Ocfs2 devel - Nov 2010 - [PATCH 0/3] Ocfs2: Adding new codes 'OCFS2_INFO_FREEINODE' and 'OCFS2_INFO_FREEFRAG' for o2info ioctl V2.

This set of patch series includes three patches:

1. Using marco to simplize duplicated codes.

2. Adding new code 'OCFS2_INODE_FREEINODE'

3. Adding new code 'OCFS2_INFO_FREEFRAG'

Changes since v1:

1. Incorporate Joel's comments to take cluster coherency into account when
   lookuping the inode/inode_blkno.

2. Using helpers somewhere to improve the readability of codes.



Tristan.

It's a best-effort attempt to simplize duplicated codes here.

Signed-off-by: Tristan Ye <tristan.ye at oracle.com>
---
 fs/ocfs2/ioctl.c |   38 ++++++++++++++++++++++++++++++--------
 1 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/fs/ocfs2/ioctl.c b/fs/ocfs2/ioctl.c
index 7a48681..731cf46 100644
--- a/fs/ocfs2/ioctl.c
+++ b/fs/ocfs2/ioctl.c
@@ -46,6 +46,22 @@ static inline void __o2info_set_request_error(struct
ocfs2_info_request *kreq,
 #define o2info_set_request_error(a, b) \
 		__o2info_set_request_error((struct ocfs2_info_request *)&(a), b)
 
+static inline void __o2info_set_request_filled(struct ocfs2_info_request *req)
+{
+	req->ir_flags |= OCFS2_INFO_FL_FILLED;
+}
+
+#define o2info_set_request_filled(a) \
+		__o2info_set_request_filled((struct ocfs2_info_request *)&(a))
+
+static inline void __o2info_clear_request_filled(struct ocfs2_info_request
*req)
+{
+	req->ir_flags &= ~OCFS2_INFO_FL_FILLED;
+}
+
+#define o2info_clear_request_filled(a) \
+		__o2info_clear_request_filled((struct ocfs2_info_request *)&(a))
+
 static int ocfs2_get_inode_attr(struct inode *inode, unsigned *flags)
 {
 	int status;
@@ -139,7 +155,8 @@ int ocfs2_info_handle_blocksize(struct inode *inode,
 		goto bail;
 
 	oib.ib_blocksize = inode->i_sb->s_blocksize;
-	oib.ib_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	o2info_set_request_filled(oib);
 
 	if (o2info_to_user(oib, req))
 		goto bail;
@@ -163,7 +180,8 @@ int ocfs2_info_handle_clustersize(struct inode *inode,
 		goto bail;
 
 	oic.ic_clustersize = osb->s_clustersize;
-	oic.ic_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	o2info_set_request_filled(oic);
 
 	if (o2info_to_user(oic, req))
 		goto bail;
@@ -187,7 +205,8 @@ int ocfs2_info_handle_maxslots(struct inode *inode,
 		goto bail;
 
 	oim.im_max_slots = osb->max_slots;
-	oim.im_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	o2info_set_request_filled(oim);
 
 	if (o2info_to_user(oim, req))
 		goto bail;
@@ -211,7 +230,8 @@ int ocfs2_info_handle_label(struct inode *inode,
 		goto bail;
 
 	memcpy(oil.il_label, osb->vol_label, OCFS2_MAX_VOL_LABEL_LEN);
-	oil.il_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	o2info_set_request_filled(oil);
 
 	if (o2info_to_user(oil, req))
 		goto bail;
@@ -235,7 +255,8 @@ int ocfs2_info_handle_uuid(struct inode *inode,
 		goto bail;
 
 	memcpy(oiu.iu_uuid_str, osb->uuid_str, OCFS2_TEXT_UUID_LEN + 1);
-	oiu.iu_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	o2info_set_request_filled(oiu);
 
 	if (o2info_to_user(oiu, req))
 		goto bail;
@@ -261,7 +282,8 @@ int ocfs2_info_handle_fs_features(struct inode *inode,
 	oif.if_compat_features = osb->s_feature_compat;
 	oif.if_incompat_features = osb->s_feature_incompat;
 	oif.if_ro_compat_features = osb->s_feature_ro_compat;
-	oif.if_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	o2info_set_request_filled(oif);
 
 	if (o2info_to_user(oif, req))
 		goto bail;
@@ -286,7 +308,7 @@ int ocfs2_info_handle_journal_size(struct inode *inode,
 
 	oij.ij_journal_size = osb->journal->j_inode->i_size;
 
