misc: clean up code around attr_list_by_handle calls

Reduce stack usage of the attr_list_by_handle calls by allocating the
buffers dynamically.  Remove some redundant bits while we're at it.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>

diff --git a/libfrog/fsprops.c b/libfrog/fsprops.c
index 88046b7a0738d6cb7b59ea1c4a0f4635a099f3a1..a25c2726cd5868ce6124a2c4ec263854619c506f 100644 (file)
--- a/libfrog/fsprops.c
+++ b/libfrog/fsprops.c
@@ -69,13 +69,14 @@ fsprops_walk_names(
        void                    *priv)
 {
        struct attrlist_cursor  cur = { };
-       char                    attrbuf[XFS_XATTR_LIST_MAX];
-       struct attrlist         *attrlist = (struct attrlist *)attrbuf;
+       struct attrlist         *attrlist;
        int                     ret;
 
-       memset(attrbuf, 0, XFS_XATTR_LIST_MAX);
+       attrlist = calloc(XFS_XATTR_LIST_MAX, 1);
+       if (!attrlist)
+               return -1;
 
-       while ((ret = attr_list_by_handle(fph->hanp, fph->hlen, attrbuf,
+       while ((ret = attr_list_by_handle(fph->hanp, fph->hlen, attrlist,
                                XFS_XATTR_LIST_MAX, XFS_IOC_ATTR_ROOT,
                                &cur)) == 0) {
                unsigned int    i;
@@ -96,6 +97,7 @@ fsprops_walk_names(
                        break;
        }
 
+       free(attrlist);
        return ret;
 }
 

diff --git a/scrub/phase5.c b/scrub/phase5.c
index f6c295c64adae1e3b25e5d30018228a28e541d03..d298d628a998649d61f39fc7a5468cb8222f72d6 100644 (file)
--- a/scrub/phase5.c
+++ b/scrub/phase5.c
@@ -190,30 +190,40 @@ check_xattr_ns_names(
        struct xfs_bulkstat             *bstat,
        const struct attrns_decode      *attr_ns)
 {
-       struct attrlist_cursor          cur;
-       char                            attrbuf[XFS_XATTR_LIST_MAX];
-       char                            keybuf[XATTR_NAME_MAX + 1];
-       struct attrlist                 *attrlist = (struct attrlist *)attrbuf;
-       struct attrlist_ent             *ent;
+       struct attrlist_cursor          cur = { };
+       char                            *keybuf;
+       struct attrlist                 *attrlist;
        struct unicrash                 *uc = NULL;
        int                             i;
        int                             error;
 
+       attrlist = calloc(XFS_XATTR_LIST_MAX, 1);
+       if (!attrlist) {
+               error = errno;
+               str_errno(ctx, descr_render(dsc));
+               return error;
+       }
+
+       keybuf = calloc(XATTR_NAME_MAX + 1, 1);
+       if (!keybuf) {
+               error = errno;
+               str_errno(ctx, descr_render(dsc));
+               goto out_attrlist;
+       }
+
        error = unicrash_xattr_init(&uc, ctx, bstat);
        if (error) {
                str_liberror(ctx, error, descr_render(dsc));
-               return error;
+               goto out_keybuf;
        }
 
-       memset(attrbuf, 0, XFS_XATTR_LIST_MAX);
-       memset(&cur, 0, sizeof(cur));
-       memset(keybuf, 0, XATTR_NAME_MAX + 1);
-       error = attr_list_by_handle(handle, sizeof(*handle), attrbuf,
-                       XFS_XATTR_LIST_MAX, attr_ns->flags, &cur);
-       while (!error) {
+       while ((error = attr_list_by_handle(handle, sizeof(*handle), attrlist,
+                               XFS_XATTR_LIST_MAX, attr_ns->flags,
+                               &cur)) == 0) {
                /* Examine the xattrs. */
                for (i = 0; i < attrlist->al_count; i++) {
-                       ent = ATTR_ENTRY(attrlist, i);
+                       struct attrlist_ent     *ent = ATTR_ENTRY(attrlist, i);
+
                        snprintf(keybuf, XATTR_NAME_MAX, "%s.%s", attr_ns->name,
                                        ent->a_name);
                        if (uc)
@@ -225,14 +235,12 @@ check_xattr_ns_names(
                                                keybuf);
                        if (error) {
                                str_liberror(ctx, error, descr_render(dsc));
-                               goto out;
+                               goto out_uc;
                        }
                }
 
                if (!attrlist->al_more)
                        break;
-               error = attr_list_by_handle(handle, sizeof(*handle), attrbuf,
-                               XFS_XATTR_LIST_MAX, attr_ns->flags, &cur);
        }
        if (error) {
                if (errno == ESTALE)
@@ -241,8 +249,12 @@ check_xattr_ns_names(
                if (errno)
                        str_errno(ctx, descr_render(dsc));
        }
-out:
+out_uc:
        unicrash_free(uc);
+out_keybuf:
+       free(keybuf);
+out_attrlist:
+       free(attrlist);
        return error;
 }