replace ->follow_link() with new method that could stay in RCU mode

new method: ->get_link(); replacement of ->follow_link().  The differences
are:
	* inode and dentry are passed separately
	* might be called both in RCU and non-RCU mode;
the former is indicated by passing it a NULL dentry.
	* when called that way it isn't allowed to block
and should return ERR_PTR(-ECHILD) if it needs to be called
in non-RCU mode.

It's a flagday change - the old method is gone, all in-tree instances
converted.  Conversion isn't hard; said that, so far very few instances
do not immediately bail out when called in RCU mode.  That'll change
in the next commits.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 06d443450f2138fc8595ef43be0e64ebc33f66f7..4fba54b9fcec04815f706cefe6dc1360eae782c3 100644 (file)
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -50,7 +50,7 @@ prototypes:
        int (*rename2) (struct inode *, struct dentry *,
                        struct inode *, struct dentry *, unsigned int);
        int (*readlink) (struct dentry *, char __user *,int);
-       const char *(*follow_link) (struct dentry *, void **);
+       const char *(*get_link) (struct dentry *, struct inode *, void **);
        void (*put_link) (struct inode *, void *);
        void (*truncate) (struct inode *);
        int (*permission) (struct inode *, int, unsigned int);
@@ -83,7 +83,7 @@ rmdir:                yes (both)      (see below)
 rename:                yes (all)       (see below)
 rename2:       yes (all)       (see below)
 readlink:      no
-follow_link:   no
+get_link:      no
 put_link:      no
 setattr:       yes
 permission:    no (may not block if called in rcu-walk mode)

diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index 3eb7c35c9698d01adadc4d2cf337c249341f7ea6..cf92a8c55594fe5bca74733114993614a0b455cb 100644 (file)
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -509,3 +509,9 @@ in your dentry operations instead.
        any symlink that might use page_follow_link_light/page_put_link() must
        have inode_nohighmem(inode) called before anything might start playing with
        its pagecache.
+--
+[mandatory]
+       ->follow_link() is replaced with ->get_link(); same API, except that
+               * ->get_link() gets inode as a separate argument
+               * ->get_link() may be called in RCU mode - in that case NULL
+                 dentry is passed

diff --git a/drivers/staging/lustre/lustre/llite/symlink.c b/drivers/staging/lustre/lustre/llite/symlink.c
index 69b203651905e93f77149754a5b9d6a021b6bf32..153fdf908328bc37076481a79927559214b2dc94 100644 (file)
--- a/drivers/staging/lustre/lustre/llite/symlink.c
+++ b/drivers/staging/lustre/lustre/llite/symlink.c
@@ -118,12 +118,14 @@ failed:
        return rc;
 }
 
-static const char *ll_follow_link(struct dentry *dentry, void **cookie)
+static const char *ll_get_link(struct dentry *dentry,
+                              struct inode *inode, void **cookie)
 {
-       struct inode *inode = d_inode(dentry);
        struct ptlrpc_request *request = NULL;
        int rc;
        char *symname = NULL;
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
 
        CDEBUG(D_VFSTRACE, "VFS Op\n");
        ll_inode_size_lock(inode);
@@ -149,7 +151,7 @@ static void ll_put_link(struct inode *unused, void *cookie)
 struct inode_operations ll_fast_symlink_inode_operations = {
        .readlink       = generic_readlink,
        .setattr        = ll_setattr,
-       .follow_link    = ll_follow_link,
+       .get_link       = ll_get_link,
        .put_link       = ll_put_link,
        .getattr        = ll_getattr,
        .permission     = ll_inode_permission,

diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 699941e906672b87eb1b5199f7966e29528e0116..8ba5a897fc0a7924b898f12a9daf49700645accb 100644 (file)
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -1223,18 +1223,25 @@ ino_t v9fs_qid2ino(struct p9_qid *qid)
 }
 
 /**
- * v9fs_vfs_follow_link - follow a symlink path
+ * v9fs_vfs_get_link - follow a symlink path
  * @dentry: dentry for symlink
+ * @inode: inode for symlink
  * @cookie: place to pass the data to put_link()
  */
 
-static const char *v9fs_vfs_follow_link(struct dentry *dentry, void **cookie)
+static const char *v9fs_vfs_get_link(struct dentry *dentry,
+                                    struct inode *inode, void **cookie)
 {
-       struct v9fs_session_info *v9ses = v9fs_dentry2v9ses(dentry);
-       struct p9_fid *fid = v9fs_fid_lookup(dentry);
+       struct v9fs_session_info *v9ses;
+       struct p9_fid *fid;
        struct p9_wstat *st;
        char *res;
 
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
+
+       v9ses = v9fs_dentry2v9ses(dentry);
+       fid = v9fs_fid_lookup(dentry);
        p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
 
        if (IS_ERR(fid))
@@ -1452,7 +1459,7 @@ static const struct inode_operations v9fs_file_inode_operations = {
 
 static const struct inode_operations v9fs_symlink_inode_operations = {
        .readlink = generic_readlink,
-       .follow_link = v9fs_vfs_follow_link,
+       .get_link = v9fs_vfs_get_link,
        .put_link = kfree_put_link,
        .getattr = v9fs_vfs_getattr,
        .setattr = v9fs_vfs_setattr,

diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index cb899af1babc3bf42b48a6064d7f9345ae0bb4a8..0cc105d804ddcf05761be66da2c48dad5fb67cb7 100644 (file)
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -899,20 +899,26 @@ error:
 }
 
 /**
- * v9fs_vfs_follow_link_dotl - follow a symlink path
+ * v9fs_vfs_get_link_dotl - follow a symlink path
  * @dentry: dentry for symlink
+ * @inode: inode for symlink
  * @cookie: place to pass the data to put_link()
  */
 
 static const char *
-v9fs_vfs_follow_link_dotl(struct dentry *dentry, void **cookie)
+v9fs_vfs_get_link_dotl(struct dentry *dentry,
+                      struct inode *inode, void **cookie)
 {
-       struct p9_fid *fid = v9fs_fid_lookup(dentry);
+       struct p9_fid *fid;
        char *target;
        int retval;
 
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
+
        p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
 
+       fid = v9fs_fid_lookup(dentry);
        if (IS_ERR(fid))
                return ERR_CAST(fid);
        retval = p9_client_readlink(fid, &target);
@@ -984,7 +990,7 @@ const struct inode_operations v9fs_file_inode_operations_dotl = {
 
 const struct inode_operations v9fs_symlink_inode_operations_dotl = {
        .readlink = generic_readlink,
-       .follow_link = v9fs_vfs_follow_link_dotl,
+       .get_link = v9fs_vfs_get_link_dotl,
        .put_link = kfree_put_link,
        .getattr = v9fs_vfs_getattr_dotl,
        .setattr = v9fs_vfs_setattr_dotl,

diff --git a/fs/affs/symlink.c b/fs/affs/symlink.c
index e3f9dc3ae8cc91890dcec2e21dbbd77ab4017c89..39d1194445e15f5165d8b27f2d03040c345b749c 100644 (file)
--- a/fs/affs/symlink.c
+++ b/fs/affs/symlink.c
@@ -20,7 +20,7 @@ static int affs_symlink_readpage(struct file *file, struct page *page)
        char                     c;
        char                     lc;
 
