nfs: move nfs_sillyrename to unlink.c

...since that's where most of the sillyrenaming code lives. A comment
block is added to the beginning as well to clarify how sillyrenaming
works. Also, make nfs_async_unlink static as nfs_sillyrename is the only
caller.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 1e9e188..86f1d41 100644 (file)
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1498,76 +1498,6 @@ static int nfs_rmdir(struct inode *dir, struct dentry *dentry)
        return error;
 }
 
-static int nfs_sillyrename(struct inode *dir, struct dentry *dentry)
-{
-       static unsigned int sillycounter;
-       const int      fileidsize  = sizeof(NFS_FILEID(dentry->d_inode))*2;
-       const int      countersize = sizeof(sillycounter)*2;
-       const int      slen        = sizeof(".nfs")+fileidsize+countersize-1;
-       char           silly[slen+1];
-       struct qstr    qsilly;
-       struct dentry *sdentry;
-       int            error = -EIO;
-
-       dfprintk(VFS, "NFS: silly-rename(%s/%s, ct=%d)\n",
-               dentry->d_parent->d_name.name, dentry->d_name.name, 
-               atomic_read(&dentry->d_count));
-       nfs_inc_stats(dir, NFSIOS_SILLYRENAME);
-
-       /*
-        * We don't allow a dentry to be silly-renamed twice.
-        */
-       error = -EBUSY;
-       if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
-               goto out;
-
-       sprintf(silly, ".nfs%*.*Lx",
-               fileidsize, fileidsize,
-               (unsigned long long)NFS_FILEID(dentry->d_inode));
-
-       /* Return delegation in anticipation of the rename */
-       nfs_inode_return_delegation(dentry->d_inode);
-
-       sdentry = NULL;
-       do {
-               char *suffix = silly + slen - countersize;
-
-               dput(sdentry);
-               sillycounter++;
-               sprintf(suffix, "%*.*x", countersize, countersize, sillycounter);
-
-               dfprintk(VFS, "NFS: trying to rename %s to %s\n",
-                               dentry->d_name.name, silly);
-               
-               sdentry = lookup_one_len(silly, dentry->d_parent, slen);
-               /*
-                * N.B. Better to return EBUSY here ... it could be
-                * dangerous to delete the file while it's in use.
-                */
-               if (IS_ERR(sdentry))
-                       goto out;
-       } while(sdentry->d_inode != NULL); /* need negative lookup */
-
-       qsilly.name = silly;
-       qsilly.len  = strlen(silly);
-       if (dentry->d_inode) {
-               error = NFS_PROTO(dir)->rename(dir, &dentry->d_name,
-                               dir, &qsilly);
-               nfs_mark_for_revalidate(dentry->d_inode);
-       } else
-               error = NFS_PROTO(dir)->rename(dir, &dentry->d_name,
-                               dir, &qsilly);
-       if (!error) {
-               nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
-               d_move(dentry, sdentry);
-               error = nfs_async_unlink(dir, dentry);
-               /* If we return 0 we don't unlink */
-       }
-       dput(sdentry);
-out:
-       return error;
-}
-
 /*
  * Remove a file after making sure there are no pending writes,
  * and after checking that the file has only one user. 

diff --git a/fs/nfs/unlink.c b/fs/nfs/unlink.c
index 2f84ada..c3ce865 100644 (file)
--- a/fs/nfs/unlink.c
+++ b/fs/nfs/unlink.c
@@ -13,9 +13,12 @@
 #include <linux/nfs_fs.h>
 #include <linux/sched.h>
 #include <linux/wait.h>
+#include <linux/namei.h>
 
