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authorMichal Marek <mmarek@suse.cz>2010-10-12 15:09:06 +0200
committerMichal Marek <mmarek@suse.cz>2010-10-12 15:09:06 +0200
commit239060b93bb30a4ad55f1ecaa512464a035cc5ba (patch)
tree77f79810e57d4fc24356eca0cd6db463e8994128 /fs/file_table.c
parent1408b15b98635a13bad2e2a50b3c2ae2ccdf625b (diff)
parente9203c988234aa512bd45ca32b52e21c7bbfc414 (diff)
Merge branch 'kbuild/rc-fixes' into kbuild/kconfig
We need to revert the temporary hack in 71ebc01, hence the merge.
Diffstat (limited to 'fs/file_table.c')
-rw-r--r--fs/file_table.c19
1 files changed, 14 insertions, 5 deletions
diff --git a/fs/file_table.c b/fs/file_table.c
index 5c7d10ead4ad..edecd36fed9b 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -289,11 +289,20 @@ struct file *fget(unsigned int fd)
EXPORT_SYMBOL(fget);
/*
- * Lightweight file lookup - no refcnt increment if fd table isn't shared.
- * You can use this only if it is guranteed that the current task already
- * holds a refcnt to that file. That check has to be done at fget() only
- * and a flag is returned to be passed to the corresponding fput_light().
- * There must not be a cloning between an fget_light/fput_light pair.
+ * Lightweight file lookup - no refcnt increment if fd table isn't shared.
+ *
+ * You can use this instead of fget if you satisfy all of the following
+ * conditions:
+ * 1) You must call fput_light before exiting the syscall and returning control
+ * to userspace (i.e. you cannot remember the returned struct file * after
+ * returning to userspace).
+ * 2) You must not call filp_close on the returned struct file * in between
+ * calls to fget_light and fput_light.
+ * 3) You must not clone the current task in between the calls to fget_light
+ * and fput_light.
+ *
+ * The fput_needed flag returned by fget_light should be passed to the
+ * corresponding fput_light.
*/
struct file *fget_light(unsigned int fd, int *fput_needed)
{