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LU-5396 all: use NULL instead of 0
[fs/lustre-release.git] / lustre / llite / lproc_llite.c
index 18f1406..a0aea00 100644 (file)
@@ -27,7 +27,7 @@
  * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2012, 2013, Intel Corporation.
+ * Copyright (c) 2012, 2014, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
 #define DEBUG_SUBSYSTEM S_LLITE
 
 #include <linux/version.h>
-#include <lustre_lite.h>
 #include <lustre_param.h>
 #include <lprocfs_status.h>
 #include <obd_support.h>
 
 #include "llite_internal.h"
+#include "vvp_internal.h"
 
 struct proc_dir_entry *proc_lustre_fs_root;
 
 #ifdef LPROCFS
 /* /proc/lustre/llite mount point registration */
-extern struct file_operations vvp_dump_pgcache_file_ops;
-struct file_operations ll_rw_extents_stats_fops;
-struct file_operations ll_rw_extents_stats_pp_fops;
-struct file_operations ll_rw_offset_stats_fops;
+static const struct file_operations ll_rw_extents_stats_fops;
+static const struct file_operations ll_rw_extents_stats_pp_fops;
+static const struct file_operations ll_rw_offset_stats_fops;
 
 static int ll_blksize_seq_show(struct seq_file *m, void *v)
 {
@@ -209,7 +208,8 @@ static int ll_xattr_cache_seq_show(struct seq_file *m, void *v)
        return seq_printf(m, "%u\n", sbi->ll_xattr_cache_enabled);
 }
 
-static ssize_t ll_xattr_cache_seq_write(struct file *file, const char *buffer,
+static ssize_t ll_xattr_cache_seq_write(struct file *file,
+                                       const char __user *buffer,
                                        size_t count, loff_t *off)
 {
        struct seq_file *m = file->private_data;
@@ -260,18 +260,25 @@ static int ll_max_readahead_mb_seq_show(struct seq_file *m, void *v)
 }
 
 static ssize_t
-ll_max_readahead_mb_seq_write(struct file *file, const char *buffer,
+ll_max_readahead_mb_seq_write(struct file *file, const char __user *buffer,
                              size_t count, loff_t *off)
 {
        struct seq_file *m = file->private_data;
        struct ll_sb_info *sbi = ll_s2sbi((struct super_block *)m->private);
-       int mult, rc, pages_number;
+       __u64 val;
+       long pages_number;
+       int mult;
+       int rc;
 
        mult = 1 << (20 - PAGE_CACHE_SHIFT);
-       rc = lprocfs_write_frac_helper(buffer, count, &pages_number, mult);
+       rc = lprocfs_write_frac_u64_helper(buffer, count, &val, mult);
        if (rc)
                return rc;
 
+       if (val > LONG_MAX)
+               return -ERANGE;
+       pages_number = (long)val;
+
        if (pages_number < 0 || pages_number > totalram_pages / 2) {
                /* 1/2 of RAM */
                CERROR("can't set file readahead more than %lu MB\n",
@@ -302,7 +309,8 @@ static int ll_max_readahead_per_file_mb_seq_show(struct seq_file *m, void *v)
 }
 
 static ssize_t
-ll_max_readahead_per_file_mb_seq_write(struct file *file, const char *buffer,
+ll_max_readahead_per_file_mb_seq_write(struct file *file,
+                                      const char __user *buffer,
                                       size_t count, loff_t *off)
 {
        struct seq_file *m = file->private_data;
@@ -345,7 +353,8 @@ static int ll_max_read_ahead_whole_mb_seq_show(struct seq_file *m, void *v)
 }
 
 static ssize_t
-ll_max_read_ahead_whole_mb_seq_write(struct file *file, const char *buffer,
+ll_max_read_ahead_whole_mb_seq_write(struct file *file,
+                                    const char __user *buffer,
                                     size_t count, loff_t *off)
 {
        struct seq_file *m = file->private_data;
@@ -381,18 +390,18 @@ static int ll_max_cached_mb_seq_show(struct seq_file *m, void *v)
        struct ll_sb_info      *sbi   = ll_s2sbi(sb);
        struct cl_client_cache *cache = &sbi->ll_cache;
        int shift = 20 - PAGE_CACHE_SHIFT;
-       int max_cached_mb;
-       int unused_mb;
+       long max_cached_mb;
+       long unused_mb;
 
