From: Vyacheslav Dubeyko <slava@xxxxxxxxxxx>
Subject: [PATCH] nilfs2: implement calculation of free inodes count
Currently, NILFS2 returns 0 as free inodes count (f_ffree) and current used inodes count as total file nodes in file system (f_files):
df -i
Filesystem Inodes IUsed IFree IUse% Mounted on
/dev/loop0 2 2 0 100% /mnt/nilfs2
This patch implements real calculation of free inodes count. First of all, it is calculated total file nodes in file system as (desc_blocks_count * groups_per_desc_block * entries_per_group). Then, it is calculated free inodes count as difference the total file nodes and used inodes count. As a result, we have such output for NILFS2:
df -i
Filesystem Inodes IUsed IFree IUse% Mounted on
/dev/loop0 4194304 2114701 2079603 51% /mnt/nilfs2
Reported-by: Clemens Eisserer <linuxhippy@xxxxxxxxx>
Signed-off-by: Vyacheslav Dubeyko <slava@xxxxxxxxxxx>
CC: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxxxxxx>
Tested-by: Vyacheslav Dubeyko <slava@xxxxxxxxxxx>
---
fs/nilfs2/alloc.c | 36 ++++++++------------------
fs/nilfs2/alloc.h | 24 ++++++++++++++++++
fs/nilfs2/ifile.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/nilfs2/ifile.h | 4 +++
fs/nilfs2/mdt.h | 2 ++
fs/nilfs2/super.c | 9 +++++--
6 files changed, 120 insertions(+), 28 deletions(-)
diff --git a/fs/nilfs2/alloc.c b/fs/nilfs2/alloc.c
index eed4d7b..6c61ae9 100644
--- a/fs/nilfs2/alloc.c
+++ b/fs/nilfs2/alloc.c
@@ -30,29 +30,6 @@
#include "mdt.h"
#include "alloc.h"
-
-/**
- * nilfs_palloc_groups_per_desc_block - get the number of groups that a group
- * descriptor block can maintain
- * @inode: inode of metadata file using this allocator
- */
-static inline unsigned long
-nilfs_palloc_groups_per_desc_block(const struct inode *inode)
-{
- return (1UL << inode->i_blkbits) /
- sizeof(struct nilfs_palloc_group_desc);
-}
-
-/**
- * nilfs_palloc_groups_count - get maximum number of groups
- * @inode: inode of metadata file using this allocator
- */
-static inline unsigned long
-nilfs_palloc_groups_count(const struct inode *inode)
-{
- return 1UL << (BITS_PER_LONG - (inode->i_blkbits + 3 /* log2(8) */));
-}
-
/**
* nilfs_palloc_init_blockgroup - initialize private variables for allocator
* @inode: inode of metadata file using this allocator
@@ -80,6 +57,13 @@ int nilfs_palloc_init_blockgroup(struct inode *inode, unsigned entry_size)
mi->mi_blocks_per_group + 1;
/* Number of blocks per descriptor including the
descriptor block */
+ atomic_set(&mi->mi_desc_blocks_count, 1);
+ /*
+ * The field mi_desc_blocks_count is used for
+ * storing knowledge about current count of
+ * desciptor blocks. Initially, it is initialized
+ * by one.
