[Ocfs2-devel] [PATCH 04/10] ocfs2: add ocfs2_init_security in mknod

Tiger Yang tiger.yang at oracle.com
Thu Nov 13 19:16:41 PST 2008


security xattr must be set when creating a new inode.
we do this in three steps. first, get security xattr's
name and value by security_operation, then calculate
and reserve the meta data and clusters needed by this
security xattr before starting transaction, finally set
it before add_entry.

Signed-off-by: Tiger Yang <tiger.yang at oracle.com>
---
 fs/ocfs2/namei.c |  107 ++++++++++++++++++++++++++++++++++++++++++++++++------
 fs/ocfs2/xattr.c |   70 +++++++++++++++++++++++++++++++++++
 fs/ocfs2/xattr.h |   17 +++++++++
 3 files changed, 182 insertions(+), 12 deletions(-)

diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index e9118fc..b361aec 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -229,6 +229,12 @@ static int ocfs2_mknod(struct inode *dir,
 	struct inode *inode = NULL;
 	struct ocfs2_alloc_context *inode_ac = NULL;
 	struct ocfs2_alloc_context *data_ac = NULL;
+	struct ocfs2_alloc_context *xattr_ac = NULL;
+	int want_clusters = 0;
+	int xattr_credits = 0;
+	struct ocfs2_security_xattr_info si = {
+		.enable = 1,
+	};
 
 	mlog_entry("(0x%p, 0x%p, %d, %lu, '%.*s')\n", dir, dentry, mode,
 		   (unsigned long)dev, dentry->d_name.len,
@@ -285,17 +291,39 @@ static int ocfs2_mknod(struct inode *dir,
 		goto leave;
 	}
 
-	/* Reserve a cluster if creating an extent based directory. */
-	if (S_ISDIR(mode) && !ocfs2_supports_inline_data(osb)) {
-		status = ocfs2_reserve_clusters(osb, 1, &data_ac);
+	/* get security xattr */
+	status = ocfs2_init_security_get(inode, dir, &si);
+	if (status) {
+		if (status == -EOPNOTSUPP)
+			si.enable = 0;
+		else {
+			mlog_errno(status);
+			goto leave;
+		}
+	}
+
+	/* calculate meta data/clusters for setting security xattr */
+	if (si.enable) {
+		status = ocfs2_calc_security_init(dir, &si, &want_clusters,
+						  &xattr_credits, &xattr_ac);
 		if (status < 0) {
-			if (status != -ENOSPC)
-				mlog_errno(status);
+			mlog_errno(status);
 			goto leave;
 		}
 	}
 
-	handle = ocfs2_start_trans(osb, OCFS2_MKNOD_CREDITS);
+	/* Reserve a cluster if creating an extent based directory. */
+	if (S_ISDIR(mode) && !ocfs2_supports_inline_data(osb))
+		want_clusters += 1;
+
+	status = ocfs2_reserve_clusters(osb, want_clusters, &data_ac);
+	if (status < 0) {
+		if (status != -ENOSPC)
+			mlog_errno(status);
+		goto leave;
+	}
+
+	handle = ocfs2_start_trans(osb, OCFS2_MKNOD_CREDITS + xattr_credits);
 	if (IS_ERR(handle)) {
 		status = PTR_ERR(handle);
 		handle = NULL;
@@ -335,6 +363,15 @@ static int ocfs2_mknod(struct inode *dir,
 		inc_nlink(dir);
 	}
 
+	if (si.enable) {
+		status = ocfs2_init_security_set(handle, inode, new_fe_bh, &si,
+						 xattr_ac, data_ac);
+		if (status < 0) {
+			mlog_errno(status);
+			goto leave;
+		}
+	}
+
 	status = ocfs2_add_entry(handle, dentry, inode,
 				 OCFS2_I(inode)->ip_blkno, parent_fe_bh,
 				 de_bh);
@@ -366,6 +403,8 @@ leave:
 	brelse(new_fe_bh);
 	brelse(de_bh);
 	brelse(parent_fe_bh);
+	kfree(si.name);
+	kfree(si.value);
 
 	if ((status < 0) && inode) {
 		clear_nlink(inode);
@@ -378,6 +417,9 @@ leave:
 	if (data_ac)
 		ocfs2_free_alloc_context(data_ac);
 
