On Thu, Apr 04, 2019 at 05:30:18PM +0100, fdmanana@xxxxxxxxxx wrote:
> From: Filipe Manana <fdmanana@xxxxxxxx>
>
> Currently fsstress does not exercise creating, reading or deleting xattrs
> on files or directories. This change adds support for setting xattrs on
> files and directories, using only the xattr user namespace (the other
> namespaces are not general purpose and are used for security, capabilities,
> ACLs, etc). This adds a counter for each file entry structure that keeps
> track of the number of xattrs set for the file entry, and each new xattr
> has a name that includes the counter's value (example: "user.x4").
> Values for the xattrs have at most 100 bytes, which is more than the
> maximum size supported for all major filesystems.
>
> Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
I've went through the xattr patches, and they look good to me overall,
thanks! Just some minor comments in this patch below.
> ---
>
> V2: Use a different name for the operation (setfattr instead of the already
> taken setxattr) and make use of the helper functions for opening and
> closing files or directories, introduced in the first patch of this
> series.
> V3: Simplified implementation to not need to open a file descriptor and
> use a path string instead.
>
> ltp/fsstress.c | 140 +++++++++++++++++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 131 insertions(+), 9 deletions(-)
>
> diff --git a/ltp/fsstress.c b/ltp/fsstress.c
> index 3ec19143..d1db19da 100644
> --- a/ltp/fsstress.c
> +++ b/ltp/fsstress.c
> @@ -27,6 +27,7 @@
> io_context_t io_ctx;
> #endif
> #include <sys/syscall.h>
> +#include <sys/xattr.h>
>
> #ifndef FS_IOC_GETFLAGS
> #define FS_IOC_GETFLAGS _IOR('f', 1, long)
> @@ -84,6 +85,7 @@ typedef enum {
> OP_RESVSP,
> OP_RMDIR,
> OP_SETATTR,
> + OP_SETFATTR,
> OP_SETXATTR,
I think it'd be better to document above three *ATTR operations in
comments.
> OP_SPLICE,
> OP_STAT,
> @@ -110,6 +112,7 @@ typedef struct opdesc {
> typedef struct fent {
> int id;
> int parent;
> + int xattr_counter;
> } fent_t;
>
> typedef struct flist {
> @@ -156,6 +159,8 @@ struct print_string {
> #define MAXFSIZE ((1ULL << 63) - 1ULL)
> #define MAXFSIZE32 ((1ULL << 40) - 1ULL)
>
> +#define XATTR_NAME_BUF_SIZE 18
> +
> void afsync_f(int, long);
> void allocsp_f(int, long);
> void aread_f(int, long);
> @@ -176,6 +181,7 @@ void fdatasync_f(int, long);
> void fiemap_f(int, long);
> void freesp_f(int, long);
> void fsync_f(int, long);
> +char *gen_random_string(int);
> void getattr_f(int, long);
> void getdents_f(int, long);
> void link_f(int, long);
> @@ -194,6 +200,7 @@ void rename_f(int, long);
> void resvsp_f(int, long);
> void rmdir_f(int, long);
> void setattr_f(int, long);
> +void setfattr_f(int, long);
> void setxattr_f(int, long);
> void splice_f(int, long);
> void stat_f(int, long);
> @@ -204,6 +211,7 @@ void unlink_f(int, long);
> void unresvsp_f(int, long);
> void write_f(int, long);
> void writev_f(int, long);
> +char *xattr_flag_to_string(int);
>
> opdesc_t ops[] = {
> /* { OP_ENUM, "name", function, freq, iswrite }, */
> @@ -245,6 +253,7 @@ opdesc_t ops[] = {
> { OP_RESVSP, "resvsp", resvsp_f, 1, 1 },
> { OP_RMDIR, "rmdir", rmdir_f, 1, 1 },
> { OP_SETATTR, "setattr", setattr_f, 0, 1 },
> + { OP_SETFATTR, "setfattr", setfattr_f, 4, 1 },
The frequency of setfattr looks a bit high to me, a buffer "write" op
has 4. Maybe 2 is more reasonable and change get/delfattr op's freq to 1?
(And rename delfattr to removefattr to match the removexattr syscall
name?)