+ */
return 0;
}
@@ -246,9 +230,9 @@ static int nilfs_palloc_get_block(struct inode *inode, unsigned long blkoff,
* @create: create flag
* @bhp: pointer to store the resultant buffer head
*/
-static int nilfs_palloc_get_desc_block(struct inode *inode,
- unsigned long group,
- int create, struct buffer_head **bhp)
+int nilfs_palloc_get_desc_block(struct inode *inode,
+ unsigned long group,
+ int create, struct buffer_head **bhp)
{
struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
diff --git a/fs/nilfs2/alloc.h b/fs/nilfs2/alloc.h
index fb72381..073b571 100644
--- a/fs/nilfs2/alloc.h
+++ b/fs/nilfs2/alloc.h
@@ -30,6 +30,28 @@
#include <linux/fs.h>
/**
+ * nilfs_palloc_groups_count - get maximum number of groups
+ * @inode: inode of metadata file using this allocator
+ */
+static inline unsigned long
+nilfs_palloc_groups_count(const struct inode *inode)
+{
+ return 1UL << (BITS_PER_LONG - (inode->i_blkbits + 3 /* log2(8) */));
+}
+
+/**
+ * nilfs_palloc_groups_per_desc_block - get the number of groups that a group
+ * descriptor block can maintain
+ * @inode: inode of metadata file using this allocator
+ */
+static inline unsigned long
+nilfs_palloc_groups_per_desc_block(const struct inode *inode)
+{
+ return (1UL << inode->i_blkbits) /
+ sizeof(struct nilfs_palloc_group_desc);
+}
+
+/**
* nilfs_palloc_entries_per_group - get the number of entries per group
* @inode: inode of metadata file using this allocator
*
@@ -45,6 +67,8 @@ nilfs_palloc_entries_per_group(const struct inode *inode)
int nilfs_palloc_init_blockgroup(struct inode *, unsigned);
int nilfs_palloc_get_entry_block(struct inode *, __u64, int,
struct buffer_head **);
+int nilfs_palloc_get_desc_block(struct inode *, unsigned long, int,
+ struct buffer_head **);
void *nilfs_palloc_block_get_entry(const struct inode *, __u64,
const struct buffer_head *, void *);
diff --git a/fs/nilfs2/ifile.c b/fs/nilfs2/ifile.c
index d8e65bd..4f25549 100644
--- a/fs/nilfs2/ifile.c
+++ b/fs/nilfs2/ifile.c
@@ -160,6 +160,79 @@ int nilfs_ifile_get_inode_block(struct inode *ifile, ino_t ino,
}
/**
+ * nilfs_count_free_inodes - calculate free inodes count
+ * @root: root object
+ * @nmaxinodes: current maximum of available inodes count [out]
+ * @nfreeinodes: free inodes count [out]
+ */
+int nilfs_count_free_inodes(struct nilfs_root *root,
+ __statfs_word *nmaxinodes,
+ __statfs_word *nfreeinodes)
+{
+ struct inode *ifile;
+ struct buffer_head *desc_bh;
+ unsigned long groups_per_desc_block, entries_per_group;
+ unsigned long entries_per_desc_block;
+ unsigned long ngroups;
+ unsigned int desc_blocks;
+ __statfs_word nused, nmax;
+ unsigned long i;
+ int err = 0;
+
+ BUG_ON(!root || !nfreeinodes || !nmaxinodes);
+
+ ifile = root->ifile;
+ *nmaxinodes = 0;
+ *nfreeinodes = 0;
+
+ ngroups = nilfs_palloc_groups_count(ifile);
+ groups_per_desc_block = nilfs_palloc_groups_per_desc_block(ifile);
+ entries_per_group = nilfs_palloc_entries_per_group(ifile);
+ nused = atomic_read(&root->inodes_count);
+ entries_per_desc_block = groups_per_desc_block * entries_per_group;
+ desc_blocks =
+ atomic_read(&NILFS_IFILE_I(ifile)->mi.mi_desc_blocks_count);
+ nmax = desc_blocks * entries_per_desc_block;
+
+ if (nused >= nmax) {
+ for (i = groups_per_desc_block * (unsigned long)desc_blocks;
