Hi Ryusuke,
This is second version of the patch.
v1->v2
* Change __statfs_word on u64 type.
* Rename nilfs_count_free_inodes() into nilfs_ifile_count_free_inodes() method.
* Introduce auxiliary functions: nilfs_palloc_count_max_entries(), nilfs_palloc_count_desc_blocks(), nilfs_palloc_mdt_file_can_grow().
* Rework processing of returned error from nilfs_ifile_count_free_inodes() in nilfs_statfs().
With the best regards,
Vyacheslav Dubeyko.
---
From: Vyacheslav Dubeyko <slava@xxxxxxxxxxx>
Subject: [PATCH v2] 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 | 85 +++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/nilfs2/alloc.h | 4 +++
fs/nilfs2/ifile.c | 52 ++++++++++++++++++++++++++++++++
fs/nilfs2/ifile.h | 2 ++
fs/nilfs2/mdt.h | 2 ++
fs/nilfs2/super.c | 15 ++++++++--
6 files changed, 158 insertions(+), 2 deletions(-)
diff --git a/fs/nilfs2/alloc.c b/fs/nilfs2/alloc.c
index eed4d7b..519600e 100644
--- a/fs/nilfs2/alloc.c
+++ b/fs/nilfs2/alloc.c
@@ -80,6 +80,13 @@ 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;
}
@@ -398,6 +405,84 @@ nilfs_palloc_rest_groups_in_desc_block(const struct inode *inode,
}
/**
+ * nilfs_palloc_count_max_entries - count max number of entries that can be
+ * described by @desc_blocks
+ * @inode: inode of metadata file using this allocator
+ * @desc_blocks: descriptor blocks count
+ */
+u64 nilfs_palloc_count_max_entries(struct inode *inode,
+ unsigned int desc_blocks)
+{
+ unsigned long ngroups;
+ unsigned long groups_per_desc_block;
+ unsigned long entries_per_group;
+ unsigned long entries_per_desc_block;
+
+ BUG_ON(!inode);
+
+ ngroups = nilfs_palloc_groups_count(inode);
+ groups_per_desc_block = nilfs_palloc_groups_per_desc_block(inode);
+ entries_per_group = nilfs_palloc_entries_per_group(inode);
+ entries_per_desc_block = groups_per_desc_block * entries_per_group;
+
+ return entries_per_desc_block * (u64)desc_blocks;
+}
+
+/**
+ * nilfs_palloc_count_desc_blocks - count descriptor blocks number
+ * @inode: inode of metadata file using this allocator
+ * @start_desc_blks: known current descriptor blocks count
+ */
+unsigned int nilfs_palloc_count_desc_blocks(struct inode *inode,
+ unsigned int start_desc_blks)
+{
+ unsigned long ngroups;
+ unsigned long groups_per_desc_block;
+ struct buffer_head *desc_bh;
+ unsigned long i;
+ unsigned int desc_blocks = start_desc_blks;
+ int err;
+
+ BUG_ON(!inode);
+
+ ngroups = nilfs_palloc_groups_count(inode);
+ groups_per_desc_block = nilfs_palloc_groups_per_desc_block(inode);
+ i = groups_per_desc_block * (unsigned long)desc_blocks;
+
+ for (; i < ngroups; i += groups_per_desc_block) {
+ err = nilfs_palloc_get_desc_block(inode, i, 0, &desc_bh);
+ if (err)
+ break;
+ else
+ desc_blocks++;
+
+ brelse(desc_bh);
+ }
+
+ return desc_blocks;
+}
+
+/**
+ * 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
+ */
+bool nilfs_palloc_mdt_file_can_grow(struct inode *inode,
+ unsigned int desc_blocks)
+{
+ unsigned long ngroups;
+ unsigned long groups_per_desc_block;
+
+ BUG_ON(!inode);
+
+ ngroups = nilfs_palloc_groups_count(inode);
+ groups_per_desc_block = nilfs_palloc_groups_per_desc_block(inode);
+
+ return (groups_per_desc_block * (u64)desc_blocks) < ngroups;
+}
+
+/**
* nilfs_palloc_prepare_alloc_entry - prepare to allocate a persistent object
* @inode: inode of metadata file using this allocator
* @req: nilfs_palloc_req structure exchanged for the allocation
diff --git a/fs/nilfs2/alloc.h b/fs/nilfs2/alloc.h
index fb72381..db1d222 100644
--- a/fs/nilfs2/alloc.h
+++ b/fs/nilfs2/alloc.h
@@ -48,6 +48,10 @@ 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 *);
+u64 nilfs_palloc_count_max_entries(struct inode *, unsigned int);
+unsigned int nilfs_palloc_count_desc_blocks(struct inode *, unsigned int);
+bool nilfs_palloc_mdt_file_can_grow(struct inode *, unsigned int);
+
/**
* nilfs_palloc_req - persistent allocator request and reply
* @pr_entry_nr: entry number (vblocknr or inode number)
diff --git a/fs/nilfs2/ifile.c b/fs/nilfs2/ifile.c
index d8e65bd..fe0e02f 100644
--- a/fs/nilfs2/ifile.c
+++ b/fs/nilfs2/ifile.c
@@ -160,6 +160,58 @@ int nilfs_ifile_get_inode_block(struct inode *ifile, ino_t ino,
}
/**
+ * nilfs_ifile_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_ifile_count_free_inodes(struct nilfs_root *root,
+ u64 *nmaxinodes,
+ u64 *nfreeinodes)
+{
+ struct inode *ifile;
+ unsigned int desc_blocks;
+ u64 nused, nmax;
+
+ BUG_ON(!root || !nfreeinodes || !nmaxinodes);
+
+ ifile = root->ifile;
+ *nmaxinodes = 0;
+ *nfreeinodes = 0;
+
+ nused = atomic_read(&root->inodes_count);
+ desc_blocks =
+ atomic_read(&NILFS_IFILE_I(ifile)->mi.mi_desc_blocks_count);
+ nmax = nilfs_palloc_count_max_entries(ifile, desc_blocks);
+
+ if (nused >= nmax) {
+ desc_blocks =
+ nilfs_palloc_count_desc_blocks(ifile, desc_blocks);
+ nmax = nilfs_palloc_count_max_entries(ifile, desc_blocks);
+
+ if (nused == nmax) {
+ if (nilfs_palloc_mdt_file_can_grow(ifile,
+ desc_blocks)) {
+ nmax =
+ nilfs_palloc_count_max_entries(ifile,
+ ++desc_blocks);
+ }
+ }
+
+ atomic_set(&NILFS_IFILE_I(ifile)->mi.mi_desc_blocks_count,
+ desc_blocks);
+
+ if (nused > nmax)
+ return -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..aee5ab01 100644
--- a/fs/nilfs2/ifile.h
+++ b/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 nilfs_root *, 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);
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..33f427a 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;
+ u64 nmaxinodes, nfreeinodes;
int err;
/*
@@ -633,14 +634,24 @@ static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf)
if (unlikely(err))
return err;
+ err = nilfs_ifile_count_free_inodes(root, &nmaxinodes, &nfreeinodes);
+ if (unlikely(err)) {
+ printk(KERN_WARNING
+ "NILFS warning: fail to count free inodes: err %d.\n",
+ err);
+ err = 0;
+ nmaxinodes = atomic_read(&root->inodes_count);
+ nfreeinodes = 0;
+ }
+
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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