From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Scrub the hash tree, keys, and values in an extended attribute structure.
Refactor the attribute code to use the transaction if the caller supplied
one to avoid buffer deadocks.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
fs/xfs/Makefile | 1
fs/xfs/libxfs/xfs_fs.h | 3 -
fs/xfs/scrub/attr.c | 239 ++++++++++++++++++++++++++++++++++++++++++++++++
fs/xfs/scrub/common.h | 2
fs/xfs/scrub/scrub.c | 8 ++
fs/xfs/scrub/scrub.h | 2
fs/xfs/xfs_attr.h | 5 +
fs/xfs/xfs_attr_list.c | 7 +
8 files changed, 264 insertions(+), 3 deletions(-)
create mode 100644 fs/xfs/scrub/attr.c
diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
index 69aa88e..4d46399 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -148,6 +148,7 @@ xfs-y += $(addprefix scrub/, \
trace.o \
agheader.o \
alloc.o \
+ attr.o \
bmap.o \
btree.o \
common.o \
diff --git a/fs/xfs/libxfs/xfs_fs.h b/fs/xfs/libxfs/xfs_fs.h
index b16d004..0834ce6 100644
--- a/fs/xfs/libxfs/xfs_fs.h
+++ b/fs/xfs/libxfs/xfs_fs.h
@@ -499,9 +499,10 @@ struct xfs_scrub_metadata {
#define XFS_SCRUB_TYPE_BMBTA 13 /* attr fork block mapping */
#define XFS_SCRUB_TYPE_BMBTC 14 /* CoW fork block mapping */
#define XFS_SCRUB_TYPE_DIR 15 /* directory */
+#define XFS_SCRUB_TYPE_XATTR 16 /* extended attribute */
/* Number of scrub subcommands. */
-#define XFS_SCRUB_TYPE_NR 16
+#define XFS_SCRUB_TYPE_NR 17
/* i: Repair this metadata. */
#define XFS_SCRUB_IFLAG_REPAIR (1 << 0)
diff --git a/fs/xfs/scrub/attr.c b/fs/xfs/scrub/attr.c
new file mode 100644
index 0000000..69a4104
--- /dev/null
+++ b/fs/xfs/scrub/attr.c
@@ -0,0 +1,239 @@
+/*
+ * Copyright (C) 2017 Oracle. All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_inode.h"
+#include "xfs_da_format.h"
+#include "xfs_da_btree.h"
+#include "xfs_dir2.h"
+#include "xfs_attr.h"
+#include "xfs_attr_leaf.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/dabtree.h"
+#include "scrub/trace.h"
+
+#include <linux/posix_acl_xattr.h>
+#include <linux/xattr.h>
+
+/* Set us up to scrub an inode's extended attributes. */
+int
+xfs_scrub_setup_xattr(
+ struct xfs_scrub_context *sc,
+ struct xfs_inode *ip)
+{
+ /* Allocate the buffer without the inode lock held. */
+ sc->buf = kmem_zalloc_large(XATTR_SIZE_MAX, KM_SLEEP);
+ if (!sc->buf)
+ return -ENOMEM;
+
+ return xfs_scrub_setup_inode_contents(sc, ip, 0);
+}
+
+/* Extended Attributes */
+
+struct xfs_scrub_xattr {
+ struct xfs_attr_list_context context;
+ struct xfs_scrub_context *sc;
+};
+
+/*
+ * Check that an extended attribute key can be looked up by hash.
+ *
+ * We use the XFS attribute list iterator (i.e. xfs_attr_list_int_ilocked)
+ * to call this function for every attribute key in an inode. Once
+ * we're here, we load the attribute value to see if any errors happen,
+ * or if we get more or less data than we expected.