-       pr_debug("follow_link(ino=%lu)\n", inode->i_ino);
+       pr_debug("get_link(ino=%lu)\n", inode->i_ino);
 
        bh = affs_bread(inode->i_sb, inode->i_ino);
        if (!bh)
@@ -71,7 +71,7 @@ const struct address_space_operations affs_symlink_aops = {
 
 const struct inode_operations affs_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = page_follow_link_light,
+       .get_link       = page_get_link,
        .put_link       = page_put_link,
        .setattr        = affs_notify_change,
 };

diff --git a/fs/autofs4/symlink.c b/fs/autofs4/symlink.c
index da0c33481bc0387788bcf4ce1792b38e141804e4..39e6f0bdf8e318ce9fb88fb7f3f9007ab3aae49d 100644 (file)
--- a/fs/autofs4/symlink.c
+++ b/fs/autofs4/symlink.c
@@ -12,10 +12,15 @@
 
 #include "autofs_i.h"
 
-static const char *autofs4_follow_link(struct dentry *dentry, void **cookie)
+static const char *autofs4_get_link(struct dentry *dentry,
+                                   struct inode *inode, void **cookie)
 {
-       struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
-       struct autofs_info *ino = autofs4_dentry_ino(dentry);
+       struct autofs_sb_info *sbi;
+       struct autofs_info *ino;
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
+       sbi = autofs4_sbi(dentry->d_sb);
+       ino = autofs4_dentry_ino(dentry);
        if (ino && !autofs4_oz_mode(sbi))
                ino->last_used = jiffies;
        return d_inode(dentry)->i_private;
@@ -23,5 +28,5 @@ static const char *autofs4_follow_link(struct dentry *dentry, void **cookie)
 
 const struct inode_operations autofs4_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = autofs4_follow_link
+       .get_link       = autofs4_get_link
 };

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 70f98bfde27757e50b20433a402b12f852a18f6e..3d4aa69f1e0cd558a083f5d2a6fa90681f5aa180 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -10096,7 +10096,7 @@ static const struct inode_operations btrfs_special_inode_operations = {
 };
 static const struct inode_operations btrfs_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = page_follow_link_light,
+       .get_link       = page_get_link,
        .put_link       = page_put_link,
        .getattr        = btrfs_getattr,
        .setattr        = btrfs_setattr,

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 498dcfa2dcdbedf393ae26fc9f7f68cf90bceb90..da55eb8bcffab89755baf5229b92ededf49dd484 100644 (file)
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1756,7 +1756,7 @@ retry:
  */
 static const struct inode_operations ceph_symlink_iops = {
        .readlink = generic_readlink,
-       .follow_link = simple_follow_link,
+       .get_link = simple_get_link,
        .setattr = ceph_setattr,
        .getattr = ceph_getattr,
        .setxattr = ceph_setxattr,

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index cbc0f4bca0c0dfa73b6a545fb6978a72b1a702ef..4593f41678ef6aa35db85814076c59cf4cd72d3e 100644 (file)
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -900,7 +900,7 @@ const struct inode_operations cifs_file_inode_ops = {
 
 const struct inode_operations cifs_symlink_inode_ops = {
        .readlink = generic_readlink,
-       .follow_link = cifs_follow_link,
+       .get_link = cifs_get_link,
        .put_link = kfree_put_link,
        .permission = cifs_permission,
        /* BB add the following two eventually */

diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h
index c3cc1609025fa3a966c2d5b10f32626214a9e4ef..6886328cf3c4ff745d0b3d8892ad4af299743875 100644 (file)
--- a/fs/cifs/cifsfs.h
+++ b/fs/cifs/cifsfs.h
@@ -120,9 +120,7 @@ extern struct vfsmount *cifs_dfs_d_automount(struct path *path);
 #endif
 
 /* Functions related to symlinks */
-extern const char *cifs_follow_link(struct dentry *direntry, void **cookie);
-extern int cifs_readlink(struct dentry *direntry, char __user *buffer,
-                        int buflen);
+extern const char *cifs_get_link(struct dentry *, struct inode *, void **);
 extern int cifs_symlink(struct inode *inode, struct dentry *direntry,
                        const char *symname);
 extern int     cifs_removexattr(struct dentry *, const char *);

diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index e3548f73bdeaa980ef1c282246688e1e3f5f21e8..6f2439b508b54aeb8df0fa5d32ce1743793a2f3c 100644 (file)
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -627,9 +627,8 @@ cifs_hl_exit:
 }
 
 const char *
-cifs_follow_link(struct dentry *direntry, void **cookie)
+cifs_get_link(struct dentry *direntry, struct inode *inode, void **cookie)
 {
-       struct inode *inode = d_inode(direntry);
        int rc = -ENOMEM;
        unsigned int xid;
        char *full_path = NULL;
@@ -639,6 +638,9 @@ cifs_follow_link(struct dentry *direntry, void **cookie)
        struct cifs_tcon *tcon;
        struct TCP_Server_Info *server;
 
+       if (!direntry)
+               return ERR_PTR(-ECHILD);
+
        xid = get_xid();
 
        tlink = cifs_sb_tlink(cifs_sb);

diff --git a/fs/coda/cnode.c b/fs/coda/cnode.c
index dd6a79ef47509c875b1457c70f3d690a112ae707..f18139c7690af04485dc1542622c208c6d05d94e 100644 (file)
--- a/fs/coda/cnode.c
+++ b/fs/coda/cnode.c
@@ -18,7 +18,7 @@ static inline int coda_fideq(struct CodaFid *fid1, struct CodaFid *fid2)
 
 static const struct inode_operations coda_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = page_follow_link_light,
+       .get_link       = page_get_link,
        .put_link       = page_put_link,
        .setattr        = coda_setattr,
 };

diff --git a/fs/configfs/symlink.c b/fs/configfs/symlink.c
index ec5c8325b503d1a1602863769ae43c067d13a047..b91c01ebb688fba60ec3cfbf71a7b7330e8a726a 100644 (file)
--- a/fs/configfs/symlink.c
+++ b/fs/configfs/symlink.c
@@ -279,11 +279,16 @@ static int configfs_getlink(struct dentry *dentry, char * path)
 