-	oij.ij_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+	o2info_set_request_filled(oij);
 
 	if (o2info_to_user(oij, req))
 		goto bail;
@@ -308,7 +330,7 @@ int ocfs2_info_handle_unknown(struct inode *inode,
 	if (o2info_from_user(oir, req))
 		goto bail;
 
-	oir.ir_flags &= ~OCFS2_INFO_FL_FILLED;
+	o2info_clear_request_filled(oir);
 
 	if (o2info_to_user(oir, req))
 		goto bail;
-- 
1.5.5

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       |  122 ++++++++++++++++++++++++++++++++++++++++++++++++
 fs/ocfs2/ocfs2_ioctl.h |   11 ++++
 2 files changed, 133 insertions(+), 0 deletions(-)

diff --git a/fs/ocfs2/ioctl.c b/fs/ocfs2/ioctl.c
index 731cf46..18812be 100644
--- a/fs/ocfs2/ioctl.c
+++ b/fs/ocfs2/ioctl.c
@@ -23,6 +23,9 @@
 #include "ioctl.h"
 #include "resize.h"
 #include "refcounttree.h"
+#include "sysfile.h"
+#include "dir.h"
+#include "buffer_head_io.h"
 
 #include <linux/ext2_fs.h>
 
@@ -62,6 +65,13 @@ static inline void __o2info_clear_request_filled(struct
ocfs2_info_request *req)
 #define o2info_clear_request_filled(a) \
 		__o2info_clear_request_filled((struct ocfs2_info_request *)&(a))
 
+static inline int __o2info_coherent(struct ocfs2_info_request *req)
+{
+	return (!(req->ir_flags & OCFS2_INFO_FL_NON_COHERENT));
+}
+
+#define o2info_coherent(a) __o2info_coherent((struct ocfs2_info_request
*)&(a))
+
 static int ocfs2_get_inode_attr(struct inode *inode, unsigned *flags)
 {
 	int status;
@@ -321,6 +331,114 @@ bail:
 	return status;
 }
 
+int ocfs2_info_scan_inode_alloc(struct ocfs2_super *osb,
+				struct inode *inode_alloc, u64 blkno,
+				struct ocfs2_info_freeinode *fi, u32 slot)
+{
+	int status = 0, unlock = 0;
+
+	struct buffer_head *bh = NULL;
+	struct ocfs2_dinode *dinode_alloc = NULL;
+
+	if (inode_alloc)
+		mutex_lock(&inode_alloc->i_mutex);
+
+	if (o2info_coherent(*fi)) {
+		status = ocfs2_inode_lock(inode_alloc, &bh, 0);
+		if (status < 0) {
+			mlog_errno(status);
+			goto bail;
+		}
+		unlock = 1;
+	} else {
+		status = ocfs2_read_blocks_sync(osb, blkno, 1, &bh);
+		if (status < 0) {
+			mlog_errno(status);
+			goto bail;
+		}
+	}
+
+	dinode_alloc = (struct ocfs2_dinode *)bh->b_data;
+
+	fi->ifi_stat[slot].lfi_total +	
le32_to_cpu(dinode_alloc->id1.bitmap1.i_total);
+	fi->ifi_stat[slot].lfi_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);
+
+	if (inode_alloc)
+		mutex_unlock(&inode_alloc->i_mutex);
+
+	if (inode_alloc)
+		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;
+	u64 blkno = -1;
+	char namebuf[40];
+	int status = -EFAULT, type = INODE_ALLOC_SYSTEM_INODE;
+	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.ifi_slotnum = osb->max_slots;
+
+	for (i = 0; i < oifi.ifi_slotnum; i++) {
+		if (o2info_coherent(oifi)) {
+			inode_alloc = ocfs2_get_system_file_inode(osb, type, i);
+			if (!inode_alloc) {
+				mlog(ML_ERROR, "unable to get alloc inode in "
+				    "slot %u\n", i);
+				status = -EIO;
+				goto bail;
+			}
+		} else {
+			ocfs2_sprintf_system_inode_name(namebuf,
+							sizeof(namebuf),
+							type, i);
+			status = ocfs2_lookup_ino_from_name(osb->sys_root_inode,
+							    namebuf,
+							    strlen(namebuf),
+							    &blkno);
+			if (status < 0) {
+				status = -ENOENT;
+				goto bail;
+			}
+		}
+
+		status = ocfs2_info_scan_inode_alloc(osb, inode_alloc, blkno, &oifi, i);
+		if (status < 0)
+			goto bail;
+	}
+
+	o2info_set_request_filled(oifi);
+
+	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)
 {
@@ -392,6 +510,10 @@ 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..6b4b39a 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 ifi_req;
+	struct ocfs2_info_local_freeinode {
+		__u64 lfi_total;
+		__u64 lfi_free;
+	} ifi_stat[OCFS2_MAX_SLOTS];
+	__u32 ifi_slotnum; /* out */
+	__u32 ifi_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

This new code is a bit more complicated than former ones, the goal is to
show user all statistics required to take a deep insight into filesystem
on how the disk is being fragmentaed.

