diff options
Diffstat (limited to 'fs/gfs2/glock.c')
-rw-r--r-- | fs/gfs2/glock.c | 257 |
1 files changed, 242 insertions, 15 deletions
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index 41b6c89e4bf7..df335c258eb0 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -33,6 +33,9 @@ #include <linux/list_sort.h> #include <linux/lockref.h> #include <linux/rhashtable.h> +#include <linux/pid_namespace.h> +#include <linux/fdtable.h> +#include <linux/file.h> #include "gfs2.h" #include "incore.h" @@ -59,6 +62,8 @@ typedef void (*glock_examiner) (struct gfs2_glock * gl); static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target); static void __gfs2_glock_dq(struct gfs2_holder *gh); +static void handle_callback(struct gfs2_glock *gl, unsigned int state, + unsigned long delay, bool remote); static struct dentry *gfs2_root; static struct workqueue_struct *glock_workqueue; @@ -730,7 +735,8 @@ static bool is_system_glock(struct gfs2_glock *gl) * */ -static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target) +static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, + unsigned int target) __releases(&gl->gl_lockref.lock) __acquires(&gl->gl_lockref.lock) { @@ -741,7 +747,8 @@ __acquires(&gl->gl_lockref.lock) if (target != LM_ST_UNLOCKED && glock_blocked_by_withdraw(gl) && gh && !(gh->gh_flags & LM_FLAG_NOEXP)) - return; + goto skip_inval; + lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP | LM_FLAG_PRIORITY); GLOCK_BUG_ON(gl, gl->gl_state == target); @@ -826,6 +833,20 @@ skip_inval: (target != LM_ST_UNLOCKED || test_bit(SDF_WITHDRAW_RECOVERY, &sdp->sd_flags))) { if (!is_system_glock(gl)) { + handle_callback(gl, LM_ST_UNLOCKED, 0, false); /* sets demote */ + /* + * Ordinarily, we would call dlm and its callback would call + * finish_xmote, which would call state_change() to the new state. + * Since we withdrew, we won't call dlm, so call state_change + * manually, but to the UNLOCKED state we desire. + */ + state_change(gl, LM_ST_UNLOCKED); + /* + * We skip telling dlm to do the locking, so we won't get a + * reply that would otherwise clear GLF_LOCK. So we clear it here. + */ + clear_bit(GLF_LOCK, &gl->gl_flags); + clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); gfs2_glock_queue_work(gl, GL_GLOCK_DFT_HOLD); goto out; } else { @@ -1018,16 +1039,18 @@ static void delete_work_func(struct work_struct *work) if (gfs2_queue_delete_work(gl, 5 * HZ)) return; } - goto out; } inode = gfs2_lookup_by_inum(sdp, no_addr, gl->gl_no_formal_ino, GFS2_BLKST_UNLINKED); - if (!IS_ERR_OR_NULL(inode)) { + if (IS_ERR(inode)) { + if (PTR_ERR(inode) == -EAGAIN && + (gfs2_queue_delete_work(gl, 5 * HZ))) + return; + } else { d_prune_aliases(inode); iput(inode); } -out: gfs2_glock_put(gl); } @@ -1436,6 +1459,15 @@ void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...) va_end(args); } +static inline bool pid_is_meaningful(const struct gfs2_holder *gh) +{ + if (!(gh->gh_flags & GL_NOPID)) + return true; + if (gh->gh_state == LM_ST_UNLOCKED) + return true; + return false; +} + /** * add_to_queue - Add a holder to the wait queue (but look for recursion) * @gh: the holder structure to add @@ -1472,10 +1504,17 @@ __acquires(&gl->gl_lockref.lock) } list_for_each_entry(gh2, &gl->gl_holders, gh_list) { - if (unlikely(gh2->gh_owner_pid == gh->gh_owner_pid && - (gh->gh_gl->gl_ops->go_type != LM_TYPE_FLOCK) && - !test_bit(HIF_MAY_DEMOTE, &gh2->gh_iflags))) - goto trap_recursive; + if (likely(gh2->gh_owner_pid != gh->gh_owner_pid)) + continue; + if (gh->gh_gl->gl_ops->go_type == LM_TYPE_FLOCK) + continue; + if (test_bit(HIF_MAY_DEMOTE, &gh2->gh_iflags)) + continue; + if (!pid_is_meaningful(gh2)) + continue; + goto trap_recursive; + } + list_for_each_entry(gh2, &gl->gl_holders, gh_list) { if (try_futile && !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) { fail: @@ -2194,6 +2233,20 @@ static void dump_glock_func(struct gfs2_glock *gl) dump_glock(NULL, gl, true); } +static void withdraw_dq(struct gfs2_glock *gl) +{ + spin_lock(&gl->gl_lockref.lock); + if (!