 }
 
-static const char *configfs_follow_link(struct dentry *dentry, void **cookie)
+static const char *configfs_get_link(struct dentry *dentry,
+                                    struct inode *inode, void **cookie)
 {
-       unsigned long page = get_zeroed_page(GFP_KERNEL);
+       unsigned long page;
        int error;
 
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
+
+       page = get_zeroed_page(GFP_KERNEL);
        if (!page)
                return ERR_PTR(-ENOMEM);
 
@@ -297,7 +302,7 @@ static const char *configfs_follow_link(struct dentry *dentry, void **cookie)
 }
 
 const struct inode_operations configfs_symlink_inode_operations = {
-       .follow_link = configfs_follow_link,
+       .get_link = configfs_get_link,
        .readlink = generic_readlink,
        .put_link = free_page_put_link,
        .setattr = configfs_setattr,

diff --git a/fs/dcache.c b/fs/dcache.c
index 5c33aeb0f68febdd03e6f478c7949fd847e9fdcd..d27f0909d9f61141b6f6073996ed56858f2249c7 100644 (file)
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1734,7 +1734,7 @@ static unsigned d_flags_for_inode(struct inode *inode)
        }
 
        if (unlikely(!(inode->i_opflags & IOP_NOFOLLOW))) {
-               if (unlikely(inode->i_op->follow_link)) {
+               if (unlikely(inode->i_op->get_link)) {
                        add_flags = DCACHE_SYMLINK_TYPE;
                        goto type_determined;
                }

diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index e2e47ba5d313a5f2aca58589e08d2d3df969bed2..5a05559cb23de68a3de4ec24af143a722c0900f3 100644 (file)
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -674,10 +674,16 @@ out:
        return rc ? ERR_PTR(rc) : buf;
 }
 
-static const char *ecryptfs_follow_link(struct dentry *dentry, void **cookie)
+static const char *ecryptfs_get_link(struct dentry *dentry,
+                                    struct inode *inode, void **cookie)
 {
        size_t len;
-       char *buf = ecryptfs_readlink_lower(dentry, &len);
+       char *buf;
+
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
+
+       buf = ecryptfs_readlink_lower(dentry, &len);
        if (IS_ERR(buf))
                return buf;
        fsstack_copy_attr_atime(d_inode(dentry),
@@ -1095,7 +1101,7 @@ out:
 
 const struct inode_operations ecryptfs_symlink_iops = {
        .readlink = generic_readlink,
-       .follow_link = ecryptfs_follow_link,
+       .get_link = ecryptfs_get_link,
        .put_link = kfree_put_link,
        .permission = ecryptfs_permission,
        .setattr = ecryptfs_setattr,

diff --git a/fs/ext2/symlink.c b/fs/ext2/symlink.c
index ae17179f3810b2dd635c81203643a14f8f4c0c10..46905119a27c96cc241e0381f41e7f9589736d17 100644 (file)
--- a/fs/ext2/symlink.c
+++ b/fs/ext2/symlink.c
@@ -22,7 +22,7 @@
 
 const struct inode_operations ext2_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = page_follow_link_light,
+       .get_link       = page_get_link,
        .put_link       = page_put_link,
        .setattr        = ext2_setattr,
 #ifdef CONFIG_EXT2_FS_XATTR
@@ -35,7 +35,7 @@ const struct inode_operations ext2_symlink_inode_operations = {
  
 const struct inode_operations ext2_fast_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = simple_follow_link,
+       .get_link       = simple_get_link,
        .setattr        = ext2_setattr,
 #ifdef CONFIG_EXT2_FS_XATTR
        .setxattr       = generic_setxattr,

diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c
index 0e6dc44c5ebf1b4dbad3c9a498b11a1b14c5fc4b..3b4bfe2ebd756965967b870098645fc4f24b1df9 100644 (file)
--- a/fs/ext4/symlink.c
+++ b/fs/ext4/symlink.c
@@ -23,17 +23,20 @@
 #include "xattr.h"
 
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
-static const char *ext4_encrypted_follow_link(struct dentry *dentry, void **cookie)
+static const char *ext4_encrypted_get_link(struct dentry *dentry,
+                                          struct inode *inode, void **cookie)
 {
        struct page *cpage = NULL;
        char *caddr, *paddr = NULL;
        struct ext4_str cstr, pstr;
-       struct inode *inode = d_inode(dentry);
        struct ext4_encrypted_symlink_data *sd;
        loff_t size = min_t(loff_t, i_size_read(inode), PAGE_SIZE - 1);
        int res;
        u32 plen, max_size = inode->i_sb->s_blocksize;
 
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
+
        res = ext4_get_encryption_info(inode);
        if (res)
                return ERR_PTR(res);
@@ -87,7 +90,7 @@ errout:
 
 const struct inode_operations ext4_encrypted_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = ext4_encrypted_follow_link,
+       .get_link       = ext4_encrypted_get_link,
        .put_link       = kfree_put_link,
        .setattr        = ext4_setattr,
        .setxattr       = generic_setxattr,
@@ -99,7 +102,7 @@ const struct inode_operations ext4_encrypted_symlink_inode_operations = {
 
 const struct inode_operations ext4_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = page_follow_link_light,
+       .get_link       = page_get_link,
        .put_link       = page_put_link,
        .setattr        = ext4_setattr,
        .setxattr       = generic_setxattr,
@@ -110,7 +113,7 @@ const struct inode_operations ext4_symlink_inode_operations = {
 
 const struct inode_operations ext4_fast_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = simple_follow_link,
+       .get_link       = simple_get_link,
        .setattr        = ext4_setattr,
        .setxattr       = generic_setxattr,
        .getxattr       = generic_getxattr,

diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 484df6850747c82314155652474001060b0f4517..2a8d84b727ce0de995084bd6bb28676415fda9a5 100644 (file)
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -315,9 +315,10 @@ fail:
        return err;
 }
 
-static const char *f2fs_follow_link(struct dentry *dentry, void **cookie)
+static const char *f2fs_get_link(struct dentry *dentry,
+                                struct inode *inode, void **cookie)
 {
-       const char *link = page_follow_link_light(dentry, cookie);
+       const char *link = page_get_link(dentry, inode, cookie);
        if (!IS_ERR(link) && !*link) {
                /* this is broken symlink case */
                page_put_link(NULL, *cookie);
@@ -924,18 +925,21 @@ static int f2fs_rename2(struct inode *old_dir, struct dentry *old_dentry,
 }
 
 #ifdef CONFIG_F2FS_FS_ENCRYPTION
-static const char *f2fs_encrypted_follow_link(struct dentry *dentry, void **cookie)
+static const char *f2fs_encrypted_get_link(struct dentry *dentry,
+                                          struct inode *inode, void **cookie)
 {
        struct page *cpage = NULL;
        char *caddr, *paddr = NULL;
        struct f2fs_str cstr;
        struct f2fs_str pstr = FSTR_INIT(NULL, 0);
-       struct inode *inode = d_inode(dentry);
        struct f2fs_encrypted_symlink_data *sd;
        loff_t size = min_t(loff_t, i_size_read(inode), PAGE_SIZE - 1);
        u32 max_size = inode->i_sb->s_blocksize;
        int res;
 