        max_cached_mb = cache->ccc_lru_max >> shift;
-       unused_mb = cfs_atomic_read(&cache->ccc_lru_left) >> shift;
+       unused_mb = atomic_long_read(&cache->ccc_lru_left) >> shift;
        return seq_printf(m,
                        "users: %d\n"
-                       "max_cached_mb: %d\n"
-                       "used_mb: %d\n"
-                       "unused_mb: %d\n"
+                       "max_cached_mb: %ld\n"
+                       "used_mb: %ld\n"
+                       "unused_mb: %ld\n"
                        "reclaim_count: %u\n",
-                       cfs_atomic_read(&cache->ccc_users),
+                       atomic_read(&cache->ccc_users),
                        max_cached_mb,
                        max_cached_mb - unused_mb,
                        unused_mb,
@@ -400,7 +409,7 @@ static int ll_max_cached_mb_seq_show(struct seq_file *m, void *v)
 }
 
 static ssize_t
-ll_max_cached_mb_seq_write(struct file *file, const char *buffer,
+ll_max_cached_mb_seq_write(struct file *file, const char __user *buffer,
                           size_t count, loff_t *off)
 {
        struct seq_file *m = file->private_data;
@@ -408,27 +417,42 @@ ll_max_cached_mb_seq_write(struct file *file, const char *buffer,
        struct ll_sb_info *sbi = ll_s2sbi(sb);
        struct cl_client_cache *cache = &sbi->ll_cache;
        struct lu_env *env;
+       __u64 val;
+       long diff = 0;
+       long nrpages = 0;
+       long pages_number;
        int refcheck;
-       int mult, rc, pages_number;
-       int diff = 0;
-       int nrpages = 0;
+       int mult;
+       long rc;
+       char kernbuf[128];
        ENTRY;
 
+       if (count >= sizeof(kernbuf))
+               RETURN(-EINVAL);
+
+       if (copy_from_user(kernbuf, buffer, count))
+               RETURN(-EFAULT);
+       kernbuf[count] = 0;
+
        mult = 1 << (20 - PAGE_CACHE_SHIFT);
-       buffer = lprocfs_find_named_value(buffer, "max_cached_mb:", &count);
-       rc = lprocfs_write_frac_helper(buffer, count, &pages_number, mult);
+       buffer += lprocfs_find_named_value(kernbuf, "max_cached_mb:", &count) -
+                 kernbuf;
+       rc = lprocfs_write_frac_u64_helper(buffer, count, &val, mult);
        if (rc)
                RETURN(rc);
 
+       if (val > LONG_MAX)
+               return -ERANGE;
+       pages_number = (long)val;
+
        if (pages_number < 0 || pages_number > totalram_pages) {
                CERROR("%s: can't set max cache more than %lu MB\n",
                       ll_get_fsname(sb, NULL, 0),
                       totalram_pages >> (20 - PAGE_CACHE_SHIFT));
                RETURN(-ERANGE);
        }
-
-       if (sbi->ll_dt_exp == NULL) /* being initialized */
-               GOTO(out, rc = 0);
+       /* Allow enough cache so clients can make well-formed RPCs */
+       pages_number = max_t(long, pages_number, PTLRPC_MAX_BRW_PAGES);
 
        spin_lock(&sbi->ll_lock);
        diff = pages_number - cache->ccc_lru_max;
@@ -436,7 +460,7 @@ ll_max_cached_mb_seq_write(struct file *file, const char *buffer,
 
        /* easy - add more LRU slots. */
        if (diff >= 0) {
-               cfs_atomic_add(diff, &cache->ccc_lru_left);
+               atomic_long_add(diff, &cache->ccc_lru_left);
                GOTO(out, rc = 0);
        }
 
@@ -446,18 +470,18 @@ ll_max_cached_mb_seq_write(struct file *file, const char *buffer,
 
        diff = -diff;
        while (diff > 0) {
-               int tmp;
+               long tmp;
 
                /* reduce LRU budget from free slots. */
                do {
-                       int ov, nv;
+                       long ov, nv;
 
-                       ov = cfs_atomic_read(&cache->ccc_lru_left);
+                       ov = atomic_long_read(&cache->ccc_lru_left);
                        if (ov == 0)
                                break;
 
