cifs: allocate buffer in the caller of build_path_from_dentry()

build_path_from_dentry() open-codes dentry_path_raw().  The reason
we can't use dentry_path_raw() in there (and postprocess the
result as needed) is that the callers of build_path_from_dentry()
expect that the object to be freed on cleanup and the string to
be used are at the same address.  That's painful, since the path
is naturally built end-to-beginning - we start at the leaf and
go through the ancestors, accumulating the pathname.

Life would be easier if we left the buffer allocation to callers.
It wouldn't be exact-sized buffer, but none of the callers keep
the result for long - it's always freed before the caller returns.
So there's no need to do exact-sized allocation; better use
__getname()/__putname(), same as we do for pathname arguments
of syscalls.  What's more, there's no need to do allocation under
spinlocks, so GFP_ATOMIC is not needed.

Next patch will replace the open-coded dentry_path_raw() (in
build_path_from_dentry_optional_prefix()) with calling the real
thing.  This patch only introduces wrappers for allocating/freeing
the buffers and switches to new calling conventions:
	build_path_from_dentry(dentry, buf)
expects buf to be address of a page-sized object or NULL,
return value is a pathname built inside that buffer on success,
ERR_PTR(-ENOMEM) if buf is NULL and ERR_PTR(-ENAMETOOLONG) if
the pathname won't fit into page.  Note that we don't need to
check for failure when allocating the buffer in the caller -
build_path_from_dentry() will do the right thing.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c
index ecee2864972da52278be9774d3a1fd658ffbf240..c87c37cf291434576ae5cbe1940421882b91c949 100644 (file)
--- a/fs/cifs/cifs_dfs_ref.c
+++ b/fs/cifs/cifs_dfs_ref.c
@@ -302,6 +302,7 @@ static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt)
        struct cifs_sb_info *cifs_sb;
        struct cifs_ses *ses;
        struct cifs_tcon *tcon;
+       void *page;
        char *full_path, *root_path;
        unsigned int xid;
        int rc;
@@ -324,10 +325,13 @@ static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt)
                goto cdda_exit;
        }
 
+       page = alloc_dentry_path();
        /* always use tree name prefix */
-       full_path = build_path_from_dentry_optional_prefix(mntpt, true);
-       if (full_path == NULL)
-               goto cdda_exit;
+       full_path = build_path_from_dentry_optional_prefix(mntpt, page, true);
+       if (IS_ERR(full_path)) {
+               mnt = ERR_CAST(full_path);
+               goto free_full_path;
+       }
 
        convert_delimiter(full_path, '\\');
 
@@ -385,7 +389,7 @@ static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt)
 free_root_path:
        kfree(root_path);
 free_full_path:
-       kfree(full_path);
+       free_dentry_path(page);
 cdda_exit:
        cifs_dbg(FYI, "leaving %s\n" , __func__);
        return mnt;

diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index ed6ea0c59cb9acaf80b60e9132803b2d2fe0b95d..c8faa3e82fe7044a1b8c3909d537728b6e6bdf4b 100644 (file)
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -69,9 +69,20 @@ extern int init_cifs_idmap(void);
 extern void exit_cifs_idmap(void);
 extern int init_cifs_spnego(void);
 extern void exit_cifs_spnego(void);
-extern const char *build_path_from_dentry(struct dentry *);
+extern const char *build_path_from_dentry(struct dentry *, void *);
 extern char *build_path_from_dentry_optional_prefix(struct dentry *direntry,
-                                                   bool prefix);
+                                                   void *page, bool prefix);
+static inline void *alloc_dentry_path(void)
+{
+       return __getname();
+}
+
+static inline void free_dentry_path(void *page)
+{
+       if (page)
+               __putname(page);
+}
+
 extern char *cifs_build_path_to_root(struct smb3_fs_context *ctx,
                                     struct cifs_sb_info *cifs_sb,
                                     struct cifs_tcon *tcon,

diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 01e26f811885c822d0a709acba30548a19e4c108..6e855f004f508452dadd19af5b15b9e453be1b7c 100644 (file)
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -79,29 +79,33 @@ cifs_build_path_to_root(struct smb3_fs_context *ctx, struct cifs_sb_info *cifs_s
 
 /* Note: caller must free return buffer */
 const char *
-build_path_from_dentry(struct dentry *direntry)
+build_path_from_dentry(struct dentry *direntry, void *page)
 {
        struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
        struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
        bool prefix = tcon->Flags & SMB_SHARE_IS_IN_DFS;
 
-       return build_path_from_dentry_optional_prefix(direntry,
+       return build_path_from_dentry_optional_prefix(direntry, page,
                                                      prefix);
 }
 
 char *
-build_path_from_dentry_optional_prefix(struct dentry *direntry, bool prefix)
+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;
+       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;
 