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
+
        res = f2fs_get_encryption_info(inode);
        if (res)
                return ERR_PTR(res);
@@ -994,7 +998,7 @@ errout:
 
 const struct inode_operations f2fs_encrypted_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = f2fs_encrypted_follow_link,
+       .get_link       = f2fs_encrypted_get_link,
        .put_link       = kfree_put_link,
        .getattr        = f2fs_getattr,
        .setattr        = f2fs_setattr,
@@ -1030,7 +1034,7 @@ const struct inode_operations f2fs_dir_inode_operations = {
 
 const struct inode_operations f2fs_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = f2fs_follow_link,
+       .get_link       = f2fs_get_link,
        .put_link       = page_put_link,
        .getattr        = f2fs_getattr,
        .setattr        = f2fs_setattr,

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 5e2e08712d3ba614a46687d5688fc2f01cd835be..148e8ef7c5418ec0a66d941664da7e5bdc8c7065 100644 (file)
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1365,14 +1365,17 @@ static int fuse_readdir(struct file *file, struct dir_context *ctx)
        return err;
 }
 
-static const char *fuse_follow_link(struct dentry *dentry, void **cookie)
+static const char *fuse_get_link(struct dentry *dentry,
+                                struct inode *inode, void **cookie)
 {
-       struct inode *inode = d_inode(dentry);
        struct fuse_conn *fc = get_fuse_conn(inode);
        FUSE_ARGS(args);
        char *link;
        ssize_t ret;
 
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
+
        link = (char *) __get_free_page(GFP_KERNEL);
        if (!link)
                return ERR_PTR(-ENOMEM);
@@ -1909,7 +1912,7 @@ static const struct inode_operations fuse_common_inode_operations = {
 
 static const struct inode_operations fuse_symlink_inode_operations = {
        .setattr        = fuse_setattr,
-       .follow_link    = fuse_follow_link,
+       .get_link       = fuse_get_link,
        .put_link       = free_page_put_link,
        .readlink       = generic_readlink,
        .getattr        = fuse_getattr,

diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 063fdfcf82758a0c77f4cc44fe7b1f873b3cbb21..1095056046cc75e0fdaff3c281ad26234ae228c3 100644 (file)
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -1712,24 +1712,29 @@ static int gfs2_rename2(struct inode *odir, struct dentry *odentry,
 }
 
 /**
- * gfs2_follow_link - Follow a symbolic link
+ * gfs2_get_link - Follow a symbolic link
  * @dentry: The dentry of the link
- * @nd: Data that we pass to vfs_follow_link()
+ * @inode: The inode of the link
+ * @cookie: place to store the information for ->put_link()
  *
  * This can handle symlinks of any size.
  *
  * Returns: 0 on success or error code
  */
 
-static const char *gfs2_follow_link(struct dentry *dentry, void **cookie)
+static const char *gfs2_get_link(struct dentry *dentry,
+                                struct inode *inode, void **cookie)
 {
-       struct gfs2_inode *ip = GFS2_I(d_inode(dentry));
+       struct gfs2_inode *ip = GFS2_I(inode);
        struct gfs2_holder i_gh;
        struct buffer_head *dibh;
        unsigned int size;
        char *buf;
        int error;
 
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
+
        gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
        error = gfs2_glock_nq(&i_gh);
        if (error) {
@@ -2132,7 +2137,7 @@ const struct inode_operations gfs2_dir_iops = {
 
 const struct inode_operations gfs2_symlink_iops = {
        .readlink = generic_readlink,
-       .follow_link = gfs2_follow_link,
+       .get_link = gfs2_get_link,
        .put_link = kfree_put_link,
        .permission = gfs2_permission,
        .setattr = gfs2_setattr,

diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index 2ac99db3750ef7b2d2bf3e9ea9e90e69320a0d83..6ce5309ecb7b0a6039dd47556bbd9cd87f473f02 100644 (file)
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -892,9 +892,13 @@ static const struct inode_operations hostfs_dir_iops = {
        .setattr        = hostfs_setattr,
 };
 
-static const char *hostfs_follow_link(struct dentry *dentry, void **cookie)
+static const char *hostfs_get_link(struct dentry *dentry,
+                                  struct inode *inode, void **cookie)
 {
-       char *link = __getname();
+       char *link;
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
+       link = __getname();
        if (link) {
                char *path = dentry_name(dentry);
                int err = -ENOMEM;
@@ -922,7 +926,7 @@ static void hostfs_put_link(struct inode *unused, void *cookie)
 
 static const struct inode_operations hostfs_link_iops = {
        .readlink       = generic_readlink,
-       .follow_link    = hostfs_follow_link,
+       .get_link       = hostfs_get_link,
        .put_link       = hostfs_put_link,
 };
 

diff --git a/fs/jffs2/symlink.c b/fs/jffs2/symlink.c
index 8ce2f240125b39803b4ebf2d681b6a95d40c33f5..2cabd649d4fb69dbdbd22aeb40d19f605f605f20 100644 (file)
--- a/fs/jffs2/symlink.c
+++ b/fs/jffs2/symlink.c
@@ -14,7 +14,7 @@
 const struct inode_operations jffs2_symlink_inode_operations =
 {
        .readlink =     generic_readlink,
-       .follow_link =  simple_follow_link,
+       .get_link =     simple_get_link,
        .setattr =      jffs2_setattr,
        .setxattr =     jffs2_setxattr,
        .getxattr =     jffs2_getxattr,

diff --git a/fs/jfs/symlink.c b/fs/jfs/symlink.c
index 5929e2363cb85eddc0d54bf3a04754383cb395db..02113282772eb6ca347a2bf63177baad7f57fc4b 100644 (file)
--- a/fs/jfs/symlink.c
+++ b/fs/jfs/symlink.c
@@ -23,7 +23,7 @@
 
 const struct inode_operations jfs_fast_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = simple_follow_link,
+       .get_link       = simple_get_link,
        .setattr        = jfs_setattr,
        .setxattr       = jfs_setxattr,
        .getxattr       = jfs_getxattr,
@@ -33,7 +33,7 @@ const struct inode_operations jfs_fast_symlink_inode_operations = {
 
 const struct inode_operations jfs_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = page_follow_link_light,
+       .get_link       = page_get_link,
        .put_link       = page_put_link,
        .setattr        = jfs_setattr,
        .setxattr       = jfs_setxattr,

diff --git a/fs/kernfs/symlink.c b/fs/kernfs/symlink.c
index db272528ab5bb01c192b5502650f29e0784663ce..ffae8579045df6c88e362afc2f23c3766cd94217 100644 (file)
--- a/fs/kernfs/symlink.c
+++ b/fs/kernfs/symlink.c
@@ -112,10 +112,15 @@ static int kernfs_getlink(struct dentry *dentry, char *path)
        return error;
 }
 