 #include "internal.h"
 #include "nfs4_fs.h"
+#include "iostat.h"
+#include "delegation.h"
 
 struct nfs_unlinkdata {
        struct hlist_node list;
@@ -244,7 +247,7 @@ void nfs_unblock_sillyrename(struct dentry *dentry)
  * @dir: parent directory of dentry
  * @dentry: dentry to unlink
  */
-int
+static int
 nfs_async_unlink(struct inode *dir, struct dentry *dentry)
 {
        struct nfs_unlinkdata *data;
@@ -303,3 +306,83 @@ nfs_complete_unlink(struct dentry *dentry, struct inode *inode)
        if (data != NULL && (NFS_STALE(inode) || !nfs_call_unlink(dentry, data)))
                nfs_free_unlinkdata(data);
 }
+
+/**
+ * nfs_sillyrename - Perform a silly-rename of a dentry
+ * @dir: inode of directory that contains dentry
+ * @dentry: dentry to be sillyrenamed
+ *
+ * NFSv2/3 is stateless and the server doesn't know when the client is
+ * holding a file open. To prevent application problems when a file is
+ * unlinked while it's still open, the client performs a "silly-rename".
+ * That is, it renames the file to a hidden file in the same directory,
+ * and only performs the unlink once the last reference to it is put.
+ *
+ * The final cleanup is done during dentry_iput.
+ */
+int
+nfs_sillyrename(struct inode *dir, struct dentry *dentry)
+{
+       static unsigned int sillycounter;
+       const int      fileidsize  = sizeof(NFS_FILEID(dentry->d_inode))*2;
+       const int      countersize = sizeof(sillycounter)*2;
+       const int      slen        = sizeof(".nfs")+fileidsize+countersize-1;
+       char           silly[slen+1];
+       struct qstr    qsilly;
+       struct dentry *sdentry;
+       int            error = -EIO;
+
+       dfprintk(VFS, "NFS: silly-rename(%s/%s, ct=%d)\n",
+               dentry->d_parent->d_name.name, dentry->d_name.name,
+               atomic_read(&dentry->d_count));
+       nfs_inc_stats(dir, NFSIOS_SILLYRENAME);
+
+       /*
+        * We don't allow a dentry to be silly-renamed twice.
+        */
+       error = -EBUSY;
+       if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
+               goto out;
+
+       sprintf(silly, ".nfs%*.*Lx",
+               fileidsize, fileidsize,
+               (unsigned long long)NFS_FILEID(dentry->d_inode));
+
+       /* Return delegation in anticipation of the rename */
+       nfs_inode_return_delegation(dentry->d_inode);
+
+       sdentry = NULL;
+       do {
+               char *suffix = silly + slen - countersize;
+
+               dput(sdentry);
+               sillycounter++;
+               sprintf(suffix, "%*.*x", countersize, countersize, sillycounter);
+
+               dfprintk(VFS, "NFS: trying to rename %s to %s\n",
+                               dentry->d_name.name, silly);
+
+               sdentry = lookup_one_len(silly, dentry->d_parent, slen);
+               /*
+                * N.B. Better to return EBUSY here ... it could be
+                * dangerous to delete the file while it's in use.
+                */
+               if (IS_ERR(sdentry))
+                       goto out;
+       } while (sdentry->d_inode != NULL); /* need negative lookup */
+
+       qsilly.name = silly;
+       qsilly.len  = strlen(silly);
+       error = NFS_PROTO(dir)->rename(dir, &dentry->d_name, dir, &qsilly);
+       if (dentry->d_inode)
+               nfs_mark_for_revalidate(dentry->d_inode);
+       if (!error) {
+               nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
+               d_move(dentry, sdentry);
+               error = nfs_async_unlink(dir, dentry);
+               /* If we return 0 we don't unlink */
+       }
+       dput(sdentry);
+out:
+       return error;
+}

diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 61c89b4..d929b18 100644 (file)
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -485,10 +485,10 @@ extern void nfs_release_automount_timer(void);
 /*
  * linux/fs/nfs/unlink.c
  */
-extern int  nfs_async_unlink(struct inode *dir, struct dentry *dentry);
 extern void nfs_complete_unlink(struct dentry *dentry, struct inode *);
 extern void nfs_block_sillyrename(struct dentry *dentry);
 extern void nfs_unblock_sillyrename(struct dentry *dentry);
+extern int  nfs_sillyrename(struct inode *dir, struct dentry *dentry);
 
 /*
  * linux/fs/nfs/write.c