+       if (unlikely(!page))
+               return ERR_PTR(-ENOMEM);
+
        dirsep = CIFS_DIR_SEP(cifs_sb);
        if (prefix)
                dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
@@ -118,17 +122,12 @@ cifs_bp_rename_retry:
        for (temp = direntry; !IS_ROOT(temp);) {
                namelen += (1 + temp->d_name.len);
                temp = temp->d_parent;
-               if (temp == NULL) {
-                       cifs_dbg(VFS, "corrupt dentry\n");
-                       rcu_read_unlock();
-                       return NULL;
-               }
        }
        rcu_read_unlock();
 
-       full_path = kmalloc(namelen+1, GFP_ATOMIC);
-       if (full_path == NULL)
-               return full_path;
+       if (namelen >= PAGE_SIZE)
+               return ERR_PTR(-ENAMETOOLONG);
+
        full_path[namelen] = 0; /* trailing null */
        rcu_read_lock();
        for (temp = direntry; !IS_ROOT(temp);) {
@@ -145,12 +144,6 @@ cifs_bp_rename_retry:
                }
                spin_unlock(&temp->d_lock);
                temp = temp->d_parent;
-               if (temp == NULL) {
-                       cifs_dbg(VFS, "corrupt dentry\n");
-                       rcu_read_unlock();
-                       kfree(full_path);
-                       return NULL;
-               }
        }
        rcu_read_unlock();
        if (namelen != dfsplen + pplen || read_seqretry(&rename_lock, seq)) {
@@ -159,7 +152,6 @@ cifs_bp_rename_retry:
                /* 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) */
-               kfree(full_path);
                goto cifs_bp_rename_retry;
        }
        /* DIR_SEP already set for byte  0 / vs \ but not for
@@ -233,7 +225,8 @@ cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,
        int desired_access;
        struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
        struct cifs_tcon *tcon = tlink_tcon(tlink);
-       const char *full_path = NULL;
+       const char *full_path;
+       void *page = alloc_dentry_path();
        FILE_ALL_INFO *buf = NULL;
        struct inode *newinode = NULL;
        int disposition;
@@ -244,9 +237,11 @@ cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,
        if (tcon->ses->server->oplocks)
                *oplock = REQ_OPLOCK;
 
-       full_path = build_path_from_dentry(direntry);
-       if (!full_path)
-               return -ENOMEM;
+       full_path = build_path_from_dentry(direntry, page);
+       if (IS_ERR(full_path)) {
+               free_dentry_path(page);
+               return PTR_ERR(full_path);
+       }
 
        if (tcon->unix_ext && cap_unix(tcon->ses) && !tcon->broken_posix_open &&
            (CIFS_UNIX_POSIX_PATH_OPS_CAP &
@@ -448,7 +443,7 @@ cifs_create_set_dentry:
 
 out:
        kfree(buf);
-       kfree(full_path);
+       free_dentry_path(page);
        return rc;
 
 out_err:
@@ -619,7 +614,8 @@ int cifs_mknod(struct user_namespace *mnt_userns, struct inode *inode,
        struct cifs_sb_info *cifs_sb;
        struct tcon_link *tlink;
        struct cifs_tcon *tcon;
-       const char *full_path = NULL;
+       const char *full_path;
+       void *page;
 
        if (!old_valid_dev(device_number))
                return -EINVAL;
@@ -629,13 +625,13 @@ int cifs_mknod(struct user_namespace *mnt_userns, struct inode *inode,
        if (IS_ERR(tlink))
                return PTR_ERR(tlink);
 
+       page = alloc_dentry_path();
        tcon = tlink_tcon(tlink);
-
        xid = get_xid();
 
-       full_path = build_path_from_dentry(direntry);
-       if (full_path == NULL) {
-               rc = -ENOMEM;
+       full_path = build_path_from_dentry(direntry, page);
+       if (IS_ERR(full_path)) {
+               rc = PTR_ERR(full_path);
                goto mknod_out;
        }
 
@@ -644,7 +640,7 @@ int cifs_mknod(struct user_namespace *mnt_userns, struct inode *inode,
                                               device_number);
 
 mknod_out:
-       kfree(full_path);
+       free_dentry_path(page);
        free_xid(xid);
        cifs_put_tlink(tlink);
        return rc;
@@ -660,7 +656,8 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
        struct tcon_link *tlink;
        struct cifs_tcon *pTcon;
        struct inode *newInode = NULL;
-       const char *full_path = NULL;
+       const char *full_path;
+       void *page;
 
        xid = get_xid();
 