The goal is achieved by scaning global bitmap from (cluster)group to group
to figure out following factors in the filesystem:

        - How many free chunks in a fixed size as user requested.
        - How many real free chunks in all size.
        - Min/Max/Avg size(in) clusters of free chunks.
        - How do free chunks distribute(in size) in terms of a histogram,
          just like following:
          ---------------------------------------------------------
          Extent Size Range :  Free extents  Free Clusters  Percent
             32K...   64K-  :             1             1    0.00%
              1M...    2M-  :             9           288    0.03%
              8M...   16M-  :             2           831    0.09%
             32M...   64M-  :             1          2047    0.23%
            128M...  256M-  :             1          8191    0.92%
            256M...  512M-  :             2         21706    2.43%
            512M... 1024M-  :            27        858623   96.29%
          ---------------------------------------------------------

Userspace ioctl() call eventually gets the above info returned by passing
a 'struct ocfs2_info_freefrag' with the chunk_size being specified
first.

Signed-off-by: Tristan Ye <tristan.ye at oracle.com>
---
 fs/ocfs2/ioctl.c       |  283 ++++++++++++++++++++++++++++++++++++++++++++++++
 fs/ocfs2/ocfs2_ioctl.h |   23 ++++
 2 files changed, 306 insertions(+), 0 deletions(-)

diff --git a/fs/ocfs2/ioctl.c b/fs/ocfs2/ioctl.c
index 18812be..c796860 100644
--- a/fs/ocfs2/ioctl.c
+++ b/fs/ocfs2/ioctl.c
@@ -26,6 +26,7 @@
 #include "sysfile.h"
 #include "dir.h"
 #include "buffer_head_io.h"
+#include "suballoc.h"
 
