diff options
author | Andreas Gruenbacher <agruenba@redhat.com> | 2022-06-24 00:29:36 +0300 |
---|---|---|
committer | Andreas Gruenbacher <agruenba@redhat.com> | 2022-06-29 14:07:53 +0300 |
commit | 56535dc695f8e215dffb9557d6bcbdf46ff785d2 (patch) | |
tree | 30f7fc17aef17946703a62fb8185cd8f7e03198f /fs/gfs2 | |
parent | 4480c27ca3eaaaae134633a594fba5601da13b4a (diff) | |
download | linux-56535dc695f8e215dffb9557d6bcbdf46ff785d2.tar.xz |
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 <agruenba@redhat.com>
Diffstat (limited to 'fs/gfs2')
-rw-r--r-- | fs/gfs2/file.c | 22 | ||||
-rw-r--r-- | fs/gfs2/glock.c | 23 |
2 files changed, 43 insertions, 2 deletions
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); } diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index 85352126e662..533ec772166d 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -2846,6 +2846,28 @@ static void gfs2_glockfd_seq_stop(struct seq_file *seq, void *iter_ptr) put_task_struct(i->task); } +static void gfs2_glockfd_seq_show_flock(struct seq_file *seq, + struct gfs2_glockfd_iter *i) +{ + struct gfs2_file *fp = i->file->private_data; + struct gfs2_holder *fl_gh = &fp->f_fl_gh; + struct lm_lockname gl_name = { .ln_type = LM_TYPE_RESERVED }; + + if (!READ_ONCE(fl_gh->gh_gl)) + return; + + spin_lock(&i->file->f_lock); + if (gfs2_holder_initialized(fl_gh)) + gl_name = fl_gh->gh_gl->gl_name; + spin_unlock(&i->file->f_lock); + + if (gl_name.ln_type != LM_TYPE_RESERVED) { + seq_printf(seq, "%d %u %u/%llx\n", + i->tgid, i->fd, gl_name.ln_type, + (unsigned long long)gl_name.ln_number); + } +} + static int gfs2_glockfd_seq_show(struct seq_file *seq, void *iter_ptr) { struct gfs2_glockfd_iter *i = seq->private; @@ -2859,6 +2881,7 @@ static int gfs2_glockfd_seq_show(struct seq_file *seq, void *iter_ptr) i->tgid, i->fd, gl->gl_name.ln_type, (unsigned long long)gl->gl_name.ln_number); } + gfs2_glockfd_seq_show_flock(seq, i); inode_unlock_shared(inode); return 0; } |