                        nv = ov > diff ? ov - diff : 0;
-                       rc = cfs_atomic_cmpxchg(&cache->ccc_lru_left, ov, nv);
+                       rc = atomic_long_cmpxchg(&cache->ccc_lru_left, ov, nv);
                        if (likely(ov == rc)) {
                                diff -= ov - nv;
                                nrpages += ov - nv;
@@ -468,6 +492,11 @@ ll_max_cached_mb_seq_write(struct file *file, const char *buffer,
                if (diff <= 0)
                        break;
 
+               if (sbi->ll_dt_exp == NULL) { /* being initialized */
+                       rc = -ENODEV;
+                       break;
+               }
+
                /* difficult - have to ask OSCs to drop LRU slots. */
                tmp = diff << 1;
                rc = obd_set_info_async(env, sbi->ll_dt_exp,
@@ -486,7 +515,7 @@ out:
                spin_unlock(&sbi->ll_lock);
                rc = count;
        } else {
-               cfs_atomic_add(nrpages, &cache->ccc_lru_left);
+               atomic_long_add(nrpages, &cache->ccc_lru_left);
        }
        return rc;
 }
@@ -500,7 +529,8 @@ static int ll_checksum_seq_show(struct seq_file *m, void *v)
        return seq_printf(m, "%u\n", (sbi->ll_flags & LL_SBI_CHECKSUM) ? 1 : 0);
 }
 
-static ssize_t ll_checksum_seq_write(struct file *file, const char *buffer,
+static ssize_t ll_checksum_seq_write(struct file *file,
+                                    const char __user *buffer,
                                     size_t count, loff_t *off)
 {
        struct seq_file *m = file->private_data;
@@ -535,7 +565,8 @@ static int ll_max_rw_chunk_seq_show(struct seq_file *m, void *v)
        return seq_printf(m, "%lu\n", ll_s2sbi(sb)->ll_max_rw_chunk);
 }
 
-static ssize_t ll_max_rw_chunk_seq_write(struct file *file, const char *buffer,
+static ssize_t ll_max_rw_chunk_seq_write(struct file *file,
+                                        const char __user *buffer,
                                         size_t count, loff_t *off)
 {
        struct seq_file *m = file->private_data;
@@ -564,8 +595,8 @@ static int ll_rd_track_id(struct seq_file *m, enum stats_track_type type)
        }
 }
 
-static int ll_wr_track_id(const char *buffer, unsigned long count, void *data,
-                         enum stats_track_type type)
+static int ll_wr_track_id(const char __user *buffer, unsigned long count,
+                         void *data, enum stats_track_type type)
 {
        struct super_block *sb = data;
         int rc, pid;
@@ -587,7 +618,8 @@ static int ll_track_pid_seq_show(struct seq_file *m, void *v)
        return ll_rd_track_id(m, STATS_TRACK_PID);
 }
 
-static ssize_t ll_track_pid_seq_write(struct file *file, const char *buffer,
+static ssize_t ll_track_pid_seq_write(struct file *file,
+                                     const char __user *buffer,
                                      size_t count, loff_t *off)
 {
        struct seq_file *seq = file->private_data;
@@ -600,7 +632,8 @@ static int ll_track_ppid_seq_show(struct seq_file *m, void *v)
        return ll_rd_track_id(m, STATS_TRACK_PPID);
 }
 
-static ssize_t ll_track_ppid_seq_write(struct file *file, const char *buffer,
+static ssize_t ll_track_ppid_seq_write(struct file *file,
+                                      const char __user *buffer,
                                       size_t count, loff_t *off)
 {
        struct seq_file *seq = file->private_data;
@@ -613,7 +646,8 @@ static int ll_track_gid_seq_show(struct seq_file *m, void *v)
        return ll_rd_track_id(m, STATS_TRACK_GID);
 }
 
-static ssize_t ll_track_gid_seq_write(struct file *file, const char *buffer,
+static ssize_t ll_track_gid_seq_write(struct file *file,
+                                     const char __user *buffer,
                                      size_t count, loff_t *off)
 {
        struct seq_file *seq = file->private_data;
@@ -629,7 +663,8 @@ static int ll_statahead_max_seq_show(struct seq_file *m, void *v)
        return seq_printf(m, "%u\n", sbi->ll_sa_max);
 }
 
-static ssize_t ll_statahead_max_seq_write(struct file *file, const char *buffer,
+static ssize_t ll_statahead_max_seq_write(struct file *file,
+                                         const char __user *buffer,
                                          size_t count, loff_t *off)
 {
        struct seq_file *m = file->private_data;
@@ -659,7 +694,8 @@ static int ll_statahead_agl_seq_show(struct seq_file *m, void *v)
                          sbi->ll_flags & LL_SBI_AGL_ENABLED ? 1 : 0);
 }
 
