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Subject[PATCH 2/2] staging: lustre: replace ll_{get,put}name() with {get,put}name()
Date
As pointed by Al Viro:

https://lkml.org/lkml/2015/4/11/243

There are bugs in ll_getname() because of wrong assumptions of returning
values from strncpy_from_user(). Moreover, what ll_getname want to do is
just to try copy the file name from userland. Since we already have
getname() for the same purpose, it's better to replace ll_getname() with
getname(), so is ll_putname().

Besides, remove unused code for checking whether namelen is 0 or not in
case LL_IOC_REMOVE_ENTRY, because zero-length file name is already
handled by getname() in the same way as ll_getname().

Suggested-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
---
drivers/staging/lustre/lustre/llite/dir.c | 60 ++++++----------------
.../staging/lustre/lustre/llite/llite_internal.h | 2 +-
drivers/staging/lustre/lustre/llite/namei.c | 2 +-
3 files changed, 18 insertions(+), 46 deletions(-)

diff --git a/drivers/staging/lustre/lustre/llite/dir.c b/drivers/staging/lustre/lustre/llite/dir.c
index a182019..c75fc38 100644
--- a/drivers/staging/lustre/lustre/llite/dir.c
+++ b/drivers/staging/lustre/lustre/llite/dir.c
@@ -1216,30 +1216,6 @@ out:
return rc;
}

-static char *
-ll_getname(const char __user *filename)
-{
- int ret = 0, len;
- char *tmp = __getname();
-
- if (!tmp)
- return ERR_PTR(-ENOMEM);
-
- len = strncpy_from_user(tmp, filename, PATH_MAX);
- if (len == 0)
- ret = -ENOENT;
- else if (len > PATH_MAX)
- ret = -ENAMETOOLONG;
-
- if (ret) {
- __putname(tmp);
- tmp = ERR_PTR(ret);
- }
- return tmp;
-}
-
-#define ll_putname(filename) __putname(filename)
-
static long ll_dir_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(file);
@@ -1441,7 +1417,7 @@ free_lmv:
return rc;
}
case LL_IOC_REMOVE_ENTRY: {
- char *filename = NULL;
+ struct filename *name = NULL;
int namelen = 0;
int rc;

@@ -1453,20 +1429,16 @@ free_lmv:
if (!(exp_connect_flags(sbi->ll_md_exp) & OBD_CONNECT_LVB_TYPE))
return -ENOTSUPP;

- filename = ll_getname((const char *)arg);
- if (IS_ERR(filename))
- return PTR_ERR(filename);
+ name = getname((const char *)arg);
+ if (IS_ERR(name))
+ return PTR_ERR(name);

- namelen = strlen(filename);
- if (namelen < 1) {
- rc = -EINVAL;
- goto out_rmdir;
- }
+ namelen = strlen(name->name);
+
+ rc = ll_rmdir_entry(inode, name->name, namelen);

- rc = ll_rmdir_entry(inode, filename, namelen);
-out_rmdir:
- if (filename)
- ll_putname(filename);
+ if (name)
+ putname(name);
return rc;
}
case LL_IOC_LOV_SWAP_LAYOUTS:
@@ -1481,16 +1453,16 @@ out_rmdir:
struct lov_user_md *lump;
struct lov_mds_md *lmm = NULL;
struct mdt_body *body;
- char *filename = NULL;
+ struct filename *name = NULL;
int lmmsize;

if (cmd == IOC_MDC_GETFILEINFO ||
cmd == IOC_MDC_GETFILESTRIPE) {
- filename = ll_getname((const char *)arg);
- if (IS_ERR(filename))
- return PTR_ERR(filename);
+ name = getname((const char *)arg);
+ if (IS_ERR(name))
+ return PTR_ERR(name);

- rc = ll_lov_getstripe_ea_info(inode, filename, &lmm,
+ rc = ll_lov_getstripe_ea_info(inode, name->name, &lmm,
&lmmsize, &request);
} else {
rc = ll_dir_getstripe(inode, &lmm, &lmmsize, &request);
@@ -1556,8 +1528,8 @@ skip_lmm:

out_req:
ptlrpc_req_finished(request);
- if (filename)
- ll_putname(filename);
+ if (name)
+ putname(name);
return rc;
}
case IOC_LOV_GETINFO: {
diff --git a/drivers/staging/lustre/lustre/llite/llite_internal.h b/drivers/staging/lustre/lustre/llite/llite_internal.h
index 2af1d72..0950565 100644
--- a/drivers/staging/lustre/lustre/llite/llite_internal.h
+++ b/drivers/staging/lustre/lustre/llite/llite_internal.h
@@ -714,7 +714,7 @@ struct inode *ll_iget(struct super_block *sb, ino_t hash,
int ll_md_blocking_ast(struct ldlm_lock *, struct ldlm_lock_desc *,
void *data, int flag);
struct dentry *ll_splice_alias(struct inode *inode, struct dentry *de);
-int ll_rmdir_entry(struct inode *dir, char *name, int namelen);
+int ll_rmdir_entry(struct inode *dir, const char *name, int namelen);

/* llite/rw.c */
int ll_prepare_write(struct file *, struct page *, unsigned from, unsigned to);
diff --git a/drivers/staging/lustre/lustre/llite/namei.c b/drivers/staging/lustre/lustre/llite/namei.c
index 890ac19..ec48d8d 100644
--- a/drivers/staging/lustre/lustre/llite/namei.c
+++ b/drivers/staging/lustre/lustre/llite/namei.c
@@ -867,7 +867,7 @@ static inline void ll_get_child_fid(struct dentry *child, struct lu_fid *fid)
/**
* Remove dir entry
**/
-int ll_rmdir_entry(struct inode *dir, char *name, int namelen)
+int ll_rmdir_entry(struct inode *dir, const char *name, int namelen)
{
struct ptlrpc_request *request = NULL;
struct md_op_data *op_data;
--
2.3.5


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