The inode cache can be altered and queried by multiple threads of
execution, even before the introduction of delayed write support for
NAND. This provides a new lock to prevent simultaneous modification of
the cache.
---
cpukit/libfs/src/jffs2/src/fs-rtems.c | 24 +++++++++++++++++++++++-
cpukit/libfs/src/jffs2/src/os-rtems.h | 2 ++
2 files changed, 25 insertions(+), 1 deletion(-)
diff --git a/cpukit/libfs/src/jffs2/src/fs-rtems.c
b/cpukit/libfs/src/jffs2/src/fs-rtems.c
index 8e8dfe8b0c..6a14bfa9b3 100644
--- a/cpukit/libfs/src/jffs2/src/fs-rtems.c
+++ b/cpukit/libfs/src/jffs2/src/fs-rtems.c
@@ -369,6 +369,7 @@ static void rtems_jffs2_free_fs_info(rtems_jffs2_fs_info
*fs_info, bool do_mount
rtems_jffs2_flash_control_destroy(fs_info->sb.s_flash_control);
rtems_jffs2_compressor_control_destroy(fs_info->sb.s_compressor_control);
rtems_recursive_mutex_destroy(&sb->s_mutex);
+ rtems_recursive_mutex_destroy(&sb->s_cache_mutex);
free(fs_info);
}
@@ -1071,7 +1072,9 @@ static void
rtems_jffs2_fsunmount(rtems_filesystem_mount_table_entry_t *mt_entry
jffs2_sum_exit(c);
+ rtems_recursive_mutex_lock(&fs_info->sb.s_cache_mutex);
icache_evict(root_i, NULL);
+ rtems_recursive_mutex_unlock(&fs_info->sb.s_cache_mutex);
assert(root_i->i_cache_next == NULL);
assert(root_i->i_count == 1);
jffs2_iput(root_i);
@@ -1388,6 +1391,7 @@ int rtems_jffs2_initialize(
spin_lock_init(&c->inocache_lock);
c->mtd = NULL;
rtems_recursive_mutex_init(&sb->s_mutex,
RTEMS_FILESYSTEM_TYPE_JFFS2);
+ rtems_recursive_mutex_init(&sb->s_cache_mutex,
RTEMS_FILESYSTEM_TYPE_JFFS2);
}
/* Start task for delayed work if it hasn't already been started */
@@ -1497,6 +1501,7 @@ int rtems_jffs2_initialize(
//
//==========================================================================
+// The s_cache_mutex must be held while calling this function
static struct _inode *new_inode(struct super_block *sb)
{
@@ -1537,6 +1542,7 @@ static struct _inode *new_inode(struct super_block *sb)
return inode;
}
+// The s_cache_mutex must be held while calling this function
static struct _inode *ilookup(struct super_block *sb, cyg_uint32 ino)
{
struct _inode *inode = NULL;
@@ -1565,12 +1571,20 @@ struct _inode *jffs2_iget(struct super_block *sb,
cyg_uint32 ino)
D2(printf("jffs2_iget\n"));
+ /*
+ * ilookup and new_inode need to be locked together since they're
+ * related manipulations of the inode cache
+ */
+ rtems_recursive_mutex_lock(&sb->s_cache_mutex);
inode = ilookup(sb, ino);
- if (inode)
+ if (inode) {
+ rtems_recursive_mutex_unlock(&sb->s_cache_mutex);
return inode;
+ }
// Not cached, so malloc it
inode = new_inode(sb);
+ rtems_recursive_mutex_unlock(&sb->s_cache_mutex);
if (inode == NULL)
return ERR_PTR(-ENOMEM);
@@ -1612,6 +1626,7 @@ void jffs2_iput(struct _inode *i)
struct _inode *parent;
// Remove from the icache linked list and free immediately
+ rtems_recursive_mutex_lock(&i->i_sb->s_cache_mutex);
if (i->i_cache_prev)
i->i_cache_prev->i_cache_next = i->i_cache_next;
if (i->i_cache_next)
@@ -1619,6 +1634,7 @@ void jffs2_iput(struct _inode *i)
parent = i->i_parent;
jffs2_clear_inode(i);
+ rtems_recursive_mutex_unlock(&i->i_sb->s_cache_mutex);
memset(i, 0x5a, sizeof(*i));
free(i);
@@ -1630,7 +1646,9 @@ void jffs2_iput(struct _inode *i)
} else {
// Evict some _other_ inode with i_count zero, leaving
// this latest one in the cache for a while
+ rtems_recursive_mutex_lock(&i->i_sb->s_cache_mutex);
icache_evict(i->i_sb->s_root, i);
+ rtems_recursive_mutex_unlock(&i->i_sb->s_cache_mutex);
}
}
@@ -1679,7 +1697,9 @@ struct _inode *jffs2_new_inode (struct _inode *dir_i, int
mode, struct jffs2_raw
c = JFFS2_SB_INFO(sb);
+ rtems_recursive_mutex_lock(&sb->s_cache_mutex);
inode = new_inode(sb);
+ rtems_recursive_mutex_unlock(&sb->s_cache_mutex);
if (!inode)
return ERR_PTR(-ENOMEM);
@@ -1784,7 +1804,9 @@ struct jffs2_inode_info *jffs2_gc_fetch_inode(struct
jffs2_sb_info *c,
holding the alloc_sem, and jffs2_do_unlink() would also
need that while decrementing nlink on any inode.
*/
+ rtems_recursive_mutex_lock(&(OFNI_BS_2SFFJ(c))->s_cache_mutex);
inode = ilookup(OFNI_BS_2SFFJ(c), inum);
+
rtems_recursive_mutex_unlock(&(OFNI_BS_2SFFJ(c))->s_cache_mutex);
if (!inode) {
jffs2_dbg(1, "ilookup() failed for ino #%u; inode is
probably deleted.\n",
inum);
diff --git a/cpukit/libfs/src/jffs2/src/os-rtems.h
b/cpukit/libfs/src/jffs2/src/os-rtems.h
index 63841a5e50..a53d909b4c 100644
--- a/cpukit/libfs/src/jffs2/src/os-rtems.h
+++ b/cpukit/libfs/src/jffs2/src/os-rtems.h
@@ -100,6 +100,8 @@ struct _inode {
struct super_block {
struct jffs2_sb_info jffs2_sb;
+ /* Protects the s_root inode cache */
+ rtems_recursive_mutex s_cache_mutex;
struct _inode * s_root;
rtems_jffs2_flash_control *s_flash_control;
rtems_jffs2_compressor_control *s_compressor_control;
--
2.39.2
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