@@ -687,11 +684,13 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
        /* can not grab the rename sem here since it would
        deadlock in the cases (beginning of sys_rename itself)
        in which we already have the sb rename sem */
-       full_path = build_path_from_dentry(direntry);
-       if (full_path == NULL) {
+       page = alloc_dentry_path();
+       full_path = build_path_from_dentry(direntry, page);
+       if (IS_ERR(full_path)) {
                cifs_put_tlink(tlink);
                free_xid(xid);
-               return ERR_PTR(-ENOMEM);
+               free_dentry_path(page);
+               return ERR_CAST(full_path);
        }
 
        if (d_really_is_positive(direntry)) {
@@ -727,7 +726,7 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
                }
                newInode = ERR_PTR(rc);
        }
-       kfree(full_path);
+       free_dentry_path(page);
        cifs_put_tlink(tlink);
        free_xid(xid);
        return d_splice_alias(newInode, direntry);

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index af49b3937e15a21e5d297c69c78bf6aadd1b52a9..3d4e6e7dac1d2341da5de5261733a9dfaca242e9 100644 (file)
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -530,7 +530,8 @@ int cifs_open(struct inode *inode, struct file *file)
        struct cifs_tcon *tcon;
        struct tcon_link *tlink;
        struct cifsFileInfo *cfile = NULL;
-       const char *full_path = NULL;
+       void *page;
+       const char *full_path;
        bool posix_open_ok = false;
        struct cifs_fid fid;
        struct cifs_pending_open open;
@@ -546,9 +547,10 @@ int cifs_open(struct inode *inode, struct file *file)
        tcon = tlink_tcon(tlink);
        server = tcon->ses->server;
 
-       full_path = build_path_from_dentry(file_dentry(file));
-       if (full_path == NULL) {
-               rc = -ENOMEM;
+       page = alloc_dentry_path();
+       full_path = build_path_from_dentry(file_dentry(file), page);
+       if (IS_ERR(full_path)) {
+               rc = PTR_ERR(full_path);
                goto out;
        }
 
@@ -640,7 +642,7 @@ int cifs_open(struct inode *inode, struct file *file)
        }
 
 out:
-       kfree(full_path);
+       free_dentry_path(page);
        free_xid(xid);
        cifs_put_tlink(tlink);
        return rc;
@@ -689,7 +691,8 @@ cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
        struct TCP_Server_Info *server;
        struct cifsInodeInfo *cinode;
        struct inode *inode;
-       const char *full_path = NULL;
+       void *page;
+       const char *full_path;
        int desired_access;
        int disposition = FILE_OPEN;
        int create_options = CREATE_NOT_DIR;
@@ -699,9 +702,8 @@ cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
        mutex_lock(&cfile->fh_mutex);
        if (!cfile->invalidHandle) {
                mutex_unlock(&cfile->fh_mutex);
-               rc = 0;
                free_xid(xid);
-               return rc;
+               return 0;
        }
 
        inode = d_inode(cfile->dentry);
@@ -715,12 +717,13 @@ cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
         * called and if the server was down that means we end up here, and we
         * can never tell if the caller already has the rename_sem.
         */
-       full_path = build_path_from_dentry(cfile->dentry);
-       if (full_path == NULL) {
-               rc = -ENOMEM;
+       page = alloc_dentry_path();
+       full_path = build_path_from_dentry(cfile->dentry, page);
+       if (IS_ERR(full_path)) {
                mutex_unlock(&cfile->fh_mutex);
+               free_dentry_path(page);
                free_xid(xid);
-               return rc;
+               return PTR_ERR(full_path);
        }
 
        cifs_dbg(FYI, "inode = 0x%p file flags 0x%x for %s\n",
@@ -838,7 +841,7 @@ reopen_success:
                cifs_relock_file(cfile);
 
 reopen_error_exit:
-       kfree(full_path);
+       free_dentry_path(page);
        free_xid(xid);
        return rc;
 }
@@ -2069,34 +2072,31 @@ cifs_get_writable_path(struct cifs_tcon *tcon, const char *name,
                       int flags,
                       struct cifsFileInfo **ret_file)
 {
-       struct list_head *tmp;
        struct cifsFileInfo *cfile;
-       struct cifsInodeInfo *cinode;
-       const char *full_path;
+       void *page = alloc_dentry_path();
 
        *ret_file = NULL;
 
        spin_lock(&tcon->open_file_lock);
-       list_for_each(tmp, &tcon->openFileList) {
-               cfile = list_entry(tmp, struct cifsFileInfo,
-                            tlist);
-               full_path = build_path_from_dentry(cfile->dentry);
-               if (full_path == NULL) {
+       list_for_each_entry(cfile, &tcon->openFileList, tlist) {
+               struct cifsInodeInfo *cinode;
+               const char *full_path = build_path_from_dentry(cfile->dentry, page);
+               if (IS_ERR(full_path)) {
                        spin_unlock(&tcon->open_file_lock);
-                       return -ENOMEM;
+                       free_dentry_path(page);
+                       return PTR_ERR(full_path);
                }
-               if (strcmp(full_path, name)) {
-                       kfree(full_path);
+               if (strcmp(full_path, name))
                        continue;
-               }
 