 #include <linux/ext2_fs.h>
 
@@ -439,6 +440,284 @@ bail:
 	return status;
 }
 
+static void o2ffg_update_histogram(struct ocfs2_info_free_chunk_list *hist,
+				   unsigned int chunksize)
+{
+	int index;
+
+	index = __ilog2_u32(chunksize);
+	if (index >= OCFS2_INFO_MAX_HIST)
+		index = OCFS2_INFO_MAX_HIST - 1;
+
+	hist->fc_chunks[index]++;
+	hist->fc_clusters[index] += chunksize;
+}
+
+static void o2ffg_update_stats(struct ocfs2_info_freefrag_stats *stats,
+			       unsigned int chunksize)
+{
+	if (chunksize > stats->ffs_max)
+		stats->ffs_max = chunksize;
+
+	if (chunksize < stats->ffs_min)
+		stats->ffs_min = chunksize;
+
+	stats->ffs_avg += chunksize;
+	stats->ffs_free_chunks_real++;
+}
+
+void ocfs2_info_update_ffg(struct ocfs2_info_freefrag *ffg,
+			   unsigned int chunksize)
+{
+	o2ffg_update_histogram(&(ffg->iff_ffs.ffs_fc_hist), chunksize);
+	o2ffg_update_stats(&(ffg->iff_ffs), chunksize);
+}
+
+int ocfs2_info_freefrag_scan_chain(struct ocfs2_super *osb,
+				   struct inode *gb_inode,
+				   struct ocfs2_dinode *gb_dinode,
+				   struct ocfs2_chain_rec *rec,
+				   struct ocfs2_info_freefrag *ffg,
+				   u32 chunks_in_group)
+{
+	int status = 0, used;
+	u64 blkno;
+
+	struct buffer_head *bh = NULL;
+	struct ocfs2_group_desc *bg = NULL;
+
+	unsigned int max_bits, num_clusters;
+	unsigned int offset = 0, cluster, chunk;
+	unsigned int chunk_free, last_chunksize = 0;
+
+	if (!le32_to_cpu(rec->c_free))
+		goto bail;
+
+	do {
+		if (!bg)
+			blkno = le64_to_cpu(rec->c_blkno);
+		else
+			blkno = le64_to_cpu(bg->bg_next_group);
+
+		if (bh) {
+			brelse(bh);
+			bh = NULL;
+		}
+
+		if (o2info_coherent(*ffg))
+			status = ocfs2_read_group_descriptor(gb_inode,
+							     gb_dinode,
+							     blkno, &bh);
+		else
+			status = ocfs2_read_blocks_sync(osb, blkno, 1, &bh);
+
+		if (status < 0) {
+			mlog(ML_ERROR, "Can't read the group descriptor # "
+			     "%llu from device.", (unsigned long long)blkno);
+			status = -EIO;
+			goto bail;
+		}
+
+		bg = (struct ocfs2_group_desc *)bh->b_data;
+
+		if (!le16_to_cpu(bg->bg_free_bits_count))
+			continue;
+
+		max_bits = le16_to_cpu(bg->bg_bits);
+		offset = 0;
+
+		for (chunk = 0; chunk < chunks_in_group; chunk++) {
+			/*
+			 * last chunk may be not an entire one.
+			 */
+			if ((offset + ffg->iff_chunksize) > max_bits)
+				num_clusters = max_bits - offset;
+			else
+				num_clusters = ffg->iff_chunksize;
+
+			chunk_free = 0;
+			for (cluster = 0; cluster < num_clusters; cluster++) {
+				used = ocfs2_test_bit(offset,
+						(unsigned long *)bg->bg_bitmap);
+				/*
+				 * - chunk_free counts free clusters in #N chunk.
+				 * - last_chunksize records the size(in) clusters
+				 *   for the last real free chunk being counted.
+				 */
+				if (!used) {
+					last_chunksize++;
+					chunk_free++;
+				}
+
+				if (used && last_chunksize) {
+					ocfs2_info_update_ffg(ffg,
+							      last_chunksize);
+					last_chunksize = 0;
+				}
+
+				offset++;
+			}
+
+			if (chunk_free == ffg->iff_chunksize)
+				ffg->iff_ffs.ffs_free_chunks++;
+		}
+
+		/*
+		 * need to update the info for last free chunk.
+		 */
+		if (last_chunksize)
+			ocfs2_info_update_ffg(ffg, last_chunksize);
+
+	} while (le64_to_cpu(bg->bg_next_group));
+
+bail:
+	brelse(bh);
+
+	mlog_exit(status);
+	return status;
+}
+
+int ocfs2_info_freefrag_scan_bitmap(struct ocfs2_super *osb,
+				    struct inode *gb_inode, u64 blkno,
+				    struct ocfs2_info_freefrag *ffg)
+{
+	u32 chunks_in_group;
+	int status = 0, unlock = 0, i;
+
+	struct buffer_head *bh = NULL;
+	struct ocfs2_chain_list *cl = NULL;
+	struct ocfs2_chain_rec *rec = NULL;
+	struct ocfs2_dinode *gb_dinode = NULL;
+
+	if (gb_inode)
+		mutex_lock(&gb_inode->i_mutex);
+
+	if (o2info_coherent(*ffg)) {
+		status = ocfs2_inode_lock(gb_inode, &bh, 0);
+		if (status < 0) {
+			mlog_errno(status);
+			goto bail;
+		}
+		unlock = 1;
+	} else {
+		status = ocfs2_read_blocks_sync(osb, blkno, 1, &bh);
+		if (status < 0) {
+			mlog_errno(status);
+			goto bail;
+		}
+	}
+
+	gb_dinode = (struct ocfs2_dinode *)bh->b_data;
+	cl = &(gb_dinode->id2.i_chain);
+
+	/* 
+	 * Chunksize(in) clusters from userspace should be
+	 * less than clusters in a group.
+	 */
+	if (ffg->iff_chunksize > le16_to_cpu(cl->cl_cpg)) {
+		status = -EINVAL;
+		goto bail;
+	}
+
+	memset(&ffg->iff_ffs, 0, sizeof(struct ocfs2_info_freefrag_stats));
+
+	ffg->iff_ffs.ffs_min = ~0U;
+	ffg->iff_ffs.ffs_clusters +		
le32_to_cpu(gb_dinode->id1.bitmap1.i_total);
+	ffg->iff_ffs.ffs_free_clusters = ffg->iff_ffs.ffs_clusters -
+			le32_to_cpu(gb_dinode->id1.bitmap1.i_used);
+
+	chunks_in_group = le16_to_cpu(cl->cl_cpg) / ffg->iff_chunksize + 1;
+
+	for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i++) {
+		rec = &(cl->cl_recs[i]);
+		status = ocfs2_info_freefrag_scan_chain(osb, gb_inode,
+							gb_dinode,
+							rec, ffg,
+							chunks_in_group);
+		if (status)
+			goto bail;
+	}
+
+	if (ffg->iff_ffs.ffs_free_chunks_real)
+		ffg->iff_ffs.ffs_avg = (ffg->iff_ffs.ffs_avg /
+					ffg->iff_ffs.ffs_free_chunks_real);
+bail:
+	if (unlock)
+		ocfs2_inode_unlock(gb_inode, 0);
+
+	if (gb_inode)
+		mutex_unlock(&gb_inode->i_mutex);
+
+	if (gb_inode)
+		iput(gb_inode);
+
+	brelse(bh);
+
+	mlog_exit(status);
+	return status;
+}
+
+int ocfs2_info_handle_freefrag(struct inode *inode,
+			       struct ocfs2_info_request __user *req)
+{
+	u64 blkno = -1;
+	char namebuf[40];
+	int status = -EFAULT, type = GLOBAL_BITMAP_SYSTEM_INODE;
+
+	struct ocfs2_info_freefrag oiff;
+	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+	struct inode *gb_inode = NULL;
+
+	if (o2info_from_user(oiff, req))
+		goto bail;
+	/*
+	 * chunksize from userspace should be power of 2.
+	 */
+	if ((oiff.iff_chunksize & (oiff.iff_chunksize - 1)) ||
+	    (!oiff.iff_chunksize)) {
+		status = -EINVAL;
+		goto bail;
+	}
+
+	if (o2info_coherent(oiff)) {
+		gb_inode = ocfs2_get_system_file_inode(osb, type,
+						       OCFS2_INVALID_SLOT);
+		if (!gb_inode) {
+			mlog(ML_ERROR, "unable to get global_bitmap inode\n");
+			status = -EIO;
+			goto bail;
+		}
+	} else {
+		ocfs2_sprintf_system_inode_name(namebuf, sizeof(namebuf), type,
+						OCFS2_INVALID_SLOT);
+		status = ocfs2_lookup_ino_from_name(osb->sys_root_inode,
+						    namebuf,
+						    strlen(namebuf),
+						    &blkno);
+		if (status < 0) {
+			status = -ENOENT;
+			goto bail;
+		}
+	}
+
+	status = ocfs2_info_freefrag_scan_bitmap(osb, gb_inode, blkno, &oiff);
+	if (status < 0)
+		goto bail;
+
+	o2info_set_request_filled(oiff);
+
+	if (o2info_to_user(oiff, req))
+		goto bail;
+
+	status = 0;
+bail:
+	if (status)
+		o2info_set_request_error(oiff, req);
+
+	return status;
+}
+
 int ocfs2_info_handle_unknown(struct inode *inode,
 			      struct ocfs2_info_request __user *req)
 {
@@ -514,6 +793,10 @@ int ocfs2_info_handle_request(struct inode *inode,
 		if (oir.ir_size == sizeof(struct ocfs2_info_freeinode))
 			status = ocfs2_info_handle_freeinode(inode, req);
 		break;
+	case OCFS2_INFO_FREEFRAG:
+		if (oir.ir_size == sizeof(struct ocfs2_info_freefrag))
+			status = ocfs2_info_handle_freefrag(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 6b4b39a..18b6770 100644
--- a/fs/ocfs2/ocfs2_ioctl.h
+++ b/fs/ocfs2/ocfs2_ioctl.h
@@ -152,6 +152,28 @@ struct ocfs2_info_freeinode {
 	__u32 ifi_pad;
 };
 