+ */
+static void
+xfs_scrub_xattr_listent(
+ struct xfs_attr_list_context *context,
+ int flags,
+ unsigned char *name,
+ int namelen,
+ int valuelen)
+{
+ struct xfs_scrub_xattr *sx;
+ struct xfs_da_args args = {0};
+ int error = 0;
+
+ sx = container_of(context, struct xfs_scrub_xattr, context);
+
+ if (flags & XFS_ATTR_INCOMPLETE) {
+ /* Incomplete attr key, just mark the inode for preening. */
+ xfs_scrub_ino_set_preen(sx->sc, NULL);
+ return;
+ }
+
+ args.flags = ATTR_KERNOTIME;
+ if (flags & XFS_ATTR_ROOT)
+ args.flags |= ATTR_ROOT;
+ else if (flags & XFS_ATTR_SECURE)
+ args.flags |= ATTR_SECURE;
+ args.geo = context->dp->i_mount->m_attr_geo;
+ args.whichfork = XFS_ATTR_FORK;
+ args.dp = context->dp;
+ args.name = name;
+ args.namelen = namelen;
+ args.hashval = xfs_da_hashname(args.name, args.namelen);
+ args.trans = context->tp;
+ args.value = sx->sc->buf;
+ args.valuelen = XATTR_SIZE_MAX;
+
+ error = xfs_attr_get_ilocked(context->dp, &args);
+ if (error == -EEXIST)
+ error = 0;
+ if (!xfs_scrub_fblock_process_error(sx->sc, XFS_ATTR_FORK, args.blkno,
+ &error))
+ goto fail_xref;
+ if (args.valuelen != valuelen)
+ xfs_scrub_fblock_set_corrupt(sx->sc, XFS_ATTR_FORK,
+ args.blkno);
+
+fail_xref:
+ return;
+}
+
+/* Scrub a attribute btree record. */
+STATIC int
+xfs_scrub_xattr_rec(
+ struct xfs_scrub_da_btree *ds,
+ int level,
+ void *rec)
+{
+ struct xfs_mount *mp = ds->state->mp;
+ struct xfs_attr_leaf_entry *ent = rec;
+ struct xfs_da_state_blk *blk;
+ struct xfs_attr_leaf_name_local *lentry;
+ struct xfs_attr_leaf_name_remote *rentry;
+ struct xfs_buf *bp;
+ xfs_dahash_t calc_hash;
+ xfs_dahash_t hash;
+ int nameidx;
+ int hdrsize;
+ unsigned int badflags;
+ int error;
+
+ blk = &ds->state->path.blk[level];
+
+ /* Check the hash of the entry. */
+ error = xfs_scrub_da_btree_hash(ds, level, &ent->hashval);
+ if (error)
+ goto out;
+
+ /* Find the attr entry's location. */
+ bp = blk->bp;
+ hdrsize = xfs_attr3_leaf_hdr_size(bp->b_addr);
+ nameidx = be16_to_cpu(ent->nameidx);
+ if (nameidx < hdrsize || nameidx >= mp->m_attr_geo->blksize) {
+ xfs_scrub_da_set_corrupt(ds, level);
+ goto out;
+ }
+
+ /* Retrieve the entry and check it. */
+ hash = be32_to_cpu(ent->hashval);
+ badflags = ~(XFS_ATTR_LOCAL | XFS_ATTR_ROOT | XFS_ATTR_SECURE |
+ XFS_ATTR_INCOMPLETE);
+ if ((ent->flags & badflags) != 0)
+ xfs_scrub_da_set_corrupt(ds, level);
+ if (ent->flags & XFS_ATTR_LOCAL) {
+ lentry = (struct xfs_attr_leaf_name_local *)
+ (((char *)bp->b_addr) + nameidx);
+ if (lentry->namelen <= 0) {
+ xfs_scrub_da_set_corrupt(ds, level);
+ goto out;
+ }
+ calc_hash = xfs_da_hashname(lentry->nameval, lentry->namelen);
+ } else {
+ rentry = (struct xfs_attr_leaf_name_remote *)
+ (((char *)bp->b_addr) + nameidx);
+ if (rentry->namelen <= 0) {
+ xfs_scrub_da_set_corrupt(ds, level);
+ goto out;
+ }
+ calc_hash = xfs_da_hashname(rentry->name, rentry->namelen);
+ }
+ if (calc_hash != hash)
+ xfs_scrub_da_set_corrupt(ds, level);
+
+out:
+ return error;
+}
+
+/* Scrub the extended attribute metadata. */
+int
+xfs_scrub_xattr(
+ struct xfs_scrub_context *sc)
+{
+ struct xfs_scrub_xattr sx = { 0 };
+ struct attrlist_cursor_kern cursor = { 0 };
+ int error = 0;
+
+ if (!xfs_inode_hasattr(sc->ip))
+ return -ENOENT;
+
+ memset(&sx, 0, sizeof(sx));
+ /* Check attribute tree structure */
+ error = xfs_scrub_da_btree(sc, XFS_ATTR_FORK, xfs_scrub_xattr_rec);
+ if (error)
+ goto out;
+
+ /* Check that every attr key can also be looked up by hash. */
+ sx.context.dp = sc->ip;
+ sx.context.cursor = &cursor;
+ sx.context.resynch = 1;
+ sx.context.put_listent = xfs_scrub_xattr_listent;
+ sx.context.tp = sc->tp;
+ sx.context.flags = ATTR_INCOMPLETE;
+ sx.sc = sc;
+
+ /*
+ * Look up every xattr in this file by name.
+ *
+ * Use the backend implementation of xfs_attr_list to call
+ * xfs_scrub_xattr_listent on every attribute key in this inode.
+ * In other words, we use the same iterator/callback mechanism
+ * that listattr uses to scrub extended attributes, though in our
+ * _listent function, we check the value of the attribute.
+ *
+ * The VFS only locks i_rwsem when modifying attrs, so keep all
+ * three locks held because that's the only way to ensure we're
+ * the only thread poking into the da btree. We traverse the da
+ * btree while holding a leaf buffer locked for the xattr name
+ * iteration, which doesn't really follow the usual buffer
+ * locking order.
