hfsplus: use atomic bitops for the superblock flags

The flags in the HFS+-specific superlock do get modified during runtime,
use atomic bitops to make the modifications SMP safe.

Signed-off-by: Christoph Hellwig <hch@tuxera.com>

1 files changed, 9 insertions, 5 deletions

diff --git a/fs/hfsplus/wrapper.c b/fs/hfsplus/wrapper.c
index c89e198e8a2a..8972c20b3216 100644
--- a/fs/hfsplus/wrapper.c
+++ b/fs/hfsplus/wrapper.c
@@ -123,7 +123,7 @@ int hfsplus_read_wrapper(struct super_block *sb)
                 if (vhdr->signature == cpu_to_be16(HFSPLUS_VOLHEAD_SIG))
                         break;
                 if (vhdr->signature == cpu_to_be16(HFSPLUS_VOLHEAD_SIGX)) {
-                        sbi->flags |= HFSPLUS_SB_HFSX;
+                        set_bit(HFSPLUS_SB_HFSX, &sbi->flags);
                         break;
                 }
                 brelse(bh);
@@ -169,10 +169,14 @@ int hfsplus_read_wrapper(struct super_block *sb)
                 return -EIO;
 
         /* should still be the same... */
-        if (vhdr->signature != (sbi->flags & HFSPLUS_SB_HFSX ?
-                                cpu_to_be16(HFSPLUS_VOLHEAD_SIGX) :
-                                cpu_to_be16(HFSPLUS_VOLHEAD_SIG)))
-                goto error;
+        if (test_bit(HFSPLUS_SB_HFSX, &sbi->flags)) {
+                if (vhdr->signature != cpu_to_be16(HFSPLUS_VOLHEAD_SIGX))
+                        goto error;
+        } else {
+                if (vhdr->signature != cpu_to_be16(HFSPLUS_VOLHEAD_SIG))
+                        goto error;
+        }
+
         sbi->s_vhbh = bh;
         sbi->s_vhdr = vhdr;