-               kfree(full_path);
                cinode = CIFS_I(d_inode(cfile->dentry));
                spin_unlock(&tcon->open_file_lock);
+               free_dentry_path(page);
                return cifs_get_writable_file(cinode, flags, ret_file);
        }
 
        spin_unlock(&tcon->open_file_lock);
+       free_dentry_path(page);
        return -ENOENT;
 }
 
@@ -2104,35 +2104,32 @@ int
 cifs_get_readable_path(struct cifs_tcon *tcon, const char *name,
                       struct cifsFileInfo **ret_file)
 {
-       struct list_head *tmp;
        struct cifsFileInfo *cfile;
-       struct cifsInodeInfo *cinode;
-       const char *full_path;
+       void *page = alloc_dentry_path();
 
        *ret_file = NULL;
 
        spin_lock(&tcon->open_file_lock);
-       list_for_each(tmp, &tcon->openFileList) {
-               cfile = list_entry(tmp, struct cifsFileInfo,
-                            tlist);
-               full_path = build_path_from_dentry(cfile->dentry);
-               if (full_path == NULL) {
+       list_for_each_entry(cfile, &tcon->openFileList, tlist) {
+               struct cifsInodeInfo *cinode;
+               const char *full_path = build_path_from_dentry(cfile->dentry, page);
+               if (IS_ERR(full_path)) {
                        spin_unlock(&tcon->open_file_lock);
-                       return -ENOMEM;
+                       free_dentry_path(page);
+                       return PTR_ERR(full_path);
                }
-               if (strcmp(full_path, name)) {
-                       kfree(full_path);
+               if (strcmp(full_path, name))
                        continue;
-               }
 
-               kfree(full_path);
                cinode = CIFS_I(d_inode(cfile->dentry));
                spin_unlock(&tcon->open_file_lock);
+               free_dentry_path(page);
                *ret_file = find_readable_file(cinode, 0);
                return *ret_file ? 0 : -ENOENT;
        }
 
        spin_unlock(&tcon->open_file_lock);
+       free_dentry_path(page);
        return -ENOENT;
 }
 

diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 0b29893f40b7355b40cd2dd56f3f291f873aa3a8..fe3a50a39f41705ba4512926964e7be3706711ae 100644 (file)
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1609,7 +1609,8 @@ int cifs_unlink(struct inode *dir, struct dentry *dentry)
 {
        int rc = 0;
        unsigned int xid;
-       const char *full_path = NULL;
+       const char *full_path;
+       void *page;
        struct inode *inode = d_inode(dentry);
        struct cifsInodeInfo *cifs_inode;
        struct super_block *sb = dir->i_sb;
@@ -1629,6 +1630,7 @@ int cifs_unlink(struct inode *dir, struct dentry *dentry)
        server = tcon->ses->server;
 
        xid = get_xid();
+       page = alloc_dentry_path();
 
        if (tcon->nodelete) {
                rc = -EACCES;
@@ -1637,9 +1639,9 @@ int cifs_unlink(struct inode *dir, struct dentry *dentry)
 
        /* Unlink can be called from rename so we can not take the
         * sb->s_vfs_rename_mutex here */
-       full_path = build_path_from_dentry(dentry);
-       if (full_path == NULL) {
-               rc = -ENOMEM;
+       full_path = build_path_from_dentry(dentry, page);
+       if (IS_ERR(full_path)) {
+               rc = PTR_ERR(full_path);
                goto unlink_out;
        }
 
@@ -1713,7 +1715,7 @@ out_reval:
        cifs_inode = CIFS_I(dir);
        CIFS_I(dir)->time = 0;  /* force revalidate of dir as well */
 unlink_out:
-       kfree(full_path);
+       free_dentry_path(page);
        kfree(attrs);
        free_xid(xid);
        cifs_put_tlink(tlink);
@@ -1867,6 +1869,7 @@ int cifs_mkdir(struct user_namespace *mnt_userns, struct inode *inode,
        struct cifs_tcon *tcon;
        struct TCP_Server_Info *server;
        const char *full_path;
+       void *page;
 
        cifs_dbg(FYI, "In cifs_mkdir, mode = %04ho inode = 0x%p\n",
                 mode, inode);
@@ -1879,9 +1882,10 @@ int cifs_mkdir(struct user_namespace *mnt_userns, struct inode *inode,
 
        xid = get_xid();
 
-       full_path = build_path_from_dentry(direntry);
-       if (full_path == NULL) {
-               rc = -ENOMEM;
+       page = alloc_dentry_path();
+       full_path = build_path_from_dentry(direntry, page);
+       if (IS_ERR(full_path)) {
+               rc = PTR_ERR(full_path);
                goto mkdir_out;
        }
 
