commit 4a9d4b024a31 ("switch fput to task_work_add") implements a
schedule_work() for completing fput(), but did not guarantee calling
__fput() after unpacking initramfs. Because of this, there is a
possibility that during boot a driver can see ETXTBSY when it tries
to load a binary from initramfs as fput() is still pending on that
binary. This patch makes sure that fput() is completed after unpacking
initramfs.Reported-by: Murali Karicheri <m-kariche...@ti.com> Signed-off-by: Lokesh Vutla <lokeshvu...@ti.com> --- Link to RFC: https://patchwork.kernel.org/patch/9520539/ Changes since v1: - Moved flush_delayed_fput() before loading default modules. Note: Reproduced on TI K2HK EVM. K2HK Queue Manager subsystem driver[1] tries to load a firmware from initramfs during boot. Sometimes loading of this firmware fails with error ETXTBSY. Digging a bit more observed that deny_write_access() is returning ETXTBSY as inode->i_writecount is > 0 for that file. This is because Unpacking initramfs does a get_write_access(from open) but hasn't done put_write_access(from fput) as it hasn't been scheduled yet. [1] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/soc/ti/knav_qmss_queue.c init/initramfs.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/init/initramfs.c b/init/initramfs.c index b32ad7d97ac9..981f286c1d16 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -18,6 +18,7 @@ #include <linux/dirent.h> #include <linux/syscalls.h> #include <linux/utime.h> +#include <linux/file.h> static ssize_t __init xwrite(int fd, const char *p, size_t count) { @@ -647,6 +648,7 @@ static int __init populate_rootfs(void) printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err); free_initrd(); #endif + flush_delayed_fput(); /* * Try loading default modules from initramfs. This gives * us a chance to load before device_initcalls. -- 2.11.0
