[Ocfs2-devel] [PATCH 1/1] Ocfs2: Add a new code 'OCFS2_INFO_FREEINODE' for o2info ioctl.

[Tristan Ye]

The new code is dedicated to calculate free inodes number of all inode_allocs,
then return the info to userpace in terms of an array.

Specially, flag 'OCFS2_INFO_FL_NON_COHERENT', manipulated by '--cluster-coherent'
from userspace, is now going to be involved. setting the flag on means no cluster
coherency considered, usually, userspace tools choose none-coherency strategy by
default for the sake of performace.

Signed-off-by: Tristan Ye <tristan.ye at oracle.com>
---
 fs/ocfs2/ioctl.c       |  101 ++++++++++++++++++++++++++++++++++++++++++++++++
 fs/ocfs2/ocfs2_ioctl.h |   11 +++++
 2 files changed, 112 insertions(+), 0 deletions(-)

diff --git a/fs/ocfs2/ioctl.c b/fs/ocfs2/ioctl.c
index 7a48681..9fa3a65 100644
--- a/fs/ocfs2/ioctl.c
+++ b/fs/ocfs2/ioctl.c
@@ -23,6 +23,7 @@
 #include "ioctl.h"
 #include "resize.h"
 #include "refcounttree.h"
+#include "sysfile.h"
 
 #include <linux/ext2_fs.h>
 
@@ -299,6 +300,102 @@ bail:
 	return status;
 }
 
+int ocfs2_info_scan_inode_alloc(struct inode *inode_alloc,
+				struct ocfs2_info_freeinode *fi,
+				__u32 slotnum,
+				int flags)
+{
+	int status = 0, unlock = 0;
+
+	struct buffer_head *bh = NULL;
+	struct ocfs2_dinode *dinode_alloc = NULL;
+
+	mutex_lock(&inode_alloc->i_mutex);
+
+	if (!(flags & OCFS2_INFO_FL_NON_COHERENT)) {
+		status = ocfs2_inode_lock(inode_alloc, &bh, 0);
+		if (status < 0) {
+			mlog_errno(status);
+			goto bail_mutex_unlock;
+		}
+		unlock = 1;
+
+	} else {
+
+		status = ocfs2_read_inode_block(inode_alloc, &bh);
+		if (status < 0) {
+			mlog_errno(status);
+			goto bail;
+		}
+	}
+
+	dinode_alloc = (struct ocfs2_dinode *)bh->b_data;
+
+	fi->ir_fi_stat[slotnum].ir_total =
+		le32_to_cpu(dinode_alloc->id1.bitmap1.i_total);
+	fi->ir_fi_stat[slotnum].ir_free =
+		le32_to_cpu(dinode_alloc->id1.bitmap1.i_total) -
+		le32_to_cpu(dinode_alloc->id1.bitmap1.i_used);
+bail:
+	if (unlock)
+		ocfs2_inode_unlock(inode_alloc, 0);
+
+bail_mutex_unlock:
+	mutex_unlock(&inode_alloc->i_mutex);
+
+	iput(inode_alloc);
+	brelse(bh);
+
+	mlog_exit(status);
+	return status;
+}
+
+int ocfs2_info_handle_freeinode(struct inode *inode,
+				struct ocfs2_info_request __user *req)
+{
+	u32 i;
+	int status = -EFAULT;
+	struct ocfs2_info_freeinode oifi;
+	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+	struct inode *inode_alloc = NULL;
+
+	if (o2info_from_user(oifi, req))
+		goto bail;
+
+	oifi.ir_slotnum = osb->max_slots;
+
+	for (i = 0; i < oifi.ir_slotnum; i++) {
+		inode_alloc =
+			ocfs2_get_system_file_inode(osb,
+						    INODE_ALLOC_SYSTEM_INODE,
+						    i);
+		if (!inode_alloc) {
+			mlog(ML_ERROR, "unable to get alloc inode in "
+			     "slot %u\n", i);
+			status = -EIO;
+			goto bail;
+		}
+
+		status = ocfs2_info_scan_inode_alloc(inode_alloc, &oifi, i,
+						     oifi.ir_request.ir_flags);
+		if (status < 0)
+			goto bail;
+	}
+
+	oifi.ir_request.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	if (o2info_to_user(oifi, req))
+		goto bail;
+
+	status = 0;
+bail:
+	if (status)
+		o2info_set_request_error(oifi, req);
+
+	return status;
+}
+
+
 int ocfs2_info_handle_unknown(struct inode *inode,
 			      struct ocfs2_info_request __user *req)
 {
@@ -370,6 +467,10 @@ int ocfs2_info_handle_request(struct inode *inode,
 		if (oir.ir_size == sizeof(struct ocfs2_info_journal_size))
 			status = ocfs2_info_handle_journal_size(inode, req);
 		break;
+	case OCFS2_INFO_FREEINODE:
+		if (oir.ir_size == sizeof(struct ocfs2_info_freeinode))
+			status = ocfs2_info_handle_freeinode(inode, req);
+		break;
 	default:
 		status = ocfs2_info_handle_unknown(inode, req);
 		break;
diff --git a/fs/ocfs2/ocfs2_ioctl.h b/fs/ocfs2/ocfs2_ioctl.h
index b46f39b..ba1a2ce 100644
--- a/fs/ocfs2/ocfs2_ioctl.h
+++ b/fs/ocfs2/ocfs2_ioctl.h
@@ -142,6 +142,16 @@ struct ocfs2_info_journal_size {
 	__u64 ij_journal_size;
 };
 
+struct ocfs2_info_freeinode {
+	struct ocfs2_info_request ir_request;
+	struct ocfs2_info_local_fi {
+		__u64 ir_total;
+		__u64 ir_free;
+	} ir_fi_stat[OCFS2_MAX_SLOTS];
+	__u32 ir_slotnum; /* out */
+	__u32 ir_pad;
+};
+
 /* Codes for ocfs2_info_request */
 enum ocfs2_info_type {
 	OCFS2_INFO_CLUSTERSIZE = 1,
@@ -151,6 +161,7 @@ enum ocfs2_info_type {
 	OCFS2_INFO_UUID,
 	OCFS2_INFO_FS_FEATURES,
 	OCFS2_INFO_JOURNAL_SIZE,
+	OCFS2_INFO_FREEINODE,
 	OCFS2_INFO_NUM_TYPES
 };
 
-- 
1.5.5