On 3.09.2018 13:14, Adam Borowski wrote:
> Fixes EXTXBSY races.
You have to be more eloquent than that and explain at least one race
condition.
>
> Signed-off-by: Adam Borowski <kilob...@angband.pl>
> ---
> cmds-filesystem.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/cmds-filesystem.c b/cmds-filesystem.c
> index 06c8311b..4c9df69f 100644
> --- a/cmds-filesystem.c
> +++ b/cmds-filesystem.c
> @@ -26,6 +26,7 @@
> #include <ftw.h>
> #include <mntent.h>
> #include <linux/limits.h>
> +#include <linux/version.h>
> #include <getopt.h>
>
> #include <btrfsutil.h>
> @@ -39,12 +40,14 @@
> #include "list_sort.h"
> #include "disk-io.h"
> #include "help.h"
> +#include "fsfeatures.h"
>
> /*
> * for btrfs fi show, we maintain a hash of fsids we've already printed.
> * This way we don't print dups if a given FS is mounted more than once.
> */
> static struct seen_fsid *seen_fsid_hash[SEEN_FSID_HASH_SIZE] = {NULL,};
> +static mode_t defrag_ro = O_RDONLY;
This brings no value whatsoever, just use O_RDONLY directly
>
> static const char * const filesystem_cmd_group_usage[] = {
> "btrfs filesystem [<group>] <command> [<args>]",
> @@ -877,7 +880,7 @@ static int defrag_callback(const char *fpath, const
> struct stat *sb,
> if ((typeflag == FTW_F) && S_ISREG(sb->st_mode)) {
> if (defrag_global_verbose)
> printf("%s\n", fpath);
> - fd = open(fpath, O_RDWR);
> + fd = open(fpath, defrag_ro);
> if (fd < 0) {
> goto error;
> }
> @@ -914,6 +917,9 @@ static int cmd_filesystem_defrag(int argc, char **argv)
> int compress_type = BTRFS_COMPRESS_NONE;
> DIR *dirstream;
>
> + if (get_running_kernel_version() < KERNEL_VERSION(4,19,0) && getuid())
> + defrag_ro = O_RDWR;
> +
> /*
> * Kernel has a different default (256K) that is supposed to be safe,
> * but it does not defragment very well. The 32M will likely lead to
> @@ -1014,7 +1020,7 @@ static int cmd_filesystem_defrag(int argc, char **argv)
> int defrag_err = 0;
>
> dirstream = NULL;
> - fd = open_file_or_dir(argv[i], &dirstream);
> + fd = open_file_or_dir3(argv[i], &dirstream, defrag_ro);
> if (fd < 0) {
> error("cannot open %s: %m", argv[i]);
> ret = -errno;
>