> { OP_SETXATTR, "setxattr", setxattr_f, 1, 1 },
> { OP_SPLICE, "splice", splice_f, 1, 1 },
> { OP_STAT, "stat", stat_f, 1, 0 },
> @@ -296,7 +305,7 @@ char *execute_cmd = NULL;
> int execute_freq = 1;
> struct print_string flag_str = {0};
>
> -void add_to_flist(int, int, int);
> +void add_to_flist(int, int, int, int);
> void append_pathname(pathname_t *, char *);
> int attr_list_path(pathname_t *, char *, const int, int, attrlist_cursor_t *);
> int attr_remove_path(pathname_t *, const char *, int);
> @@ -315,6 +324,7 @@ int fent_to_name(pathname_t *, flist_t *, fent_t *);
> void fix_parent(int, int);
> void free_pathname(pathname_t *);
> int generate_fname(fent_t *, int, pathname_t *, int *, int *);
> +void generate_xattr_name(int, char *);
> int get_fname(int, long, pathname_t *, flist_t **, fent_t **, int *);
> void init_pathname(pathname_t *);
> int lchown_path(pathname_t *, uid_t, gid_t);
> @@ -716,7 +726,7 @@ translate_flags(int flags, const char *delim,
> }
>
> void
> -add_to_flist(int ft, int id, int parent)
> +add_to_flist(int ft, int id, int parent, int xattr_counter)
> {
> fent_t *fep;
> flist_t *ftp;
> @@ -729,6 +739,7 @@ add_to_flist(int ft, int id, int parent)
> fep = &ftp->fents[ftp->nfiles++];
> fep->id = id;
> fep->parent = parent;
> + fep->xattr_counter = xattr_counter;
> }
>
> void
> @@ -1122,6 +1133,12 @@ generate_fname(fent_t *fep, int ft, pathname_t *name, int *idp, int *v)
> return 1;
> }
>
> +void generate_xattr_name(int xattr_num, char *buffer)
> +{
> + memcpy(buffer, "user.x", 6);
> + sprintf(buffer + 6, "%d", xattr_num);
I think it's better to pass the buffer length too and check against it
to avoid buffer overflow.
Thanks,
Eryu
> +}
> +
> /*
> * Get file
> * Input: "which" to choose the file-types eg. non-directory
> @@ -3030,7 +3047,7 @@ creat_f(int opno, long r)
> if (xfsctl(f.path, fd, XFS_IOC_FSSETXATTR, &a) < 0)
> e1 = errno;
> }
> - add_to_flist(type, id, parid);
> + add_to_flist(type, id, parid, 0);
> close(fd);
> }
> if (v) {
> @@ -3495,6 +3512,28 @@ fsync_f(int opno, long r)
> close(fd);
> }
>
> +char *
> +gen_random_string(int len)
> +{
> + static const char charset[] = "0123456789"
> + "abcdefghijklmnopqrstuvwxyz"
> + "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
> + int i;
> + char *s;
> +
> + if (len == 0)
> + return NULL;
> +
> + s = malloc(len);
> + if (!s)
> + return NULL;
> +
> + for (i = 0; i < len; i++)
> + s[i] = charset[random() % sizeof(charset)];
> +
> + return s;
> +}
> +
> void
> getattr_f(int opno, long r)
> {
> @@ -3551,6 +3590,7 @@ link_f(int opno, long r)
> int e;
> pathname_t f;
> fent_t *fep;
> + fent_t *fep_src;
> flist_t *flp;
> int id;
> pathname_t l;
> @@ -3559,7 +3599,7 @@ link_f(int opno, long r)
> int v1;
>
> init_pathname(&f);
> - if (!get_fname(FT_NOTDIR, r, &f, &flp, NULL, &v1)) {
> + if (!get_fname(FT_NOTDIR, r, &f, &flp, &fep_src, &v1)) {
> if (v1)
> printf("%d/%d: link - no file\n", procid, opno);
> free_pathname(&f);
> @@ -3586,7 +3626,7 @@ link_f(int opno, long r)
> e = link_path(&f, &l) < 0 ? errno : 0;
> check_cwd();
> if (e == 0)
> - add_to_flist(flp - flist, id, parid);
> + add_to_flist(flp - flist, id, parid, fep_src->xattr_counter);
> if (v) {
> printf("%d/%d: link %s %s %d\n", procid, opno, f.path, l.path,
> e);
> @@ -3626,7 +3666,7 @@ mkdir_f(int opno, long r)
> e = mkdir_path(&f, 0777) < 0 ? errno : 0;
> check_cwd();
> if (e == 0)
> - add_to_flist(FT_DIR, id, parid);
> + add_to_flist(FT_DIR, id, parid, 0);
> if (v) {
> printf("%d/%d: mkdir %s %d\n", procid, opno, f.path, e);