+#define OCFS2_INFO_MAX_HIST     (32)
+
+struct ocfs2_info_freefrag {
+	struct ocfs2_info_request iff_req;
+	struct ocfs2_info_freefrag_stats { /* (out) */
+		struct ocfs2_info_free_chunk_list {
+			__u32 fc_chunks[OCFS2_INFO_MAX_HIST];
+			__u32 fc_clusters[OCFS2_INFO_MAX_HIST];
+		} ffs_fc_hist;
+		__u32 ffs_clusters;
+		__u32 ffs_free_clusters;
+		__u32 ffs_free_chunks;
+		__u32 ffs_free_chunks_real;
+		__u32 ffs_min; /* Minimum free chunksize in clusters */
+		__u32 ffs_max;
+		__u32 ffs_avg;
+		__u32 ffs_pad;
+	} iff_ffs;
+	__u32 iff_chunksize; /* chunksize in clusters(in) */
+	__u32 iff_pad;
+};
+
 /* Codes for ocfs2_info_request */
 enum ocfs2_info_type {
 	OCFS2_INFO_CLUSTERSIZE = 1,
@@ -162,6 +184,7 @@ enum ocfs2_info_type {
 	OCFS2_INFO_FS_FEATURES,
 	OCFS2_INFO_JOURNAL_SIZE,
 	OCFS2_INFO_FREEINODE,
+	OCFS2_INFO_FREEFRAG,
 	OCFS2_INFO_NUM_TYPES
 };
 
