Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull the big VFS changes from Al Viro:
 "This one is *big* and changes quite a few things around VFS.  What's in there:

   - the first of two really major architecture changes - death to open
     intents.

     The former is finally there; it was very long in making, but with
     Miklos getting through really hard and messy final push in
     fs/namei.c, we finally have it.  Unlike his variant, this one
     doesn't introduce struct opendata; what we have instead is
     ->atomic_open() taking preallocated struct file * and passing
     everything via its fields.

     Instead of returning struct file *, it returns -E...  on error, 0
     on success and 1 in "deal with it yourself" case (e.g.  symlink
     found on server, etc.).

     See comments before fs/namei.c:atomic_open().  That made a lot of
     goodies finally possible and quite a few are in that pile:
     ->lookup(), ->d_revalidate() and ->create() do not get struct
     nameidata * anymore; ->lookup() and ->d_revalidate() get lookup
     flags instead, ->create() gets "do we want it exclusive" flag.

     With the introduction of new helper (kern_path_locked()) we are rid
     of all struct nameidata instances outside of fs/namei.c; it's still
     visible in namei.h, but not for long.  Come the next cycle,
     declaration will move either to fs/internal.h or to fs/namei.c
     itself.  [me, miklos, hch]

   - The second major change: behaviour of final fput().  Now we have
     __fput() done without any locks held by caller *and* not from deep
     in call stack.

     That obviously lifts a lot of constraints on the locking in there.
     Moreover, it's legal now to call fput() from atomic contexts (which
     has immediately simplified life for aio.c).  We also don't need
     anti-recursion logics in __scm_destroy() anymore.

     There is a price, though - the damn thing has become partially
     asynchronous.  For fput() from normal process we are guaranteed
     that pending __fput() will be done before the caller returns to
     userland, exits or gets stopped for ptrace.

     For kernel threads and atomic contexts it's done via
     schedule_work(), so theoretically we might need a way to make sure
     it's finished; so far only one such place had been found, but there
     might be more.

     There's flush_delayed_fput() (do all pending __fput()) and there's
     __fput_sync() (fput() analog doing __fput() immediately).  I hope
     we won't need them often; see warnings in fs/file_table.c for
     details.  [me, based on task_work series from Oleg merged last
     cycle]

   - sync series from Jan

   - large part of "death to sync_supers()" work from Artem; the only
     bits missing here are exofs and ext4 ones.  As far as I understand,
     those are going via the exofs and ext4 trees resp.; once they are
     in, we can put ->write_super() to the rest, along with the thread
     calling it.

   - preparatory bits from unionmount series (from dhowells).

   - assorted cleanups and fixes all over the place, as usual.

  This is not the last pile for this cycle; there's at least jlayton's
  ESTALE work and fsfreeze series (the latter - in dire need of fixes,
  so I'm not sure it'll make the cut this cycle).  I'll probably throw
  symlink/hardlink restrictions stuff from Kees into the next pile, too.
  Plus there's a lot of misc patches I hadn't thrown into that one -
  it's large enough as it is..."

* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (127 commits)
  ext4: switch EXT4_IOC_RESIZE_FS to mnt_want_write_file()
  btrfs: switch btrfs_ioctl_balance() to mnt_want_write_file()
  switch dentry_open() to struct path, make it grab references itself
  spufs: shift dget/mntget towards dentry_open()
  zoran: don't bother with struct file * in zoran_map
  ecryptfs: don't reinvent the wheels, please - use struct completion
  don't expose I_NEW inodes via dentry->d_inode
  tidy up namei.c a bit
  unobfuscate follow_up() a bit
  ext3: pass custom EOF to generic_file_llseek_size()
  ext4: use core vfs llseek code for dir seeks
  vfs: allow custom EOF in generic_file_llseek code
  vfs: Avoid unnecessary WB_SYNC_NONE writeback during sys_sync and reorder sync passes
  vfs: Remove unnecessary flushing of block devices
  vfs: Make sys_sync writeout also block device inodes
  vfs: Create function for iterating over block devices
  vfs: Reorder operations during sys_sync
  quota: Move quota syncing to ->sync_fs method
  quota: Split dquot_quota_sync() to writeback and cache flushing part
  vfs: Move noop_backing_dev_info check from sync into writeback
  ...

