From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:38960 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751791AbaDYK0x (ORCPT ); Fri, 25 Apr 2014 06:26:53 -0400 Date: Fri, 25 Apr 2014 18:26:41 +0800 From: Liu Bo To: Filipe David Borba Manana Cc: linux-btrfs@vger.kernel.org Subject: Re: [PATCH] Btrfs-progs: allow compression property gets for read-only subvolumes Message-ID: <20140425102640.GA6138@localhost.localdomain> Reply-To: bo.li.liu@oracle.com References: <1397591247-25376-1-git-send-email-fdmanana@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1397591247-25376-1-git-send-email-fdmanana@gmail.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Tue, Apr 15, 2014 at 08:47:27PM +0100, Filipe David Borba Manana wrote: > Because the function open_file_or_dir() always opened the input file in > read/write mode (O_RDWR), we were not able to due a compression property > get against a file living in a read-only subvolume/snapshot. > Fix this by opening the file with O_RDONLY mode if we're doing a property > get. Reviewed-by: Liu Bo thanks, -liubo > > Signed-off-by: Filipe David Borba Manana > --- > props.c | 3 ++- > utils.c | 9 +++++++-- > utils.h | 1 + > 3 files changed, 10 insertions(+), 3 deletions(-) > > diff --git a/props.c b/props.c > index 4d0aeea..bd74975 100644 > --- a/props.c > +++ b/props.c > @@ -119,8 +119,9 @@ static int prop_compression(enum prop_object_type type, > DIR *dirstream = NULL; > char *buf = NULL; > char *xattr_name = NULL; > + int open_flags = value ? O_RDWR : O_RDONLY; > > - fd = open_file_or_dir(object, &dirstream); > + fd = open_file_or_dir3(object, &dirstream, open_flags); > if (fd == -1) { > ret = -errno; > fprintf(stderr, "ERROR: open %s failed. %s\n", > diff --git a/utils.c b/utils.c > index 0bfb9d9..458ba54 100644 > --- a/utils.c > +++ b/utils.c > @@ -1625,7 +1625,7 @@ u64 parse_size(char *s) > return strtoull(s, NULL, 10) * mult; > } > > -int open_file_or_dir(const char *fname, DIR **dirstream) > +int open_file_or_dir3(const char *fname, DIR **dirstream, int open_flags) > { > int ret; > struct stat st; > @@ -1641,7 +1641,7 @@ int open_file_or_dir(const char *fname, DIR **dirstream) > return -1; > fd = dirfd(*dirstream); > } else if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)) { > - fd = open(fname, O_RDWR); > + fd = open(fname, open_flags); > } else { > /* > * we set this on purpose, in case the caller output > @@ -1658,6 +1658,11 @@ int open_file_or_dir(const char *fname, DIR **dirstream) > return fd; > } > > +int open_file_or_dir(const char *fname, DIR **dirstream) > +{ > + return open_file_or_dir3(fname, dirstream, O_RDWR); > +} > + > void close_file_or_dir(int fd, DIR *dirstream) > { > if (dirstream) > diff --git a/utils.h b/utils.h > index 06ec938..fc581ca 100644 > --- a/utils.h > +++ b/utils.h > @@ -73,6 +73,7 @@ int btrfs_scan_block_devices(int run_ioctl); > u64 parse_size(char *s); > u64 arg_strtou64(const char *str); > int open_file_or_dir(const char *fname, DIR **dirstream); > +int open_file_or_dir3(const char *fname, DIR **dirstream, int open_flags); > void close_file_or_dir(int fd, DIR *dirstream); > int get_fs_info(char *path, struct btrfs_ioctl_fs_info_args *fi_args, > struct btrfs_ioctl_dev_info_args **di_ret); > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html