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From: Valerie Aurora <vaurora@redhat.com>
To: Jan Blunck <jblunck@suse.de>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Christoph Hellwig <hch@infradead.org>,
	Andy Whitcroft <apw@canonical.com>,
	Scott James Remnant <scott@canonica
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	Theodore Tso <tytso@mit.edu>,
	linux-ext4@vger.kernel.org, Jan Blunck <jblunck@suse.de>
Subject: [PATCH 32/41] fallthru: ext2 fallthru support
Date: Wed, 21 Oct 2009 12:19:30 -0700	[thread overview]
Message-ID: <1256152779-10054-33-git-send-email-vaurora@redhat.com> (raw)
In-Reply-To: <1256152779-10054-32-git-send-email-vaurora@redhat.com>

Add support for fallthru directory entries to ext2.

XXX - Makes up inode number for fallthru entry
XXX - Might be better implemented as special symlinks

Cc: Theodore Tso <tytso@mit.edu>
Cc: linux-ext4@vger.kernel.org
Signed-off-by: Valerie Aurora <vaurora@redhat.com>
Signed-off-by: Jan Blunck <jblunck@suse.de>
---
 fs/ext2/dir.c           |   92 ++++++++++++++++++++++++++++++++++++++++++++--
 fs/ext2/ext2.h          |    1 +
 fs/ext2/namei.c         |   20 ++++++++++
 include/linux/ext2_fs.h |    1 +
 4 files changed, 110 insertions(+), 4 deletions(-)

diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
index d4628c0..2665bc6 100644
--- a/fs/ext2/dir.c
+++ b/fs/ext2/dir.c
@@ -219,7 +219,8 @@ static inline int ext2_match (int len, const char * const name,
 {
 	if (len != de->name_len)
 		return 0;
-	if (!de->inode && (de->file_type != EXT2_FT_WHT))
+	if (!de->inode && ((de->file_type != EXT2_FT_WHT) &&
+			   (de->file_type != EXT2_FT_FALLTHRU)))
 		return 0;
 	return !memcmp(name, de->name, len);
 }
@@ -256,6 +257,7 @@ static unsigned char ext2_filetype_table[EXT2_FT_MAX] = {
 	[EXT2_FT_SOCK]		= DT_SOCK,
 	[EXT2_FT_SYMLINK]	= DT_LNK,
 	[EXT2_FT_WHT]		= DT_WHT,
+	[EXT2_FT_FALLTHRU]	= DT_UNKNOWN,
 };
 
 #define S_SHIFT 12
@@ -342,6 +344,24 @@ ext2_readdir (struct file * filp, void * dirent, filldir_t filldir)
 					ext2_put_page(page);
 					return 0;
 				}
+			} else if (de->file_type == EXT2_FT_FALLTHRU) {
+				int over;
+				unsigned char d_type = DT_UNKNOWN;
+
+				offset = (char *)de - kaddr;
+				/* XXX We don't know the inode number
+				 * of the directory entry in the
+				 * underlying file system.  Should
+				 * look it up, either on fallthru
+				 * creation at first readdir or now at
+				 * filldir time. */
+				over = filldir(dirent, de->name, de->name_len,
+					       (n<<PAGE_CACHE_SHIFT) | offset,
+					       123 /* Made up ino */, d_type);
+				if (over) {
+					ext2_put_page(page);
+					return 0;
+				}
 			}
 			filp->f_pos += ext2_rec_len_from_disk(de->rec_len);
 		}
@@ -463,6 +483,10 @@ ino_t ext2_inode_by_dentry(struct inode *dir, struct dentry *dentry)
 			spin_lock(&dentry->d_lock);
 			dentry->d_flags |= DCACHE_WHITEOUT;
 			spin_unlock(&dentry->d_lock);
+		} else if(!res && de->file_type == EXT2_FT_FALLTHRU) {
+			spin_lock(&dentry->d_lock);
+			dentry->d_flags |= DCACHE_FALLTHRU;
+			spin_unlock(&dentry->d_lock);
 		}
 		ext2_put_page(page);
 	}
@@ -532,6 +556,7 @@ static ext2_dirent * ext2_append_entry(struct dentry * dentry,
 				de->name_len = 0;
 				de->rec_len = ext2_rec_len_to_disk(chunk_size);
 				de->inode = 0;
+				de->file_type = 0;
 				goto got_it;
 			}
 			if (de->rec_len == 0) {
@@ -545,6 +570,7 @@ static ext2_dirent * ext2_append_entry(struct dentry * dentry,
 			name_len = EXT2_DIR_REC_LEN(de->name_len);
 			rec_len = ext2_rec_len_from_disk(de->rec_len);
 			if (!de->inode && (de->file_type != EXT2_FT_WHT) &&
+			    (de->file_type != EXT2_FT_FALLTHRU) &&
 			    (rec_len >= reclen))
 				goto got_it;
 			if (rec_len >= name_len + reclen)
@@ -587,7 +613,8 @@ int ext2_add_link (struct dentry *dentry, struct inode *inode)
 
