HPFS: Introduce a global mutex and lock it on every callback from VFS.

Introduce a global mutex and lock it on every callback from VFS.

Performance doesn't matter, reviewing the whole code for locking correctness
would be too complicated, so simply lock it all.

Signed-off-by: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/fs/hpfs/buffer.c b/fs/hpfs/buffer.c
index 793cb9d943d2..7cef5d5c3608 100644
--- a/fs/hpfs/buffer.c
+++ b/fs/hpfs/buffer.c
@@ -32,6 +32,8 @@ void *hpfs_map_sector(struct super_block *s, unsigned secno, struct buffer_head
 {
         struct buffer_head *bh;
 
+        hpfs_lock_assert(s);
+
         cond_resched();
 
         *bhp = bh = sb_bread(s, secno);
@@ -50,6 +52,8 @@ void *hpfs_get_sector(struct super_block *s, unsigned secno, struct buffer_head
         struct buffer_head *bh;
         /*return hpfs_map_sector(s, secno, bhp, 0);*/
 
+        hpfs_lock_assert(s);
+
         cond_resched();
 
         if ((*bhp = bh = sb_getblk(s, secno)) != NULL) {
@@ -70,6 +74,8 @@ void *hpfs_map_4sectors(struct super_block *s, unsigned secno, struct quad_buffe
         struct buffer_head *bh;
         char *data;
 
+        hpfs_lock_assert(s);
+
         cond_resched();
 
         if (secno & 3) {
@@ -125,6 +131,8 @@ void *hpfs_get_4sectors(struct super_block *s, unsigned secno,
 {
         cond_resched();
 
+        hpfs_lock_assert(s);
+
         if (secno & 3) {
                 printk("HPFS: hpfs_get_4sectors: unaligned read\n");
                 return NULL;