luck/tmp_suning_uos_patched
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Rename struct file->f_ep_lock

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This lock moves out of the CONFIG_EPOLL ifdef and becomes f_lock.  For now,
epoll remains the only user, but a future patch will use it to protect
f_flags as well.

Cc: Davide Libenzi <davidel@xmailserver.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
Jonathan Corbet 2009-02-06 13:52:43 -07:00
parent 041b62374c
commit 6849991490
4 changed files with 9 additions and 7 deletions
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12
fs/eventpoll.c
View File

@ -417,10 +417,10 @@ static int ep_remove(struct eventpoll *ep, struct epitem *epi)
ep_unregister_pollwait(ep, epi);
/* Remove the current item from the list of epoll hooks */
spin_lock(&file->f_ep_lock);
spin_lock(&file->f_lock);
if (ep_is_linked(&epi->fllink))
list_del_init(&epi->fllink);
spin_unlock(&file->f_ep_lock);
spin_unlock(&file->f_lock);
rb_erase(&epi->rbn, &ep->rbr);
@ -538,7 +538,7 @@ void eventpoll_release_file(struct file *file)
struct epitem *epi;
/*
* We don't want to get "file->f_ep_lock" because it is not
* We don't want to get "file->f_lock" because it is not
* necessary. It is not necessary because we're in the "struct file"
* cleanup path, and this means that noone is using this file anymore.
* So, for example, epoll_ctl() cannot hit here sicne if we reach this
@ -547,6 +547,8 @@ void eventpoll_release_file(struct file *file)
* will correctly serialize the operation. We do need to acquire
* "ep->mtx" after "epmutex" because ep_remove() requires it when called
* from anywhere but ep_free().
*
* Besides, ep_remove() acquires the lock, so we can't hold it here.
*/
mutex_lock(&epmutex);
@ -785,9 +787,9 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event,
goto error_unregister;
/* Add the current item to the list of active epoll hook for this file */
spin_lock(&tfile->f_ep_lock);
spin_lock(&tfile->f_lock);
list_add_tail(&epi->fllink, &tfile->f_ep_links);
spin_unlock(&tfile->f_ep_lock);
spin_unlock(&tfile->f_lock);
/*
* Add the current item to the RB tree. All RB tree operations are

1
fs/file_table.c
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@ -127,6 +127,7 @@ struct file *get_empty_filp(void)
atomic_long_set(&f->f_count, 1);
rwlock_init(&f->f_owner.lock);
f->f_cred = get_cred(cred);
spin_lock_init(&f->f_lock);
eventpoll_init_file(f);
/* f->f_version: 0 */
return f;

1
include/linux/eventpoll.h
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@ -61,7 +61,6 @@ struct file;
static inline void eventpoll_init_file(struct file *file)
{
INIT_LIST_HEAD(&file->f_ep_links);
spin_lock_init(&file->f_ep_lock);
}

2
include/linux/fs.h
View File

@ -848,6 +848,7 @@ struct file {
#define f_dentry f_path.dentry
#define f_vfsmnt f_path.mnt
const struct file_operations *f_op;
spinlock_t f_lock; /* f_ep_links */
atomic_long_t f_count;
unsigned int f_flags;
fmode_t f_mode;
@ -866,7 +867,6 @@ struct file {
#ifdef CONFIG_EPOLL
/* Used by fs/eventpoll.c to link all the hooks to this file */
struct list_head f_ep_links;
spinlock_t f_ep_lock;
#endif /* #ifdef CONFIG_EPOLL */
struct address_space *f_mapping;
#ifdef CONFIG_DEBUG_WRITECOUNT