Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[mirror_ubuntu-bionic-kernel.git] / fs / cifs / cifs_debug.c

/*
 *   fs/cifs_debug.c
 *
 *   Copyright (C) International Business Machines  Corp., 2000,2005
 *
 *   Modified by Steve French (sfrench@us.ibm.com)
 *
 *   This program is free software;  you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program;  if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <asm/uaccess.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "cifsfs.h"

void
cifs_dump_mem(char *label, void *data, int length)
{
        int i, j;
        int *intptr = data;
        char *charptr = data;
        char buf[10], line[80];

        printk(KERN_DEBUG "%s: dump of %d bytes of data at 0x%p\n",
                label, length, data);
        for (i = 0; i < length; i += 16) {
                line[0] = 0;
                for (j = 0; (j < 4) && (i + j * 4 < length); j++) {
                        sprintf(buf, " %08x", intptr[i / 4 + j]);
                        strcat(line, buf);
                }
                buf[0] = ' ';
                buf[2] = 0;
                for (j = 0; (j < 16) && (i + j < length); j++) {
                        buf[1] = isprint(charptr[i + j]) ? charptr[i + j] : '.';
                        strcat(line, buf);
                }
                printk(KERN_DEBUG "%s\n", line);
        }
}

#ifdef CONFIG_CIFS_DEBUG2
void cifs_dump_detail(void *buf)
{
        struct smb_hdr *smb = (struct smb_hdr *)buf;

        cERROR(1, "Cmd: %d Err: 0x%x Flags: 0x%x Flgs2: 0x%x Mid: %d Pid: %d",
                  smb->Command, smb->Status.CifsError,
                  smb->Flags, smb->Flags2, smb->Mid, smb->Pid);
        cERROR(1, "smb buf %p len %d", smb, smbCalcSize(smb));
}

void cifs_dump_mids(struct TCP_Server_Info *server)
{
        struct list_head *tmp;
        struct mid_q_entry *mid_entry;

        if (server == NULL)
                return;

        cERROR(1, "Dump pending requests:");
        spin_lock(&GlobalMid_Lock);
        list_for_each(tmp, &server->pending_mid_q) {
                mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
                cERROR(1, "State: %d Cmd: %d Pid: %d Cbdata: %p Mid %llu",
                        mid_entry->mid_state,
                        le16_to_cpu(mid_entry->command),
                        mid_entry->pid,
                        mid_entry->callback_data,
                        mid_entry->mid);
#ifdef CONFIG_CIFS_STATS2
                cERROR(1, "IsLarge: %d buf: %p time rcv: %ld now: %ld",
                        mid_entry->large_buf,
                        mid_entry->resp_buf,
                        mid_entry->when_received,
                        jiffies);
#endif /* STATS2 */
                cERROR(1, "IsMult: %d IsEnd: %d", mid_entry->multiRsp,
                          mid_entry->multiEnd);
                if (mid_entry->resp_buf) {
                        cifs_dump_detail(mid_entry->resp_buf);
                        cifs_dump_mem("existing buf: ",
                                mid_entry->resp_buf, 62);
                }
        }
        spin_unlock(&GlobalMid_Lock);
}
#endif /* CONFIG_CIFS_DEBUG2 */

#ifdef CONFIG_PROC_FS
static int cifs_debug_data_proc_show(struct seq_file *m, void *v)
{
        struct list_head *tmp1, *tmp2, *tmp3;
        struct mid_q_entry *mid_entry;
        struct TCP_Server_Info *server;
        struct cifs_ses *ses;
        struct cifs_tcon *tcon;
        int i, j;
        __u32 dev_type;

        seq_puts(m,
                    "Display Internal CIFS Data Structures for Debugging\n"
                    "---------------------------------------------------\n");
        seq_printf(m, "CIFS Version %s\n", CIFS_VERSION);
        seq_printf(m, "Features:");
#ifdef CONFIG_CIFS_DFS_UPCALL
        seq_printf(m, " dfs");
#endif
#ifdef CONFIG_CIFS_FSCACHE
        seq_printf(m, " fscache");
#endif
#ifdef CONFIG_CIFS_WEAK_PW_HASH
        seq_printf(m, " lanman");
#endif
#ifdef CONFIG_CIFS_POSIX
        seq_printf(m, " posix");
#endif
#ifdef CONFIG_CIFS_UPCALL
        seq_printf(m, " spnego");
#endif
#ifdef CONFIG_CIFS_XATTR
        seq_printf(m, " xattr");
#endif
#ifdef CONFIG_CIFS_ACL
        seq_printf(m, " acl");
#endif
        seq_putc(m, '\n');
        seq_printf(m, "Active VFS Requests: %d\n", GlobalTotalActiveXid);
        seq_printf(m, "Servers:");