+ i < ngroups;
+ i += groups_per_desc_block) {
+
+ err = nilfs_palloc_get_desc_block(ifile, i, 0,
+ &desc_bh);
+ if (err)
+ break;
+ else
+ desc_blocks++;
+
+ brelse(desc_bh);
+ }
+
+ nmax = entries_per_desc_block * desc_blocks;
+
+ if (nused == nmax) {
+ desc_blocks++;
+ if ((desc_blocks * groups_per_desc_block) < ngroups)
+ nmax += entries_per_desc_block;
+ else
+ desc_blocks--;
+ }
+
+ atomic_set(&NILFS_IFILE_I(ifile)->mi.mi_desc_blocks_count,
+ desc_blocks);
+
+ if (nused > nmax)
+ return err ? err : -ERANGE;
+ }
+
+ *nmaxinodes = nmax;
+ *nfreeinodes = nmax - nused;
+
+ return 0;
+}
+
+/**
* nilfs_ifile_read - read or get ifile inode
* @sb: super block instance
* @root: root object
diff --git a/fs/nilfs2/ifile.h b/fs/nilfs2/ifile.h
index 59b6f2b..57a8564 100644
--- a/fs/nilfs2/ifile.h
+++ b/fs/nilfs2/ifile.h
@@ -27,6 +27,7 @@
#include <linux/fs.h>
#include <linux/buffer_head.h>
+#include <linux/statfs.h>
#include <linux/nilfs2_fs.h>
#include "mdt.h"
#include "alloc.h"
@@ -49,6 +50,9 @@ int nilfs_ifile_create_inode(struct inode *, ino_t *, struct buffer_head **);
int nilfs_ifile_delete_inode(struct inode *, ino_t);
int nilfs_ifile_get_inode_block(struct inode *, ino_t, struct buffer_head **);
+int nilfs_count_free_inodes(struct nilfs_root *,
+ __statfs_word *, __statfs_word *);
+
int nilfs_ifile_read(struct super_block *sb, struct nilfs_root *root,
size_t inode_size, struct nilfs_inode *raw_inode,
struct inode **inodep);
diff --git a/fs/nilfs2/mdt.h b/fs/nilfs2/mdt.h
index ab172e8..c01b6fb 100644
--- a/fs/nilfs2/mdt.h
+++ b/fs/nilfs2/mdt.h
@@ -53,6 +53,7 @@ struct nilfs_shadow_map {
* @mi_shadow: shadow of bmap and page caches
* @mi_blocks_per_group: number of blocks in a group
* @mi_blocks_per_desc_block: number of blocks per descriptor block
+ * @mi_desc_blocks_count: number of descriptor blocks
*/
struct nilfs_mdt_info {
struct rw_semaphore mi_sem;
@@ -64,6 +65,7 @@ struct nilfs_mdt_info {
struct nilfs_shadow_map *mi_shadow;
unsigned long mi_blocks_per_group;
unsigned long mi_blocks_per_desc_block;
+ atomic_t mi_desc_blocks_count;
};
static inline struct nilfs_mdt_info *NILFS_MDT(const struct inode *inode)
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index c7d1f9f..548676b 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -609,6 +609,7 @@ static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
unsigned long overhead;
unsigned long nrsvblocks;
sector_t nfreeblocks;
+ __statfs_word nmaxinodes, nfreeinodes;
int err;
/*
@@ -633,14 +634,18 @@ static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
if (unlikely(err))
return err;
+ err = nilfs_count_free_inodes(root, &nmaxinodes, &nfreeinodes);
+ if (unlikely(err))
+ return err;
+
buf->f_type = NILFS_SUPER_MAGIC;
buf->f_bsize = sb->s_blocksize;
buf->f_blocks = blocks - overhead;
buf->f_bfree = nfreeblocks;
buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?
(buf->f_bfree - nrsvblocks) : 0;
- buf->f_files = atomic_read(&root->inodes_count);
- buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
+ buf->f_files = nmaxinodes;
+ buf->f_ffree = nfreeinodes;
buf->f_namelen = NILFS_NAME_LEN;
buf->f_fsid.val[0] = (u32)id;
buf->f_fsid.val[1] = (u32)(id >> 32);
--
1.7.9.5
--
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