From: Tycho Andersen <tandersen@xxxxxxxxxxx>
In future patches, we'll need a count of the number of open file
descriptors for misc NOFILE cgroup migration, so introduce a helper to do
this.
Signed-off-by: Tycho Andersen <tandersen@xxxxxxxxxxx>
---
fs/file.c | 10 ++++++++++
include/linux/fdtable.h | 2 ++
2 files changed, 12 insertions(+)
diff --git a/fs/file.c b/fs/file.c
index b1633c00bd3c..539bead2364e 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -285,6 +285,16 @@ static unsigned int count_possible_open_files(struct fdtable *fdt)
return i;
}
+u64 count_open_files(struct fdtable *fdt)
+{
+ int i;
+ u64 retval = 0;
+
+ for (i = 0; i < DIV_ROUND_UP(fdt->max_fds, BITS_PER_LONG); i++)
+ retval += hweight64((__u64)fdt->open_fds[i]);
+ return retval;
+}
+
/*
* Note that a sane fdtable size always has to be a multiple of
* BITS_PER_LONG, since we have bitmaps that are sized by this.
diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h
index bc4c3287a65e..d74234c5d4e9 100644
--- a/include/linux/fdtable.h
+++ b/include/linux/fdtable.h
@@ -77,6 +77,8 @@ struct dentry;
#define files_fdtable(files) \
rcu_dereference_check_fdtable((files), (files)->fdt)
+u64 count_open_files(struct fdtable *fdt);
+
/*
* The caller must ensure that fd table isn't shared or hold rcu or file lock
*/
--
2.34.1
