LU-744 llite: reimplement ll_get_fsname()

ll_get_fsname() used to allocate a piece of memory to store fsname,
this is not needed and error prone because it requires the caller
to free that piece of memory.

Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Change-Id: Ibc077b46728a1358e51a345ec13c966fc947c428
Reviewed-on: http://review.whamcloud.com/3704
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Fan Yong <yong.fan@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>

diff --git a/lustre/llite/dir.c b/lustre/llite/dir.c
index 013f54f..80fe011 100644 (file)
--- a/lustre/llite/dir.c
+++ b/lustre/llite/dir.c
@@ -652,23 +652,6 @@ int ll_send_mgc_param(struct obd_export *mgc, char *string)
         return rc;
 }
 
-char *ll_get_fsname(struct inode *inode)
-{
-        struct lustre_sb_info *lsi = s2lsi(inode->i_sb);
-        char *ptr, *fsname;
-        int len;
-
-        OBD_ALLOC(fsname, MGS_PARAM_MAXLEN);
-        len = strlen(lsi->lsi_lmd->lmd_profile);
-        ptr = strrchr(lsi->lsi_lmd->lmd_profile, '-');
-        if (ptr && (strcmp(ptr, "-client") == 0))
-                len -= 7;
-        strncpy(fsname, lsi->lsi_lmd->lmd_profile, len);
-        fsname[len] = '\0';
-
-        return fsname;
-}
-
 int ll_dir_setstripe(struct inode *inode, struct lov_user_md *lump,
                      int set_default)
 {
@@ -678,8 +661,8 @@ int ll_dir_setstripe(struct inode *inode, struct lov_user_md *lump,
         int rc = 0;
         struct lustre_sb_info *lsi = s2lsi(inode->i_sb);
         struct obd_device *mgc = lsi->lsi_mgc;
-        char *fsname = NULL, *param = NULL;
         int lum_size;
+       ENTRY;
 
         if (lump != NULL) {
                 /*
@@ -732,38 +715,44 @@ int ll_dir_setstripe(struct inode *inode, struct lov_user_md *lump,
          LOV_USER_MAGIC_V3 have the same initial fields so we do not
          need the make the distiction between the 2 versions */
         if (set_default && mgc->u.cli.cl_mgc_mgsexp) {
-                OBD_ALLOC(param, MGS_PARAM_MAXLEN);
-
-                /* Get fsname and assume devname to be -MDT0000. */
-                fsname = ll_get_fsname(inode);
-                /* Set root stripesize */
-                sprintf(param, "%s-MDT0000.lov.stripesize=%u", fsname,
-                        lump ? le32_to_cpu(lump->lmm_stripe_size) : 0);
-                rc = ll_send_mgc_param(mgc->u.cli.cl_mgc_mgsexp, param);
-                if (rc)
-                        goto end;
+               char *param = NULL;
+               char *buf;
+
+               OBD_ALLOC(param, MGS_PARAM_MAXLEN);
+               if (param == NULL)
+                       GOTO(end, rc = -ENOMEM);
+
+               buf = param;
+               /* Get fsname and assume devname to be -MDT0000. */
+               ll_get_fsname(inode->i_sb, buf, MTI_NAME_MAXLEN);
+               strcat(buf, "-MDT0000.lov");
+               buf += strlen(buf);
+
+               /* Set root stripesize */
+               sprintf(buf, ".stripesize=%u",
+                       lump ? le32_to_cpu(lump->lmm_stripe_size) : 0);
+               rc = ll_send_mgc_param(mgc->u.cli.cl_mgc_mgsexp, param);
+               if (rc)
+                       GOTO(end, rc);
+
+               /* Set root stripecount */
+               sprintf(buf, ".stripecount=%hd",
+                       lump ? le16_to_cpu(lump->lmm_stripe_count) : 0);
+               rc = ll_send_mgc_param(mgc->u.cli.cl_mgc_mgsexp, param);
+               if (rc)
+                       GOTO(end, rc);
+
+               /* Set root stripeoffset */
+               sprintf(buf, ".stripeoffset=%hd",
+                       lump ? le16_to_cpu(lump->lmm_stripe_offset) :
+                       (typeof(lump->lmm_stripe_offset))(-1));
+               rc = ll_send_mgc_param(mgc->u.cli.cl_mgc_mgsexp, param);
 
