[PATCH] knfsd: nfsd4: reboot recovery

This patch adds the code to create and remove client subdirectories from the
recovery directory, as described in the previous patch comment.

Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 190 insertions, 0 deletions

diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index 2dc9851a1d37..2805c5245eac 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -120,6 +120,70 @@ out:
         return status;
 }
 
+static int
+nfsd4_rec_fsync(struct dentry *dentry)
+{
+        struct file *filp;
+        int status = nfs_ok;
+
+        dprintk("NFSD: nfs4_fsync_rec_dir\n");
+        filp = dentry_open(dget(dentry), mntget(rec_dir.mnt), O_RDWR);
+        if (IS_ERR(filp)) {
+                status = PTR_ERR(filp);
+                goto out;
+        }
+        if (filp->f_op && filp->f_op->fsync)
+                status = filp->f_op->fsync(filp, filp->f_dentry, 0);
+        fput(filp);
+out:
+        if (status)
+                printk("nfsd4: unable to sync recovery directory\n");
+        return status;
+}
+
+int
+nfsd4_create_clid_dir(struct nfs4_client *clp)
+{
+        char *dname = clp->cl_recdir;
+        struct dentry *dentry;
+        uid_t uid;
+        gid_t gid;
+        int status;
+
+        dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname);
+
+        if (!rec_dir_init || clp->cl_firststate)
+                return 0;
+
+        nfs4_save_user(&uid, &gid);
+
+        /* lock the parent */
+        down(&rec_dir.dentry->d_inode->i_sem);
+
+        dentry = lookup_one_len(dname, rec_dir.dentry, HEXDIR_LEN-1);
+        if (IS_ERR(dentry)) {
+                status = PTR_ERR(dentry);
+                goto out_unlock;
+        }
+        status = -EEXIST;
+        if (dentry->d_inode) {
+                dprintk("NFSD: nfsd4_create_clid_dir: DIRECTORY EXISTS\n");
+                goto out_put;
+        }
+        status = vfs_mkdir(rec_dir.dentry->d_inode, dentry, S_IRWXU);
+out_put:
+        dput(dentry);
+out_unlock:
+        up(&rec_dir.dentry->d_inode->i_sem);
+        if (status == 0) {
+                clp->cl_firststate = 1;
+                status = nfsd4_rec_fsync(rec_dir.dentry);
+        }
+        nfs4_reset_user(uid, gid);
+        dprintk("NFSD: nfsd4_create_clid_dir returns %d\n", status);
+        return status;
+}
+
 typedef int (recdir_func)(struct dentry *, struct dentry *);
 