-static const char *kernfs_iop_follow_link(struct dentry *dentry, void **cookie)
+static const char *kernfs_iop_get_link(struct dentry *dentry,
+                                      struct inode *inode, void **cookie)
 {
        int error = -ENOMEM;
-       unsigned long page = get_zeroed_page(GFP_KERNEL);
+       unsigned long page;
+
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
+       page = get_zeroed_page(GFP_KERNEL);
        if (!page)
                return ERR_PTR(-ENOMEM);
        error = kernfs_getlink(dentry, (char *)page);
@@ -132,7 +137,7 @@ const struct inode_operations kernfs_symlink_iops = {
        .getxattr       = kernfs_iop_getxattr,
        .listxattr      = kernfs_iop_listxattr,
        .readlink       = generic_readlink,
-       .follow_link    = kernfs_iop_follow_link,
+       .get_link       = kernfs_iop_get_link,
        .put_link       = free_page_put_link,
        .setattr        = kernfs_iop_setattr,
        .getattr        = kernfs_iop_getattr,

diff --git a/fs/libfs.c b/fs/libfs.c
index c7cbfb092e9467db1795145816faa91e1eda731f..8dc37fc4b6df23df9f35cc3b18feb4c887699eee 100644 (file)
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -1092,14 +1092,15 @@ simple_nosetlease(struct file *filp, long arg, struct file_lock **flp,
 }
 EXPORT_SYMBOL(simple_nosetlease);
 
-const char *simple_follow_link(struct dentry *dentry, void **cookie)
+const char *simple_get_link(struct dentry *dentry, struct inode *inode,
+                           void **cookie)
 {
-       return d_inode(dentry)->i_link;
+       return inode->i_link;
 }
-EXPORT_SYMBOL(simple_follow_link);
+EXPORT_SYMBOL(simple_get_link);
 
 const struct inode_operations simple_symlink_inode_operations = {
-       .follow_link = simple_follow_link,
+       .get_link = simple_get_link,
        .readlink = generic_readlink
 };
 EXPORT_SYMBOL(simple_symlink_inode_operations);

diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index 67a23bfd73035db19d6e7b43a7eaeeb53a4b4928..3cce709a87295bf6ad45899eed53667e1a6b40b7 100644 (file)
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -435,7 +435,7 @@ static const struct address_space_operations minix_aops = {
 
 static const struct inode_operations minix_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = page_follow_link_light,
+       .get_link       = page_get_link,
        .put_link       = page_put_link,
        .getattr        = minix_getattr,
 };

diff --git a/fs/namei.c b/fs/namei.c
index 2808958e6c67041ad6cc8eba7cd294fe30c1e5e6..1da3064311e255f26ceeb0690434a306e373a729 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -842,7 +842,7 @@ static inline void path_to_nameidata(const struct path *path,
 }
 
 /*
- * Helper to directly jump to a known parsed path from ->follow_link,
+ * Helper to directly jump to a known parsed path from ->get_link,
  * caller must have taken a reference to path beforehand.
  */
 void nd_jump_link(struct path *path)
@@ -1005,10 +1005,18 @@ const char *get_link(struct nameidata *nd)
        res = inode->i_link;
        if (!res) {
                if (nd->flags & LOOKUP_RCU) {
-                       if (unlikely(unlazy_walk(nd, NULL, 0)))
-                               return ERR_PTR(-ECHILD);
+                       res = inode->i_op->get_link(NULL, inode,
+                                                   &last->cookie);
+                       if (res == ERR_PTR(-ECHILD)) {
+                               if (unlikely(unlazy_walk(nd, NULL, 0)))
+                                       return ERR_PTR(-ECHILD);
+                               res = inode->i_op->get_link(dentry, inode,
+                                                           &last->cookie);
+                       }
+               } else {
+                       res = inode->i_op->get_link(dentry, inode,
+                                                   &last->cookie);
                }
-               res = inode->i_op->follow_link(dentry, &last->cookie);
                if (IS_ERR_OR_NULL(res)) {
                        last->cookie = NULL;
                        return res;
@@ -4495,8 +4503,8 @@ EXPORT_SYMBOL(readlink_copy);
 
 /*
  * A helper for ->readlink().  This should be used *ONLY* for symlinks that
- * have ->follow_link() touching nd only in nd_set_link().  Using (or not
- * using) it for any given inode is up to filesystem.
+ * have ->get_link() not calling nd_jump_link().  Using (or not using) it
+ * for any given inode is up to filesystem.
  */
 int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen)
 {
@@ -4506,7 +4514,7 @@ int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen)
        int res;
 
        if (!link) {
-               link = inode->i_op->follow_link(dentry, &cookie);
+               link = inode->i_op->get_link(dentry, inode, &cookie);
                if (IS_ERR(link))
                        return PTR_ERR(link);
        }
@@ -4518,26 +4526,27 @@ int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen)
 EXPORT_SYMBOL(generic_readlink);
 
 /* get the link contents into pagecache */
-static const char *page_getlink(struct dentry * dentry, void **cookie)
+const char *page_get_link(struct dentry *dentry, struct inode *inode,
+                                void **cookie)
 {
        char *kaddr;
        struct page *page;
-       struct address_space *mapping = dentry->d_inode->i_mapping;
+       struct address_space *mapping = inode->i_mapping;
+
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
+
        page = read_mapping_page(mapping, 0, NULL);
        if (IS_ERR(page))
                return (char*)page;
        *cookie = page;
        BUG_ON(mapping_gfp_mask(mapping) & __GFP_HIGHMEM);
        kaddr = page_address(page);
-       nd_terminate_link(kaddr, dentry->d_inode->i_size, PAGE_SIZE - 1);
+       nd_terminate_link(kaddr, inode->i_size, PAGE_SIZE - 1);
        return kaddr;
 }
 