@@ -1924,7 +1928,7 @@ mkdir_out:
         * attributes are invalid now.
         */
        CIFS_I(inode)->time = 0;
-       kfree(full_path);
+       free_dentry_path(page);
        free_xid(xid);
        cifs_put_tlink(tlink);
        return rc;
@@ -1938,16 +1942,17 @@ int cifs_rmdir(struct inode *inode, struct dentry *direntry)
        struct tcon_link *tlink;
        struct cifs_tcon *tcon;
        struct TCP_Server_Info *server;
-       const char *full_path = NULL;
+       const char *full_path;
+       void *page = alloc_dentry_path();
        struct cifsInodeInfo *cifsInode;
 
        cifs_dbg(FYI, "cifs_rmdir, inode = 0x%p\n", inode);
 
        xid = get_xid();
 
-       full_path = build_path_from_dentry(direntry);
-       if (full_path == NULL) {
-               rc = -ENOMEM;
+       full_path = build_path_from_dentry(direntry, page);
+       if (IS_ERR(full_path)) {
+               rc = PTR_ERR(full_path);
                goto rmdir_exit;
        }
 
@@ -1997,7 +2002,7 @@ int cifs_rmdir(struct inode *inode, struct dentry *direntry)
                current_time(inode);
 
 rmdir_exit:
-       kfree(full_path);
+       free_dentry_path(page);
        free_xid(xid);
        return rc;
 }
@@ -2072,8 +2077,8 @@ cifs_rename2(struct user_namespace *mnt_userns, struct inode *source_dir,
             struct dentry *source_dentry, struct inode *target_dir,
             struct dentry *target_dentry, unsigned int flags)
 {
-       const char *from_name = NULL;
-       const char *to_name = NULL;
+       const char *from_name, *to_name;
+       void *page1, *page2;
        struct cifs_sb_info *cifs_sb;
        struct tcon_link *tlink;
        struct cifs_tcon *tcon;
@@ -2091,21 +2096,19 @@ cifs_rename2(struct user_namespace *mnt_userns, struct inode *source_dir,
                return PTR_ERR(tlink);
        tcon = tlink_tcon(tlink);
 
+       page1 = alloc_dentry_path();
+       page2 = alloc_dentry_path();
        xid = get_xid();
 
-       /*
-        * we already have the rename sem so we do not need to
-        * grab it again here to protect the path integrity
-        */
-       from_name = build_path_from_dentry(source_dentry);
-       if (from_name == NULL) {
-               rc = -ENOMEM;
+       from_name = build_path_from_dentry(source_dentry, page1);
+       if (IS_ERR(from_name)) {
+               rc = PTR_ERR(from_name);
                goto cifs_rename_exit;
        }
 
-       to_name = build_path_from_dentry(target_dentry);
-       if (to_name == NULL) {
-               rc = -ENOMEM;
+       to_name = build_path_from_dentry(target_dentry, page2);
+       if (IS_ERR(to_name)) {
+               rc = PTR_ERR(to_name);
                goto cifs_rename_exit;
        }
 
@@ -2177,8 +2180,8 @@ unlink_target:
 
 cifs_rename_exit:
        kfree(info_buf_source);
-       kfree(from_name);
-       kfree(to_name);
+       free_dentry_path(page2);
+       free_dentry_path(page1);
        free_xid(xid);
        cifs_put_tlink(tlink);
        return rc;
@@ -2317,7 +2320,8 @@ int cifs_revalidate_dentry_attr(struct dentry *dentry)
        int rc = 0;
        struct inode *inode = d_inode(dentry);
        struct super_block *sb = dentry->d_sb;
-       const char *full_path = NULL;
+       const char *full_path;
+       void *page;
        int count = 0;
 
        if (inode == NULL)
@@ -2328,11 +2332,10 @@ int cifs_revalidate_dentry_attr(struct dentry *dentry)
 
        xid = get_xid();
 
-       /* can not safely grab the rename sem here if rename calls revalidate
-          since that would deadlock */
-       full_path = build_path_from_dentry(dentry);
-       if (full_path == NULL) {
-               rc = -ENOMEM;
+       page = alloc_dentry_path();
+       full_path = build_path_from_dentry(dentry, page);
+       if (IS_ERR(full_path)) {
+               rc = PTR_ERR(full_path);
                goto out;
        }
 
@@ -2351,7 +2354,7 @@ again:
        if (rc == -EAGAIN && count++ < 10)
                goto again;
 out:
-       kfree(full_path);
+       free_dentry_path(page);
        free_xid(xid);
 
        return rc;
@@ -2613,7 +2616,8 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs)
 {
        int rc;
        unsigned int xid;
-       const char *full_path = NULL;
+       const char *full_path;
+       void *page = alloc_dentry_path();
        struct inode *inode = d_inode(direntry);
        struct cifsInodeInfo *cifsInode = CIFS_I(inode);
        struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
@@ -2634,9 +2638,9 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs)
        if (rc < 0)
                goto out;
 