 	err = -EEXIST;
 	if (ext2_match (namelen, name, de)) {
-		if (de->file_type == EXT2_FT_WHT)
+		if ((de->file_type == EXT2_FT_WHT) ||
+		    (de->file_type == EXT2_FT_FALLTHRU))
 			goto got_it;
 		goto out_unlock;
 	}
@@ -602,7 +629,8 @@ got_it:
 							&page, NULL);
 	if (err)
 		goto out_unlock;
-	if (de->inode || ((de->file_type == EXT2_FT_WHT) &&
+	if (de->inode || (((de->file_type == EXT2_FT_WHT) ||
+			   (de->file_type == EXT2_FT_FALLTHRU)) &&
 			  !ext2_match (namelen, name, de))) {
 		ext2_dirent *de1 = (ext2_dirent *) ((char *) de + name_len);
 		de1->rec_len = ext2_rec_len_to_disk(rec_len - name_len);
@@ -627,6 +655,60 @@ out_unlock:
 }
 
 /*
+ * Create a fallthru entry.
+ */
+int ext2_fallthru_entry (struct inode *dir, struct dentry *dentry)
+{
+	const char *name = dentry->d_name.name;
+	int namelen = dentry->d_name.len;
+	unsigned short rec_len, name_len;
+	ext2_dirent * de;
+	struct page *page;
+	loff_t pos;
+	int err;
+
+	de = ext2_append_entry(dentry, &page);
+	if (IS_ERR(de))
+		return PTR_ERR(de);
+
+	err = -EEXIST;
+	if (ext2_match (namelen, name, de))
+		goto out_unlock;
+
+	name_len = EXT2_DIR_REC_LEN(de->name_len);
+	rec_len = ext2_rec_len_from_disk(de->rec_len);
+
+	pos = page_offset(page) +
+		(char*)de - (char*)page_address(page);
+	err = __ext2_write_begin(NULL, page->mapping, pos, rec_len, 0,
+							&page, NULL);
+	if (err)
+		goto out_unlock;
+	if (de->inode || (de->file_type == EXT2_FT_WHT) ||
+	    (de->file_type == EXT2_FT_FALLTHRU)) {
+		ext2_dirent *de1 = (ext2_dirent *) ((char *) de + name_len);
+		de1->rec_len = ext2_rec_len_to_disk(rec_len - name_len);
+		de->rec_len = ext2_rec_len_to_disk(name_len);
+		de = de1;
+	}
+	de->name_len = namelen;
+	memcpy(de->name, name, namelen);
+	de->inode = 0;
+	de->file_type = EXT2_FT_FALLTHRU;
+	err = ext2_commit_chunk(page, pos, rec_len);
+	dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
+	EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL;
+	mark_inode_dirty(dir);
+	/* OFFSET_CACHE */
+out_put:
+	ext2_put_page(page);
+	return err;
+out_unlock:
+	unlock_page(page);
+	goto out_put;
+}
+
+/*
  * ext2_delete_entry deletes a directory entry by merging it with the
  * previous entry. Page is up-to-date. Releases the page.
  */
@@ -711,7 +793,9 @@ int ext2_whiteout_entry (struct inode * dir, struct dentry * dentry,
 	 */
 	if (ext2_match (namelen, name, de))
 		de->inode = 0;
-	if (de->inode || (de->file_type == EXT2_FT_WHT)) {