 struct dentry_list {
@@ -202,6 +266,111 @@ out:
 }
 
 static int
+nfsd4_remove_clid_file(struct dentry *dir, struct dentry *dentry)
+{
+        int status;
+
+        if (!S_ISREG(dir->d_inode->i_mode)) {
+                printk("nfsd4: non-file found in client recovery directory\n");
+                return -EINVAL;
+        }
+        down(&dir->d_inode->i_sem);
+        status = vfs_unlink(dir->d_inode, dentry);
+        up(&dir->d_inode->i_sem);
+        return status;
+}
+
+static int
+nfsd4_clear_clid_dir(struct dentry *dir, struct dentry *dentry)
+{
+        int status;
+
+        /* For now this directory should already be empty, but we empty it of
+         * any regular files anyway, just in case the directory was created by
+         * a kernel from the future.... */
+        nfsd4_list_rec_dir(dentry, nfsd4_remove_clid_file);
+        down(&dir->d_inode->i_sem);
+        status = vfs_rmdir(dir->d_inode, dentry);
+        up(&dir->d_inode->i_sem);
+        return status;
+}
+
+static int
+nfsd4_unlink_clid_dir(char *name, int namlen)
+{
+        struct dentry *dentry;
+        int status;
+
+        dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name);
+
+        dentry = lookup_one_len(name, rec_dir.dentry, namlen);
+        if (IS_ERR(dentry)) {
+                status = PTR_ERR(dentry);
+                return status;
+        }
+        status = -ENOENT;
+        if (!dentry->d_inode)
+                goto out;
+
+        status = nfsd4_clear_clid_dir(rec_dir.dentry, dentry);
+out:
+        dput(dentry);
+        return status;
+}
+
+void
+nfsd4_remove_clid_dir(struct nfs4_client *clp)
+{
+        uid_t uid;
+        gid_t gid;
+        int status;
+
+        if (!rec_dir_init || !clp->cl_firststate)
+                return;
+
+        nfs4_save_user(&uid, &gid);
+        status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1);
+        nfs4_reset_user(uid, gid);
+        if (status == 0)
+                status = nfsd4_rec_fsync(rec_dir.dentry);
+        if (status)
+                printk("NFSD: Failed to remove expired client state directory"
+                                " %.*s\n", HEXDIR_LEN, clp->cl_recdir);
+        return;
+}
+
+static int
+purge_old(struct dentry *parent, struct dentry *child)
+{
+        int status;
+
+        if (nfs4_has_reclaimed_state(child->d_name.name))
+                return nfs_ok;
+
+        status = nfsd4_clear_clid_dir(parent, child);
+        if (status)
+                printk("failed to remove client recovery directory %s\n",
+                                child->d_name.name);
+        /* Keep trying, success or failure: */
+        return nfs_ok;
+}
+
+void
+nfsd4_recdir_purge_old(void) {
+        int status;
+
+        if (!rec_dir_init)
+                return;
+        status = nfsd4_list_rec_dir(rec_dir.dentry, purge_old);
+        if (status == 0)
+                status = nfsd4_rec_fsync(rec_dir.dentry);
+        if (status)
+                printk("nfsd4: failed to purge old clients from recovery"
+                        " directory %s\n", rec_dir.dentry->d_name.name);
+        return;
+}
+
+static int
 load_recdir(struct dentry *parent, struct dentry *child)
 {
         if (child->d_name.len != HEXDIR_LEN - 1) {
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 6b9d23c39afe..6cca358cd650 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -905,6 +905,7 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp, struct nfsd4_setclientid_confi
                         conf = find_confirmed_client_by_str(unconf->cl_recdir,
                                                                         hash);
                         if (conf) {
+                                nfsd4_remove_clid_dir(conf);
                                 expire_client(conf);
                         }
                         move_to_confirmed(unconf);
@@ -1691,6 +1692,7 @@ nfs4_set_claim_prev(struct nfsd4_open *open, int *status)
                         *status = nfserr_reclaim_bad;
                 else {
                         open->op_stateowner->so_confirmed = 1;
+                        open->op_stateowner->so_client->cl_firststate = 1;
                         open->op_stateowner->so_seqid--;
                 }
         }
@@ -1903,6 +1905,7 @@ static void
 end_grace(void)
 {
         dprintk("NFSD: end of grace period\n");
+        nfsd4_recdir_purge_old();
         in_grace = 0;
 }
 
@@ -1932,6 +1935,7 @@ nfs4_laundromat(void)
                 }
                 dprintk("NFSD: purging unused client (clientid %08x)\n",
                         clp->cl_clientid.cl_id);
+                nfsd4_remove_clid_dir(clp);
                 expire_client(clp);
         }
         INIT_LIST_HEAD(&reaplist);
@@ -2320,6 +2324,8 @@ nfsd4_open_confirm(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfs
                          stp->st_stateid.si_stateownerid,
                          stp->st_stateid.si_fileid,
                          stp->st_stateid.si_generation);
+
+        nfsd4_create_clid_dir(sop->so_client);
 out:
         if (oc->oc_stateowner)
                 nfs4_get_stateowner(oc->oc_stateowner);
@@ -3089,6 +3095,16 @@ alloc_reclaim(void)
         return kmalloc(sizeof(struct nfs4_client_reclaim), GFP_KERNEL);
 }
 
+int
+nfs4_has_reclaimed_state(const char *name)
+{
+        unsigned int strhashval = clientstr_hashval(name);
+        struct nfs4_client *clp;
+
+        clp = find_confirmed_client_by_str(name, strhashval);
+        return clp ? 1 : 0;
+}
+
 /*
  * failure => all reset bets are off, nfserr_no_grace...
  */
diff --git a/include/linux/nfsd/state.h b/include/linux/nfsd/state.h
index 19481ab122df..a84a3fa99be1 100644
--- a/include/linux/nfsd/state.h
+++ b/include/linux/nfsd/state.h
@@ -131,6 +131,7 @@ struct nfs4_client {
         nfs4_verifier           cl_confirm;     /* generated by server */
         struct nfs4_callback    cl_callback;    /* callback info */
         atomic_t                cl_count;       /* ref count */
+        u32                     cl_firststate;  /* recovery dir creation */
 };
 
 /* struct nfs4_client_reset
@@ -282,6 +283,10 @@ extern void nfsd4_init_recdir(char *recdir_name);
 extern int nfsd4_recdir_load(void);
 extern void nfsd4_shutdown_recdir(void);
 extern int nfs4_client_to_reclaim(const char *name);
+extern int nfs4_has_reclaimed_state(const char *name);
+extern void nfsd4_recdir_purge_old(void);
+extern int nfsd4_create_clid_dir(struct nfs4_client *clp);
+extern void nfsd4_remove_clid_dir(struct nfs4_client *clp);
 
 static inline void
 nfs4_put_stateowner(struct nfs4_stateowner *so)