-       full_path = build_path_from_dentry(direntry);
-       if (full_path == NULL) {
-               rc = -ENOMEM;
+       full_path = build_path_from_dentry(direntry, page);
+       if (IS_ERR(full_path)) {
+               rc = PTR_ERR(full_path);
                goto out;
        }
 
@@ -2748,7 +2752,7 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs)
                cifsInode->time = 0;
 out:
        kfree(args);
-       kfree(full_path);
+       free_dentry_path(page);
        free_xid(xid);
        return rc;
 }
@@ -2764,7 +2768,8 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
        struct cifsInodeInfo *cifsInode = CIFS_I(inode);
        struct cifsFileInfo *wfile;
        struct cifs_tcon *tcon;
-       const char *full_path = NULL;
+       const char *full_path;
+       void *page = alloc_dentry_path();
        int rc = -EACCES;
        __u32 dosattr = 0;
        __u64 mode = NO_CHANGE_64;
@@ -2778,16 +2783,13 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
                attrs->ia_valid |= ATTR_FORCE;
 
        rc = setattr_prepare(&init_user_ns, direntry, attrs);
-       if (rc < 0) {
-               free_xid(xid);
-               return rc;
-       }
+       if (rc < 0)
+               goto cifs_setattr_exit;
 
-       full_path = build_path_from_dentry(direntry);
-       if (full_path == NULL) {
-               rc = -ENOMEM;
-               free_xid(xid);
-               return rc;
+       full_path = build_path_from_dentry(direntry, page);
+       if (IS_ERR(full_path)) {
+               rc = PTR_ERR(full_path);
+               goto cifs_setattr_exit;
        }
 
        /*
@@ -2937,8 +2939,8 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
        mark_inode_dirty(inode);
 
 cifs_setattr_exit:
-       kfree(full_path);
        free_xid(xid);
+       free_dentry_path(page);
        return rc;
 }
 

diff --git a/fs/cifs/ioctl.c b/fs/cifs/ioctl.c
index aba573dd86acde806d4a44ba04dfc4df95f0f107..08d99fec593e5194dc483781e055c17dc3809df4 100644 (file)
--- a/fs/cifs/ioctl.c
+++ b/fs/cifs/ioctl.c
@@ -43,12 +43,15 @@ static long cifs_ioctl_query_info(unsigned int xid, struct file *filep,
        struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
        struct dentry *dentry = filep->f_path.dentry;
        const unsigned char *path;
+       void *page = alloc_dentry_path();
        __le16 *utf16_path = NULL, root_path;
        int rc = 0;
 
-       path = build_path_from_dentry(dentry);
-       if (path == NULL)
-               return -ENOMEM;
+       path = build_path_from_dentry(dentry, page);
+       if (IS_ERR(path)) {
+               free_dentry_path(page);
+               return PTR_ERR(path);
+       }
 
        cifs_dbg(FYI, "%s %s\n", __func__, path);
 
@@ -73,7 +76,7 @@ static long cifs_ioctl_query_info(unsigned int xid, struct file *filep,
  ici_exit:
        if (utf16_path != &root_path)
                kfree(utf16_path);
-       kfree(path);
+       free_dentry_path(page);
        return rc;
 }
 

diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index 18e0e31a6d3915d597e4936f086c2c21978ef684..616e1bc0cc0a05f29c470924c7505959d7d116e2 100644 (file)
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -510,8 +510,8 @@ cifs_hardlink(struct dentry *old_file, struct inode *inode,
 {
        int rc = -EACCES;
        unsigned int xid;
-       const char *from_name = NULL;
-       const char *to_name = NULL;
+       const char *from_name, *to_name;
+       void *page1, *page2;
        struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
        struct tcon_link *tlink;
        struct cifs_tcon *tcon;
@@ -524,11 +524,17 @@ cifs_hardlink(struct dentry *old_file, struct inode *inode,
        tcon = tlink_tcon(tlink);
 
        xid = get_xid();
+       page1 = alloc_dentry_path();
+       page2 = alloc_dentry_path();
 
-       from_name = build_path_from_dentry(old_file);
-       to_name = build_path_from_dentry(direntry);
-       if ((from_name == NULL) || (to_name == NULL)) {
-               rc = -ENOMEM;
+       from_name = build_path_from_dentry(old_file, page1);
+       if (IS_ERR(from_name)) {
+               rc = PTR_ERR(from_name);
+               goto cifs_hl_exit;
+       }
+       to_name = build_path_from_dentry(direntry, page2);
+       if (IS_ERR(to_name)) {
+               rc = PTR_ERR(to_name);
                goto cifs_hl_exit;
        }
 