-const char *page_follow_link_light(struct dentry *dentry, void **cookie)
-{
-       return page_getlink(dentry, cookie);
-}
-EXPORT_SYMBOL(page_follow_link_light);
+EXPORT_SYMBOL(page_get_link);
 
 void page_put_link(struct inode *unused, void *cookie)
 {
@@ -4549,7 +4558,9 @@ EXPORT_SYMBOL(page_put_link);
 int page_readlink(struct dentry *dentry, char __user *buffer, int buflen)
 {
        void *cookie = NULL;
-       int res = readlink_copy(buffer, buflen, page_getlink(dentry, &cookie));
+       int res = readlink_copy(buffer, buflen,
+                               page_get_link(dentry, d_inode(dentry),
+                                             &cookie));
        if (cookie)
                page_put_link(NULL, cookie);
        return res;
@@ -4600,7 +4611,7 @@ EXPORT_SYMBOL(page_symlink);
 
 const struct inode_operations page_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = page_follow_link_light,
+       .get_link       = page_get_link,
        .put_link       = page_put_link,
 };
 EXPORT_SYMBOL(page_symlink_inode_operations);

diff --git a/fs/ncpfs/inode.c b/fs/ncpfs/inode.c
index bb856f7e05fd86fcc28b8611a6bd58abe53c86d9..3ab6cdbcde6012699d1ab51ed7eeb94daf62e24a 100644 (file)
--- a/fs/ncpfs/inode.c
+++ b/fs/ncpfs/inode.c
@@ -244,7 +244,7 @@ static void ncp_set_attr(struct inode *inode, struct ncp_entry_info *nwinfo)
 #if defined(CONFIG_NCPFS_EXTRAS) || defined(CONFIG_NCPFS_NFS_NS)
 static const struct inode_operations ncp_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = page_follow_link_light,
+       .get_link       = page_get_link,
        .put_link       = page_put_link,
        .setattr        = ncp_notify_change,
 };

diff --git a/fs/nfs/symlink.c b/fs/nfs/symlink.c
index abd93bf015d6465c85cfc0b9a9fc88af7aa73e9d..8ade8a812607f135d099d76d7b0964c65b8564bf 100644 (file)
--- a/fs/nfs/symlink.c
+++ b/fs/nfs/symlink.c
@@ -42,12 +42,15 @@ error:
        return -EIO;
 }
 
-static const char *nfs_follow_link(struct dentry *dentry, void **cookie)
+static const char *nfs_get_link(struct dentry *dentry,
+                               struct inode *inode, void **cookie)
 {
-       struct inode *inode = d_inode(dentry);
        struct page *page;
        void *err;
 
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
+
        err = ERR_PTR(nfs_revalidate_mapping(inode, inode->i_mapping));
        if (err)
                return err;
@@ -64,7 +67,7 @@ static const char *nfs_follow_link(struct dentry *dentry, void **cookie)
  */
 const struct inode_operations nfs_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = nfs_follow_link,
+       .get_link       = nfs_get_link,
        .put_link       = page_put_link,
        .getattr        = nfs_getattr,
        .setattr        = nfs_setattr,

diff --git a/fs/nilfs2/namei.c b/fs/nilfs2/namei.c
index 90b3ba960b9b6746d2b96856d7ff4c3a3e063490..63dddb7d4b181f6f45208635cd6de6a4867c7346 100644 (file)
--- a/fs/nilfs2/namei.c
+++ b/fs/nilfs2/namei.c
@@ -569,7 +569,7 @@ const struct inode_operations nilfs_special_inode_operations = {
 
 const struct inode_operations nilfs_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = page_follow_link_light,
+       .get_link       = page_get_link,
        .put_link       = page_put_link,
        .permission     = nilfs_permission,
 };

diff --git a/fs/ocfs2/symlink.c b/fs/ocfs2/symlink.c
index 66edce7ecfd78f807451bdbf724cfabc071dbd5a..b4e79bc720f7a40a3a77474fb47e42bdb74158b0 100644 (file)
--- a/fs/ocfs2/symlink.c
+++ b/fs/ocfs2/symlink.c
@@ -88,7 +88,7 @@ const struct address_space_operations ocfs2_fast_symlink_aops = {
 
 const struct inode_operations ocfs2_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = page_follow_link_light,
+       .get_link       = page_get_link,
        .put_link       = page_put_link,
        .getattr        = ocfs2_getattr,
        .setattr        = ocfs2_setattr,

diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 4060ffde87225c81114d086c000773d4019255b5..38a0b8b9f8b9b8978abb8ad77dfe9e5c0612adf5 100644 (file)
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -137,17 +137,21 @@ struct ovl_link_data {
        void *cookie;
 };
 
-static const char *ovl_follow_link(struct dentry *dentry, void **cookie)
+static const char *ovl_get_link(struct dentry *dentry,
+                               struct inode *inode, void **cookie)
 {
        struct dentry *realdentry;
        struct inode *realinode;
        struct ovl_link_data *data = NULL;
        const char *ret;
 
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
+
        realdentry = ovl_dentry_real(dentry);
        realinode = realdentry->d_inode;
 
-       if (WARN_ON(!realinode->i_op->follow_link))
+       if (WARN_ON(!realinode->i_op->get_link))
                return ERR_PTR(-EPERM);
 
        if (realinode->i_op->put_link) {
@@ -157,7 +161,7 @@ static const char *ovl_follow_link(struct dentry *dentry, void **cookie)
                data->realdentry = realdentry;
        }
 
-       ret = realinode->i_op->follow_link(realdentry, cookie);
+       ret = realinode->i_op->get_link(realdentry, realinode, cookie);
        if (IS_ERR_OR_NULL(ret)) {
                kfree(data);
                return ret;
@@ -378,7 +382,7 @@ static const struct inode_operations ovl_file_inode_operations = {
 
 static const struct inode_operations ovl_symlink_inode_operations = {
        .setattr        = ovl_setattr,
-       .follow_link    = ovl_follow_link,
+       .get_link       = ovl_get_link,
        .put_link       = ovl_put_link,
        .readlink       = ovl_readlink,
        .getattr        = ovl_getattr,

diff --git a/fs/proc/base.c b/fs/proc/base.c
index bd3e9e68125b8933b2e32a4fea2e2282397dc1cd..1a489e2b9768d0e81d081fb84f9f09eb61745c1d 100644 (file)
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1564,12 +1564,15 @@ static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
                return -ENOENT;
 }
 
-static const char *proc_pid_follow_link(struct dentry *dentry, void **cookie)
+static const char *proc_pid_get_link(struct dentry *dentry,
+                                    struct inode *inode, void **cookie)
 {
-       struct inode *inode = d_inode(dentry);
        struct path path;
        int error = -EACCES;
 
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
+
        /* Are we allowed to snoop on the tasks file descriptors? */
        if (!proc_fd_access_allowed(inode))
                goto out;
@@ -1630,7 +1633,7 @@ out:
 
 const struct inode_operations proc_pid_link_inode_operations = {
        .readlink       = proc_pid_readlink,
-       .follow_link    = proc_pid_follow_link,
+       .get_link       = proc_pid_get_link,
        .setattr        = proc_setattr,
 };
 
@@ -1895,7 +1898,7 @@ static const struct dentry_operations tid_map_files_dentry_operations = {
        .d_delete       = pid_delete_dentry,
 };
 