-static ssize_t ll_statahead_agl_seq_write(struct file *file, const char *buffer,
+static ssize_t ll_statahead_agl_seq_write(struct file *file,
+                                         const char __user *buffer,
                                          size_t count, loff_t *off)
 {
        struct seq_file *m = file->private_data;
@@ -703,7 +739,8 @@ static int ll_lazystatfs_seq_show(struct seq_file *m, void *v)
                          (sbi->ll_flags & LL_SBI_LAZYSTATFS) ? 1 : 0);
 }
 
-static ssize_t ll_lazystatfs_seq_write(struct file *file, const char *buffer,
+static ssize_t ll_lazystatfs_seq_write(struct file *file,
+                                      const char __user *buffer,
                                        size_t count, loff_t *off)
 {
        struct seq_file *m = file->private_data;
@@ -723,20 +760,65 @@ static ssize_t ll_lazystatfs_seq_write(struct file *file, const char *buffer,
 }
 LPROC_SEQ_FOPS(ll_lazystatfs);
 
-static int ll_maxea_size_seq_show(struct seq_file *m, void *v)
+static int ll_max_easize_seq_show(struct seq_file *m, void *v)
 {
        struct super_block *sb = m->private;
        struct ll_sb_info *sbi = ll_s2sbi(sb);
        unsigned int ealen;
        int rc;
 
-        rc = ll_get_max_mdsize(sbi, &ealen);
-        if (rc)
-                return rc;
+       rc = ll_get_max_mdsize(sbi, &ealen);
+       if (rc)
+               return rc;
+
+       return seq_printf(m, "%u\n", ealen);
+}
+LPROC_SEQ_FOPS_RO(ll_max_easize);
+
+static int ll_defult_easize_seq_show(struct seq_file *m, void *v)
+{
+       struct super_block *sb = m->private;
+       struct ll_sb_info *sbi = ll_s2sbi(sb);
+       unsigned int ealen;
+       int rc;
+
+       rc = ll_get_default_mdsize(sbi, &ealen);
+       if (rc)
+               return rc;
 
        return seq_printf(m, "%u\n", ealen);
 }
-LPROC_SEQ_FOPS_RO(ll_maxea_size);
+LPROC_SEQ_FOPS_RO(ll_defult_easize);
+
+static int ll_max_cookiesize_seq_show(struct seq_file *m, void *v)
+{
+       struct super_block *sb = m->private;
+       struct ll_sb_info *sbi = ll_s2sbi(sb);
+       unsigned int cookielen;
+       int rc;
+
+       rc = ll_get_max_cookiesize(sbi, &cookielen);
+       if (rc)
+               return rc;
+
+       return seq_printf(m, "%u\n", cookielen);
+}
+LPROC_SEQ_FOPS_RO(ll_max_cookiesize);
+
+static int ll_defult_cookiesize_seq_show(struct seq_file *m, void *v)
+{
+       struct super_block *sb = m->private;
+       struct ll_sb_info *sbi = ll_s2sbi(sb);
+       unsigned int cookielen;
+       int rc;
+
+       rc = ll_get_default_cookiesize(sbi, &cookielen);
+       if (rc)
+               return rc;
+
+       return seq_printf(m, "%u\n", cookielen);
+}
+LPROC_SEQ_FOPS_RO(ll_defult_cookiesize);
 
 static int ll_sbi_flags_seq_show(struct seq_file *m, void *v)
 {
@@ -767,15 +849,115 @@ static int ll_unstable_stats_seq_show(struct seq_file *m, void *v)
        struct super_block      *sb    = m->private;
        struct ll_sb_info       *sbi   = ll_s2sbi(sb);
        struct cl_client_cache  *cache = &sbi->ll_cache;
-       int pages, mb;
+       long pages;
+       int mb;
 
-       pages = cfs_atomic_read(&cache->ccc_unstable_nr);
+       pages = atomic_long_read(&cache->ccc_unstable_nr);
        mb    = (pages * PAGE_CACHE_SIZE) >> 20;
 
