hugetlbfs: per mount huge page sizes

Add the ability to configure the hugetlb hstate used on a per mount basis.

- Add a new pagesize= option to the hugetlbfs mount that allows setting
  the page size
- This option causes the mount code to find the hstate corresponding to the
  specified size, and sets up a pointer to the hstate in the mount's
  superblock.
- Change the hstate accessors to use this information rather than the
  global_hstate they were using (requires a slight change in mm/memory.c
  so we don't NULL deref in the error-unmap path -- see comments).

[np: take hstate out of hugetlbfs inode and vma->vm_private_data]

Acked-by: Adam Litke <agl@us.ibm.com>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 36 insertions, 9 deletions

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 516c581b5371..dbd01d262ca4 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -53,6 +53,7 @@ int sysctl_hugetlb_shm_group;
 enum {
         Opt_size, Opt_nr_inodes,
         Opt_mode, Opt_uid, Opt_gid,
+        Opt_pagesize,
         Opt_err,
 };
 
@@ -62,6 +63,7 @@ static match_table_t tokens = {
         {Opt_mode,      "mode=%o"},
         {Opt_uid,       "uid=%u"},
         {Opt_gid,       "gid=%u"},
+        {Opt_pagesize,  "pagesize=%s"},
         {Opt_err,       NULL},
 };
 
@@ -750,6 +752,8 @@ hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
         char *p, *rest;
         substring_t args[MAX_OPT_ARGS];
         int option;
+        unsigned long long size = 0;
+        enum { NO_SIZE, SIZE_STD, SIZE_PERCENT } setsize = NO_SIZE;
 
         if (!options)
                 return 0;
@@ -780,17 +784,13 @@ hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
                         break;
 
                 case Opt_size: {
-                        unsigned long long size;
                         /* memparse() will accept a K/M/G without a digit */
                         if (!isdigit(*args[0].from))
                                 goto bad_val;
                         size = memparse(args[0].from, &rest);
-                        if (*rest == '%') {
-                                size <<= HPAGE_SHIFT;
-                                size *= max_huge_pages;
-                                do_div(size, 100);
-                        }
-                        pconfig->nr_blocks = (size >> HPAGE_SHIFT);
+                        setsize = SIZE_STD;
+                        if (*rest == '%')
+                                setsize = SIZE_PERCENT;
                         break;
                 }
 
@@ -801,6 +801,19 @@ hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
                         pconfig->nr_inodes = memparse(args[0].from, &rest);
                         break;
 
+                case Opt_pagesize: {
+                        unsigned long ps;
+                        ps = memparse(args[0].from, &rest);
+                        pconfig->hstate = size_to_hstate(ps);
+                        if (!pconfig->hstate) {
+                                printk(KERN_ERR
+                                "hugetlbfs: Unsupported page size %lu MB\n",
+                                        ps >> 20);
+                                return -EINVAL;
+                        }
+                        break;
+                }
+
                 default:
                         printk(KERN_ERR "hugetlbfs: Bad mount option: \"%s\"\n",
                                  p);
@@ -808,6 +821,18 @@ hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
                         break;
                 }
         }
+
+        /* Do size after hstate is set up */
+        if (setsize > NO_SIZE) {
+                struct hstate *h = pconfig->hstate;
+                if (setsize == SIZE_PERCENT) {
+                        size <<= huge_page_shift(h);
+                        size *= h->max_huge_pages;
+                        do_div(size, 100);
+                }
+                pconfig->nr_blocks = (size >> huge_page_shift(h));
+        }
+
         return 0;
 
 bad_val:
@@ -832,6 +857,7 @@ hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
         config.uid = current->fsuid;
         config.gid = current->fsgid;
         config.mode = 0755;
+        config.hstate = &default_hstate;
         ret = hugetlbfs_parse_options(data, &config);
         if (ret)
                 return ret;
@@ -840,14 +866,15 @@ hugetlbfs_fill_super(struct super_block *sb, void *data, int silent)
         if (!sbinfo)
                 return -ENOMEM;
         sb->s_fs_info = sbinfo;
+        sbinfo->hstate = config.hstate;
         spin_lock_init(&sbinfo->stat_lock);
         sbinfo->max_blocks = config.nr_blocks;
         sbinfo->free_blocks = config.nr_blocks;
         sbinfo->max_inodes = config.nr_inodes;
         sbinfo->free_inodes = config.nr_inodes;
         sb->s_maxbytes = MAX_LFS_FILESIZE;
-        sb->s_blocksize = HPAGE_SIZE;
-        sb->s_blocksize_bits = HPAGE_SHIFT;
+        sb->s_blocksize = huge_page_size(config.hstate);
+        sb->s_blocksize_bits = huge_page_shift(config.hstate);
         sb->s_magic = HUGETLBFS_MAGIC;
         sb->s_op = &hugetlbfs_ops;
         sb->s_time_gran = 1;