        i = 0;
        spin_lock(&cifs_tcp_ses_lock);
        list_for_each(tmp1, &cifs_tcp_ses_list) {
                server = list_entry(tmp1, struct TCP_Server_Info,
                                    tcp_ses_list);
                i++;
                list_for_each(tmp2, &server->smb_ses_list) {
                        ses = list_entry(tmp2, struct cifs_ses,
                                         smb_ses_list);
                        if ((ses->serverDomain == NULL) ||
                                (ses->serverOS == NULL) ||
                                (ses->serverNOS == NULL)) {
                                seq_printf(m, "\n%d) entry for %s not fully "
                                           "displayed\n\t", i, ses->serverName);
                        } else {
                                seq_printf(m,
                                    "\n%d) Name: %s  Domain: %s Uses: %d OS:"
                                    " %s\n\tNOS: %s\tCapability: 0x%x\n\tSMB"
                                    " session status: %d\t",
                                i, ses->serverName, ses->serverDomain,
                                ses->ses_count, ses->serverOS, ses->serverNOS,
                                ses->capabilities, ses->status);
                        }
                        seq_printf(m, "TCP status: %d\n\tLocal Users To "
                                   "Server: %d SecMode: 0x%x Req On Wire: %d",
                                   server->tcpStatus, server->srv_count,
                                   server->sec_mode, in_flight(server));

#ifdef CONFIG_CIFS_STATS2
                        seq_printf(m, " In Send: %d In MaxReq Wait: %d",
                                atomic_read(&server->in_send),
                                atomic_read(&server->num_waiters));
#endif

                        seq_puts(m, "\n\tShares:");
                        j = 0;
                        list_for_each(tmp3, &ses->tcon_list) {
                                tcon = list_entry(tmp3, struct cifs_tcon,
                                                  tcon_list);
                                ++j;
                                dev_type = le32_to_cpu(tcon->fsDevInfo.DeviceType);
                                seq_printf(m, "\n\t%d) %s Mounts: %d ", j,
                                           tcon->treeName, tcon->tc_count);
                                if (tcon->nativeFileSystem) {
                                        seq_printf(m, "Type: %s ",
                                                   tcon->nativeFileSystem);
                                }
                                seq_printf(m, "DevInfo: 0x%x Attributes: 0x%x"
                                        "\nPathComponentMax: %d Status: 0x%d",
                                        le32_to_cpu(tcon->fsDevInfo.DeviceCharacteristics),
                                        le32_to_cpu(tcon->fsAttrInfo.Attributes),
                                        le32_to_cpu(tcon->fsAttrInfo.MaxPathNameComponentLength),
                                        tcon->tidStatus);
                                if (dev_type == FILE_DEVICE_DISK)
                                        seq_puts(m, " type: DISK ");
                                else if (dev_type == FILE_DEVICE_CD_ROM)
                                        seq_puts(m, " type: CDROM ");
                                else
                                        seq_printf(m, " type: %d ", dev_type);

                                if (tcon->need_reconnect)
                                        seq_puts(m, "\tDISCONNECTED ");
                                seq_putc(m, '\n');
                        }

                        seq_puts(m, "\n\tMIDs:\n");

                        spin_lock(&GlobalMid_Lock);
                        list_for_each(tmp3, &server->pending_mid_q) {
                                mid_entry = list_entry(tmp3, struct mid_q_entry,
                                        qhead);
                                seq_printf(m, "\tState: %d com: %d pid:"
                                              " %d cbdata: %p mid %llu\n",
                                              mid_entry->mid_state,
                                              le16_to_cpu(mid_entry->command),
                                              mid_entry->pid,
                                              mid_entry->callback_data,
                                              mid_entry->mid);
                        }
                        spin_unlock(&GlobalMid_Lock);
                }
        }
        spin_unlock(&cifs_tcp_ses_lock);
        seq_putc(m, '\n');