+	if (de->inode || (((de->file_type == EXT2_FT_WHT) ||
+			   (de->file_type == EXT2_FT_FALLTHRU)) &&
+			  !ext2_match (namelen, name, de))) {
 		ext2_dirent *de1 = (ext2_dirent *) ((char *) de + name_len);
 		de1->rec_len = ext2_rec_len_to_disk(rec_len - name_len);
 		de->rec_len = ext2_rec_len_to_disk(name_len);
diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
index a7f057f..328fc1c 100644
--- a/fs/ext2/ext2.h
+++ b/fs/ext2/ext2.h
@@ -108,6 +108,7 @@ extern struct ext2_dir_entry_2 * ext2_find_entry (struct inode *,struct qstr *,
 extern int ext2_delete_entry (struct ext2_dir_entry_2 *, struct page *);
 extern int ext2_whiteout_entry (struct inode *, struct dentry *,
 				struct ext2_dir_entry_2 *, struct page *);
+extern int ext2_fallthru_entry (struct inode *, struct dentry *);
 extern int ext2_empty_dir (struct inode *);
 extern struct ext2_dir_entry_2 * ext2_dotdot (struct inode *, struct page **);
 extern void ext2_set_link(struct inode *, struct ext2_dir_entry_2 *, struct page *, struct inode *, int);
diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c
index 9c4eef2..2ac44f1 100644
--- a/fs/ext2/namei.c
+++ b/fs/ext2/namei.c
@@ -333,6 +333,7 @@ static int ext2_whiteout(struct inode *dir, struct dentry *dentry,
 		goto out;
 
 	spin_lock(&new_dentry->d_lock);
+	new_dentry->d_flags &= ~DCACHE_FALLTHRU;
 	new_dentry->d_flags |= DCACHE_WHITEOUT;
 	spin_unlock(&new_dentry->d_lock);
 	d_add(new_dentry, NULL);
@@ -351,6 +352,24 @@ out:
 	return err;
 }
 
+/*
+ * Create a fallthru entry.
+ */
+static int ext2_fallthru (struct inode *dir, struct dentry *dentry)
+{
+	int err;
+
+	err = ext2_fallthru_entry(dir, dentry);
+	if (err)
+		return err;
+
+	d_instantiate(dentry, NULL);
+	spin_lock(&dentry->d_lock);
+	dentry->d_flags |= DCACHE_FALLTHRU;
+	spin_unlock(&dentry->d_lock);
+	return 0;
+}
+
 static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
 	struct inode * new_dir,	struct dentry * new_dentry )
 {
@@ -451,6 +470,7 @@ const struct inode_operations ext2_dir_inode_operations = {
 	.rmdir		= ext2_rmdir,
 	.mknod		= ext2_mknod,
 	.whiteout	= ext2_whiteout,
+	.fallthru	= ext2_fallthru,
 	.rename		= ext2_rename,
 #ifdef CONFIG_EXT2_FS_XATTR
 	.setxattr	= generic_setxattr,
diff --git a/include/linux/ext2_fs.h b/include/linux/ext2_fs.h
index bd10826..f6b68ec 100644
--- a/include/linux/ext2_fs.h
+++ b/include/linux/ext2_fs.h
@@ -577,6 +577,7 @@ enum {
 	EXT2_FT_SOCK,
 	EXT2_FT_SYMLINK,
 	EXT2_FT_WHT,
+	EXT2_FT_FALLTHRU,
 	EXT2_FT_MAX
 };
 