+	if (xattr_ac)
+		ocfs2_free_alloc_context(xattr_ac);
+
 	mlog_exit(status);
 
 	return status;
@@ -1508,6 +1550,12 @@ static int ocfs2_symlink(struct inode *dir,
 	handle_t *handle = NULL;
 	struct ocfs2_alloc_context *inode_ac = NULL;
 	struct ocfs2_alloc_context *data_ac = NULL;
+	struct ocfs2_alloc_context *xattr_ac = NULL;
+	int want_clusters = 0;
+	int xattr_credits = 0;
+	struct ocfs2_security_xattr_info si = {
+		.enable = 1,
+	};
 
 	mlog_entry("(0x%p, 0x%p, symname='%s' actual='%.*s')\n", dir,
 		   dentry, symname, dentry->d_name.len, dentry->d_name.name);
@@ -1561,17 +1609,39 @@ static int ocfs2_symlink(struct inode *dir,
 		goto bail;
 	}
 
-	/* don't reserve bitmap space for fast symlinks. */
-	if (l > ocfs2_fast_symlink_chars(sb)) {
-		status = ocfs2_reserve_clusters(osb, 1, &data_ac);
+	/* get security xattr */
+	status = ocfs2_init_security_get(inode, dir, &si);
+	if (status) {
+		if (status == -EOPNOTSUPP)
+			si.enable = 0;
+		else {
+			mlog_errno(status);
+			goto bail;
+		}
+	}
+
+	/* calculate meta data/clusters for setting security xattr */
+	if (si.enable) {
+		status = ocfs2_calc_security_init(dir, &si, &want_clusters,
+						  &xattr_credits, &xattr_ac);
 		if (status < 0) {
-			if (status != -ENOSPC)
-				mlog_errno(status);
+			mlog_errno(status);
 			goto bail;
 		}
 	}
 
-	handle = ocfs2_start_trans(osb, credits);
+	/* don't reserve bitmap space for fast symlinks. */
+	if (l > ocfs2_fast_symlink_chars(sb))
+		want_clusters += 1;
+
+	status = ocfs2_reserve_clusters(osb, want_clusters, &data_ac);
+	if (status < 0) {
+		if (status != -ENOSPC)
+			mlog_errno(status);
+		goto bail;
+	}
+
+	handle = ocfs2_start_trans(osb, credits + xattr_credits);
 	if (IS_ERR(handle)) {
 		status = PTR_ERR(handle);
 		handle = NULL;
@@ -1632,6 +1702,15 @@ static int ocfs2_symlink(struct inode *dir,
 		}
 	}
 
+	if (si.enable) {
+		status = ocfs2_init_security_set(handle, inode, new_fe_bh, &si,
+						 xattr_ac, data_ac);
+		if (status < 0) {
+			mlog_errno(status);
+			goto bail;
+		}
+	}
+
 	status = ocfs2_add_entry(handle, dentry, inode,
 				 le64_to_cpu(fe->i_blkno), parent_fe_bh,
 				 de_bh);
@@ -1658,10 +1737,14 @@ bail:
 	brelse(new_fe_bh);
 	brelse(parent_fe_bh);
 	brelse(de_bh);
+	kfree(si.name);
+	kfree(si.value);
 	if (inode_ac)
 		ocfs2_free_alloc_context(inode_ac);
 	if (data_ac)
 		ocfs2_free_alloc_context(data_ac);
+	if (xattr_ac)
+		ocfs2_free_alloc_context(xattr_ac);
 	if ((status < 0) && inode) {
 		clear_nlink(inode);
 		iput(inode);
diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index 9a1dc6a..9688862 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -81,6 +81,9 @@ struct ocfs2_xattr_set_ctxt {
 
 #define OCFS2_XATTR_ROOT_SIZE	(sizeof(struct ocfs2_xattr_def_value_root))
 #define OCFS2_XATTR_INLINE_SIZE	80
+#define OCFS2_XATTR_FREE_IN_IBODY	(OCFS2_MIN_XATTR_INLINE_SIZE \
+					 - sizeof(struct ocfs2_xattr_header) \
+					 - sizeof(__u32))
 
 static struct ocfs2_xattr_def_value_root def_xv = {
 	.xv.xr_list.l_count = cpu_to_le16(1),
@@ -343,6 +346,52 @@ static void ocfs2_xattr_hash_entry(struct inode *inode,
 	return;
 }
 