        /* BB add code to dump additional info such as TCP session info now */
        return 0;
}

static int cifs_debug_data_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, cifs_debug_data_proc_show, NULL);
}

static const struct file_operations cifs_debug_data_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = cifs_debug_data_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

#ifdef CONFIG_CIFS_STATS
static ssize_t cifs_stats_proc_write(struct file *file,
                const char __user *buffer, size_t count, loff_t *ppos)
{
        char c;
        int rc;
        struct list_head *tmp1, *tmp2, *tmp3;
        struct TCP_Server_Info *server;
        struct cifs_ses *ses;
        struct cifs_tcon *tcon;

        rc = get_user(c, buffer);
        if (rc)
                return rc;

        if (c == '1' || c == 'y' || c == 'Y' || c == '0') {
#ifdef CONFIG_CIFS_STATS2
                atomic_set(&totBufAllocCount, 0);
                atomic_set(&totSmBufAllocCount, 0);
#endif /* CONFIG_CIFS_STATS2 */
                spin_lock(&cifs_tcp_ses_lock);
                list_for_each(tmp1, &cifs_tcp_ses_list) {
                        server = list_entry(tmp1, struct TCP_Server_Info,
                                            tcp_ses_list);
                        list_for_each(tmp2, &server->smb_ses_list) {
                                ses = list_entry(tmp2, struct cifs_ses,
                                                 smb_ses_list);
                                list_for_each(tmp3, &ses->tcon_list) {
                                        tcon = list_entry(tmp3,
                                                          struct cifs_tcon,
                                                          tcon_list);
                                        atomic_set(&tcon->num_smbs_sent, 0);
                                        atomic_set(&tcon->num_writes, 0);
                                        atomic_set(&tcon->num_reads, 0);
                                        atomic_set(&tcon->num_oplock_brks, 0);
                                        atomic_set(&tcon->num_opens, 0);
                                        atomic_set(&tcon->num_posixopens, 0);
                                        atomic_set(&tcon->num_posixmkdirs, 0);
                                        atomic_set(&tcon->num_closes, 0);
                                        atomic_set(&tcon->num_deletes, 0);
                                        atomic_set(&tcon->num_mkdirs, 0);
                                        atomic_set(&tcon->num_rmdirs, 0);
                                        atomic_set(&tcon->num_renames, 0);
                                        atomic_set(&tcon->num_t2renames, 0);
                                        atomic_set(&tcon->num_ffirst, 0);
                                        atomic_set(&tcon->num_fnext, 0);
                                        atomic_set(&tcon->num_fclose, 0);
                                        atomic_set(&tcon->num_hardlinks, 0);
                                        atomic_set(&tcon->num_symlinks, 0);
                                        atomic_set(&tcon->num_locks, 0);
                                }
                        }
                }
                spin_unlock(&cifs_tcp_ses_lock);
        }

        return count;
}

static int cifs_stats_proc_show(struct seq_file *m, void *v)
{
        int i;
        struct list_head *tmp1, *tmp2, *tmp3;
        struct TCP_Server_Info *server;
        struct cifs_ses *ses;
        struct cifs_tcon *tcon;

        seq_printf(m,
                        "Resources in use\nCIFS Session: %d\n",
                        sesInfoAllocCount.counter);
        seq_printf(m, "Share (unique mount targets): %d\n",
                        tconInfoAllocCount.counter);
        seq_printf(m, "SMB Request/Response Buffer: %d Pool size: %d\n",
                        bufAllocCount.counter,
                        cifs_min_rcv + tcpSesAllocCount.counter);
        seq_printf(m, "SMB Small Req/Resp Buffer: %d Pool size: %d\n",
                        smBufAllocCount.counter, cifs_min_small);
#ifdef CONFIG_CIFS_STATS2
        seq_printf(m, "Total Large %d Small %d Allocations\n",
                                atomic_read(&totBufAllocCount),
                                atomic_read(&totSmBufAllocCount));
#endif /* CONFIG_CIFS_STATS2 */

        seq_printf(m, "Operations (MIDs): %d\n", atomic_read(&midCount));
        seq_printf(m,
                "\n%d session %d share reconnects\n",
                tcpSesReconnectCount.counter, tconInfoReconnectCount.counter);

