Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935244AbaGYRhn (ORCPT ); Fri, 25 Jul 2014 13:37:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33444 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935161AbaGYRhj (ORCPT ); Fri, 25 Jul 2014 13:37:39 -0400 From: Abhi Das To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, cluster-devel@redhat.com Cc: Abhi Das Subject: [RFC PATCH 1/2] fs: Add dirreadahead syscall and VFS hooks Date: Fri, 25 Jul 2014 12:37:30 -0500 Message-Id: <1406309851-10628-2-git-send-email-adas@redhat.com> In-Reply-To: <1406309851-10628-1-git-send-email-adas@redhat.com> References: <1406309851-10628-1-git-send-email-adas@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Also adds a void *opaque field to struct dir_context that can be used by filesystems to temporarily store any context as this struct gets passed around in the fs. Signed-off-by: Abhi Das --- arch/x86/syscalls/syscall_32.tbl | 1 + arch/x86/syscalls/syscall_64.tbl | 1 + fs/readdir.c | 49 ++++++++++++++++++++++++++++++++++++++++ include/linux/fs.h | 3 +++ 4 files changed, 54 insertions(+) diff --git a/arch/x86/syscalls/syscall_32.tbl b/arch/x86/syscalls/syscall_32.tbl index d6b8679..3e0ef85 100644 --- a/arch/x86/syscalls/syscall_32.tbl +++ b/arch/x86/syscalls/syscall_32.tbl @@ -360,3 +360,4 @@ 351 i386 sched_setattr sys_sched_setattr 352 i386 sched_getattr sys_sched_getattr 353 i386 renameat2 sys_renameat2 +354 i386 dirreadahead sys_dirreadahead diff --git a/arch/x86/syscalls/syscall_64.tbl b/arch/x86/syscalls/syscall_64.tbl index ec255a1..2ec0991 100644 --- a/arch/x86/syscalls/syscall_64.tbl +++ b/arch/x86/syscalls/syscall_64.tbl @@ -323,6 +323,7 @@ 314 common sched_setattr sys_sched_setattr 315 common sched_getattr sys_sched_getattr 316 common renameat2 sys_renameat2 +317 common dirreadahead sys_dirreadahead # # x32-specific system call numbers start at 512 to avoid cache impact diff --git a/fs/readdir.c b/fs/readdir.c index 33fd922..d216db7 100644 --- a/fs/readdir.c +++ b/fs/readdir.c @@ -198,6 +198,7 @@ SYSCALL_DEFINE3(getdents, unsigned int, fd, struct linux_dirent __user * lastdirent; struct getdents_callback buf = { .ctx.actor = filldir, + .ctx.opaque = NULL, .count = count, .current_dir = dirent }; @@ -278,6 +279,7 @@ SYSCALL_DEFINE3(getdents64, unsigned int, fd, struct linux_dirent64 __user * lastdirent; struct getdents_callback64 buf = { .ctx.actor = filldir64, + .ctx.opaque = NULL, .count = count, .current_dir = dirent }; @@ -304,3 +306,50 @@ SYSCALL_DEFINE3(getdents64, unsigned int, fd, fdput(f); return error; } + +SYSCALL_DEFINE3(dirreadahead, unsigned int, fd, + loff_t __user *, offset, unsigned int, count) +{ + struct fd f; + struct inode *inode; + int error = -ENOTDIR; + loff_t off = 0; + struct dir_context ctx = {.actor = NULL, .opaque = NULL}; + + if (!count) + return -EINVAL; + + f = fdget(fd); + if (!f.file) + return -EBADF; + + inode = f.file->f_path.dentry->d_inode; + + error = -ENOTSUPP; + if (!f.file->f_op || !f.file->f_op->dir_readahead) + goto out; + + error = security_file_permission(f.file, MAY_READ); + if (error) + goto out; + + error = -EFAULT; + if (__get_user(ctx.pos, offset)) + goto out; + + error = mutex_lock_killable(&inode->i_mutex); + if (error) + goto out; + + error = -ENOENT; + if (!IS_DEADDIR(inode)) { + error = f.file->f_op->dir_readahead(f.file, &ctx, count); + if (__put_user(ctx.pos, offset)) + error = -EFAULT; + file_accessed(f.file); + } + mutex_unlock(&inode->i_mutex); +out: + fdput(f); + return error; +} diff --git a/include/linux/fs.h b/include/linux/fs.h index 338e6f7..fae4a6e 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1438,9 +1438,11 @@ int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags); * to have different dirent layouts depending on the binary type. */ typedef int (*filldir_t)(void *, const char *, int, loff_t, u64, unsigned); + struct dir_context { const filldir_t actor; loff_t pos; + void *opaque; }; struct block_device_operations; @@ -1463,6 +1465,7 @@ struct file_operations { ssize_t (*read_iter) (struct kiocb *, struct iov_iter *); ssize_t (*write_iter) (struct kiocb *, struct iov_iter *); int (*iterate) (struct file *, struct dir_context *); + int (*dir_readahead) (struct file *, struct dir_context *, unsigned int); unsigned int (*poll) (struct file *, struct poll_table_struct *); long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); long (*compat_ioctl) (struct file *, unsigned int, unsigned long); -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/