* reduce overhead:
* (fid->f_oid >> 16 & oxFFFF)/FID
*/
-#define MAX_PCC_DATABASE_PATH (6 * 5 + FID_NOBRACE_LEN + 1)
+#define PCC_DATASET_MAX_PATH (6 * 5 + FID_NOBRACE_LEN + 1)
static int pcc_fid2dataset_path(char *buf, int sz, struct lu_fid *fid)
{
return scnprintf(buf, sz, "%04x/%04x/%04x/%04x/%04x/%04x/"
RETURN(rc < 0 ? rc : 0);
}
-static int pcc_fid2dataset_fullpath(char *buf, int sz, struct lu_fid *fid,
- struct pcc_dataset *dataset)
-{
- return scnprintf(buf, sz, "%s/%04x/%04x/%04x/%04x/%04x/%04x/"
- DFID_NOBRACE,
- dataset->pccd_pathname,
- (fid)->f_oid & 0xFFFF,
- (fid)->f_oid >> 16 & 0xFFFF,
- (unsigned int)((fid)->f_seq & 0xFFFF),
- (unsigned int)((fid)->f_seq >> 16 & 0xFFFF),
- (unsigned int)((fid)->f_seq >> 32 & 0xFFFF),
- (unsigned int)((fid)->f_seq >> 48 & 0xFFFF),
- PFID(fid));
-}
-
/* Must be called with pcci->pcci_lock held */
static void pcc_inode_attach_init(struct pcc_dataset *dataset,
struct pcc_inode *pcci,
return pcci->pcci_layout_gen != CL_LAYOUT_GEN_NONE;
}
+static struct dentry *pcc_lookup(struct dentry *base, char *pathname)
+{
+ char *ptr = NULL, *component;
+ struct dentry *parent;
+ struct dentry *child = ERR_PTR(-ENOENT);
+
+ ptr = pathname;
+
+ /* move past any initial '/' to the start of the first path component*/
+ while (*ptr == '/')
+ ptr++;
+
+ /* store the start of the first path component */
+ component = ptr;
+
+ parent = dget(base);
+ while (ptr) {
+ /* find the start of the next component - if we don't find it,
+ * the current component is the last component
+ */
+ ptr = strchr(ptr, '/');
+ /* put a NUL char in place of the '/' before the next compnent
+ * so we can treat this component as a string; note the full
+ * path string is NUL terminated to this is not needed for the
+ * last component
+ */
+ if (ptr)
+ *ptr = '\0';
+
+ /* look up the current component */
+ inode_lock(parent->d_inode);
+ child = lookup_one_len(component, parent, strlen(component));
+ inode_unlock(parent->d_inode);
+
+ /* repair the path string: put '/' back in place of the NUL */
+ if (ptr)
+ *ptr = '/';
+
+ dput(parent);
+
+ if (IS_ERR_OR_NULL(child))
+ break;
+
+ /* we may find a cached negative dentry */
+ if (!d_is_positive(child)) {
+ dput(child);
+ child = NULL;
+ break;
+ }
+
+ /* descend in to the next level of the path */
+ parent = child;
+
+ /* move the pointer past the '/' to the next component */
+ if (ptr)
+ ptr++;
+ component = ptr;
+ }
+
+ /* NULL child means we didn't find anything */
+ if (!child)
+ child = ERR_PTR(-ENOENT);
+
+ return child;
+}
+
static int pcc_try_dataset_attach(struct inode *inode, __u32 gen,
enum lu_pcc_type type,
struct pcc_dataset *dataset,
struct ll_inode_info *lli = ll_i2info(inode);
struct pcc_inode *pcci = lli->lli_pcc_inode;
const struct cred *old_cred;
- struct dentry *pcc_dentry;
- struct path path;
- char *pathname;
+ struct dentry *pcc_dentry = NULL;
+ char pathname[PCC_DATASET_MAX_PATH];
__u32 pcc_gen;
int rc;
!(dataset->pccd_flags & PCC_DATASET_RWPCC))
RETURN(0);
- OBD_ALLOC(pathname, PATH_MAX);
- if (pathname == NULL)
- RETURN(-ENOMEM);
-
- pcc_fid2dataset_fullpath(pathname, PATH_MAX, &lli->lli_fid, dataset);
+ rc = pcc_fid2dataset_path(pathname, PCC_DATASET_MAX_PATH,
+ &lli->lli_fid);
old_cred = override_creds(pcc_super_cred(inode->i_sb));
- rc = kern_path(pathname, LOOKUP_FOLLOW, &path);
- if (rc)
+ pcc_dentry = pcc_lookup(dataset->pccd_path.dentry, pathname);
+ if (IS_ERR(pcc_dentry)) {
+ rc = PTR_ERR(pcc_dentry);
+ CDEBUG(D_CACHE, "%s: path lookup error on "DFID":%s: rc = %d\n",
+ ll_i2sbi(inode)->ll_fsname, PFID(&lli->lli_fid),
+ pathname, rc);
/* ignore this error */
GOTO(out, rc = 0);
+ }
- pcc_dentry = path.dentry;
rc = ll_vfs_getxattr(pcc_dentry, pcc_dentry->d_inode, pcc_xattr_layout,
&pcc_gen, sizeof(pcc_gen));
if (rc < 0)
/* ignore this error */
- GOTO(out_put_path, rc = 0);
+ GOTO(out_put_pcc_dentry, rc = 0);
rc = 0;
/* The file is still valid cached in PCC, attach it immediately. */
if (!pcci) {
OBD_SLAB_ALLOC_PTR_GFP(pcci, pcc_inode_slab, GFP_NOFS);
if (pcci == NULL)
- GOTO(out_put_path, rc = -ENOMEM);
+ GOTO(out_put_pcc_dentry, rc = -ENOMEM);
pcc_inode_init(pcci, lli);
dget(pcc_dentry);
pcc_layout_gen_set(pcci, gen);
*cached = true;
}
-out_put_path:
- path_put(&path);
+out_put_pcc_dentry:
+ dput(pcc_dentry);
out:
revert_creds(old_cred);
- OBD_FREE(pathname, PATH_MAX);
RETURN(rc);
}
struct dentry *child;
int rc = 0;
- OBD_ALLOC(path, MAX_PCC_DATABASE_PATH);
+ OBD_ALLOC(path, PCC_DATASET_MAX_PATH);
if (path == NULL)
return -ENOMEM;
- pcc_fid2dataset_path(path, MAX_PCC_DATABASE_PATH, fid);
+ pcc_fid2dataset_path(path, PCC_DATASET_MAX_PATH, fid);
base = pcc_mkdir_p(dataset->pccd_path.dentry, path, 0);
if (IS_ERR(base)) {
GOTO(out, rc);
}
- snprintf(path, MAX_PCC_DATABASE_PATH, DFID_NOBRACE, PFID(fid));
+ snprintf(path, PCC_DATASET_MAX_PATH, DFID_NOBRACE, PFID(fid));
child = pcc_create(base, path, 0);
if (IS_ERR(child)) {
rc = PTR_ERR(child);
out_base:
dput(base);
out:
- OBD_FREE(path, MAX_PCC_DATABASE_PATH);
+ OBD_FREE(path, PCC_DATASET_MAX_PATH);
return rc;
}