On Thu, Oct 31, 2019 at 02:41:48PM +0800, kaixuxia wrote:
> Support the EXCHANGE renameat2 syscall in fsstress.
>
> In order to maintain filelist/filename integrity, we restrict
> rexchange to files of the same type.
>
> Signed-off-by: kaixuxia <kaixuxia@xxxxxxxxxxx>
> ---
Looks good to me and no errors on a quick test:
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
> ltp/fsstress.c | 117 ++++++++++++++++++++++++++++++++++++++++++++++-----------
> 1 file changed, 96 insertions(+), 21 deletions(-)
>
> diff --git a/ltp/fsstress.c b/ltp/fsstress.c
> index ecc1adc..0125571 100644
> --- a/ltp/fsstress.c
> +++ b/ltp/fsstress.c
> @@ -69,6 +69,9 @@ static int renameat2(int dfd1, const char *path1,
> #ifndef RENAME_NOREPLACE
> #define RENAME_NOREPLACE (1 << 0) /* Don't overwrite target */
> #endif
> +#ifndef RENAME_EXCHANGE
> +#define RENAME_EXCHANGE (1 << 1) /* Exchange source and dest */
> +#endif
> #ifndef RENAME_WHITEOUT
> #define RENAME_WHITEOUT (1 << 2) /* Whiteout source */
> #endif
> @@ -115,6 +118,7 @@ typedef enum {
> OP_REMOVEFATTR,
> OP_RENAME,
> OP_RNOREPLACE,
> + OP_REXCHANGE,
> OP_RWHITEOUT,
> OP_RESVSP,
> OP_RMDIR,
> @@ -235,6 +239,7 @@ void readv_f(int, long);
> void removefattr_f(int, long);
> void rename_f(int, long);
> void rnoreplace_f(int, long);
> +void rexchange_f(int, long);
> void rwhiteout_f(int, long);
> void resvsp_f(int, long);
> void rmdir_f(int, long);
> @@ -296,6 +301,7 @@ opdesc_t ops[] = {
> { OP_REMOVEFATTR, "removefattr", removefattr_f, 1, 1 },
> { OP_RENAME, "rename", rename_f, 2, 1 },
> { OP_RNOREPLACE, "rnoreplace", rnoreplace_f, 2, 1 },
> + { OP_REXCHANGE, "rexchange", rexchange_f, 2, 1 },
> { OP_RWHITEOUT, "rwhiteout", rwhiteout_f, 2, 1 },
> { OP_RESVSP, "resvsp", resvsp_f, 1, 1 },
> { OP_RMDIR, "rmdir", rmdir_f, 1, 1 },
> @@ -371,7 +377,8 @@ void del_from_flist(int, int);
> int dirid_to_name(char *, int);
> void doproc(void);
> int fent_to_name(pathname_t *, flist_t *, fent_t *);
> -void fix_parent(int, int);
> +bool fents_ancestor_check(fent_t *, fent_t *);
> +void fix_parent(int, int, bool);
> void free_pathname(pathname_t *);
> int generate_fname(fent_t *, int, pathname_t *, int *, int *);
> int generate_xattr_name(int, char *, int);
> @@ -1117,8 +1124,22 @@ fent_to_name(pathname_t *name, flist_t *flp, fent_t *fep)
> return 1;
> }
>
> +bool
> +fents_ancestor_check(fent_t *fep, fent_t *dfep)
> +{
> + fent_t *tmpfep;
> +
> + for (tmpfep = fep; tmpfep->parent != -1;
> + tmpfep = dirid_to_fent(tmpfep->parent)) {
> + if (tmpfep->parent == dfep->id)
> + return true;
> + }
> +
> + return false;
> +}
> +
> void
> -fix_parent(int oldid, int newid)
> +fix_parent(int oldid, int newid, bool swap)
> {
> fent_t *fep;
> flist_t *flp;
> @@ -1129,6 +1150,8 @@ fix_parent(int oldid, int newid)
> for (j = 0, fep = flp->fents; j < flp->nfiles; j++, fep++) {
> if (fep->parent == oldid)
> fep->parent = newid;
> + else if (swap && fep->parent == newid)
> + fep->parent = oldid;
> }
> }
> }
> @@ -4256,6 +4279,7 @@ out:
>
> struct print_flags renameat2_flags [] = {
> { RENAME_NOREPLACE, "NOREPLACE"},
> + { RENAME_EXCHANGE, "EXCHANGE"},
> { RENAME_WHITEOUT, "WHITEOUT"},
> { -1, NULL}
> };
> @@ -4291,41 +4315,86 @@ do_renameat2(int opno, long r, int mode)
> return;
> }
>
> - /* get an existing directory for the destination parent directory name */
> - if (!get_fname(FT_DIRm, random(), NULL, NULL, &dfep, &v))
> - parid = -1;
> - else
> - parid = dfep->id;
> - v |= v1;
> + /*
> + * Both pathnames must exist for the RENAME_EXCHANGE, and in
> + * order to maintain filelist/filename integrity, we should
> + * restrict exchange operation to files of the same type.
