From 56535dc695f8e215dffb9557d6bcbdf46ff785d2 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Thu, 23 Jun 2022 23:29:36 +0200 Subject: gfs2: Add flocks to glockfd debugfs file Include flock glocks in the "glockfd" debugfs file. Those are similar to the iopen glocks; while an open file is holding an flock, it is holding the file's flock glock. We cannot take f_fl_mutex in gfs2_glockfd_seq_show_flock() or else dumping the "glockfd" file would block on flock operations. Instead, use the file->f_lock spin lock to protect the f_fl_gh.gh_gl glock pointer. Signed-off-by: Andreas Gruenbacher --- fs/gfs2/file.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) (limited to 'fs/gfs2/file.c') diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index 2cceb193dcd8..25f4080bc973 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -1444,6 +1444,22 @@ static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl) return dlm_posix_lock(ls->ls_dlm, ip->i_no_addr, file, cmd, fl); } +static void __flock_holder_uninit(struct file *file, struct gfs2_holder *fl_gh) +{ + struct gfs2_glock *gl = fl_gh->gh_gl; + + /* + * Make sure gfs2_glock_put() won't sleep under the file->f_lock + * spinlock. + */ + + gfs2_glock_hold(gl); + spin_lock(&file->f_lock); + gfs2_holder_uninit(fl_gh); + spin_unlock(&file->f_lock); + gfs2_glock_put(gl); +} + static int do_flock(struct file *file, int cmd, struct file_lock *fl) { struct gfs2_file *fp = file->private_data; @@ -1475,7 +1491,9 @@ static int do_flock(struct file *file, int cmd, struct file_lock *fl) &gfs2_flock_glops, CREATE, &gl); if (error) goto out; + spin_lock(&file->f_lock); gfs2_holder_init(gl, state, flags, fl_gh); + spin_unlock(&file->f_lock); gfs2_glock_put(gl); } for (sleeptime = 1; sleeptime <= 4; sleeptime <<= 1) { @@ -1486,7 +1504,7 @@ static int do_flock(struct file *file, int cmd, struct file_lock *fl) msleep(sleeptime); } if (error) { - gfs2_holder_uninit(fl_gh); + __flock_holder_uninit(file, fl_gh); if (error == GLR_TRYFAILED) error = -EAGAIN; } else { @@ -1508,7 +1526,7 @@ static void do_unflock(struct file *file, struct file_lock *fl) locks_lock_file_wait(file, fl); if (gfs2_holder_initialized(fl_gh)) { gfs2_glock_dq(fl_gh); - gfs2_holder_uninit(fl_gh); + __flock_holder_uninit(file, fl_gh); } mutex_unlock(&fp->f_fl_mutex); } -- cgit v1.2.3