__lockref_is_dead(&gl->gl_lockref) && + glock_blocked_by_withdraw(gl)) + do_error(gl, LM_OUT_ERROR); /* remove pending waiters */ + spin_unlock(&gl->gl_lockref.lock); +} + +void gfs2_gl_dq_holders(struct gfs2_sbd *sdp) +{ + glock_hash_walk(withdraw_dq, sdp); +} + /** * gfs2_gl_hash_clear - Empty out the glock hash table * @sdp: the filesystem @@ -2272,19 +2325,24 @@ static const char *hflags2str(char *buf, u16 flags, unsigned long iflags) static void dump_holder(struct seq_file *seq, const struct gfs2_holder *gh, const char *fs_id_buf) { - struct task_struct *gh_owner = NULL; + const char *comm = "(none)"; + pid_t owner_pid = 0; char flags_buf[32]; rcu_read_lock(); - if (gh->gh_owner_pid) + if (pid_is_meaningful(gh)) { + struct task_struct *gh_owner; + + comm = "(ended)"; + owner_pid = pid_nr(gh->gh_owner_pid); gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID); + if (gh_owner) + comm = gh_owner->comm; + } gfs2_print_dbg(seq, "%s H: s:%s f:%s e:%d p:%ld [%s] %pS\n", fs_id_buf, state2str(gh->gh_state), hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags), - gh->gh_error, - gh->gh_owner_pid ? (long)pid_nr(gh->gh_owner_pid) : -1, - gh_owner ? gh_owner->comm : "(ended)", - (void *)gh->gh_ip); + gh->gh_error, (long)owner_pid, comm, (void *)gh->gh_ip); rcu_read_unlock(); } @@ -2699,6 +2757,172 @@ static const struct file_operations gfs2_glstats_fops = { .release = gfs2_glocks_release, }; +struct gfs2_glockfd_iter { + struct super_block *sb; + unsigned int tgid; + struct task_struct *task; + unsigned int fd; + struct file *file; +}; + +static struct task_struct *gfs2_glockfd_next_task(struct gfs2_glockfd_iter *i) +{ + struct pid_namespace *ns = task_active_pid_ns(current); + struct pid *pid; + + if (i->task) + put_task_struct(i->task); + + rcu_read_lock(); +retry: + i->task = NULL; + pid = find_ge_pid(i->tgid, ns); + if (pid) { + i->tgid = pid_nr_ns(pid, ns); + i->task = pid_task(pid, PIDTYPE_TGID); + if (!i->task) { + i->tgid++; + goto retry; + } + get_task_struct(i->task); + } + rcu_read_unlock(); + return i->task; +} + +static struct file *gfs2_glockfd_next_file(struct gfs2_glockfd_iter *i) +{ + if (i->file) { + fput(i->file); + i->file = NULL; + } + + rcu_read_lock(); + for(;; i->fd++) { + struct inode *inode; + + i->file = task_lookup_next_fd_rcu(i->task, &i->fd); + if (!i->file) { + i->fd = 0; + break; + } + inode = file_inode(i->file); + if (inode->i_sb != i->sb) + continue; + if (get_file_rcu(i->file)) + break; + } + rcu_read_unlock(); + return i->file; +} + +static void *gfs2_glockfd_seq_start(struct seq_file *seq, loff_t *pos) +{ + struct gfs2_glockfd_iter *i = seq->private; + + if (*pos) + return NULL; + while (gfs2_glockfd_next_task(i)) { + if (gfs2_glockfd_next_file(i)) + return i; + i->tgid++; + } + return NULL; +} + +static void *gfs2_glockfd_seq_next(struct seq_file *seq, void *iter_ptr, + loff_t *pos) +{ + struct gfs2_glockfd_iter *i = seq->private; + + (*pos)++; + i->fd++; + do { + if (gfs2_glockfd_next_file(i)) + return i; + i->tgid++; + } while (gfs2_glockfd_next_task(i)); + return NULL; +} + +static void gfs2_glockfd_seq_stop(struct seq_file *seq, void *iter_ptr) +{ + struct gfs2_glockfd_iter *i = seq->private; + + if (i->file) + fput(i->file); + if (i->task) + 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; + struct inode *inode = file_inode(i->file); + struct gfs2_glock *gl; + + inode_lock_shared(inode); + gl = GFS2_I(inode)->i_iopen_gh.gh_gl; + if (gl) { + seq_printf(seq, "%d %u %u/%llx\n", + 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; +} + +static const struct seq_operations gfs2_glockfd_seq_ops = { + .start = gfs2_glockfd_seq_start, + .next = gfs2_glockfd_seq_next, + .stop = gfs2_glockfd_seq_stop, + .show = gfs2_glockfd_seq_show, +}; + +static int gfs2_glockfd_open(struct inode *inode, struct file *file) +{ + struct gfs2_glockfd_iter *i; + struct gfs2_sbd *sdp = inode->i_private; + + i = __seq_open_private(file, &gfs2_glockfd_seq_ops, + sizeof(struct gfs2_glockfd_iter)); + if (!i) + return -ENOMEM; + i->sb = sdp->sd_vfs; + return 0; +} + +static const struct file_operations gfs2_glockfd_fops = { + .owner = THIS_MODULE, + .open = gfs2_glockfd_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release_private, +}; + DEFINE_SEQ_ATTRIBUTE(gfs2_sbstats); void gfs2_create_debugfs_file(struct gfs2_sbd *sdp) @@ -2708,6 +2932,9 @@ void gfs2_create_debugfs_file(struct gfs2_sbd *sdp) debugfs_create_file("glocks", S_IFREG | S_IRUGO, sdp->debugfs_dir, sdp, &gfs2_glocks_fops); + debugfs_create_file("glockfd", S_IFREG | S_IRUGO, sdp->debugfs_dir, sdp, + &gfs2_glockfd_fops); + debugfs_create_file("glstats", S_IFREG | S_IRUGO, sdp->debugfs_dir, sdp, &gfs2_glstats_fops); |