-- 
1.6.3.3

  reply	other threads:[~2009-10-21 19:19 UTC|newest]

Thread overview: 100+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-10-21 19:18 [RFC PATCH 00/40] Writable overlays (union mounts) Valerie Aurora
2009-10-21 19:18 ` [PATCH 01/41] VFS: BUG() if somebody tries to rehash an already hashed dentry Valerie Aurora
2009-10-21 19:19   ` [PATCH 02/41] VFS: propagate mnt_flags into do_loopback Valerie Aurora
2009-10-21 19:19     ` [PATCH 03/41] VFS: Make lookup_hash() return a struct path Valerie Aurora
2009-10-21 19:19       ` [PATCH 04/41] VFS: Remove unnecessary micro-optimization in cached_lookup() Valerie Aurora
2009-10-21 19:19         ` [PATCH 05/41] VFS: Make real_lookup() return a struct path Valerie Aurora
2009-10-21 19:19           ` [PATCH 06/41] VFS: Introduce dput() variant that maintains a kill-list Valerie Aurora
2009-10-21 19:19             ` [PATCH 07/41] VFS: Add read-only users count to superblock Valerie Aurora
2009-10-21 19:19               ` [PATCH 08/41] Don't replace nameidata path when following links Valerie Aurora
2009-10-21 19:19                 ` [PATCH 09/41] whiteout: Don't return information about whiteouts to userspace Valerie Aurora
2009-10-21 19:19                   ` [PATCH 10/41] whiteout: Add vfs_whiteout() and whiteout inode operation Valerie Aurora
2009-10-21 19:19                     ` [PATCH 11/41] whiteout: Set S_OPAQUE inode flag when creating directories Valerie Aurora
2009-10-21 19:19                       ` [PATCH 12/41] union-mount: Allow removal of a directory Valerie Aurora
2009-10-21 19:19                         ` [PATCH 13/41] whiteout: tmpfs whiteout support Valerie Aurora
2009-10-21 19:19                           ` [PATCH 14/41] whiteout: Split of ext2_append_link() from ext2_add_link() Valerie Aurora
2009-10-21 19:19                             ` [PATCH 15/41] whiteout: ext2 whiteout support Valerie Aurora
2009-10-21 19:19                               ` [PATCH 16/41] whiteout: jffs2 " Valerie Aurora
2009-10-21 19:19                                 ` [PATCH 17/41] whiteout: Add path_whiteout() helper Valerie Aurora
2009-10-21 19:19                                   ` [PATCH 18/41] union-mount: Documentation Valerie Aurora
2009-10-21 19:19                                     ` [PATCH 19/41] union-mount: Introduce MNT_UNION and MS_UNION flags Valerie Aurora
2009-10-21 19:19                                       ` [PATCH 20/41] union-mount: Introduce union_mount structure Valerie Aurora
2009-10-21 19:19                                         ` [PATCH 21/41] union-mount: Drive the union cache via dcache Valerie Aurora
2009-10-21 19:19                                           ` [PATCH 22/41] union-mount: Some checks during namespace changes Valerie Aurora
2009-10-21 19:19                                             ` [PATCH 23/41] union-mount: Changes to the namespace handling Valerie Aurora
2009-10-21 19:19                                               ` [PATCH 24/41] union-mount: Make lookup work for union-mounted file systems Valerie Aurora
2009-10-21 19:19                                                 ` [PATCH 25/41] union-mount: stop lookup when directory has S_OPAQUE flag set Valerie Aurora
2009-10-21 19:19                                                   ` [PATCH 26/41] union-mount: stop lookup when finding a whiteout Valerie Aurora
2009-10-21 19:19                                                     ` [PATCH 27/41] union-mount: in-kernel file copy between union mounted filesystems Valerie Aurora
2009-10-21 19:19                                                       ` [PATCH 28/41] union-mount: call do_whiteout() on unlink and rmdir Valerie Aurora
2009-10-21 19:19                                                         ` [PATCH 29/41] union-mount: Always create topmost directory on open Valerie Aurora
2009-10-21 19:19                                                           ` [PATCH 30/41] fallthru: Basic fallthru definitions Valerie Aurora
