Browse Source

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@gmail.com>
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Joern Engel <joern@logfs.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
master
Vyacheslav Dubeyko 8 years ago
committed by Linus Torvalds
parent
commit
c7ef972c44
  1. 63
      fs/nilfs2/alloc.c
  2. 2
      fs/nilfs2/alloc.h
  3. 22
      fs/nilfs2/ifile.c
  4. 2
      fs/nilfs2/ifile.h
  5. 25
      fs/nilfs2/super.c

63
fs/nilfs2/alloc.c

@ -397,6 +397,69 @@ nilfs_palloc_rest_groups_in_desc_block(const struct inode *inode,
max - curr + 1);
}
/**
* nilfs_palloc_count_desc_blocks - count descriptor blocks number
* @inode: inode of metadata file using this allocator
* @desc_blocks: descriptor blocks number [out]
*/
static int nilfs_palloc_count_desc_blocks(struct inode *inode,
unsigned long *desc_blocks)
{
unsigned long blknum;
int ret;
ret = nilfs_bmap_last_key(NILFS_I(inode)->i_bmap, &blknum);
if (likely(!ret))
*desc_blocks = DIV_ROUND_UP(
blknum, NILFS_MDT(inode)->mi_blocks_per_desc_block);
return ret;
}
/**
* nilfs_palloc_mdt_file_can_grow - check potential opportunity for
* MDT file growing
* @inode: inode of metadata file using this allocator
* @desc_blocks: known current descriptor blocks count
*/
static inline bool nilfs_palloc_mdt_file_can_grow(struct inode *inode,
unsigned long desc_blocks)
{
return (nilfs_palloc_groups_per_desc_block(inode) * desc_blocks) <
nilfs_palloc_groups_count(inode);
}
/**
* nilfs_palloc_count_max_entries - count max number of entries that can be
* described by descriptor blocks count
* @inode: inode of metadata file using this allocator
* @nused: current number of used entries
* @nmaxp: max number of entries [out]
*/
int nilfs_palloc_count_max_entries(struct inode *inode, u64 nused, u64 *nmaxp)
{
unsigned long desc_blocks = 0;
u64 entries_per_desc_block, nmax;
int err;
err = nilfs_palloc_count_desc_blocks(inode, &desc_blocks);
if (unlikely(err))
return err;
entries_per_desc_block = (u64)nilfs_palloc_entries_per_group(inode) *
nilfs_palloc_groups_per_desc_block(inode);
nmax = entries_per_desc_block * desc_blocks;
if (nused == nmax &&
nilfs_palloc_mdt_file_can_grow(inode, desc_blocks))
nmax += entries_per_desc_block;
if (nused > nmax)
return -ERANGE;
*nmaxp = nmax;
return 0;
}
/**
* nilfs_palloc_prepare_alloc_entry - prepare to allocate a persistent object
* @inode: inode of metadata file using this allocator

2
fs/nilfs2/alloc.h

@ -48,6 +48,8 @@ int nilfs_palloc_get_entry_block(struct inode *, __u64, int,
void *nilfs_palloc_block_get_entry(const struct inode *, __u64,
const struct buffer_head *, void *);
int nilfs_palloc_count_max_entries(struct inode *, u64, u64 *);
/**
* nilfs_palloc_req - persistent allocator request and reply
* @pr_entry_nr: entry number (vblocknr or inode number)

22
fs/nilfs2/ifile.c

@ -159,6 +159,28 @@ int nilfs_ifile_get_inode_block(struct inode *ifile, ino_t ino,
return err;
}
/**
* nilfs_ifile_count_free_inodes - calculate free inodes count
* @ifile: ifile inode
* @nmaxinodes: current maximum of available inodes count [out]
* @nfreeinodes: free inodes count [out]
*/
int nilfs_ifile_count_free_inodes(struct inode *ifile,
u64 *nmaxinodes, u64 *nfreeinodes)
{
u64 nused;
int err;
*nmaxinodes = 0;
*nfreeinodes = 0;
nused = atomic_read(&NILFS_I(ifile)->i_root->inodes_count);
err = nilfs_palloc_count_max_entries(ifile, nused, nmaxinodes);
if (likely(!err))
*nfreeinodes = *nmaxinodes - nused;
return err;
}
/**
* nilfs_ifile_read - read or get ifile inode
* @sb: super block instance

2
fs/nilfs2/ifile.h

@ -49,6 +49,8 @@ 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_ifile_count_free_inodes(struct inode *, u64 *, u64 *);
int nilfs_ifile_read(struct super_block *sb, struct nilfs_root *root,
size_t inode_size, struct nilfs_inode *raw_inode,
struct inode **inodep);

25
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;
u64 nmaxinodes, nfreeinodes;
int err;
/*
@ -633,14 +634,34 @@ static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
if (unlikely(err))
return err;
err = nilfs_ifile_count_free_inodes(root->ifile,
&nmaxinodes, &nfreeinodes);
if (unlikely(err)) {
printk(KERN_WARNING
"NILFS warning: fail to count free inodes: err %d.\n",
err);
if (err == -ERANGE) {
/*
* If nilfs_palloc_count_max_entries() returns
* -ERANGE error code then we simply treat
* curent inodes count as maximum possible and
* zero as free inodes value.
*/
nmaxinodes = atomic_read(&root->inodes_count);
nfreeinodes = 0;
err = 0;
} else
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);

Loading…
Cancel
Save