+static int ocfs2_xattr_entry_real_size(int name_len, size_t value_len)
+{
+	int size = 0;
+
+	if (value_len <= OCFS2_XATTR_INLINE_SIZE)
+		size = OCFS2_XATTR_SIZE(name_len) + OCFS2_XATTR_SIZE(value_len);
+	else
+		size = OCFS2_XATTR_SIZE(name_len) + OCFS2_XATTR_ROOT_SIZE;
+	size += sizeof(struct ocfs2_xattr_entry);
+
+	return size;
+}
+
+int ocfs2_calc_security_init(struct inode *dir,
+			     struct ocfs2_security_xattr_info *si,
+			     int *want_clusters,
+			     int *xattr_credits,
+			     struct ocfs2_alloc_context **xattr_ac)
+{
+	int ret = 0;
+	struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
+	int s_size = ocfs2_xattr_entry_real_size(strlen(si->name),
+						 si->value_len);
+
+	/*
+	 * The max space of security xattr taken inline is
+	 * 256(name) + 80(value) + 16(entry) = 352 bytes,
+	 * So reserve one metadata block for it is ok.
+	 */
+	if (dir->i_sb->s_blocksize == OCFS2_MIN_BLOCKSIZE ||
+	    s_size > OCFS2_XATTR_FREE_IN_IBODY) {
+		ret = ocfs2_reserve_new_metadata_blocks(osb, 1, xattr_ac);
+		if (ret) {
+			mlog_errno(ret);
+			return ret;
+		}
+		*xattr_credits += OCFS2_XATTR_BLOCK_CREATE_CREDITS;
+	}
+
+	/* reserve clusters for xattr value which will be set in B tree*/
+	if (si->value_len > OCFS2_XATTR_INLINE_SIZE)
+		*want_clusters += ocfs2_clusters_for_bytes(dir->i_sb,
+							   si->value_len);
+	return ret;
+}
+
 static int ocfs2_xattr_extend_allocation(struct inode *inode,
 					 u32 clusters_to_add,
 					 struct buffer_head *xattr_bh,
@@ -5022,6 +5071,27 @@ static int ocfs2_xattr_security_set(struct inode *inode, const char *name,
 			       size, flags);
 }
 
+int ocfs2_init_security_get(struct inode *inode,
+			    struct inode *dir,
+			    struct ocfs2_security_xattr_info *si)
+{
+	return security_inode_init_security(inode, dir, &si->name, &si->value,
+					    &si->value_len);
+}
+
+int ocfs2_init_security_set(handle_t *handle,
+			    struct inode *inode,
+			    struct buffer_head *di_bh,
+			    struct ocfs2_security_xattr_info *si,
+			    struct ocfs2_alloc_context *xattr_ac,
+			    struct ocfs2_alloc_context *data_ac)
+{
+	return ocfs2_xattr_set_handle(handle, inode, di_bh,
+				     OCFS2_XATTR_INDEX_SECURITY,
+				     si->name, si->value, si->value_len, 0,
+				     xattr_ac, data_ac);
+}
+
 struct xattr_handler ocfs2_xattr_security_handler = {
 	.prefix	= XATTR_SECURITY_PREFIX,
 	.list	= ocfs2_xattr_security_list,
diff --git a/fs/ocfs2/xattr.h b/fs/ocfs2/xattr.h
index 55c5256..188ef6b 100644
--- a/fs/ocfs2/xattr.h
+++ b/fs/ocfs2/xattr.h
@@ -30,6 +30,13 @@ enum ocfs2_xattr_type {
 	OCFS2_XATTR_MAX
 };
 
+struct ocfs2_security_xattr_info {
+	int enable;
+	char *name;
+	void *value;
+	size_t value_len;
+};
+
 extern struct xattr_handler ocfs2_xattr_user_handler;
 extern struct xattr_handler ocfs2_xattr_trusted_handler;
 extern struct xattr_handler ocfs2_xattr_security_handler;
@@ -43,5 +50,15 @@ int ocfs2_xattr_set_handle(handle_t *, struct inode *, struct buffer_head *,
 			   struct ocfs2_alloc_context *,
 			   struct ocfs2_alloc_context *);
 int ocfs2_xattr_remove(struct inode *, struct buffer_head *);
+int ocfs2_init_security_get(struct inode *, struct inode *,
+			    struct ocfs2_security_xattr_info *);
+int ocfs2_init_security_set(handle_t *, struct inode *,
+			    struct buffer_head *,
+			    struct ocfs2_security_xattr_info *,
+			    struct ocfs2_alloc_context *,
+			    struct ocfs2_alloc_context *);
+int ocfs2_calc_security_init(struct inode *,
+			     struct ocfs2_security_xattr_info *,
+			     int *, int *, struct ocfs2_alloc_context **);
 
 #endif /* OCFS2_XATTR_H */
-- 
1.5.4.1




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