-static int proc_map_files_get_link(struct dentry *dentry, struct path *path)
+static int map_files_get_link(struct dentry *dentry, struct path *path)
 {
        unsigned long vm_start, vm_end;
        struct vm_area_struct *vma;
@@ -1945,20 +1948,21 @@ struct map_files_info {
  * path to the file in question.
  */
 static const char *
-proc_map_files_follow_link(struct dentry *dentry, void **cookie)
+proc_map_files_get_link(struct dentry *dentry,
+                       struct inode *inode, void **cookie)
 {
        if (!capable(CAP_SYS_ADMIN))
                return ERR_PTR(-EPERM);
 
-       return proc_pid_follow_link(dentry, NULL);
+       return proc_pid_get_link(dentry, inode, NULL);
 }
 
 /*
- * Identical to proc_pid_link_inode_operations except for follow_link()
+ * Identical to proc_pid_link_inode_operations except for get_link()
  */
 static const struct inode_operations proc_map_files_link_inode_operations = {
        .readlink       = proc_pid_readlink,
-       .follow_link    = proc_map_files_follow_link,
+       .get_link       = proc_map_files_get_link,
        .setattr        = proc_setattr,
 };
 
@@ -1975,7 +1979,7 @@ proc_map_files_instantiate(struct inode *dir, struct dentry *dentry,
                return -ENOENT;
 
        ei = PROC_I(inode);
-       ei->op.proc_get_link = proc_map_files_get_link;
+       ei->op.proc_get_link = map_files_get_link;
 
        inode->i_op = &proc_map_files_link_inode_operations;
        inode->i_size = 64;

diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index bd95b9fdebb005cd9912c3b80027cfc1659fc530..10360b2687943e8965dbded80cac6441d93bcac2 100644 (file)
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -393,9 +393,10 @@ static const struct file_operations proc_reg_file_ops_no_compat = {
 };
 #endif
 
-static const char *proc_follow_link(struct dentry *dentry, void **cookie)
+static const char *proc_get_link(struct dentry *dentry,
+                                struct inode *inode, void **cookie)
 {
-       struct proc_dir_entry *pde = PDE(d_inode(dentry));
+       struct proc_dir_entry *pde = PDE(inode);
        if (unlikely(!use_pde(pde)))
                return ERR_PTR(-EINVAL);
        *cookie = pde;
@@ -409,7 +410,7 @@ static void proc_put_link(struct inode *unused, void *p)
 
 const struct inode_operations proc_link_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = proc_follow_link,
+       .get_link       = proc_get_link,
        .put_link       = proc_put_link,
 };
 

diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index f6e8354b8cea20a936f6a4f8ae0335fd7fa36bd4..63861c15e109d9eadb09e95438872467170ae796 100644 (file)
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -30,14 +30,17 @@ static const struct proc_ns_operations *ns_entries[] = {
        &mntns_operations,
 };
 
-static const char *proc_ns_follow_link(struct dentry *dentry, void **cookie)
+static const char *proc_ns_get_link(struct dentry *dentry,
+                                   struct inode *inode, void **cookie)
 {
-       struct inode *inode = d_inode(dentry);
        const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
        struct task_struct *task;
        struct path ns_path;
        void *error = ERR_PTR(-EACCES);
 
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
+
        task = get_proc_task(inode);
        if (!task)
                return error;
@@ -74,7 +77,7 @@ static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int bufl
 
 static const struct inode_operations proc_ns_link_inode_operations = {
        .readlink       = proc_ns_readlink,
-       .follow_link    = proc_ns_follow_link,
+       .get_link       = proc_ns_get_link,
        .setattr        = proc_setattr,
 };
 

diff --git a/fs/proc/self.c b/fs/proc/self.c
index 113b8d061fc023858ab152a5033e029d085f27a6..9dd0ae6aefdb09738e772d9afb65f0b21a9928dd 100644 (file)
--- a/fs/proc/self.c
+++ b/fs/proc/self.c
@@ -18,12 +18,15 @@ static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
        return readlink_copy(buffer, buflen, tmp);
 }
 
-static const char *proc_self_follow_link(struct dentry *dentry, void **cookie)
+static const char *proc_self_get_link(struct dentry *dentry,
+                                     struct inode *inode, void **cookie)
 {
-       struct pid_namespace *ns = dentry->d_sb->s_fs_info;
+       struct pid_namespace *ns = inode->i_sb->s_fs_info;
        pid_t tgid = task_tgid_nr_ns(current, ns);
        char *name;
 
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
        if (!tgid)
                return ERR_PTR(-ENOENT);
        /* 11 for max length of signed int in decimal + NULL term */
@@ -36,7 +39,7 @@ static const char *proc_self_follow_link(struct dentry *dentry, void **cookie)
 
 static const struct inode_operations proc_self_inode_operations = {
        .readlink       = proc_self_readlink,
-       .follow_link    = proc_self_follow_link,
+       .get_link       = proc_self_get_link,
        .put_link       = kfree_put_link,
 };
 

diff --git a/fs/proc/thread_self.c b/fs/proc/thread_self.c
index 947b0f4fd0a194057334762bafeff3548c276568..50eef6f3e67108c9240e5926c53c884efa1c5564 100644 (file)
--- a/fs/proc/thread_self.c
+++ b/fs/proc/thread_self.c
@@ -19,13 +19,16 @@ static int proc_thread_self_readlink(struct dentry *dentry, char __user *buffer,
        return readlink_copy(buffer, buflen, tmp);
 }
 
-static const char *proc_thread_self_follow_link(struct dentry *dentry, void **cookie)
+static const char *proc_thread_self_get_link(struct dentry *dentry,
+                                            struct inode *inode, void **cookie)
 {
-       struct pid_namespace *ns = dentry->d_sb->s_fs_info;
+       struct pid_namespace *ns = inode->i_sb->s_fs_info;
        pid_t tgid = task_tgid_nr_ns(current, ns);
        pid_t pid = task_pid_nr_ns(current, ns);
        char *name;
 