@@ -587,8 +593,8 @@ cifs_hardlink(struct dentry *old_file, struct inode *inode,
        }
 
 cifs_hl_exit:
-       kfree(from_name);
-       kfree(to_name);
+       free_dentry_path(page1);
+       free_dentry_path(page2);
        free_xid(xid);
        cifs_put_tlink(tlink);
        return rc;
@@ -600,7 +606,8 @@ cifs_get_link(struct dentry *direntry, struct inode *inode,
 {
        int rc = -ENOMEM;
        unsigned int xid;
-       const char *full_path = NULL;
+       const char *full_path;
+       void *page;
        char *target_path = NULL;
        struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
        struct tcon_link *tlink = NULL;
@@ -620,11 +627,13 @@ cifs_get_link(struct dentry *direntry, struct inode *inode,
        tcon = tlink_tcon(tlink);
        server = tcon->ses->server;
 
-       full_path = build_path_from_dentry(direntry);
-       if (!full_path) {
+       page = alloc_dentry_path();
+       full_path = build_path_from_dentry(direntry, page);
+       if (IS_ERR(full_path)) {
                free_xid(xid);
                cifs_put_tlink(tlink);
-               return ERR_PTR(-ENOMEM);
+               free_dentry_path(page);
+               return ERR_CAST(full_path);
        }
 
        cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
@@ -649,7 +658,7 @@ cifs_get_link(struct dentry *direntry, struct inode *inode,
                                                &target_path, reparse_point);
        }
 
-       kfree(full_path);
+       free_dentry_path(page);
        free_xid(xid);
        cifs_put_tlink(tlink);
        if (rc != 0) {
@@ -669,7 +678,8 @@ cifs_symlink(struct user_namespace *mnt_userns, struct inode *inode,
        struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
        struct tcon_link *tlink;
        struct cifs_tcon *pTcon;
-       const char *full_path = NULL;
+       const char *full_path;
+       void *page = alloc_dentry_path();
        struct inode *newinode = NULL;
 
        xid = get_xid();
@@ -681,9 +691,9 @@ cifs_symlink(struct user_namespace *mnt_userns, struct inode *inode,
        }
        pTcon = tlink_tcon(tlink);
 
-       full_path = build_path_from_dentry(direntry);
-       if (full_path == NULL) {
-               rc = -ENOMEM;
+       full_path = build_path_from_dentry(direntry, page);
+       if (IS_ERR(full_path)) {
+               rc = PTR_ERR(full_path);
                goto symlink_exit;
        }
 
@@ -719,7 +729,7 @@ cifs_symlink(struct user_namespace *mnt_userns, struct inode *inode,
                }
        }
 symlink_exit:
-       kfree(full_path);
+       free_dentry_path(page);
        cifs_put_tlink(tlink);
        free_xid(xid);
        return rc;

diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index 67c3177a1fda72e0c7a1a7268563b2d2946672a5..7531e890588184d7770bffad61ae22f1893e1802 100644 (file)
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -942,13 +942,14 @@ int cifs_readdir(struct file *file, struct dir_context *ctx)
        char *tmp_buf = NULL;
        char *end_of_smb;
        unsigned int max_len;
-       const char *full_path = NULL;
+       const char *full_path;
+       void *page = alloc_dentry_path();
 
        xid = get_xid();
 
-       full_path = build_path_from_dentry(file_dentry(file));
-       if (full_path == NULL) {
-               rc = -ENOMEM;
+       full_path = build_path_from_dentry(file_dentry(file), page);
+       if (IS_ERR(full_path)) {
+               rc = PTR_ERR(full_path);
                goto rddir2_exit;
        }
 
@@ -1043,7 +1044,7 @@ int cifs_readdir(struct file *file, struct dir_context *ctx)
        kfree(tmp_buf);
 
 rddir2_exit:
-       kfree(full_path);
+       free_dentry_path(page);
        free_xid(xid);
        return rc;
 }

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 30cfbebdd8b4ce6ab5b4a7c7ed333a903f1f892c..65fc65b26d84c9997c876be88a0ccdd6aacab8e9 100644 (file)
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -2217,20 +2217,21 @@ smb3_notify(const unsigned int xid, struct file *pfile,
        struct smb3_notify notify;
        struct dentry *dentry = pfile->f_path.dentry;
        struct inode *inode = file_inode(pfile);
-       struct cifs_sb_info *cifs_sb;
+       struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
        struct cifs_open_parms oparms;
        struct cifs_fid fid;
        struct cifs_tcon *tcon;
-       const unsigned char *path = NULL;
+       const unsigned char *path;
+       void *page = alloc_dentry_path();
        __le16 *utf16_path = NULL;
        u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
        int rc = 0;
 