-       return seq_printf(m, "unstable_pages: %8d\n"
-                               "unstable_mb:    %8d\n", pages, mb);
+       return seq_printf(m, "unstable_check:     %8d\n"
+                            "unstable_pages: %12ld\n"
+                            "unstable_mb:        %8d\n",
+                         cache->ccc_unstable_check, pages, mb);
+}
+
+static ssize_t ll_unstable_stats_seq_write(struct file *file,
+                                          const char __user *buffer,
+                                          size_t count, loff_t *unused)
+{
+       struct seq_file *seq = file->private_data;
+       struct ll_sb_info *sbi = ll_s2sbi((struct super_block *)seq->private);
+       char kernbuf[128];
+       int val, rc;
+
+       if (count == 0)
+               return 0;
+       if (count >= sizeof(kernbuf))
+               return -EINVAL;
+
+       if (copy_from_user(kernbuf, buffer, count))
+               return -EFAULT;
+       kernbuf[count] = 0;
+
+       buffer += lprocfs_find_named_value(kernbuf, "unstable_check:", &count) -
+                 kernbuf;
+       rc = lprocfs_write_helper(buffer, count, &val);
+       if (rc < 0)
+               return rc;
+
+       /* borrow lru lock to set the value */
+       spin_lock(&sbi->ll_cache.ccc_lru_lock);
+       sbi->ll_cache.ccc_unstable_check = !!val;
+       spin_unlock(&sbi->ll_cache.ccc_lru_lock);
+
+       return count;
 }
-LPROC_SEQ_FOPS_RO(ll_unstable_stats);
+LPROC_SEQ_FOPS(ll_unstable_stats);
+
+static int ll_root_squash_seq_show(struct seq_file *m, void *v)
+{
+       struct super_block *sb = m->private;
+       struct ll_sb_info *sbi = ll_s2sbi(sb);
+       struct root_squash_info *squash = &sbi->ll_squash;
+
+       return seq_printf(m, "%u:%u\n", squash->rsi_uid, squash->rsi_gid);
+}
+
+static ssize_t ll_root_squash_seq_write(struct file *file,
+                                       const char __user *buffer,
+                                       size_t count, loff_t *off)
+{
+       struct seq_file *m = file->private_data;
+       struct super_block *sb = m->private;
+       struct ll_sb_info *sbi = ll_s2sbi(sb);
+       struct root_squash_info *squash = &sbi->ll_squash;
+
+       return lprocfs_wr_root_squash(buffer, count, squash,
+                                     ll_get_fsname(sb, NULL, 0));
+}
+LPROC_SEQ_FOPS(ll_root_squash);
+
+static int ll_nosquash_nids_seq_show(struct seq_file *m, void *v)
+{
+       struct super_block *sb = m->private;
+       struct ll_sb_info *sbi = ll_s2sbi(sb);
+       struct root_squash_info *squash = &sbi->ll_squash;
+       int len, rc;
+
+       down_read(&squash->rsi_sem);
+       if (!list_empty(&squash->rsi_nosquash_nids)) {
+               len = cfs_print_nidlist(m->buf + m->count, m->size - m->count,
+                                       &squash->rsi_nosquash_nids);
+               m->count += len;
+               rc = seq_printf(m, "\n");
+       } else {
+               rc = seq_printf(m, "NONE\n");
+       }
+       up_read(&squash->rsi_sem);
+
+       return rc;
+}
+
+static ssize_t ll_nosquash_nids_seq_write(struct file *file,
+                                         const char __user *buffer,
+                                         size_t count, loff_t *off)
+{
+       struct seq_file *m = file->private_data;
+       struct super_block *sb = m->private;
+       struct ll_sb_info *sbi = ll_s2sbi(sb);
+       struct root_squash_info *squash = &sbi->ll_squash;
+       int rc;
+
+       rc = lprocfs_wr_nosquash_nids(buffer, count, squash,
+                                     ll_get_fsname(sb, NULL, 0));
+       if (rc < 0)
+               return rc;
+
+       ll_compute_rootsquash_state(sbi);
+
+       return rc;
+}
+LPROC_SEQ_FOPS(ll_nosquash_nids);
 
