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Diffstat (limited to 'ext2fs')
-rw-r--r--ext2fs/pager.c43
1 files changed, 27 insertions, 16 deletions
diff --git a/ext2fs/pager.c b/ext2fs/pager.c
index 558c87e4..8869c652 100644
--- a/ext2fs/pager.c
+++ b/ext2fs/pager.c
@@ -598,7 +598,8 @@ pager_clear_user_data (struct user_pager_info *upi)
if (upi->type == FILE_DATA)
{
spin_lock (&node_to_page_lock);
- upi->node->dn->fileinfo = 0;
+ if (upi->node->dn->fileinfo == upi)
+ upi->node->dn->fileinfo = 0;
spin_unlock (&node_to_page_lock);
diskfs_nrele_light (upi->node);
@@ -662,21 +663,31 @@ diskfs_get_filemap (struct node *node)
|| (S_ISLNK (node->dn_stat.st_mode)));
spin_lock (&node_to_page_lock);
- if (!node->dn->fileinfo)
- {
- upi = malloc (sizeof (struct user_pager_info));
- upi->type = FILE_DATA;
- upi->node = node;
- diskfs_nref_light (node);
- upi->p =
- pager_create (upi, pager_bucket, MAY_CACHE, MEMORY_OBJECT_COPY_DELAY);
- node->dn->fileinfo = upi;
- right = pager_get_port (node->dn->fileinfo->p);
- ports_port_deref (node->dn->fileinfo->p);
- }
- else
- /* XXX race; see ufs/pager.c here. */
- right = pager_get_port (node->dn->fileinfo->p);
+ do
+ if (!node->dn->fileinfo)
+ {
+ upi = malloc (sizeof (struct user_pager_info));
+ upi->type = FILE_DATA;
+ upi->node = node;
+ diskfs_nref_light (node);
+ upi->p =
+ pager_create (upi, pager_bucket, MAY_CACHE,
+ MEMORY_OBJECT_COPY_DELAY);
+ node->dn->fileinfo = upi;
+ right = pager_get_port (node->dn->fileinfo->p);
+ ports_port_deref (node->dn->fileinfo->p);
+ }
+ else
+ {
+ /* Because NP->dn->fileinfo->p is not a real reference,
+ this might be nearly deallocated. If that's so, then
+ the port right will be null. In that case, clear here
+ and loop. The deallocation will complete separately. */
+ right = pager_get_port (node->dn->fileinfo->p);
+ if (right == MACH_PORT_NULL)
+ node->dn->fileinfo = 0;
+ }
+ while (right == MACH_PORT_NULL);
spin_unlock (&node_to_page_lock);
mach_port_insert_right (mach_task_self (), right, right,