> + */
> + if (mode == RENAME_EXCHANGE) {
> + which = 1 << (flp - flist);
> + init_pathname(&newf);
> + if (!get_fname(which, random(), &newf, NULL, &dfep, &v)) {
> + if (v)
> + printf("%d/%d: rename - no target filename\n",
> + procid, opno);
> + free_pathname(&newf);
> + free_pathname(&f);
> + return;
> + }
> + if (which == FT_DIRm && (fents_ancestor_check(fep, dfep) ||
> + fents_ancestor_check(dfep, fep))) {
> + if (v)
> + printf("%d/%d: rename(REXCHANGE) %s and %s "
> + "have ancestor-descendant relationship\n",
> + procid, opno, f.path, newf.path);
> + free_pathname(&newf);
> + free_pathname(&f);
> + return;
> + }
> + v |= v1;
> + id = dfep->id;
> + parid = dfep->parent;
> + } else {
> + /*
> + * Get an existing directory for the destination parent
> + * directory name.
> + */
> + if (!get_fname(FT_DIRm, random(), NULL, NULL, &dfep, &v))
> + parid = -1;
> + else
> + parid = dfep->id;
> + v |= v1;
>
> - /* generate a new path using an existing parent directory in name */
> - init_pathname(&newf);
> - e = generate_fname(dfep, flp - flist, &newf, &id, &v1);
> - v |= v1;
> - if (!e) {
> - if (v) {
> - (void)fent_to_name(&f, &flist[FT_DIR], dfep);
> - printf("%d/%d: rename - no filename from %s\n",
> - procid, opno, f.path);
> + /*
> + * Generate a new path using an existing parent directory
> + * in name.
> + */
> + init_pathname(&newf);
> + e = generate_fname(dfep, flp - flist, &newf, &id, &v1);
> + v |= v1;
> + if (!e) {
> + if (v) {
> + (void)fent_to_name(&f, &flist[FT_DIR], dfep);
> + printf("%d/%d: rename - no filename from %s\n",
> + procid, opno, f.path);
> + }
> + free_pathname(&newf);
> + free_pathname(&f);
> + return;
> }
> - free_pathname(&newf);
> - free_pathname(&f);
> - return;
> }
> e = rename_path(&f, &newf, mode) < 0 ? errno : 0;
> check_cwd();
> if (e == 0) {
> int xattr_counter = fep->xattr_counter;
> + bool swap = (mode == RENAME_EXCHANGE) ? true : false;
>
> oldid = fep->id;
> oldparid = fep->parent;
>
> + /*
> + * Swap the parent ids for RENAME_EXCHANGE, and replace the
> + * old parent id for the others.
> + */
> if (flp - flist == FT_DIR)
> - fix_parent(oldid, id);
> + fix_parent(oldid, id, swap);
>
> if (mode == RENAME_WHITEOUT) {
> fep->xattr_counter = 0;
> add_to_flist(flp - flist, id, parid, xattr_counter);
> + } else if (mode == RENAME_EXCHANGE) {
> + fep->xattr_counter = dfep->xattr_counter;
> + dfep->xattr_counter = xattr_counter;
> } else {
> del_from_flist(flp - flist, fep - flp->fents);
> add_to_flist(flp - flist, id, parid, xattr_counter);
> @@ -4359,6 +4428,12 @@ rnoreplace_f(int opno, long r)
> }
>
> void
> +rexchange_f(int opno, long r)
> +{
> + do_renameat2(opno, r, RENAME_EXCHANGE);
> +}
> +
> +void
> rwhiteout_f(int opno, long r)
> {
> do_renameat2(opno, r, RENAME_WHITEOUT);
> --
> 1.8.3.1
>
