lockd: unlock lockd locks held for a certain filesystem
Add /proc/fs/nfsd/unlock_filesystem, which allows e.g.:
shell> echo /mnt/sfs1 > /proc/fs/nfsd/unlock_filesystem
so that a filesystem can be unmounted before allowing a peer nfsd to
take over nfs service for the filesystem.
Signed-off-by: S. Wendy Cheng <wcheng@redhat.com>
Cc: Lon Hohberger <lhh@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
fs/lockd/svcsubs.c | 66 +++++++++++++++++++++++++++++++++++++++-----
fs/nfsd/nfsctl.c | 65 +++++++++++++++++++++++++++++++++++++++++++
include/linux/lockd/lockd.h | 7 ++++
3 files changed, 131 insertions(+), 7 deletions(-)
diff --git a/fs/lockd/svcsubs.c b/fs/lockd/svcsubs.c
index 1adcf93..d1c48b5 100644
--- a/fs/lockd/svcsubs.c
+++ b/fs/lockd/svcsubs.c
@@ -196,6 +196,12 @@
return 0;
}
+static int
+nlmsvc_always_match(void *dummy1, struct nlm_host *dummy2)
+{
+ return 1;
+}
+
/*
* Inspect a single file
*/
@@ -232,7 +238,8 @@
* Loop over all files in the file table.
*/
static int
-nlm_traverse_files(void *data, nlm_host_match_fn_t match)
+nlm_traverse_files(void *data, nlm_host_match_fn_t match,
+ int (*is_failover_file)(void *data, struct nlm_file *file))
{
struct hlist_node *pos, *next;
struct nlm_file *file;
@@ -241,6 +248,8 @@
mutex_lock(&nlm_file_mutex);
for (i = 0; i < FILE_NRHASH; i++) {
hlist_for_each_entry_safe(file, pos, next, &nlm_files[i], f_list) {
+ if (is_failover_file && !is_failover_file(data, file))
+ continue;
file->f_count++;
mutex_unlock(&nlm_file_mutex);
@@ -345,7 +354,7 @@
nlmsvc_mark_resources(void)
{
dprintk("lockd: nlmsvc_mark_resources\n");
- nlm_traverse_files(NULL, nlmsvc_mark_host);
+ nlm_traverse_files(NULL, nlmsvc_mark_host, NULL);
}
/*
@@ -356,7 +365,7 @@
{
dprintk("lockd: nlmsvc_free_host_resources\n");
- if (nlm_traverse_files(host, nlmsvc_same_host)) {
+ if (nlm_traverse_files(host, nlmsvc_same_host, NULL)) {
printk(KERN_WARNING
"lockd: couldn't remove all locks held by %s\n",
host->h_name);
@@ -376,10 +385,28 @@
* turn, which is about as inefficient as it gets.
* Now we just do it once in nlm_traverse_files.
*/
- nlm_traverse_files(NULL, nlmsvc_is_client);
+ nlm_traverse_files(NULL, nlmsvc_is_client, NULL);
}
static int
+nlmsvc_match_sb(void *datap, struct nlm_file *file)
+{
+ struct super_block *sb = datap;
+
+ return sb == file->f_file->f_path.mnt->mnt_sb;
+}
+
+int
+nlmsvc_unlock_all_by_sb(struct super_block *sb)
+{
+ int ret;
+
+ ret = nlm_traverse_files(sb, nlmsvc_always_match, nlmsvc_match_sb);
+ return ret ? -EIO : 0;
+}
+EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_sb);
+
+static int
nlmsvc_match_ip(void *datap, struct nlm_host *host)
{
__be32 *server_addr = datap;
@@ -391,7 +418,7 @@
nlmsvc_unlock_all_by_ip(__be32 server_addr)
{
int ret;
- ret = nlm_traverse_files(&server_addr, nlmsvc_match_ip);
+ ret = nlm_traverse_files(&server_addr, nlmsvc_match_ip, NULL);
return ret ? -EIO : 0;
}
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 7706f6c..42f3820 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -56,6 +56,7 @@
NFSD_List,
NFSD_Fh,
NFSD_FO_UnlockIP,
+ NFSD_FO_UnlockFS,
NFSD_Threads,
NFSD_Pool_Threads,
NFSD_Versions,
@@ -93,6 +94,7 @@
#endif
static ssize_t failover_unlock_ip(struct file *file, char *buf, size_t size);
+static ssize_t failover_unlock_fs(struct file *file, char *buf, size_t size);
static ssize_t (*write_op[])(struct file *, char *, size_t) = {
[NFSD_Svc] = write_svc,
@@ -104,6 +106,7 @@
[NFSD_Getfs] = write_getfs,
[NFSD_Fh] = write_filehandle,
[NFSD_FO_UnlockIP] = failover_unlock_ip,
+ [NFSD_FO_UnlockFS] = failover_unlock_fs,
[NFSD_Threads] = write_threads,
[NFSD_Pool_Threads] = write_pool_threads,
[NFSD_Versions] = write_versions,
@@ -329,6 +332,33 @@
return nlmsvc_unlock_all_by_ip(server_ip);
}
+static ssize_t failover_unlock_fs(struct file *file, char *buf, size_t size)
+{
+ struct nameidata nd;
+ char *fo_path;
+ int error;
+
+ /* sanity check */
+ if (size == 0)
+ return -EINVAL;
+
+ if (buf[size-1] != '\n')
+ return -EINVAL;
+
+ fo_path = buf;
+ if (qword_get(&buf, fo_path, size) < 0)
+ return -EINVAL;
+
+ error = path_lookup(fo_path, 0, &nd);
+ if (error)
+ return error;
+
+ error = nlmsvc_unlock_all_by_sb(nd.path.mnt->mnt_sb);
+
+ path_put(&nd.path);
+ return error;
+}
+
static ssize_t write_filehandle(struct file *file, char *buf, size_t size)
{
/* request is:
@@ -733,6 +763,8 @@
[NFSD_List] = {"exports", &exports_operations, S_IRUGO},
[NFSD_FO_UnlockIP] = {"unlock_ip",
&transaction_ops, S_IWUSR|S_IRUSR},
+ [NFSD_FO_UnlockFS] = {"unlock_filesystem",
+ &transaction_ops, S_IWUSR|S_IRUSR},
[NFSD_Fh] = {"filehandle", &transaction_ops, S_IWUSR|S_IRUSR},
[NFSD_Threads] = {"threads", &transaction_ops, S_IWUSR|S_IRUSR},
[NFSD_Pool_Threads] = {"pool_threads", &transaction_ops, S_IWUSR|S_IRUSR},
diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h
index bcb93fc..102d928 100644
--- a/include/linux/lockd/lockd.h
+++ b/include/linux/lockd/lockd.h
@@ -223,6 +223,7 @@
/*
* Cluster failover support
*/
+int nlmsvc_unlock_all_by_sb(struct super_block *sb);
int nlmsvc_unlock_all_by_ip(__be32 server_addr);
static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)