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
        if (!pid)
                return ERR_PTR(-ENOENT);
        name = kmalloc(PROC_NUMBUF + 6 + PROC_NUMBUF, GFP_KERNEL);
@@ -37,7 +40,7 @@ static const char *proc_thread_self_follow_link(struct dentry *dentry, void **co
 
 static const struct inode_operations proc_thread_self_inode_operations = {
        .readlink       = proc_thread_self_readlink,
-       .follow_link    = proc_thread_self_follow_link,
+       .get_link       = proc_thread_self_get_link,
        .put_link       = kfree_put_link,
 };
 

diff --git a/fs/reiserfs/namei.c b/fs/reiserfs/namei.c
index 4fc2326fac038458821140e6e0cc2c5abcc6c0cd..ecbf11e961abe2c581e574f47c1e5a3b1fb9dcc7 100644 (file)
--- a/fs/reiserfs/namei.c
+++ b/fs/reiserfs/namei.c
@@ -1665,7 +1665,7 @@ const struct inode_operations reiserfs_dir_inode_operations = {
  */
 const struct inode_operations reiserfs_symlink_inode_operations = {
        .readlink = generic_readlink,
-       .follow_link = page_follow_link_light,
+       .get_link       = page_get_link,
        .put_link = page_put_link,
        .setattr = reiserfs_setattr,
        .setxattr = reiserfs_setxattr,

diff --git a/fs/squashfs/symlink.c b/fs/squashfs/symlink.c
index 12806dffb3454ed1a898bbdd7b2ca272d071694f..7c635a5da7833e5b406c3119f22e66602d720b0c 100644 (file)
--- a/fs/squashfs/symlink.c
+++ b/fs/squashfs/symlink.c
@@ -119,7 +119,7 @@ const struct address_space_operations squashfs_symlink_aops = {
 
 const struct inode_operations squashfs_symlink_inode_ops = {
        .readlink = generic_readlink,
-       .follow_link = page_follow_link_light,
+       .get_link = page_get_link,
        .put_link = page_put_link,
        .getxattr = generic_getxattr,
        .listxattr = squashfs_listxattr

diff --git a/fs/sysv/inode.c b/fs/sysv/inode.c
index ef8bcdb80acabbd58d82fe9af25403474c532a73..80a40bcb721c7680bfc6eec65d915d3c788024bb 100644 (file)
--- a/fs/sysv/inode.c
+++ b/fs/sysv/inode.c
@@ -146,7 +146,7 @@ static inline void write3byte(struct sysv_sb_info *sbi,
 
 static const struct inode_operations sysv_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = page_follow_link_light,
+       .get_link       = page_get_link,
        .put_link       = page_put_link,
        .getattr        = sysv_getattr,
 };

diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index 0edc128561476a804656fba068810cf47a76fa32..eff62801acbf10524e31f8ad7816c160e6f88a90 100644 (file)
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -1608,7 +1608,7 @@ const struct inode_operations ubifs_file_inode_operations = {
 
 const struct inode_operations ubifs_symlink_inode_operations = {
        .readlink    = generic_readlink,
-       .follow_link = simple_follow_link,
+       .get_link    = simple_get_link,
        .setattr     = ubifs_setattr,
        .getattr     = ubifs_getattr,
        .setxattr    = ubifs_setxattr,

diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 245268a0cdf06e4d518ee915a0add70ef5a42dc6..f638fd58b5b3e1687138978165167565b4fd66e3 100644 (file)
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -414,13 +414,17 @@ xfs_vn_rename(
  * uio is kmalloced for this reason...
  */
 STATIC const char *
-xfs_vn_follow_link(
+xfs_vn_get_link(
        struct dentry           *dentry,
+       struct inode            *inode,
        void                    **cookie)
 {
        char                    *link;
        int                     error = -ENOMEM;
 
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
+
        link = kmalloc(MAXPATHLEN+1, GFP_KERNEL);
        if (!link)
                goto out_err;
@@ -1172,7 +1176,7 @@ static const struct inode_operations xfs_dir_ci_inode_operations = {
 
 static const struct inode_operations xfs_symlink_inode_operations = {
        .readlink               = generic_readlink,
-       .follow_link            = xfs_vn_follow_link,
+       .get_link               = xfs_vn_get_link,
        .put_link               = kfree_put_link,
        .getattr                = xfs_vn_getattr,
        .setattr                = xfs_vn_setattr,

diff --git a/include/linux/fs.h b/include/linux/fs.h
index dfeda44b9ba446ef59e368cafdb1acc61b323d3f..d2fdf09a4407508235f8d40dddbdfba2fd3fb60a 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1633,7 +1633,7 @@ struct file_operations {
 
 struct inode_operations {
        struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
-       const char * (*follow_link) (struct dentry *, void **);
+       const char * (*get_link) (struct dentry *, struct inode *, void **);
        int (*permission) (struct inode *, int);
        struct posix_acl * (*get_acl)(struct inode *, int);
 
@@ -2736,7 +2736,7 @@ extern const struct file_operations generic_ro_fops;
 
 extern int readlink_copy(char __user *, int, const char *);
 extern int page_readlink(struct dentry *, char __user *, int);
-extern const char *page_follow_link_light(struct dentry *, void **);
+extern const char *page_get_link(struct dentry *, struct inode *, void **);
 extern void page_put_link(struct inode *, void *);
 extern int __page_symlink(struct inode *inode, const char *symname, int len,
                int nofs);
@@ -2754,7 +2754,7 @@ void __inode_sub_bytes(struct inode *inode, loff_t bytes);
 void inode_sub_bytes(struct inode *inode, loff_t bytes);
 loff_t inode_get_bytes(struct inode *inode);
 void inode_set_bytes(struct inode *inode, loff_t bytes);
-const char *simple_follow_link(struct dentry *, void **);
+const char *simple_get_link(struct dentry *, struct inode *, void **);
 extern const struct inode_operations simple_symlink_inode_operations;
 
 extern int iterate_dir(struct file *, struct dir_context *);

diff --git a/mm/shmem.c b/mm/shmem.c
index 64bf5acb49fe111ee3b5665daad5434d87766d01..684dbc32e2334939bb95621e9902b5600eb28edb 100644 (file)
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2496,10 +2496,14 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
        return 0;
 }
 
-static const char *shmem_follow_link(struct dentry *dentry, void **cookie)
+static const char *shmem_get_link(struct dentry *dentry,
+                                 struct inode *inode, void **cookie)
 {
        struct page *page = NULL;
-       int error = shmem_getpage(d_inode(dentry), 0, &page, SGP_READ, NULL);
+       int error;
+       if (!dentry)
+               return ERR_PTR(-ECHILD);
+       error = shmem_getpage(inode, 0, &page, SGP_READ, NULL);
        if (error)
                return ERR_PTR(error);
        unlock_page(page);
@@ -2656,7 +2660,7 @@ static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size)
 
 static const struct inode_operations shmem_short_symlink_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = simple_follow_link,
+       .get_link       = simple_get_link,
 #ifdef CONFIG_TMPFS_XATTR
        .setxattr       = shmem_setxattr,
        .getxattr       = shmem_getxattr,
@@ -2667,7 +2671,7 @@ static const struct inode_operations shmem_short_symlink_operations = {
 
 static const struct inode_operations shmem_symlink_inode_operations = {
        .readlink       = generic_readlink,
-       .follow_link    = shmem_follow_link,
+       .get_link       = shmem_get_link,
        .put_link       = shmem_put_link,
 #ifdef CONFIG_TMPFS_XATTR
        .setxattr       = shmem_setxattr,