix_acl_release(acl);
> -
> -	return error;
> -}
> -
> -static int gfs2_xattr_system_set(struct dentry *dentry, const char *name,
> -				 const void *value, size_t size, int flags,
> -				 int xtype)
> -{
> -	struct inode *inode = dentry->d_inode;
> -	struct gfs2_sbd *sdp = GFS2_SB(inode);
> -	struct posix_acl *acl = NULL;
> -	int error = 0, type;
> -
> -	if (!sdp->sd_args.ar_posix_acl)
> -		return -EOPNOTSUPP;
> -
> -	type = gfs2_acl_type(name);
> -	if (type < 0)
> -		return type;
> -	if (flags & XATTR_CREATE)
> -		return -EINVAL;
> -	if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
> -		return value ? -EACCES : 0;
> -	if (!uid_eq(current_fsuid(), inode->i_uid) && !capable(CAP_FOWNER))
> -		return -EPERM;
> -	if (S_ISLNK(inode->i_mode))
> -		return -EOPNOTSUPP;
> -
> -	if (!value)
> -		goto set_acl;
> -
> -	acl = posix_acl_from_xattr(&init_user_ns, value, size);
> -	if (!acl) {
> -		/*
> -		 * acl_set_file(3) may request that we set default ACLs with
> -		 * zero length -- defend (gracefully) against that here.
> -		 */
> -		goto out;
> -	}
> -	if (IS_ERR(acl)) {
> -		error = PTR_ERR(acl);
> -		goto out;
> -	}
> -
> -	error = posix_acl_valid(acl);
> -	if (error)
> -		goto out_release;
> -
> -	error = -EINVAL;
>  	if (acl->a_count > GFS2_ACL_MAX_ENTRIES)
> -		goto out_release;
> +		return -EINVAL;
>  
>  	if (type == ACL_TYPE_ACCESS) {
>  		umode_t mode = inode->i_mode;
> +
>  		error = posix_acl_equiv_mode(acl, &mode);
> +		if (error < 0)
> +			return error;
>  
> -		if (error <= 0) {
> -			posix_acl_release(acl);
> +		if (error == 0)
>  			acl = NULL;
>  
> -			if (error < 0)
> -				return error;
> -		}
> -
>  		error = gfs2_set_mode(inode, mode);
>  		if (error)
> -			goto out_release;
> +			return error;
>  	}
>  
> -set_acl:
> -	error = __gfs2_xattr_set(inode, name, value, size, 0, GFS2_EATYPE_SYS);
> -	if (!error) {
> -		if (acl)
> -			set_cached_acl(inode, type, acl);
> -		else
> -			forget_cached_acl(inode, type);
> +	if (acl) {
> +		len = posix_acl_to_xattr(&init_user_ns, acl, NULL, 0);
> +		if (len == 0)
> +			return 0;
> +		data = kmalloc(len, GFP_NOFS);
> +		if (data == NULL)
> +			return -ENOMEM;
> +		error = posix_acl_to_xattr(&init_user_ns, acl, data, len);
> +		if (error < 0)
> +			goto out;
> +	} else {
> +		data = NULL;
> +		len = 0;
>  	}
> -out_release:
> -	posix_acl_release(acl);
> +
> +	error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS);
> +	if (error)
> +		goto out;
> +
> +	if (acl)
> +		set_cached_acl(inode, type, acl);
> +	else
> +		forget_cached_acl(inode, type);
>  out:
> +	kfree(data);
>  	return error;
>  }
> -
> -const struct xattr_handler gfs2_xattr_system_handler = {
> -	.prefix = XATTR_SYSTEM_PREFIX,
> -	.flags  = GFS2_EATYPE_SYS,
> -	.get    = gfs2_xattr_system_get,
> -	.set    = gfs2_xattr_system_set,
> -};
> -
> diff --git a/fs/gfs2/acl.h b/fs/gfs2/acl.h
> index 0da38dc..301260c 100644
> --- a/fs/gfs2/acl.h
> +++ b/fs/gfs2/acl.h
> @@ -17,8 +17,6 @@
>  #define GFS2_ACL_MAX_ENTRIES		25
>  
>  extern struct posix_acl *gfs2_get_acl(struct inode *inode, int type);
> -extern int gfs2_acl_create(struct gfs2_inode *dip, struct inode *inode);
> -extern int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr);
> -extern const struct xattr_handler gfs2_xattr_system_handler;
> +extern int gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type);
>  
>  #endif /* __ACL_DOT_H__ */
> diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
