[Cluster-devel] Re: [PATCH 1/2] NLM failover unlock commands
J. Bruce Fields
bfields at fieldses.org
Mon Jan 14 23:07:42 UTC 2008
On Sat, Jan 12, 2008 at 02:03:55AM -0500, Wendy Cheng wrote:
> This is a combined patch that has:
>
> * changes made by Christoph Hellwig
> * code segment that handles f_locks so we would not walk inode->i_flock
> list twice.
>
> If agreed, please re-add your "ack-by" and "signed-off" lines
> respectively. Thanks ...
>
> -- Wendy
Comments below--
> Two new NFSD procfs files are added:
> /proc/fs/nfsd/unlock_ip
> /proc/fs/nfsd/unlock_filesystem
>
> They are intended to allow admin or user mode script to release NLM locks
> based on either a path name or a server in-bound ip address (ipv4 for now)
> as;
>
> shell> echo 10.1.1.2 > /proc/fs/nfsd/unlock_ip
> shell> echo /mnt/sfs1 > /proc/fs/nfsd/unlock_filesystem
>
> Signed-off-by: S. Wendy Cheng <wcheng at redhat.com>
> Signed-off-by: Lon Hohberger <lhh at redhat.com>
>
> fs/lockd/svcsubs.c | 68 ++++++++++++++++++++++++++++++++++++++------
> fs/nfsd/nfsctl.c | 62 ++++++++++++++++++++++++++++++++++++++++
> include/linux/lockd/lockd.h | 7 ++++
> 3 files changed, 129 insertions(+), 8 deletions(-)
>
> --- linux-o/fs/nfsd/nfsctl.c 2008-01-04 10:01:08.000000000 -0500
> +++ linux/fs/nfsd/nfsctl.c 2008-01-11 19:08:02.000000000 -0500
> @@ -22,6 +22,7 @@
> #include <linux/seq_file.h>
> #include <linux/pagemap.h>
> #include <linux/init.h>
> +#include <linux/inet.h>
> #include <linux/string.h>
> #include <linux/smp_lock.h>
> #include <linux/ctype.h>
> @@ -35,6 +36,7 @@
> #include <linux/nfsd/cache.h>
> #include <linux/nfsd/xdr.h>
> #include <linux/nfsd/syscall.h>
> +#include <linux/lockd/lockd.h>
>
> #include <asm/uaccess.h>
>
> @@ -52,6 +54,8 @@ enum {
> NFSD_Getfs,
> NFSD_List,
> NFSD_Fh,
> + NFSD_FO_UnlockIP,
> + NFSD_FO_UnlockFS,
> NFSD_Threads,
> NFSD_Pool_Threads,
> NFSD_Versions,
> @@ -88,6 +92,9 @@ static ssize_t write_leasetime(struct fi
> 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,
> [NFSD_Add] = write_add,
> @@ -97,6 +104,8 @@ static ssize_t (*write_op[])(struct file
> [NFSD_Getfd] = write_getfd,
> [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,
> @@ -288,6 +297,55 @@ static ssize_t write_getfd(struct file *
> return err;
> }
>
> +static ssize_t failover_unlock_ip(struct file *file, char *buf, size_t size)
> +{
> + __be32 server_ip;
> + char *fo_path;
> + char *mesg;
> +
> + /* sanity check */
> + if (size <= 0)
> + return -EINVAL;
Not only is size never negative, it's actually an unsigned type here, so
this is a no-op.
> +
> + if (buf[size-1] == '\n')
> + buf[size-1] = 0;
The other write methods in this file actually just do
if (buf[size-1] != '\n')
return -EINVAL;
I don't know why. But absent some reason, I'd rather these two new
files behaved the same as existing ones.
> +
> + fo_path = mesg = buf;
> + if (qword_get(&mesg, fo_path, size) < 0)
> + return -EINVAL;
"mesg" is unneeded here, right? You can just do:
fo_path = buf;
if (qword_get(&buf, buf, size) < 0)
> +
> + server_ip = in_aton(fo_path);
It'd be nice if we could sanity-check this. (Is there code already in
the kernel someplace to do this?)
And, this isn't your problem for now, but eventually I guess this will
have to accept an ivp6 address as well?
> + return nlmsvc_failover_ip(server_ip);
> +}
> +
> +static ssize_t failover_unlock_fs(struct file *file, char *buf, size_t size)
> +{
> + struct nameidata nd;
> + char *fo_path;
> + char *mesg;
> + int error;
> +
> + /* sanity check */
> + if (size <= 0)
> + return -EINVAL;
> +
> + if (buf[size-1] == '\n')
> + buf[size-1] = 0;
> +
> + fo_path = mesg = buf;
> + if (qword_get(&mesg, fo_path, size) < 0)
> + return -EINVAL;
Same comments as above.