        seq_printf(m,
                "Total vfs operations: %d maximum at one time: %d\n",
                GlobalCurrentXid, GlobalMaxActiveXid);

        i = 0;
        spin_lock(&cifs_tcp_ses_lock);
        list_for_each(tmp1, &cifs_tcp_ses_list) {
                server = list_entry(tmp1, struct TCP_Server_Info,
                                    tcp_ses_list);
                list_for_each(tmp2, &server->smb_ses_list) {
                        ses = list_entry(tmp2, struct cifs_ses,
                                         smb_ses_list);
                        list_for_each(tmp3, &ses->tcon_list) {
                                tcon = list_entry(tmp3,
                                                  struct cifs_tcon,
                                                  tcon_list);
                                i++;
                                seq_printf(m, "\n%d) %s", i, tcon->treeName);
                                if (tcon->need_reconnect)
                                        seq_puts(m, "\tDISCONNECTED ");
                                seq_printf(m, "\nSMBs: %d Oplock Breaks: %d",
                                        atomic_read(&tcon->num_smbs_sent),
                                        atomic_read(&tcon->num_oplock_brks));
                                seq_printf(m, "\nReads:  %d Bytes: %lld",
                                        atomic_read(&tcon->num_reads),
                                        (long long)(tcon->bytes_read));
                                seq_printf(m, "\nWrites: %d Bytes: %lld",
                                        atomic_read(&tcon->num_writes),
                                        (long long)(tcon->bytes_written));
                                seq_printf(m, "\nFlushes: %d",
                                        atomic_read(&tcon->num_flushes));
                                seq_printf(m, "\nLocks: %d HardLinks: %d "
                                              "Symlinks: %d",
                                        atomic_read(&tcon->num_locks),
                                        atomic_read(&tcon->num_hardlinks),
                                        atomic_read(&tcon->num_symlinks));
                                seq_printf(m, "\nOpens: %d Closes: %d "
                                              "Deletes: %d",
                                        atomic_read(&tcon->num_opens),
                                        atomic_read(&tcon->num_closes),
                                        atomic_read(&tcon->num_deletes));
                                seq_printf(m, "\nPosix Opens: %d "
                                              "Posix Mkdirs: %d",
                                        atomic_read(&tcon->num_posixopens),
                                        atomic_read(&tcon->num_posixmkdirs));
                                seq_printf(m, "\nMkdirs: %d Rmdirs: %d",
                                        atomic_read(&tcon->num_mkdirs),
                                        atomic_read(&tcon->num_rmdirs));
                                seq_printf(m, "\nRenames: %d T2 Renames %d",
                                        atomic_read(&tcon->num_renames),
                                        atomic_read(&tcon->num_t2renames));
                                seq_printf(m, "\nFindFirst: %d FNext %d "
                                              "FClose %d",
                                        atomic_read(&tcon->num_ffirst),
                                        atomic_read(&tcon->num_fnext),
                                        atomic_read(&tcon->num_fclose));
                        }
                }
        }
        spin_unlock(&cifs_tcp_ses_lock);

        seq_putc(m, '\n');
        return 0;
}

static int cifs_stats_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, cifs_stats_proc_show, NULL);
}

static const struct file_operations cifs_stats_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = cifs_stats_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
        .write          = cifs_stats_proc_write,
};
#endif /* STATS */

static struct proc_dir_entry *proc_fs_cifs;
static const struct file_operations cifsFYI_proc_fops;
static const struct file_operations cifs_lookup_cache_proc_fops;
static const struct file_operations traceSMB_proc_fops;
static const struct file_operations cifs_multiuser_mount_proc_fops;
static const struct file_operations cifs_security_flags_proc_fops;
static const struct file_operations cifs_linux_ext_proc_fops;

void
cifs_proc_init(void)
{
        proc_fs_cifs = proc_mkdir("fs/cifs", NULL);
        if (proc_fs_cifs == NULL)
                return;

        proc_create("DebugData", 0, proc_fs_cifs, &cifs_debug_data_proc_fops);