> index 7119504..92b8959 100644
> --- a/fs/gfs2/inode.c
> +++ b/fs/gfs2/inode.c
> @@ -552,6 +552,7 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
>  			     unsigned int size, int excl, int *opened)
>  {
>  	const struct qstr *name = &dentry->d_name;
> +	struct posix_acl *default_acl, *acl;
>  	struct gfs2_holder ghs[2];
>  	struct inode *inode = NULL;
>  	struct gfs2_inode *dip = GFS2_I(dir), *ip;
> @@ -611,10 +612,14 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
>  	if (!inode)
>  		goto fail_gunlock;
>  
> +	error = posix_acl_create(dir, &mode, &default_acl, &acl);
> +	if (error)
> +		goto fail_free_vfs_inode;
> +
>  	ip = GFS2_I(inode);
>  	error = gfs2_rs_alloc(ip);
>  	if (error)
> -		goto fail_free_inode;
> +		goto fail_free_acls;
>  
>  	inode->i_mode = mode;
>  	set_nlink(inode, S_ISDIR(mode) ? 2 : 1);
> @@ -682,7 +687,16 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
>  	gfs2_set_iop(inode);
>  	insert_inode_hash(inode);
>  
> -	error = gfs2_acl_create(dip, inode);
> +	if (default_acl) {
> +		error = gfs2_set_acl(inode, default_acl, ACL_TYPE_DEFAULT);
> +		posix_acl_release(default_acl);
> +	}
> +	if (acl) {
> +		if (!error)
> +			error = gfs2_set_acl(inode, acl, ACL_TYPE_ACCESS);
> +		posix_acl_release(acl);
> +	}
> +
>  	if (error)
>  		goto fail_gunlock3;
>  
> @@ -716,6 +730,12 @@ fail_free_inode:
>  	if (ip->i_gl)
>  		gfs2_glock_put(ip->i_gl);
>  	gfs2_rs_delete(ip, NULL);
> +fail_free_acls:
> +	if (default_acl)
> +		posix_acl_release(default_acl);
> +	if (acl)
> +		posix_acl_release(acl);
> +fail_free_vfs_inode:
>  	free_inode_nonrcu(inode);
>  	inode = NULL;
>  fail_gunlock:
> @@ -1678,10 +1698,11 @@ static int gfs2_setattr(struct dentry *dentry, struct iattr *attr)
>  		error = gfs2_setattr_size(inode, attr->ia_size);
>  	else if (attr->ia_valid & (ATTR_UID | ATTR_GID))
>  		error = setattr_chown(inode, attr);
> -	else if ((attr->ia_valid & ATTR_MODE) && IS_POSIXACL(inode))
> -		error = gfs2_acl_chmod(ip, attr);
> -	else
> +	else {
>  		error = gfs2_setattr_simple(inode, attr);
> +		if (!error && attr->ia_valid & ATTR_MODE)
> +			error = posix_acl_chmod(inode, inode->i_mode);
> +	}
>  
>  out:
>  	if (!error)
> @@ -1841,6 +1862,7 @@ const struct inode_operations gfs2_file_iops = {
>  	.removexattr = gfs2_removexattr,
>  	.fiemap = gfs2_fiemap,
>  	.get_acl = gfs2_get_acl,
> +	.set_acl = gfs2_set_acl,
>  };
>  
>  const struct inode_operations gfs2_dir_iops = {
> @@ -1862,6 +1884,7 @@ const struct inode_operations gfs2_dir_iops = {
>  	.removexattr = gfs2_removexattr,
>  	.fiemap = gfs2_fiemap,
>  	.get_acl = gfs2_get_acl,
> +	.set_acl = gfs2_set_acl,
>  	.atomic_open = gfs2_atomic_open,
>  };
>  
> diff --git a/fs/gfs2/xattr.c b/fs/gfs2/xattr.c
> index 8c6a6f6..0b81f78 100644
> --- a/fs/gfs2/xattr.c
> +++ b/fs/gfs2/xattr.c
> @@ -13,6 +13,7 @@
>  #include <linux/buffer_head.h>
>  #include <linux/xattr.h>
>  #include <linux/gfs2_ondisk.h>
> +#include <linux/posix_acl_xattr.h>
>  #include <asm/uaccess.h>
>  
>  #include "gfs2.h"
> @@ -1500,7 +1501,8 @@ static const struct xattr_handler gfs2_xattr_security_handler = {
>  const struct xattr_handler *gfs2_xattr_handlers[] = {
>  	&gfs2_xattr_user_handler,
>  	&gfs2_xattr_security_handler,
> -	&gfs2_xattr_system_handler,
> +	&posix_acl_access_xattr_handler,
> +	&posix_acl_default_xattr_handler,
>  	NULL,
>  };
>  



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