From d24a10b9f8ed548981696cd36e2b4f16e6f360b1 Mon Sep 17 00:00:00 2001 From: Tristan Ye Date: Tue, 24 May 2011 15:27:17 +0800 Subject: Ocfs2: Add a new code 'OCFS2_INFO_FREEFRAG' for o2info ioctl. 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 --- fs/ocfs2/ocfs2_ioctl.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'fs/ocfs2/ocfs2_ioctl.h') diff --git a/fs/ocfs2/ocfs2_ioctl.h b/fs/ocfs2/ocfs2_ioctl.h index 6b4b39a83662..18b6770dc468 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 }; -- cgit v1.2.3-70-g09d2