#ifdef CONFIG_CIFS_STATS
        proc_create("Stats", 0, proc_fs_cifs, &cifs_stats_proc_fops);
#endif /* STATS */
        proc_create("cifsFYI", 0, proc_fs_cifs, &cifsFYI_proc_fops);
        proc_create("traceSMB", 0, proc_fs_cifs, &traceSMB_proc_fops);
        proc_create("LinuxExtensionsEnabled", 0, proc_fs_cifs,
                    &cifs_linux_ext_proc_fops);
        proc_create("MultiuserMount", 0, proc_fs_cifs,
                    &cifs_multiuser_mount_proc_fops);
        proc_create("SecurityFlags", 0, proc_fs_cifs,
                    &cifs_security_flags_proc_fops);
        proc_create("LookupCacheEnabled", 0, proc_fs_cifs,
                    &cifs_lookup_cache_proc_fops);
}

void
cifs_proc_clean(void)
{
        if (proc_fs_cifs == NULL)
                return;

        remove_proc_entry("DebugData", proc_fs_cifs);
        remove_proc_entry("cifsFYI", proc_fs_cifs);
        remove_proc_entry("traceSMB", proc_fs_cifs);
#ifdef CONFIG_CIFS_STATS
        remove_proc_entry("Stats", proc_fs_cifs);
#endif
        remove_proc_entry("MultiuserMount", proc_fs_cifs);
        remove_proc_entry("SecurityFlags", proc_fs_cifs);
        remove_proc_entry("LinuxExtensionsEnabled", proc_fs_cifs);
        remove_proc_entry("LookupCacheEnabled", proc_fs_cifs);
        remove_proc_entry("fs/cifs", NULL);
}

static int cifsFYI_proc_show(struct seq_file *m, void *v)
{
        seq_printf(m, "%d\n", cifsFYI);
        return 0;
}

static int cifsFYI_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, cifsFYI_proc_show, NULL);
}

static ssize_t cifsFYI_proc_write(struct file *file, const char __user *buffer,
                size_t count, loff_t *ppos)
{
        char c;
        int rc;

        rc = get_user(c, buffer);
        if (rc)
                return rc;
        if (c == '0' || c == 'n' || c == 'N')
                cifsFYI = 0;
        else if (c == '1' || c == 'y' || c == 'Y')
                cifsFYI = 1;
        else if ((c > '1') && (c <= '9'))
                cifsFYI = (int) (c - '0'); /* see cifs_debug.h for meanings */

        return count;
}

static const struct file_operations cifsFYI_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = cifsFYI_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
        .write          = cifsFYI_proc_write,
};

static int cifs_linux_ext_proc_show(struct seq_file *m, void *v)
{
        seq_printf(m, "%d\n", linuxExtEnabled);
        return 0;
}

static int cifs_linux_ext_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, cifs_linux_ext_proc_show, NULL);
}

static ssize_t cifs_linux_ext_proc_write(struct file *file,
                const char __user *buffer, size_t count, loff_t *ppos)
{
        char c;
        int rc;

        rc = get_user(c, buffer);
        if (rc)
                return rc;
        if (c == '0' || c == 'n' || c == 'N')
                linuxExtEnabled = 0;
        else if (c == '1' || c == 'y' || c == 'Y')
                linuxExtEnabled = 1;

        return count;
}

static const struct file_operations cifs_linux_ext_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = cifs_linux_ext_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
        .write          = cifs_linux_ext_proc_write,
};

static int cifs_lookup_cache_proc_show(struct seq_file *m, void *v)
{
        seq_printf(m, "%d\n", lookupCacheEnabled);
        return 0;
}

static int cifs_lookup_cache_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, cifs_lookup_cache_proc_show, NULL);
}

static ssize_t cifs_lookup_cache_proc_write(struct file *file,
                const char __user *buffer, size_t count, loff_t *ppos)
{
        char c;
        int rc;

        rc = get_user(c, buffer);
        if (rc)
                return rc;
        if (c == '0' || c == 'n' || c == 'N')
                lookupCacheEnabled = 0;
        else if (c == '1' || c == 'y' || c == 'Y')
                lookupCacheEnabled = 1;

        return count;
}

static const struct file_operations cifs_lookup_cache_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = cifs_lookup_cache_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
        .write          = cifs_lookup_cache_proc_write,
};

static int traceSMB_proc_show(struct seq_file *m, void *v)
{
        seq_printf(m, "%d\n", traceSMB);
        return 0;
}

