Commit 17efa372 authored by Wendy Cheng's avatar Wendy Cheng Committed by J. Bruce Fields
Browse files

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: default avatarS. Wendy Cheng <wcheng@redhat.com>
Cc: Lon Hohberger  <lhh@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJ. 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(-)
parent 4373ea84

fs/lockd/svcsubs.c

+32 −5
Original line number Diff line number Diff line
@@ -196,6 +196,12 @@ again: 
	return 0;

}



static int

nlmsvc_always_match(void *dummy1, struct nlm_host *dummy2)

{

	return 1;

}



/*

 * Inspect a single file

 */
@@ -232,7 +238,8 @@ nlm_file_inuse(struct nlm_file *file) 
 * 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 @@ nlm_traverse_files(void *data, nlm_host_match_fn_t match) 
	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 @@ void 
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 @@ nlmsvc_free_host_resources(struct nlm_host *host) 
{

	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);
@@ -376,8 +385,26 @@ nlmsvc_invalidate_all(void) 
	 * 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)
@@ -391,7 +418,7 @@ int 
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;



}

fs/nfsd/nfsctl.c

+32 −0
Original line number Diff line number Diff line
@@ -56,6 +56,7 @@ enum { 
	NFSD_List,

	NFSD_Fh,

	NFSD_FO_UnlockIP,

	NFSD_FO_UnlockFS,

	NFSD_Threads,

	NFSD_Pool_Threads,

	NFSD_Versions,
@@ -93,6 +94,7 @@ static ssize_t write_recoverydir(struct file *file, char *buf, size_t size); 
#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 @@ static ssize_t (*write_op[])(struct file *, char *, size_t) = { 
	[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 @@ static ssize_t failover_unlock_ip(struct file *file, char *buf, size_t size) 
	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 @@ static int nfsd_fill_super(struct super_block * sb, void * data, int silent) 
		[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},

include/linux/lockd/lockd.h

+1 −0
Original line number Diff line number Diff line
@@ -223,6 +223,7 @@ void nlmsvc_invalidate_all(void); 
/*

 * 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)

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