-- 
1.5.5

On Tue, Nov 16, 2010 at 06:13:40PM +0800, Tristan Ye
wrote:
> @@ -139,7 +155,8 @@ int ocfs2_info_handle_blocksize(struct inode *inode,
>  		goto bail;
>  
>  	oib.ib_blocksize = inode->i_sb->s_blocksize;
> -	oib.ib_req.ir_flags |= OCFS2_INFO_FL_FILLED;
> +
> +	o2info_set_request_filled(oib);
	There's no need to add the extra line of whitespace for all of
these.  They're quite readable.

Joel

-- 

To spot the expert, pick the one who predicts the job will take the
longest and cost the most.

Joel Becker
Senior Development Manager
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127

On Tue, Nov 16, 2010 at 06:13:41PM +0800, Tristan Ye
wrote:
> +	if (inode_alloc)
> +		iput(inode_alloc);
	Do the iput up in the calling function where it matches the
get_system_file_inode() call.  This just makes it easier to spot the
get/put pair.

Joel

-- 

"Under capitalism, man exploits man.  Under Communism, it's just 
   the opposite."
				 - John Kenneth Galbraith

Joel Becker
Senior Development Manager
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127

On Tue, Nov 16, 2010 at 06:13:42PM +0800, Tristan Ye
wrote:
> +static void o2ffg_update_histogram(struct ocfs2_info_free_chunk_list
*hist,
> +				   unsigned int chunksize)
> +{
> +	int index;
> +
> +	index = __ilog2_u32(chunksize);
> +	if (index >= OCFS2_INFO_MAX_HIST)
> +		index = OCFS2_INFO_MAX_HIST - 1;
> +
> +	hist->fc_chunks[index]++;
> +	hist->fc_clusters[index] += chunksize;
> +}
> +
> +static void o2ffg_update_stats(struct ocfs2_info_freefrag_stats *stats,
> +			       unsigned int chunksize)
> +{
> +	if (chunksize > stats->ffs_max)
> +		stats->ffs_max = chunksize;
> +
> +	if (chunksize < stats->ffs_min)
> +		stats->ffs_min = chunksize;
> +
> +	stats->ffs_avg += chunksize;
> +	stats->ffs_free_chunks_real++;
> +}
	MUCH more readable.
> +int ocfs2_info_freefrag_scan_bitmap(struct ocfs2_super *osb,
> +				    struct inode *gb_inode, u64 blkno,
> +				    struct ocfs2_info_freefrag *ffg)
> +{
> +	u32 chunks_in_group;
> +	int status = 0, unlock = 0, i;
> +
> +	struct buffer_head *bh = NULL;
> +	struct ocfs2_chain_list *cl = NULL;
> +	struct ocfs2_chain_rec *rec = NULL;
> +	struct ocfs2_dinode *gb_dinode = NULL;
> +
> +	if (gb_inode)
> +		mutex_lock(&gb_inode->i_mutex);
> +
> +	if (o2info_coherent(*ffg)) {
> +		status = ocfs2_inode_lock(gb_inode, &bh, 0);
> +		if (status < 0) {
> +			mlog_errno(status);
> +			goto bail;
> +		}
> +		unlock = 1;
> +	} else {
> +		status = ocfs2_read_blocks_sync(osb, blkno, 1, &bh);
> +		if (status < 0) {
> +			mlog_errno(status);
> +			goto bail;
> +		}
> +	}
> +
> +	gb_dinode = (struct ocfs2_dinode *)bh->b_data;
> +	cl = &(gb_dinode->id2.i_chain);
	This is safe because we never remove a chain entry from an
inode.  However, if we ever shrink disks, we'll need to coordinate with
this code.  Perhaps we should comment that.

Joel

-- 

"Also, all of life's big problems include the words
'indictment' or
	'inoperable.' Everything else is small stuff."
	- Alton Brown

Joel Becker
Senior Development Manager
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127