From ee2ffa0dfdd2db19705f2ba1c6a4c0bfe8122dd8 Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Wed, 18 Aug 2010 04:37:35 +1000 Subject: fs: cleanup files_lock locking fs: cleanup files_lock locking Lock tty_files with a new spinlock, tty_files_lock; provide helpers to manipulate the per-sb files list; unexport the files_lock spinlock. Cc: linux-kernel@vger.kernel.org Cc: Christoph Hellwig Cc: Alan Cox Acked-by: Andi Kleen Acked-by: Greg Kroah-Hartman Signed-off-by: Nick Piggin Signed-off-by: Al Viro --- fs/file_table.c | 42 ++++++++++++++++++------------------------ 1 file changed, 18 insertions(+), 24 deletions(-) (limited to 'fs/file_table.c') diff --git a/fs/file_table.c b/fs/file_table.c index edecd36fed9..6f0e62ecfdd 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -32,8 +32,7 @@ struct files_stat_struct files_stat = { .max_files = NR_FILE }; -/* public. Not pretty! */ -__cacheline_aligned_in_smp DEFINE_SPINLOCK(files_lock); +static __cacheline_aligned_in_smp DEFINE_SPINLOCK(files_lock); /* SLAB cache for file structures */ static struct kmem_cache *filp_cachep __read_mostly; @@ -249,7 +248,7 @@ static void __fput(struct file *file) cdev_put(inode->i_cdev); fops_put(file->f_op); put_pid(file->f_owner.pid); - file_kill(file); + file_sb_list_del(file); if (file->f_mode & FMODE_WRITE) drop_file_write_access(file); file->f_path.dentry = NULL; @@ -328,31 +327,29 @@ struct file *fget_light(unsigned int fd, int *fput_needed) return file; } - void put_filp(struct file *file) { if (atomic_long_dec_and_test(&file->f_count)) { security_file_free(file); - file_kill(file); + file_sb_list_del(file); file_free(file); } } -void file_move(struct file *file, struct list_head *list) +void file_sb_list_add(struct file *file, struct super_block *sb) { - if (!list) - return; - file_list_lock(); - list_move(&file->f_u.fu_list, list); - file_list_unlock(); + spin_lock(&files_lock); + BUG_ON(!list_empty(&file->f_u.fu_list)); + list_add(&file->f_u.fu_list, &sb->s_files); + spin_unlock(&files_lock); } -void file_kill(struct file *file) +void file_sb_list_del(struct file *file) { if (!list_empty(&file->f_u.fu_list)) { - file_list_lock(); + spin_lock(&files_lock); list_del_init(&file->f_u.fu_list); - file_list_unlock(); + spin_unlock(&files_lock); } } @@ -361,7 +358,7 @@ int fs_may_remount_ro(struct super_block *sb) struct file *file; /* Check that no files are currently opened for writing. */ - file_list_lock(); + spin_lock(&files_lock); list_for_each_entry(file, &sb->s_files, f_u.fu_list) { struct inode *inode = file->f_path.dentry->d_inode; @@ -373,10 +370,10 @@ int fs_may_remount_ro(struct super_block *sb) if (S_ISREG(inode->i_mode) && (file->f_mode & FMODE_WRITE)) goto too_bad; } - file_list_unlock(); + spin_unlock(&files_lock); return 1; /* Tis' cool bro. */ too_bad: - file_list_unlock(); + spin_unlock(&files_lock); return 0; } @@ -392,7 +389,7 @@ void mark_files_ro(struct super_block *sb) struct file *f; retry: - file_list_lock(); + spin_lock(&files_lock); list_for_each_entry(f, &sb->s_files, f_u.fu_list) { struct vfsmount *mnt; if (!S_ISREG(f->f_path.dentry->d_inode->i_mode)) @@ -408,16 +405,13 @@ retry: continue; file_release_write(f); mnt = mntget(f->f_path.mnt); - file_list_unlock(); - /* - * This can sleep, so we can't hold - * the file_list_lock() spinlock. - */ + /* This can sleep, so we can't hold the spinlock. */ + spin_unlock(&files_lock); mnt_drop_write(mnt); mntput(mnt); goto retry; } - file_list_unlock(); + spin_unlock(&files_lock); } void __init files_init(unsigned long mempages) -- cgit v1.2.3