static int traceSMB_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, traceSMB_proc_show, NULL);
}

static ssize_t traceSMB_proc_write(struct file *file, const char __user *buffer,
                size_t count, loff_t *ppos)
{
        char c;
        int rc;

        rc = get_user(c, buffer);
        if (rc)
                return rc;
        if (c == '0' || c == 'n' || c == 'N')
                traceSMB = 0;
        else if (c == '1' || c == 'y' || c == 'Y')
                traceSMB = 1;

        return count;
}

static const struct file_operations traceSMB_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = traceSMB_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
        .write          = traceSMB_proc_write,
};

static int cifs_multiuser_mount_proc_show(struct seq_file *m, void *v)
{
        seq_printf(m, "%d\n", multiuser_mount);
        return 0;
}

static int cifs_multiuser_mount_proc_open(struct inode *inode, struct file *fh)
{
        return single_open(fh, cifs_multiuser_mount_proc_show, NULL);
}

static ssize_t cifs_multiuser_mount_proc_write(struct file *file,
                const char __user *buffer, size_t count, loff_t *ppos)
{
        char c;
        int rc;
        static bool warned;

        rc = get_user(c, buffer);
        if (rc)
                return rc;
        if (c == '0' || c == 'n' || c == 'N')
                multiuser_mount = 0;
        else if (c == '1' || c == 'y' || c == 'Y') {
                multiuser_mount = 1;
                if (!warned) {
                        warned = true;
                        printk(KERN_WARNING "CIFS VFS: The legacy multiuser "
                                "mount code is scheduled to be deprecated in "
                                "3.5. Please switch to using the multiuser "
                                "mount option.");
                }
        }

        return count;
}

static const struct file_operations cifs_multiuser_mount_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = cifs_multiuser_mount_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
        .write          = cifs_multiuser_mount_proc_write,
};

static int cifs_security_flags_proc_show(struct seq_file *m, void *v)
{
        seq_printf(m, "0x%x\n", global_secflags);
        return 0;
}

static int cifs_security_flags_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, cifs_security_flags_proc_show, NULL);
}

static ssize_t cifs_security_flags_proc_write(struct file *file,
                const char __user *buffer, size_t count, loff_t *ppos)
{
        unsigned int flags;
        char flags_string[12];
        char c;

        if ((count < 1) || (count > 11))
                return -EINVAL;

        memset(flags_string, 0, 12);

        if (copy_from_user(flags_string, buffer, count))
                return -EFAULT;

        if (count < 3) {
                /* single char or single char followed by null */
                c = flags_string[0];
                if (c == '0' || c == 'n' || c == 'N') {
                        global_secflags = CIFSSEC_DEF; /* default */
                        return count;
                } else if (c == '1' || c == 'y' || c == 'Y') {
                        global_secflags = CIFSSEC_MAX;
                        return count;
                } else if (!isdigit(c)) {
                        cERROR(1, "invalid flag %c", c);
                        return -EINVAL;
                }
        }
        /* else we have a number */

        flags = simple_strtoul(flags_string, NULL, 0);

        cFYI(1, "sec flags 0x%x", flags);

        if (flags <= 0)  {
                cERROR(1, "invalid security flags %s", flags_string);
                return -EINVAL;
        }

        if (flags & ~CIFSSEC_MASK) {
                cERROR(1, "attempt to set unsupported security flags 0x%x",
                        flags & ~CIFSSEC_MASK);
                return -EINVAL;
        }
        /* flags look ok - update the global security flags for cifs module */
        global_secflags = flags;
        if (global_secflags & CIFSSEC_MUST_SIGN) {
                /* requiring signing implies signing is allowed */
                global_secflags |= CIFSSEC_MAY_SIGN;
                cFYI(1, "packet signing now required");
        } else if ((global_secflags & CIFSSEC_MAY_SIGN) == 0) {
                cFYI(1, "packet signing disabled");
        }
        /* BB should we turn on MAY flags for other MUST options? */
        return count;
}

static const struct file_operations cifs_security_flags_proc_fops = {
        .owner          = THIS_MODULE,
        .open           = cifs_security_flags_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
        .write          = cifs_security_flags_proc_write,
};
#else
inline void cifs_proc_init(void)
{
}

inline void cifs_proc_clean(void)
{
}
#endif /* PROC_FS */