The cost is that we might need to flip '/' to '\\' in more than
just the prefix. Needs profiling, but I suspect that we won't
get slowdown on that.
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
fs/cifs/dir.c | 83 +++++++++++++++--------------------------------------------
1 file changed, 21 insertions(+), 62 deletions(-)
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 6e855f004f50..3febf667d119 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -93,20 +93,16 @@ char *
build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
bool prefix)
{
- struct dentry *temp;
- int namelen;
int dfsplen;
int pplen = 0;
- char *full_path = page;
- char dirsep;
struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
- unsigned seq;
+ char dirsep = CIFS_DIR_SEP(cifs_sb);
+ char *s;
if (unlikely(!page))
return ERR_PTR(-ENOMEM);
- dirsep = CIFS_DIR_SEP(cifs_sb);
if (prefix)
dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
else
@@ -115,74 +111,37 @@ build_path_from_dentry_optional_prefix(struct dentry *direntry, void *page,
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH)
pplen = cifs_sb->prepath ? strlen(cifs_sb->prepath) + 1 : 0;
-cifs_bp_rename_retry:
- namelen = dfsplen + pplen;
- seq = read_seqbegin(&rename_lock);
- rcu_read_lock();
- for (temp = direntry; !IS_ROOT(temp);) {
- namelen += (1 + temp->d_name.len);
- temp = temp->d_parent;
- }
- rcu_read_unlock();
-
- if (namelen >= PAGE_SIZE)
+ s = dentry_path_raw(direntry, page, PAGE_SIZE);
+ if (IS_ERR(s))
+ return s;
+ if (s < (char *)page + pplen + dfsplen)
return ERR_PTR(-ENAMETOOLONG);
-
- full_path[namelen] = 0; /* trailing null */
- rcu_read_lock();
- for (temp = direntry; !IS_ROOT(temp);) {
- spin_lock(&temp->d_lock);
- namelen -= 1 + temp->d_name.len;
- if (namelen < 0) {
- spin_unlock(&temp->d_lock);
- break;
- } else {
- full_path[namelen] = dirsep;
- strncpy(full_path + namelen + 1, temp->d_name.name,
- temp->d_name.len);
- cifs_dbg(FYI, "name: %s\n", full_path + namelen);
- }
- spin_unlock(&temp->d_lock);
- temp = temp->d_parent;
- }
- rcu_read_unlock();
- if (namelen != dfsplen + pplen || read_seqretry(&rename_lock, seq)) {
- cifs_dbg(FYI, "did not end path lookup where expected. namelen=%ddfsplen=%d\n",
- namelen, dfsplen);
- /* presumably this is only possible if racing with a rename
- of one of the parent directories (we can not lock the dentries
- above us to prevent this, but retrying should be harmless) */
- goto cifs_bp_rename_retry;
- }
- /* DIR_SEP already set for byte 0 / vs \ but not for
- subsequent slashes in prepath which currently must
- be entered the right way - not sure if there is an alternative
- since the '\' is a valid posix character so we can not switch
- those safely to '/' if any are found in the middle of the prepath */
- /* BB test paths to Windows with '/' in the midst of prepath */
-
if (pplen) {
- int i;
-
cifs_dbg(FYI, "using cifs_sb prepath <%s>\n", cifs_sb->prepath);
- memcpy(full_path+dfsplen+1, cifs_sb->prepath, pplen-1);
- full_path[dfsplen] = dirsep;
- for (i = 0; i < pplen-1; i++)
- if (full_path[dfsplen+1+i] == '/')
- full_path[dfsplen+1+i] = CIFS_DIR_SEP(cifs_sb);
+ s -= pplen;
+ memcpy(s + 1, cifs_sb->prepath, pplen - 1);
+ *s = '/';
}
+ if (dirsep != '/') {
+ /* BB test paths to Windows with '/' in the midst of prepath */
+ char *p;
+ for (p = s; *p; p++)
+ if (*p == '/')
+ *p = dirsep;
+ }
if (dfsplen) {
- strncpy(full_path, tcon->treeName, dfsplen);
+ s -= dfsplen;
+ memcpy(page, tcon->treeName, dfsplen);
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
int i;
for (i = 0; i < dfsplen; i++) {
- if (full_path[i] == '\\')
- full_path[i] = '/';
+ if (s[i] == '\\')
+ s[i] = '/';
}
}
}
- return full_path;
+ return s;
}
/*
--
2.11.0
