X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=fs%2Fanon_inodes.c;h=f42be069e085b2d212b8cc633d61f418be6801f5;hb=709b934b0fa7f5ee5f4cb271460281c0910fe78e;hp=40fe3a3222e499251abda536332f52a5dea2d884;hpb=0b662c64840fb281e5948ab6f9d60f84817277d0;p=linux-2.6-omap-h63xx.git diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c index 40fe3a3222e..f42be069e08 100644 --- a/fs/anon_inodes.c +++ b/fs/anon_inodes.c @@ -53,7 +53,7 @@ static struct dentry_operations anon_inodefs_dentry_operations = { }; /** - * anon_inode_getfd - creates a new file instance by hooking it up to and + * anon_inode_getfd - creates a new file instance by hooking it up to an * anonymous inode, and a dentry that describe the "class" * of the file * @@ -66,7 +66,7 @@ static struct dentry_operations anon_inodefs_dentry_operations = { * * Creates a new file by hooking it on a single inode. This is useful for files * that do not need to have a full-fledged inode in order to operate correctly. - * All the files created with anon_inode_getfd() will share a single inode, by + * All the files created with anon_inode_getfd() will share a single inode, * hence saving memory and avoiding code duplication for the file/inode/dentry * setup. */ @@ -76,25 +76,15 @@ int anon_inode_getfd(int *pfd, struct inode **pinode, struct file **pfile, { struct qstr this; struct dentry *dentry; - struct inode *inode; struct file *file; int error, fd; if (IS_ERR(anon_inode_inode)) return -ENODEV; - file = get_empty_filp(); - if (!file) - return -ENFILE; - - inode = igrab(anon_inode_inode); - if (IS_ERR(inode)) { - error = PTR_ERR(inode); - goto err_put_filp; - } error = get_unused_fd(); if (error < 0) - goto err_iput; + return error; fd = error; /* @@ -108,42 +98,50 @@ int anon_inode_getfd(int *pfd, struct inode **pinode, struct file **pfile, dentry = d_alloc(anon_inode_mnt->mnt_sb->s_root, &this); if (!dentry) goto err_put_unused_fd; + + /* + * We know the anon_inode inode count is always greater than zero, + * so we can avoid doing an igrab() and we can use an open-coded + * atomic_inc(). + */ + atomic_inc(&anon_inode_inode->i_count); + dentry->d_op = &anon_inodefs_dentry_operations; /* Do not publish this dentry inside the global dentry hash table */ dentry->d_flags &= ~DCACHE_UNHASHED; - d_instantiate(dentry, inode); + d_instantiate(dentry, anon_inode_inode); - file->f_path.mnt = mntget(anon_inode_mnt); - file->f_path.dentry = dentry; - file->f_mapping = inode->i_mapping; + error = -ENFILE; + file = alloc_file(anon_inode_mnt, dentry, + FMODE_READ | FMODE_WRITE, fops); + if (!file) + goto err_dput; + file->f_mapping = anon_inode_inode->i_mapping; file->f_pos = 0; file->f_flags = O_RDWR; - file->f_op = fops; - file->f_mode = FMODE_READ | FMODE_WRITE; file->f_version = 0; file->private_data = priv; fd_install(fd, file); *pfd = fd; - *pinode = inode; + *pinode = anon_inode_inode; *pfile = file; return 0; +err_dput: + dput(dentry); err_put_unused_fd: put_unused_fd(fd); -err_iput: - iput(inode); -err_put_filp: - put_filp(file); return error; } +EXPORT_SYMBOL_GPL(anon_inode_getfd); /* - * A single inode exist for all anon_inode files. Contrary to pipes, - * anon_inode inodes has no per-instance data associated, so we can avoid - * the allocation of multiple of them. + * A single inode exists for all anon_inode files. Contrary to pipes, + * anon_inode inodes have no associated per-instance data, so we need + * only allocate one of them. */ static struct inode *anon_inode_mkinode(void) {