-                /* Set root stripecount */
-                sprintf(param, "%s-MDT0000.lov.stripecount=%hd", fsname,
-                        lump ? le16_to_cpu(lump->lmm_stripe_count) : 0);
-                rc = ll_send_mgc_param(mgc->u.cli.cl_mgc_mgsexp, param);
-                if (rc)
-                        goto end;
-
-                /* Set root stripeoffset */
-                sprintf(param, "%s-MDT0000.lov.stripeoffset=%hd", fsname,
-                        lump ? le16_to_cpu(lump->lmm_stripe_offset) :
-                        (typeof(lump->lmm_stripe_offset))(-1));
-                rc = ll_send_mgc_param(mgc->u.cli.cl_mgc_mgsexp, param);
-                if (rc)
-                        goto end;
 end:
-                if (fsname)
-                        OBD_FREE(fsname, MGS_PARAM_MAXLEN);
-                if (param)
-                        OBD_FREE(param, MGS_PARAM_MAXLEN);
-        }
-        return rc;
+               if (param != NULL)
+                       OBD_FREE(param, MGS_PARAM_MAXLEN);
+       }
+       RETURN(rc);
 }
 
 int ll_dir_getstripe(struct inode *inode, struct lov_mds_md **lmmp,

diff --git a/lustre/llite/llite_internal.h b/lustre/llite/llite_internal.h
index ab60e58..e5732de 100644 (file)
--- a/lustre/llite/llite_internal.h
+++ b/lustre/llite/llite_internal.h
@@ -668,7 +668,6 @@ int ll_dir_read(struct inode *inode, __u64 *_pos, void *cookie,
                filldir_t filldir);
 
 int ll_get_mdt_idx(struct inode *inode);
-char *ll_get_fsname(struct inode *inode);
 /* llite/namei.c */
 int ll_objects_destroy(struct ptlrpc_request *request,
                        struct inode *dir);
@@ -835,6 +834,7 @@ struct md_op_data *ll_prep_md_op_data(struct md_op_data *op_data,
                                       int mode, __u32 opc, void *data);
 void ll_finish_md_op_data(struct md_op_data *op_data);
 int ll_get_obd_name(struct inode *inode, unsigned int cmd, unsigned long arg);
+char *ll_get_fsname(struct super_block *sb, char *buf, int buflen);
 
 /* llite/llite_nfs.c */
 extern struct export_operations lustre_export_operations;

diff --git a/lustre/llite/llite_lib.c b/lustre/llite/llite_lib.c
index 9769ec3..08936e2 100644 (file)
--- a/lustre/llite/llite_lib.c
+++ b/lustre/llite/llite_lib.c
@@ -2157,12 +2157,9 @@ int ll_prep_inode(struct inode **inode,
        ibits = MDS_INODELOCK_LAYOUT;
        if (S_ISREG(md.body->mode) && sbi->ll_flags & LL_SBI_LAYOUT_LOCK &&
            md.lsm != NULL && !ll_have_md_lock(*inode, &ibits, LCK_MINMODE)) {
-               char *fsname = ll_get_fsname(*inode);
                CERROR("%s: inode "DFID" (%p) layout lock not granted.\n",
-                       fsname, PFID(ll_inode2fid(*inode)),
-                       *inode);
-               if (fsname)
-                       OBD_FREE(fsname, MGS_PARAM_MAXLEN);
+                       ll_get_fsname(sb, NULL, 0),
+                       PFID(ll_inode2fid(*inode)), *inode);
        }
 
 out:
@@ -2363,3 +2360,36 @@ int ll_get_obd_name(struct inode *inode, unsigned int cmd, unsigned long arg)
 
         RETURN(0);
 }
+
+/**
+ * Get lustre file system name by \a sbi. If \a buf is provided(non-NULL), the
+ * fsname will be returned in this buffer; otherwise, a static buffer will be
+ * used to store the fsname and returned to caller.
+ */
+char *ll_get_fsname(struct super_block *sb, char *buf, int buflen)
+{
+       static char fsname_static[MTI_NAME_MAXLEN];
+       struct lustre_sb_info *lsi = s2lsi(sb);
+       char *ptr;
+       int len;
+
+       if (buf == NULL) {
+               /* this means the caller wants to use static buffer
+                * and it doesn't care about race. Usually this is
+                * in error reporting path */
+               buf = fsname_static;
+               buflen = sizeof(fsname_static);
+       }
+
+       len = strlen(lsi->lsi_lmd->lmd_profile);
+       ptr = strrchr(lsi->lsi_lmd->lmd_profile, '-');
+       if (ptr && (strcmp(ptr, "-client") == 0))
+               len -= 7;
+
+       if (unlikely(len >= buflen))
+               len = buflen - 1;
+       strncpy(buf, lsi->lsi_lmd->lmd_profile, len);
+       buf[len] = '\0';
+
+       return buf;
+}