1 files changed, 46 insertions, 31 deletions

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 3e8094b..00894ff 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -576,7 +576,7 @@ static int is_root_ceph_dentry(struct inode *inode, struct dentry *dentry)
  * the MDS so that it gets our 'caps wanted' value in a single op.
  */
 static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
-				  struct nameidata *nd)
+				  unsigned int flags)
 {
 	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
 	struct ceph_mds_client *mdsc = fsc->mdsc;
@@ -594,14 +594,6 @@ static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
 	if (err < 0)
 		return ERR_PTR(err);
 
-	/* open (but not create!) intent? */
-	if (nd &&
-	    (nd->flags & LOOKUP_OPEN) &&
-	    !(nd->intent.open.flags & O_CREAT)) {
-		int mode = nd->intent.open.create_mode & ~current->fs->umask;
-		return ceph_lookup_open(dir, dentry, nd, mode, 1);
-	}
-
 	/* can we conclude ENOENT locally? */
 	if (dentry->d_inode == NULL) {
 		struct ceph_inode_info *ci = ceph_inode(dir);
@@ -642,13 +634,51 @@ static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
 	return dentry;
 }
 
+int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
+		     struct file *file, unsigned flags, umode_t mode,
+		     int *opened)
+{
+	int err;
+	struct dentry *res = NULL;
+
+	if (!(flags & O_CREAT)) {
+		if (dentry->d_name.len > NAME_MAX)
+			return -ENAMETOOLONG;
+
+		err = ceph_init_dentry(dentry);
+		if (err < 0)
+			return err;
+
+		return ceph_lookup_open(dir, dentry, file, flags, mode, opened);
+	}
+
+	if (d_unhashed(dentry)) {
+		res = ceph_lookup(dir, dentry, 0);
+		if (IS_ERR(res))
+			return PTR_ERR(res);
+
+		if (res)
+			dentry = res;
+	}
+
+	/* We don't deal with positive dentries here */
+	if (dentry->d_inode)
+		return finish_no_open(file, res);
+
+	*opened |= FILE_CREATED;
+	err = ceph_lookup_open(dir, dentry, file, flags, mode, opened);
+	dput(res);
+
+	return err;
+}
+
 /*
  * If we do a create but get no trace back from the MDS, follow up with
  * a lookup (the VFS expects us to link up the provided dentry).
  */
 int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
 {
-	struct dentry *result = ceph_lookup(dir, dentry, NULL);
+	struct dentry *result = ceph_lookup(dir, dentry, 0);
 
 	if (result && !IS_ERR(result)) {
 		/*
@@ -700,25 +730,9 @@ static int ceph_mknod(struct inode *dir, struct dentry *dentry,
 }
 
 static int ceph_create(struct inode *dir, struct dentry *dentry, umode_t mode,
-		       struct nameidata *nd)
+		       bool excl)
 {
-	dout("create in dir %p dentry %p name '%.*s'\n",
-	     dir, dentry, dentry->d_name.len, dentry->d_name.name);
-
-	if (ceph_snap(dir) != CEPH_NOSNAP)
-		return -EROFS;
-
-	if (nd) {
-		BUG_ON((nd->flags & LOOKUP_OPEN) == 0);
-		dentry = ceph_lookup_open(dir, dentry, nd, mode, 0);
-		/* hrm, what should i do here if we get aliased? */
-		if (IS_ERR(dentry))
-			return PTR_ERR(dentry);
-		return 0;
-	}
-
-	/* fall back to mknod */
-	return ceph_mknod(dir, dentry, (mode & ~S_IFMT) | S_IFREG, 0);
+	return ceph_mknod(dir, dentry, mode, 0);
 }
 
 static int ceph_symlink(struct inode *dir, struct dentry *dentry,
@@ -1028,12 +1042,12 @@ static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry)
 /*
  * Check if cached dentry can be trusted.
  */
-static int ceph_d_revalidate(struct dentry *dentry, struct nameidata *nd)
+static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
 {
 	int valid = 0;
 	struct inode *dir;
 
-	if (nd && nd->flags & LOOKUP_RCU)
+	if (flags & LOOKUP_RCU)
 		return -ECHILD;
 
 	dout("d_revalidate %p '%.*s' inode %p offset %lld\n", dentry,
@@ -1080,7 +1094,7 @@ static void ceph_d_release(struct dentry *dentry)
 }
 
 static int ceph_snapdir_d_revalidate(struct dentry *dentry,
-					  struct nameidata *nd)
+					  unsigned int flags)
 {
 	/*
 	 * Eventually, we'll want to revalidate snapped metadata
@@ -1357,6 +1371,7 @@ const struct inode_operations ceph_dir_iops = {
 	.rmdir = ceph_unlink,
 	.rename = ceph_rename,
 	.create = ceph_create,
+	.atomic_open = ceph_atomic_open,
 };
 
 const struct dentry_operations ceph_dentry_ops = {