> printf("%d/%d: mkdir add id=%d,parent=%d\n", procid, opno, id, parid);
> @@ -3664,7 +3704,7 @@ mknod_f(int opno, long r)
> e = mknod_path(&f, S_IFCHR|0444, 0) < 0 ? errno : 0;
> check_cwd();
> if (e == 0)
> - add_to_flist(FT_DEV, id, parid);
> + add_to_flist(FT_DEV, id, parid, 0);
> if (v) {
> printf("%d/%d: mknod %s %d\n", procid, opno, f.path, e);
> printf("%d/%d: mknod add id=%d,parent=%d\n", procid, opno, id, parid);
> @@ -4040,12 +4080,14 @@ rename_f(int opno, long r)
> e = rename_path(&f, &newf) < 0 ? errno : 0;
> check_cwd();
> if (e == 0) {
> + int xattr_counter = fep->xattr_counter;
> +
> if (flp - flist == FT_DIR) {
> oldid = fep->id;
> fix_parent(oldid, id);
> }
> del_from_flist(flp - flist, fep - flp->fents);
> - add_to_flist(flp - flist, id, parid);
> + add_to_flist(flp - flist, id, parid, xattr_counter);
> }
> if (v) {
> printf("%d/%d: rename %s to %s %d\n", procid, opno, f.path,
> @@ -4168,6 +4210,76 @@ setattr_f(int opno, long r)
> }
>
> void
> +setfattr_f(int opno, long r)
> +{
> + int e;
> + pathname_t f;
> + fent_t *fep;
> + int v;
> + int value_len;
> + char name[XATTR_NAME_BUF_SIZE];
> + char *value = NULL;
> + int flag = 0;
> + int xattr_num;
> +
> + init_pathname(&f);
> + if (!get_fname(FT_REGFILE | FT_DIRm, r, &f, NULL, &fep, &v)) {
> + if (v)
> + printf("%d/%d: setfattr - no filename\n", procid, opno);
> + goto out;
> + }
> + check_cwd();
> +
> + if ((fep->xattr_counter > 0) && (random() % 2)) {
> + /*
> + * Use an existing xattr name for replacing its value or
> + * create again a xattr that was previously deleted.
> + */
> + xattr_num = (random() % fep->xattr_counter) + 1;
> + if (random() % 2)
> + flag = XATTR_REPLACE;
> + } else {
> + /* Use a new xattr name. */
> + xattr_num = fep->xattr_counter + 1;
> + /*
> + * Don't always use the create flag because even if our xattr
> + * counter is 0, we may still have xattrs associated to this
> + * file (this happens when xattrs are added to a file through
> + * one of its other hard links), so we can end up updating an
> + * existing xattr too.
> + */
> + if (random() % 2)
> + flag = XATTR_CREATE;
> + }
> +
> + /*
> + * The maximum supported value size depends on the filesystem
> + * implementation, but 100 bytes is a safe value for most filesystems
> + * at least.
> + */
> + value_len = random() % 101;
> + value = gen_random_string(value_len);
> + if (!value && value_len > 0) {
> + if (v)
> + printf("%d/%d: setfattr - file %s failed to allocate value with %d bytes\n",
> + procid, opno, f.path, value_len);
> + goto out;
> + }
> + generate_xattr_name(xattr_num, name);
> +
> + e = setxattr(f.path, name, value, value_len, flag) < 0 ? errno : 0;
> + if (e == 0)
> + fep->xattr_counter++;
> + if (v)
> + printf("%d/%d: setfattr file %s name %s flag %s value length %d: %d\n",
> + procid, opno, f.path, name, xattr_flag_to_string(flag),
> + value_len, e);
> +out:
> + free(value);
> + free_pathname(&f);
> +}
> +
> +void
> stat_f(int opno, long r)
> {
> int e;
> @@ -4229,7 +4341,7 @@ symlink_f(int opno, long r)
> e = symlink_path(val, &f) < 0 ? errno : 0;
> check_cwd();
> if (e == 0)
> - add_to_flist(FT_SYM, id, parid);
> + add_to_flist(FT_SYM, id, parid, 0);
> free(val);
> if (v) {
> printf("%d/%d: symlink %s %d\n", procid, opno, f.path, e);
> @@ -4498,3 +4610,13 @@ writev_f(int opno, long r)
> free_pathname(&f);
> close(fd);
> }
> +
> +char *
> +xattr_flag_to_string(int flag)
> +{
> + if (flag == XATTR_CREATE)
> + return "create";
> + if (flag == XATTR_REPLACE)
> + return "replace";
> + return "none";
> +}
> --
> 2.11.0
>
