From f15146380d28b746df3c8b81b392812eb982382a Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Tue, 12 Jul 2011 20:48:39 +0200 Subject: fs: seq_file - add event counter to simplify poll() support Moving the event counter into the dynamically allocated 'struc seq_file' allows poll() support without the need to allocate its own tracking structure. All current users are switched over to use the new counter. Requested-by: Andrew Morton akpm@linux-foundation.org Acked-by: NeilBrown Tested-by: Lucas De Marchi lucas.demarchi@profusion.mobi Signed-off-by: Kay Sievers Signed-off-by: Al Viro --- drivers/md/md.c | 26 ++++++++------------------ fs/namespace.c | 4 ++-- fs/proc/base.c | 2 +- include/linux/mnt_namespace.h | 1 - include/linux/seq_file.h | 1 + mm/swapfile.c | 29 ++++++++--------------------- 6 files changed, 20 insertions(+), 43 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 91e31e260b4..dfc9425db70 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -6394,16 +6394,11 @@ static void md_seq_stop(struct seq_file *seq, void *v) mddev_put(mddev); } -struct mdstat_info { - int event; -}; - static int md_seq_show(struct seq_file *seq, void *v) { mddev_t *mddev = v; sector_t sectors; mdk_rdev_t *rdev; - struct mdstat_info *mi = seq->private; struct bitmap *bitmap; if (v == (void*)1) { @@ -6415,7 +6410,7 @@ static int md_seq_show(struct seq_file *seq, void *v) spin_unlock(&pers_lock); seq_printf(seq, "\n"); - mi->event = atomic_read(&md_event_count); + seq->poll_event = atomic_read(&md_event_count); return 0; } if (v == (void*)2) { @@ -6527,26 +6522,21 @@ static const struct seq_operations md_seq_ops = { static int md_seq_open(struct inode *inode, struct file *file) { + struct seq_file *seq; int error; - struct mdstat_info *mi = kmalloc(sizeof(*mi), GFP_KERNEL); - if (mi == NULL) - return -ENOMEM; error = seq_open(file, &md_seq_ops); if (error) - kfree(mi); - else { - struct seq_file *p = file->private_data; - p->private = mi; - mi->event = atomic_read(&md_event_count); - } + return error; + + seq = file->private_data; + seq->poll_event = atomic_read(&md_event_count); return error; } static unsigned int mdstat_poll(struct file *filp, poll_table *wait) { - struct seq_file *m = filp->private_data; - struct mdstat_info *mi = m->private; + struct seq_file *seq = filp->private_data; int mask; poll_wait(filp, &md_event_waiters, wait); @@ -6554,7 +6544,7 @@ static unsigned int mdstat_poll(struct file *filp, poll_table *wait) /* always allow read */ mask = POLLIN | POLLRDNORM; - if (mi->event != atomic_read(&md_event_count)) + if (seq->poll_event != atomic_read(&md_event_count)) mask |= POLLERR | POLLPRI; return mask; } diff --git a/fs/namespace.c b/fs/namespace.c index fe59bd145d2..cda50fe9250 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -934,8 +934,8 @@ int mnt_had_events(struct proc_mounts *p) int res = 0; br_read_lock(vfsmount_lock); - if (p->event != ns->event) { - p->event = ns->event; + if (p->m.poll_event != ns->event) { + p->m.poll_event = ns->event; res = 1; } br_read_unlock(vfsmount_lock); diff --git a/fs/proc/base.c b/fs/proc/base.c index be1ff932033..3dc5e2a5cc3 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -673,7 +673,7 @@ static int mounts_open_common(struct inode *inode, struct file *file, p->m.private = p; p->ns = ns; p->root = root; - p->event = ns->event; + p->m.poll_event = ns->event; return 0; diff --git a/include/linux/mnt_namespace.h b/include/linux/mnt_namespace.h index 0b89efc6f21..29304855652 100644 --- a/include/linux/mnt_namespace.h +++ b/include/linux/mnt_namespace.h @@ -18,7 +18,6 @@ struct proc_mounts { struct seq_file m; /* must be the first element */ struct mnt_namespace *ns; struct path root; - int event; }; struct fs_struct; diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h index 03c0232b416..be720cd2038 100644 --- a/include/linux/seq_file.h +++ b/include/linux/seq_file.h @@ -23,6 +23,7 @@ struct seq_file { u64 version; struct mutex lock; const struct seq_operations *op; + int poll_event; void *private; }; diff --git a/mm/swapfile.c b/mm/swapfile.c index ff8dc1a18cb..1b8c3390724 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1681,19 +1681,14 @@ out: } #ifdef CONFIG_PROC_FS -struct proc_swaps { - struct seq_file seq; - int event; -}; - static unsigned swaps_poll(struct file *file, poll_table *wait) { - struct proc_swaps *s = file->private_data; + struct seq_file *seq = file->private_data; poll_wait(file, &proc_poll_wait, wait); - if (s->event != atomic_read(&proc_poll_event)) { - s->event = atomic_read(&proc_poll_event); + if (seq->poll_event != atomic_read(&proc_poll_event)) { + seq->poll_event = atomic_read(&proc_poll_event); return POLLIN | POLLRDNORM | POLLERR | POLLPRI; } @@ -1783,24 +1778,16 @@ static const struct seq_operations swaps_op = { static int swaps_open(struct inode *inode, struct file *file) { - struct proc_swaps *s; + struct seq_file *seq; int ret; - s = kmalloc(sizeof(struct proc_swaps), GFP_KERNEL); - if (!s) - return -ENOMEM; - - file->private_data = s; - ret = seq_open(file, &swaps_op); - if (ret) { - kfree(s); + if (ret) return ret; - } - s->seq.private = s; - s->event = atomic_read(&proc_poll_event); - return ret; + seq = file->private_data; + seq->poll_event = atomic_read(&proc_poll_event); + return 0; } static const struct file_operations proc_swaps_operations = { -- cgit v1.2.3