 struct lprocfs_seq_vars lprocfs_llite_obd_vars[] = {
        { .name =       "uuid",
@@ -825,19 +1007,29 @@ struct lprocfs_seq_vars lprocfs_llite_obd_vars[] = {
        { .name =       "lazystatfs",
          .fops =       &ll_lazystatfs_fops                     },
        { .name =       "max_easize",
-         .fops =       &ll_maxea_size_fops                     },
+         .fops =       &ll_max_easize_fops                     },
+       { .name =       "default_easize",
+         .fops =       &ll_defult_easize_fops                  },
+       { .name =       "max_cookiesize",
+         .fops =       &ll_max_cookiesize_fops                 },
+       { .name =       "default_cookiesize",
+         .fops =       &ll_defult_cookiesize_fops              },
        { .name =       "sbi_flags",
          .fops =       &ll_sbi_flags_fops                      },
        { .name =       "xattr_cache",
          .fops =       &ll_xattr_cache_fops                    },
        { .name =       "unstable_stats",
          .fops =       &ll_unstable_stats_fops                 },
-       { 0 }
+       { .name =       "root_squash",
+         .fops =       &ll_root_squash_fops                    },
+       { .name =       "nosquash_nids",
+         .fops =       &ll_nosquash_nids_fops                  },
+       { NULL }
 };
 
 #define MAX_STRING_SIZE 128
 
-struct llite_file_opcode {
+static const struct llite_file_opcode {
         __u32       opcode;
         __u32       type;
         const char *opname;
@@ -902,7 +1094,8 @@ void ll_stats_ops_tally(struct ll_sb_info *sbi, int op, int count)
                  sbi->ll_stats_track_id == current->parent->pid)
                 lprocfs_counter_add(sbi->ll_stats, op, count);
        else if (sbi->ll_stats_track_type == STATS_TRACK_GID &&
-                sbi->ll_stats_track_id == current_gid())
+                sbi->ll_stats_track_id ==
+                       from_kgid(&init_user_ns, current_gid()))
                lprocfs_counter_add(sbi->ll_stats, op, count);
 }
 EXPORT_SYMBOL(ll_stats_ops_tally);
@@ -1164,24 +1357,39 @@ static int ll_rw_extents_stats_pp_seq_show(struct seq_file *seq, void *v)
 }
 
 static ssize_t ll_rw_extents_stats_pp_seq_write(struct file *file,
-                                                const char *buf, size_t len,
-                                                loff_t *off)
+                                               const char __user *buf,
+                                               size_t len,
+                                               loff_t *off)
 {
-        struct seq_file *seq = file->private_data;
-        struct ll_sb_info *sbi = seq->private;
-        struct ll_rw_extents_info *io_extents = &sbi->ll_rw_extents_info;
-        int i;
-        int value = 1, rc = 0;
+       struct seq_file *seq = file->private_data;
+       struct ll_sb_info *sbi = seq->private;
+       struct ll_rw_extents_info *io_extents = &sbi->ll_rw_extents_info;
+       int i;
+       int value = 1, rc = 0;
 
-        rc = lprocfs_write_helper(buf, len, &value);
-        if (rc < 0 && (strcmp(buf, "disabled") == 0 ||
-                       strcmp(buf, "Disabled") == 0))
-                value = 0;
+       if (len == 0)
+               return -EINVAL;
 
-        if (value == 0)
-                sbi->ll_rw_stats_on = 0;
-        else
-                sbi->ll_rw_stats_on = 1;
+       rc = lprocfs_write_helper(buf, len, &value);
+       if (rc < 0 && len < 16) {
+               char kernbuf[16];
+
+               if (copy_from_user(kernbuf, buf, len))
+                       return -EFAULT;
+               kernbuf[len] = 0;
+
+               if (kernbuf[len - 1] == '\n')
+                       kernbuf[len - 1] = 0;
+
+               if (strcmp(kernbuf, "disabled") == 0 ||
+                   strcmp(kernbuf, "Disabled") == 0)
+                       value = 0;
+       }
+
+       if (value == 0)
+               sbi->ll_rw_stats_on = 0;
+       else
+               sbi->ll_rw_stats_on = 1;
 
        spin_lock(&sbi->ll_pp_extent_lock);
        for (i = 0; i < LL_PROCESS_HIST_MAX; i++) {
@@ -1223,24 +1431,40 @@ static int ll_rw_extents_stats_seq_show(struct seq_file *seq, void *v)
        return 0;
 }
 
