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-rw-r--r--fs/fat/fatent.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
index ab171ea8e869..2c1b73fb82ae 100644
--- a/fs/fat/fatent.c
+++ b/fs/fat/fatent.c
@@ -17,6 +17,8 @@ struct fatent_operations {
int (*ent_next)(struct fat_entry *);
};
+static DEFINE_SPINLOCK(fat12_entry_lock);
+
static void fat12_ent_blocknr(struct super_block *sb, int entry,
int *offset, sector_t *blocknr)
{
@@ -116,10 +118,13 @@ static int fat12_ent_get(struct fat_entry *fatent)
u8 **ent12_p = fatent->u.ent12_p;
int next;
+ spin_lock(&fat12_entry_lock);
if (fatent->entry & 1)
next = (*ent12_p[0] >> 4) | (*ent12_p[1] << 4);
else
next = (*ent12_p[1] << 8) | *ent12_p[0];
+ spin_unlock(&fat12_entry_lock);
+
next &= 0x0fff;
if (next >= BAD_FAT12)
next = FAT_ENT_EOF;
@@ -151,6 +156,7 @@ static void fat12_ent_put(struct fat_entry *fatent, int new)
if (new == FAT_ENT_EOF)
new = EOF_FAT12;
+ spin_lock(&fat12_entry_lock);
if (fatent->entry & 1) {
*ent12_p[0] = (new << 4) | (*ent12_p[0] & 0x0f);
*ent12_p[1] = new >> 4;
@@ -158,6 +164,7 @@ static void fat12_ent_put(struct fat_entry *fatent, int new)
*ent12_p[0] = new & 0xff;
*ent12_p[1] = (*ent12_p[1] & 0xf0) | (new >> 8);
}
+ spin_unlock(&fat12_entry_lock);
mark_buffer_dirty(fatent->bhs[0]);
if (fatent->nr_bhs == 2)