2009-10-21 19:19                                                             ` [PATCH 31/41] fallthru: Support for fallthru entries in union mount lookup Valerie Aurora
2009-10-21 19:19                                                               ` Valerie Aurora [this message]
2009-10-21 19:19                                                                 ` [PATCH 33/41] fallthru: jffs2 fallthru support Valerie Aurora
2009-10-21 19:19                                                                   ` [PATCH 34/41] fallthru: tmpfs " Valerie Aurora
2009-10-21 19:19                                                                     ` [PATCH 35/41] union-mount: Copy up directory entries on first readdir() Valerie Aurora
2009-10-21 19:19                                                                       ` [PATCH 36/41] union-mount: Increment read-only users count for read-only layer Valerie Aurora
2009-10-21 19:19                                                                         ` [PATCH 37/41] union-mount: Check read-only/read-write status of layers Valerie Aurora
2009-10-21 19:19                                                                           ` [PATCH 38/41] union-mount: Make pivot_root work with union mounts Valerie Aurora
2009-10-21 19:19                                                                             ` [PATCH 39/41] union-mount: Ignore read-only file system in permission checks Valerie Aurora
2009-10-21 19:19                                                                               ` [PATCH 40/41] union-mount: Make truncate work in all its glorious UNIX variations Valerie Aurora
2009-10-21 19:19                                                                                 ` [PATCH 41/41] union-mount: Add support for rename by __union_copyup() Valerie Aurora
2009-12-01  4:57                                                                                   ` Erez Zadok
2009-12-01  4:50                                                                                 ` [PATCH 40/41] union-mount: Make truncate work in all its glorious UNIX variations Erez Zadok
2009-12-01  4:34                                                                               ` [PATCH 39/41] union-mount: Ignore read-only file system in permission checks Erez Zadok
2009-12-01  4:26                                                                             ` [PATCH 38/41] union-mount: Make pivot_root work with union mounts Erez Zadok
2009-12-01  4:18                                                                       ` [PATCH 35/41] union-mount: Copy up directory entries on first readdir() Erez Zadok
2009-12-01  4:17                                                                     ` [PATCH 34/41] fallthru: tmpfs fallthru support Erez Zadok
2009-12-01  4:17                                                                   ` [PATCH 33/41] fallthru: jffs2 " Erez Zadok
2009-12-01  4:17                                                                 ` [PATCH 32/41] fallthru: ext2 " Erez Zadok
2009-12-01  4:15                                                               ` [PATCH 31/41] fallthru: Support for fallthru entries in union mount lookup Erez Zadok
2009-12-01  4:14                                                             ` [PATCH 30/41] fallthru: Basic fallthru definitions Erez Zadok
2009-12-01  4:14                                                           ` [PATCH 29/41] union-mount: Always create topmost directory on open Erez Zadok
2009-12-01  4:13                                                       ` [PATCH 27/41] union-mount: in-kernel file copy between union mounted filesystems Erez Zadok
2009-12-01  4:11                                                     ` [PATCH 26/41] union-mount: stop lookup when finding a whiteout Erez Zadok
2009-12-01  4:10                                                   ` [PATCH 25/41] union-mount: stop lookup when directory has S_OPAQUE flag set Erez Zadok