-static ssize_t ll_rw_extents_stats_seq_write(struct file *file, const char *buf,
-                                        size_t len, loff_t *off)
+static ssize_t ll_rw_extents_stats_seq_write(struct file *file,
+                                            const char __user *buf,
+                                            size_t len, loff_t *off)
 {
-        struct seq_file *seq = file->private_data;
-        struct ll_sb_info *sbi = seq->private;
-        struct ll_rw_extents_info *io_extents = &sbi->ll_rw_extents_info;
-        int i;
-        int value = 1, rc = 0;
+       struct seq_file *seq = file->private_data;
+       struct ll_sb_info *sbi = seq->private;
+       struct ll_rw_extents_info *io_extents = &sbi->ll_rw_extents_info;
+       int i;
+       int value = 1, rc = 0;
 
-        rc = lprocfs_write_helper(buf, len, &value);
-        if (rc < 0 && (strcmp(buf, "disabled") == 0 ||
-                       strcmp(buf, "Disabled") == 0))
-                value = 0;
+       if (len == 0)
+               return -EINVAL;
+
+       rc = lprocfs_write_helper(buf, len, &value);
+       if (rc < 0 && len < 16) {
+               char kernbuf[16];
+
+               if (copy_from_user(kernbuf, buf, len))
+                       return -EFAULT;
+               kernbuf[len] = 0;
+
+               if (kernbuf[len - 1] == '\n')
+                       kernbuf[len - 1] = 0;
+
+               if (strcmp(kernbuf, "disabled") == 0 ||
+                   strcmp(kernbuf, "Disabled") == 0)
+                       value = 0;
+       }
+
+       if (value == 0)
+               sbi->ll_rw_stats_on = 0;
+       else
+               sbi->ll_rw_stats_on = 1;
 
-        if (value == 0)
-                sbi->ll_rw_stats_on = 0;
-        else
-                sbi->ll_rw_stats_on = 1;
        spin_lock(&sbi->ll_pp_extent_lock);
        for (i = 0; i <= LL_PROCESS_HIST_MAX; i++) {
                io_extents->pp_extents[i].pid = 0;
@@ -1251,7 +1475,6 @@ static ssize_t ll_rw_extents_stats_seq_write(struct file *file, const char *buf,
 
        return len;
 }
-
 LPROC_SEQ_FOPS(ll_rw_extents_stats);
 
 void ll_rw_stats_tally(struct ll_sb_info *sbi, pid_t pid,
@@ -1413,25 +1636,40 @@ static int ll_rw_offset_stats_seq_show(struct seq_file *seq, void *v)
        return 0;
 }
 
-static ssize_t ll_rw_offset_stats_seq_write(struct file *file, const char *buf,
-                                       size_t len, loff_t *off)
+static ssize_t ll_rw_offset_stats_seq_write(struct file *file,
+                                           const char __user *buf,
+                                           size_t len, loff_t *off)
 {
-        struct seq_file *seq = file->private_data;
-        struct ll_sb_info *sbi = seq->private;
-        struct ll_rw_process_info *process_info = sbi->ll_rw_process_info;
-        struct ll_rw_process_info *offset_info = sbi->ll_rw_offset_info;
-        int value = 1, rc = 0;
+       struct seq_file *seq = file->private_data;
+       struct ll_sb_info *sbi = seq->private;
+       struct ll_rw_process_info *process_info = sbi->ll_rw_process_info;
+       struct ll_rw_process_info *offset_info = sbi->ll_rw_offset_info;
+       int value = 1, rc = 0;
 
-        rc = lprocfs_write_helper(buf, len, &value);
+       if (len == 0)
+               return -EINVAL;
 
-        if (rc < 0 && (strcmp(buf, "disabled") == 0 ||
-                           strcmp(buf, "Disabled") == 0))
-                value = 0;
+       rc = lprocfs_write_helper(buf, len, &value);
 
-        if (value == 0)
-                sbi->ll_rw_stats_on = 0;
-        else
-                sbi->ll_rw_stats_on = 1;
+       if (rc < 0 && len < 16) {
+               char kernbuf[16];
+
+               if (copy_from_user(kernbuf, buf, len))
+                       return -EFAULT;
+               kernbuf[len] = 0;
+
+               if (kernbuf[len - 1] == '\n')
+                       kernbuf[len - 1] = 0;
+
+               if (strcmp(kernbuf, "disabled") == 0 ||
+                   strcmp(kernbuf, "Disabled") == 0)
+                       value = 0;
+       }
+
+       if (value == 0)
+               sbi->ll_rw_stats_on = 0;
+       else
+               sbi->ll_rw_stats_on = 1;
 
        spin_lock(&sbi->ll_process_lock);
        sbi->ll_offset_process_count = 0;