-       path = build_path_from_dentry(dentry);
-       if (path == NULL)
-               return -ENOMEM;
-
-       cifs_sb = CIFS_SB(inode->i_sb);
+       path = build_path_from_dentry(dentry, page);
+       if (IS_ERR(path)) {
+               rc = PTR_ERR(path);
+               goto notify_exit;
+       }
 
        utf16_path = cifs_convert_path_to_utf16(path + 1, cifs_sb);
        if (utf16_path == NULL) {
@@ -2264,7 +2265,7 @@ smb3_notify(const unsigned int xid, struct file *pfile,
        cifs_dbg(FYI, "change notify for path %s rc %d\n", path, rc);
 
 notify_exit:
-       kfree(path);
+       free_dentry_path(page);
        kfree(utf16_path);
        return rc;
 }

diff --git a/fs/cifs/xattr.c b/fs/cifs/xattr.c
index 0195a9be3d284a7fdc7058adc6e79b6b7bb918ee..e351b945135bb4e938aff6671804f78e292d2ab1 100644 (file)
--- a/fs/cifs/xattr.c
+++ b/fs/cifs/xattr.c
@@ -113,6 +113,7 @@ static int cifs_xattr_set(const struct xattr_handler *handler,
        struct tcon_link *tlink;
        struct cifs_tcon *pTcon;
        const char *full_path;
+       void *page;
 
        tlink = cifs_sb_tlink(cifs_sb);
        if (IS_ERR(tlink))
@@ -120,10 +121,11 @@ static int cifs_xattr_set(const struct xattr_handler *handler,
        pTcon = tlink_tcon(tlink);
 
        xid = get_xid();
+       page = alloc_dentry_path();
 
-       full_path = build_path_from_dentry(dentry);
-       if (full_path == NULL) {
-               rc = -ENOMEM;
+       full_path = build_path_from_dentry(dentry, page);
+       if (IS_ERR(full_path)) {
+               rc = PTR_ERR(full_path);
                goto out;
        }
        /* return dos attributes as pseudo xattr */
@@ -235,7 +237,7 @@ static int cifs_xattr_set(const struct xattr_handler *handler,
        }
 
 out:
-       kfree(full_path);
+       free_dentry_path(page);
        free_xid(xid);
        cifs_put_tlink(tlink);
        return rc;
@@ -298,6 +300,7 @@ static int cifs_xattr_get(const struct xattr_handler *handler,
        struct tcon_link *tlink;
        struct cifs_tcon *pTcon;
        const char *full_path;
+       void *page;
 
        tlink = cifs_sb_tlink(cifs_sb);
        if (IS_ERR(tlink))
@@ -305,10 +308,11 @@ static int cifs_xattr_get(const struct xattr_handler *handler,
        pTcon = tlink_tcon(tlink);
 
        xid = get_xid();
+       page = alloc_dentry_path();
 
-       full_path = build_path_from_dentry(dentry);
-       if (full_path == NULL) {
-               rc = -ENOMEM;
+       full_path = build_path_from_dentry(dentry, page);
+       if (IS_ERR(full_path)) {
+               rc = PTR_ERR(full_path);
                goto out;
        }
 
@@ -401,7 +405,7 @@ static int cifs_xattr_get(const struct xattr_handler *handler,
                rc = -EOPNOTSUPP;
 
 out:
-       kfree(full_path);
+       free_dentry_path(page);
        free_xid(xid);
        cifs_put_tlink(tlink);
        return rc;
@@ -415,6 +419,7 @@ ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
        struct tcon_link *tlink;
        struct cifs_tcon *pTcon;
        const char *full_path;
+       void *page;
 
        if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_XATTR)
                return -EOPNOTSUPP;
@@ -425,10 +430,11 @@ ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
        pTcon = tlink_tcon(tlink);
 
        xid = get_xid();
+       page = alloc_dentry_path();
 
-       full_path = build_path_from_dentry(direntry);
-       if (full_path == NULL) {
-               rc = -ENOMEM;
+       full_path = build_path_from_dentry(direntry, page);
+       if (IS_ERR(full_path)) {
+               rc = PTR_ERR(full_path);
                goto list_ea_exit;
        }
        /* return dos attributes as pseudo xattr */
@@ -442,7 +448,7 @@ ssize_t cifs_listxattr(struct dentry *direntry, char *data, size_t buf_size)
                rc = pTcon->ses->server->ops->query_all_EAs(xid, pTcon,
                                full_path, NULL, data, buf_size, cifs_sb);
 list_ea_exit:
-       kfree(full_path);
+       free_dentry_path(page);
        free_xid(xid);
        cifs_put_tlink(tlink);
        return rc;