2009-12-01  4:10                                                 ` [PATCH 24/41] union-mount: Make lookup work for union-mounted file systems Erez Zadok
2009-11-30  9:15                                               ` [PATCH 23/41] union-mount: Changes to the namespace handling Erez Zadok
2009-11-30  9:04                                             ` [PATCH 22/41] union-mount: Some checks during namespace changes Erez Zadok
2009-11-30  8:57                                           ` [PATCH 21/41] union-mount: Drive the union cache via dcache Erez Zadok
2009-11-30  8:46                                         ` [PATCH 20/41] union-mount: Introduce union_mount structure Erez Zadok
2010-01-26 22:38                                           ` Valerie Aurora
2009-11-30  8:02                                       ` [PATCH 19/41] union-mount: Introduce MNT_UNION and MS_UNION flags Erez Zadok
2010-01-26 20:03                                         ` Valerie Aurora
2009-12-01  5:37                                     ` [PATCH 18/41] union-mount: Documentation Erez Zadok
2009-11-30  7:57                                   ` [PATCH 17/41] whiteout: Add path_whiteout() helper Erez Zadok
2010-01-26 20:02                                     ` Valerie Aurora
2009-10-21 22:50                                 ` [PATCH 16/41] whiteout: jffs2 whiteout support David Woodhouse
2009-10-27  2:21                                   ` Valerie Aurora
2009-11-30  7:51                                 ` Erez Zadok
2010-01-26 19:52                                   ` Valerie Aurora
2009-10-21 21:17                               ` [PATCH 15/41] whiteout: ext2 " Andreas Dilger
2009-10-27  2:14                                 ` Valerie Aurora
2009-11-30  7:45                               ` Erez Zadok
2009-11-30  6:32                             ` [PATCH 14/41] whiteout: Split of ext2_append_link() from ext2_add_link() Erez Zadok
2009-11-30  6:26                           ` [PATCH 13/41] whiteout: tmpfs whiteout support Erez Zadok
2010-01-21  2:02                             ` Valerie Aurora
2009-11-30  6:13                         ` [PATCH 12/41] union-mount: Allow removal of a directory Erez Zadok
2010-01-21  0:52                           ` Valerie Aurora
2009-10-27 14:36                     ` [PATCH 10/41] whiteout: Add vfs_whiteout() and whiteout inode operation Eric Paris
2009-10-27 21:22                       ` Valerie Aurora
2009-11-30  3:04                     ` Erez Zadok
2010-01-21  0:35                       ` Valerie Aurora
2009-11-30  2:53                   ` [PATCH 09/41] whiteout: Don't return information about whiteouts to userspace Erez Zadok
2010-01-21  0:19                     ` Valerie Aurora
2009-11-30  2:44                 ` [PATCH 08/41] Don't replace nameidata path when following links Erez Zadok
2009-11-30  2:33               ` [PATCH 07/41] VFS: Add read-only users count to superblock Erez Zadok
2009-11-30  2:28             ` [PATCH 06/41] VFS: Introduce dput() variant that maintains a kill-list Erez Zadok
2010-01-20 23:31               ` Valerie Aurora
2009-11-30  2:11           ` [PATCH 05/41] VFS: Make real_lookup() return a struct path Erez Zadok
2009-11-30  2:07         ` [PATCH 04/41] VFS: Remove unnecessary micro-optimization in cached_lookup() Erez Zadok
2009-12-10 21:25           ` Valerie Aurora
2009-11-30  2:02       ` [PATCH 03/41] VFS: Make lookup_hash() return a struct path Erez Zadok
2009-12-10 21:23         ` Valerie Aurora
2009-11-30  6:04       ` Erez Zadok
2009-12-10 21:24         ` Valerie Aurora
2009-11-30  1:43   ` [PATCH 01/41] VFS: BUG() if somebody tries to rehash an already hashed dentry Erez Zadok
2009-12-10 20:20     ` Valerie Aurora
2009-10-22  2:44 ` [RFC PATCH 00/40] Writable overlays (union mounts) hooanon05
2009-10-27  2:23   ` Valerie Aurora

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