1 files changed, 58 insertions, 17 deletions

diff --git a/drivers/staging/lustre/lustre/obdclass/linkea.c b/drivers/staging/lustre/lustre/obdclass/linkea.c
index 0b1d2f0a422c..9af86d3d56e4 100644
--- a/drivers/staging/lustre/lustre/obdclass/linkea.c
+++ b/drivers/staging/lustre/lustre/obdclass/linkea.c
@@ -26,9 +26,9 @@
  * Author: Di Wang <di.wang@intel.com>
  */
 
-#include "../include/lustre/lustre_idl.h"
-#include "../include/obd.h"
-#include "../include/lustre_linkea.h"
+#include <uapi/linux/lustre/lustre_idl.h>
+#include <obd.h>
+#include <lustre_linkea.h>
 
 int linkea_data_new(struct linkea_data *ldata, struct lu_buf *buf)
 {
@@ -39,6 +39,8 @@ int linkea_data_new(struct linkea_data *ldata, struct lu_buf *buf)
 	ldata->ld_leh->leh_magic = LINK_EA_MAGIC;
 	ldata->ld_leh->leh_len = sizeof(struct link_ea_header);
 	ldata->ld_leh->leh_reccount = 0;
+	ldata->ld_leh->leh_overflow_time = 0;
+	ldata->ld_leh->leh_padding = 0;
 	return 0;
 }
 EXPORT_SYMBOL(linkea_data_new);
@@ -53,11 +55,15 @@ int linkea_init(struct linkea_data *ldata)
 		leh->leh_magic = LINK_EA_MAGIC;
 		leh->leh_reccount = __swab32(leh->leh_reccount);
 		leh->leh_len = __swab64(leh->leh_len);
-		/* entries are swabbed by linkea_entry_unpack */
+		leh->leh_overflow_time = __swab32(leh->leh_overflow_time);
+		leh->leh_padding = __swab32(leh->leh_padding);
+		/* individual entries are swabbed by linkea_entry_unpack() */
 	}
+
 	if (leh->leh_magic != LINK_EA_MAGIC)
 		return -EINVAL;
-	if (leh->leh_reccount == 0)
+
+	if (leh->leh_reccount == 0 && leh->leh_overflow_time == 0)
 		return -ENODATA;
 
 	ldata->ld_leh = leh;
@@ -65,6 +71,18 @@ int linkea_init(struct linkea_data *ldata)
 }
 EXPORT_SYMBOL(linkea_init);
 
+int linkea_init_with_rec(struct linkea_data *ldata)
+{
+	int rc;
+
+	rc = linkea_init(ldata);
+	if (!rc && ldata->ld_leh->leh_reccount == 0)
+		rc = -ENODATA;
+
+	return rc;
+}
+EXPORT_SYMBOL(linkea_init_with_rec);
+
 /**
  * Pack a link_ea_entry.
  * All elements are stored as chars to avoid alignment issues.
@@ -94,6 +112,8 @@ EXPORT_SYMBOL(linkea_entry_pack);
 void linkea_entry_unpack(const struct link_ea_entry *lee, int *reclen,
 			 struct lu_name *lname, struct lu_fid *pfid)
 {
+	LASSERT(lee);
+
 	*reclen = (lee->lee_reclen[0] << 8) | lee->lee_reclen[1];
 	memcpy(pfid, &lee->lee_parent_fid, sizeof(*pfid));
 	fid_be_to_cpu(pfid, pfid);
@@ -110,25 +130,44 @@ EXPORT_SYMBOL(linkea_entry_unpack);
 int linkea_add_buf(struct linkea_data *ldata, const struct lu_name *lname,
 		   const struct lu_fid *pfid)
 {
-	LASSERT(ldata->ld_leh);
+	struct link_ea_header *leh = ldata->ld_leh;
+	int reclen;
+
+	LASSERT(leh);
 
 	if (!lname || !pfid)
 		return -EINVAL;
 
-	ldata->ld_reclen = lname->ln_namelen + sizeof(struct link_ea_entry);
-	if (ldata->ld_leh->leh_len + ldata->ld_reclen >
-	    ldata->ld_buf->lb_len) {
+	reclen = lname->ln_namelen + sizeof(struct link_ea_entry);
+	if (unlikely(leh->leh_len + reclen > MAX_LINKEA_SIZE)) {
+		/*
+		 * Use 32-bits to save the overflow time, although it will
+		 * shrink the ktime_get_real_seconds() returned 64-bits value
+		 * to 32-bits value, it is still quite large and can be used
+		 * for about 140 years. That is enough.
+		 */
+		leh->leh_overflow_time = ktime_get_real_seconds();
+		if (unlikely(leh->leh_overflow_time == 0))
+			leh->leh_overflow_time++;
+
+		CDEBUG(D_INODE, "No enough space to hold linkea entry '" DFID ": %.*s' at %u\n",
+		       PFID(pfid), lname->ln_namelen,
+		       lname->ln_name, leh->leh_overflow_time);
+		return 0;
+	}
+
+	if (leh->leh_len + reclen > ldata->ld_buf->lb_len) {
 		if (lu_buf_check_and_grow(ldata->ld_buf,
-					  ldata->ld_leh->leh_len +
-					  ldata->ld_reclen) < 0)
+					  leh->leh_len + reclen) < 0)
 			return -ENOMEM;
+
+		leh = ldata->ld_leh = ldata->ld_buf->lb_buf;
 	}
 
-	ldata->ld_leh = ldata->ld_buf->lb_buf;
-	ldata->ld_lee = ldata->ld_buf->lb_buf + ldata->ld_leh->leh_len;
+	ldata->ld_lee = ldata->ld_buf->lb_buf + leh->leh_len;
 	ldata->ld_reclen = linkea_entry_pack(ldata->ld_lee, lname, pfid);
-	ldata->ld_leh->leh_len += ldata->ld_reclen;
-	ldata->ld_leh->leh_reccount++;
+	leh->leh_len += ldata->ld_reclen;
+	leh->leh_reccount++;
 	CDEBUG(D_INODE, "New link_ea name '" DFID ":%.*s' is added\n",
 	       PFID(pfid), lname->ln_namelen, lname->ln_name);
 	return 0;
@@ -139,6 +178,7 @@ EXPORT_SYMBOL(linkea_add_buf);
 void linkea_del_buf(struct linkea_data *ldata, const struct lu_name *lname)
 {
 	LASSERT(ldata->ld_leh && ldata->ld_lee);
+	LASSERT(ldata->ld_leh->leh_reccount > 0);
 
 	ldata->ld_leh->leh_reccount--;
 	ldata->ld_leh->leh_len -= ldata->ld_reclen;
@@ -174,8 +214,9 @@ int linkea_links_find(struct linkea_data *ldata, const struct lu_name *lname,
 
 	LASSERT(ldata->ld_leh);
 
-	/* link #0 */
-	ldata->ld_lee = (struct link_ea_entry *)(ldata->ld_leh + 1);
+	/* link #0, if leh_reccount == 0 we skip the loop and return -ENOENT */
+	if (likely(ldata->ld_leh->leh_reccount > 0))
+		ldata->ld_lee = (struct link_ea_entry *)(ldata->ld_leh + 1);
 
 	for (count = 0; count < ldata->ld_leh->leh_reccount; count++) {
 		linkea_entry_unpack(ldata->ld_lee, &ldata->ld_reclen,