* match the state "is the filp on a fasync list".
*
*/
-static int fasync_remove_entry(struct file *filp, struct fasync_struct **fapp)
+int fasync_remove_entry(struct file *filp, struct fasync_struct **fapp)
{
struct fasync_struct *fa, **fp;
int result = 0;
return result;
}
+struct fasync_struct *fasync_alloc(void)
+{
+ return kmem_cache_alloc(fasync_cache, GFP_KERNEL);
+}
+
/*
- * Add a fasync entry. Return negative on error, positive if
- * added, and zero if did nothing but change an existing one.
+ * NOTE! This can be used only for unused fasync entries:
+ * entries that actually got inserted on the fasync list
+ * need to be released by rcu - see fasync_remove_entry.
+ */
+void fasync_free(struct fasync_struct *new)
+{
+ kmem_cache_free(fasync_cache, new);
+}
+
+/*
+ * Insert a new entry into the fasync list. Return the pointer to the
+ * old one if we didn't use the new one.
*
* NOTE! It is very important that the FASYNC flag always
* match the state "is the filp on a fasync list".
*/
-static int fasync_add_entry(int fd, struct file *filp, struct fasync_struct **fapp)
+struct fasync_struct *fasync_insert_entry(int fd, struct file *filp, struct fasync_struct **fapp, struct fasync_struct *new)
{
- struct fasync_struct *new, *fa, **fp;
- int result = 0;
-
- new = kmem_cache_alloc(fasync_cache, GFP_KERNEL);
- if (!new)
- return -ENOMEM;
+ struct fasync_struct *fa, **fp;
spin_lock(&filp->f_lock);
spin_lock(&fasync_lock);
spin_lock_irq(&fa->fa_lock);
fa->fa_fd = fd;
spin_unlock_irq(&fa->fa_lock);
-
- kmem_cache_free(fasync_cache, new);
goto out;
}
new->fa_fd = fd;
new->fa_next = *fapp;
rcu_assign_pointer(*fapp, new);
- result = 1;
filp->f_flags |= FASYNC;
out:
spin_unlock(&fasync_lock);
spin_unlock(&filp->f_lock);
- return result;
+ return fa;
+}
+
+/*
+ * Add a fasync entry. Return negative on error, positive if
+ * added, and zero if did nothing but change an existing one.
+ */
+static int fasync_add_entry(int fd, struct file *filp, struct fasync_struct **fapp)
+{
+ struct fasync_struct *new;
+
+ new = fasync_alloc();
+ if (!new)
+ return -ENOMEM;
+
+ /*
+ * fasync_insert_entry() returns the old (update) entry if
+ * it existed.
+ *
+ * So free the (unused) new entry and return 0 to let the
+ * caller know that we didn't add any new fasync entries.
+ */
+ if (fasync_insert_entry(fd, filp, fapp, new)) {
+ fasync_free(new);
+ return 0;
+ }
+
+ return 1;
}
/*
static int __init fcntl_init(void)
{
- /* please add new bits here to ensure allocation uniqueness */
- BUILD_BUG_ON(19 - 1 /* for O_RDONLY being 0 */ != HWEIGHT32(
+ /*
+ * Please add new bits here to ensure allocation uniqueness.
+ * Exceptions: O_NONBLOCK is a two bit define on parisc; O_NDELAY
+ * is defined as O_NONBLOCK on some platforms and not on others.
+ */
+ BUILD_BUG_ON(18 - 1 /* for O_RDONLY being 0 */ != HWEIGHT32(
O_RDONLY | O_WRONLY | O_RDWR |
O_CREAT | O_EXCL | O_NOCTTY |
- O_TRUNC | O_APPEND | O_NONBLOCK |
+ O_TRUNC | O_APPEND | /* O_NONBLOCK | */
__O_SYNC | O_DSYNC | FASYNC |
O_DIRECT | O_LARGEFILE | O_DIRECTORY |
O_NOFOLLOW | O_NOATIME | O_CLOEXEC |