> +
> + error = path_lookup(fo_path, 0, &nd);
> + if (error)
> + return error;
> +
> + error = nlmsvc_failover_path(&nd);
> +
> + path_release(&nd);
> + return error;
> +}
> +
> static ssize_t write_filehandle(struct file *file, char *buf, size_t size)
> {
> /* request is:
> @@ -646,6 +704,10 @@ static int nfsd_fill_super(struct super_
> [NFSD_Getfd] = {".getfd", &transaction_ops, S_IWUSR|S_IRUSR},
> [NFSD_Getfs] = {".getfs", &transaction_ops, S_IWUSR|S_IRUSR},
> [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},
> --- linux-o/fs/lockd/svcsubs.c 2008-01-04 10:01:08.000000000 -0500
> +++ linux/fs/lockd/svcsubs.c 2008-01-11 19:08:28.000000000 -0500
> @@ -18,6 +18,8 @@
> #include <linux/lockd/lockd.h>
> #include <linux/lockd/share.h>
> #include <linux/lockd/sm_inter.h>
> +#include <linux/module.h>
> +#include <linux/mount.h>
>
> #define NLMDBG_FACILITY NLMDBG_SVCSUBS
>
> @@ -87,7 +89,7 @@ nlm_lookup_file(struct svc_rqst *rqstp,
> unsigned int hash;
> __be32 nfserr;
>
> - nlm_debug_print_fh("nlm_file_lookup", f);
> + nlm_debug_print_fh("nlm_lookup_file", f);
>
> hash = file_hash(f);
>
> @@ -123,6 +125,9 @@ nlm_lookup_file(struct svc_rqst *rqstp,
>
> hlist_add_head(&file->f_list, &nlm_files[hash]);
>
> + /* fill in f_iaddr for nlm lock failover */
> + file->f_iaddr = rqstp->rq_daddr;
> +
> found:
> dprintk("lockd: found file %p (count %d)\n", file, file->f_count);
> *result = file;
> @@ -194,6 +199,12 @@ again:
> return 0;
> }
>
> +static int
> +nlmsvc_always_match(struct nlm_host *dummy1, struct nlm_host *dummy2)
> +{
> + return 1;
> +}
> +
> /*
> * Inspect a single file
> */
> @@ -230,27 +241,37 @@ nlm_file_inuse(struct nlm_file *file)
> * Loop over all files in the file table.
> */
> static int
> -nlm_traverse_files(struct nlm_host *host, nlm_host_match_fn_t match)
> +nlm_traverse_files(void *data, nlm_host_match_fn_t match,
> + int (*failover)(void *data, struct nlm_file *file))
> {
> struct hlist_node *pos, *next;
> struct nlm_file *file;
> - int i, ret = 0;
> + int i, ret = 0, inspect_file;
>
> 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) {
> file->f_count++;
> mutex_unlock(&nlm_file_mutex);
> + inspect_file = 1;
>
> /* Traverse locks, blocks and shares of this file
> * and update file->f_locks count */
> - if (nlm_inspect_file(host, file, match))
> +
> + if (unlikely(failover)) {
> + if (!failover(data, file)) {
> + inspect_file = 0;
> + file->f_locks = nlm_file_inuse(file);
> + }
> + }
> +
> + if (inspect_file && nlm_inspect_file(data, file, match))
> ret = 1;
This seems quite complicated! I don't have an alternative suggestion,
though.
--b.
>
> mutex_lock(&nlm_file_mutex);
> file->f_count--;
> /* No more references to this file. Let go of it. */
> - if (list_empty(&file->f_blocks) && !file->f_locks
> + if (!file->f_locks && list_empty(&file->f_blocks)
> && !file->f_shares && !file->f_count) {
> hlist_del(&file->f_list);
> nlmsvc_ops->fclose(file->f_file);
> @@ -337,7 +358,7 @@ 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);
> }
>
> /*
> @@ -348,7 +369,7 @@ nlmsvc_free_host_resources(struct nlm_ho
> {
> 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);
> @@ -368,5 +389,36 @@ 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_failover_file_ok_path(void *datap, struct nlm_file *file)
> +{
> + struct nameidata *nd = datap;
> + return nd->mnt == file->f_file->f_path.mnt;
> +}
> +
> +int
> +nlmsvc_failover_path(struct nameidata *nd)
> +{
> + return nlm_traverse_files(nd, nlmsvc_always_match,
> + nlmsvc_failover_file_ok_path);
> +}
> +EXPORT_SYMBOL_GPL(nlmsvc_failover_path);
> +
> +static int
> +nlmsvc_failover_file_ok_ip(void *datap, struct nlm_file *file)
> +{
> + __be32 *server_addr = datap;
> +
> + return file->f_iaddr.addr.s_addr == *server_addr;
> +}
> +
> +int
> +nlmsvc_failover_ip(__be32 server_addr)
> +{
> + return nlm_traverse_files(&server_addr, nlmsvc_always_match,
> + nlmsvc_failover_file_ok_ip);
> }
> +EXPORT_SYMBOL_GPL(nlmsvc_failover_ip);
> --- linux-o/include/linux/lockd/lockd.h 2008-01-04 10:01:08.000000000 -0500
> +++ linux/include/linux/lockd/lockd.h 2008-01-11 18:24:45.000000000 -0500
> @@ -113,6 +113,7 @@ struct nlm_file {
> unsigned int f_locks; /* guesstimate # of locks */
> unsigned int f_count; /* reference count */
> struct mutex f_mutex; /* avoid concurrent access */
> + union svc_addr_u f_iaddr; /* server ip for failover */
> };
>
> /*
> @@ -214,6 +215,12 @@ void nlmsvc_mark_resources(void);
> void nlmsvc_free_host_resources(struct nlm_host *);
> void nlmsvc_invalidate_all(void);
>
> +/*
> + * Cluster failover support
> + */
> +int nlmsvc_failover_path(struct nameidata *nd);
> +int nlmsvc_failover_ip(__be32 server_addr);
> +
> static __inline__ struct inode *
> nlmsvc_file_inode(struct nlm_file *file)
> {
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