+ */
+ error = xfs_attr_list_int_ilocked(&sx.context);
+ if (!xfs_scrub_fblock_process_error(sc, XFS_ATTR_FORK, 0, &error))
+ goto out;
+out:
+ return error;
+}
diff --git a/fs/xfs/scrub/common.h b/fs/xfs/scrub/common.h
index 7cd4a78..b938429 100644
--- a/fs/xfs/scrub/common.h
+++ b/fs/xfs/scrub/common.h
@@ -95,6 +95,8 @@ int xfs_scrub_setup_inode_bmap_data(struct xfs_scrub_context *sc,
struct xfs_inode *ip);
int xfs_scrub_setup_directory(struct xfs_scrub_context *sc,
struct xfs_inode *ip);
+int xfs_scrub_setup_xattr(struct xfs_scrub_context *sc,
+ struct xfs_inode *ip);
void xfs_scrub_ag_free(struct xfs_scrub_context *sc, struct xfs_scrub_ag *sa);
int xfs_scrub_ag_init(struct xfs_scrub_context *sc, xfs_agnumber_t agno,
diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c
index 4a44727..7ad9f54 100644
--- a/fs/xfs/scrub/scrub.c
+++ b/fs/xfs/scrub/scrub.c
@@ -148,6 +148,10 @@ xfs_scrub_teardown(
iput(VFS_I(sc->ip));
sc->ip = NULL;
}
+ if (sc->buf) {
+ kmem_free(sc->buf);
+ sc->buf = NULL;
+ }
return error;
}
@@ -221,6 +225,10 @@ static const struct xfs_scrub_meta_ops meta_scrub_ops[] = {
.setup = xfs_scrub_setup_directory,
.scrub = xfs_scrub_directory,
},
+ { /* extended attributes */
+ .setup = xfs_scrub_setup_xattr,
+ .scrub = xfs_scrub_xattr,
+ },
};
/* This isn't a stable feature, warn once per day. */
diff --git a/fs/xfs/scrub/scrub.h b/fs/xfs/scrub/scrub.h
index 844506e..d31ff58 100644
--- a/fs/xfs/scrub/scrub.h
+++ b/fs/xfs/scrub/scrub.h
@@ -59,6 +59,7 @@ struct xfs_scrub_context {
const struct xfs_scrub_meta_ops *ops;
struct xfs_trans *tp;
struct xfs_inode *ip;
+ void *buf;
uint ilock_flags;
bool try_harder;
@@ -83,5 +84,6 @@ int xfs_scrub_bmap_data(struct xfs_scrub_context *sc);
int xfs_scrub_bmap_attr(struct xfs_scrub_context *sc);
int xfs_scrub_bmap_cow(struct xfs_scrub_context *sc);
int xfs_scrub_directory(struct xfs_scrub_context *sc);
+int xfs_scrub_xattr(struct xfs_scrub_context *sc);
#endif /* __XFS_SCRUB_SCRUB_H__ */
diff --git a/fs/xfs/xfs_attr.h b/fs/xfs/xfs_attr.h
index 5d5a5e2..d07bf27 100644
--- a/fs/xfs/xfs_attr.h
+++ b/fs/xfs/xfs_attr.h
@@ -48,6 +48,8 @@ struct xfs_attr_list_context;
#define ATTR_KERNOTIME 0x1000 /* [kernel] don't update inode timestamps */
#define ATTR_KERNOVAL 0x2000 /* [kernel] get attr size only, not value */
+#define ATTR_INCOMPLETE 0x4000 /* [kernel] return INCOMPLETE attr keys */
+
#define XFS_ATTR_FLAGS \
{ ATTR_DONTFOLLOW, "DONTFOLLOW" }, \
{ ATTR_ROOT, "ROOT" }, \
@@ -56,7 +58,8 @@ struct xfs_attr_list_context;
{ ATTR_CREATE, "CREATE" }, \
{ ATTR_REPLACE, "REPLACE" }, \
{ ATTR_KERNOTIME, "KERNOTIME" }, \
- { ATTR_KERNOVAL, "KERNOVAL" }
+ { ATTR_KERNOVAL, "KERNOVAL" }, \
+ { ATTR_INCOMPLETE, "INCOMPLETE" }
/*
* The maximum size (into the kernel or returned from the kernel) of an
diff --git a/fs/xfs/xfs_attr_list.c b/fs/xfs/xfs_attr_list.c
index 7740c8a..5816786 100644
--- a/fs/xfs/xfs_attr_list.c
+++ b/fs/xfs/xfs_attr_list.c
@@ -407,7 +407,8 @@ xfs_attr3_leaf_list_int(
cursor->offset = 0;
}
- if (entry->flags & XFS_ATTR_INCOMPLETE)
+ if ((entry->flags & XFS_ATTR_INCOMPLETE) &&
+ !(context->flags & ATTR_INCOMPLETE))
continue; /* skip incomplete entries */
if (entry->flags & XFS_ATTR_LOCAL) {
@@ -583,6 +584,10 @@ xfs_attr_list(
(cursor->hashval || cursor->blkno || cursor->offset))
return -EINVAL;
+ /* Only internal consumers can retrieve incomplete attrs. */
+ if (flags & ATTR_INCOMPLETE)
+ return -EINVAL;
+
/*
* Check for a properly aligned buffer.
*/
--
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