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From: Valerie Aurora <valerie.aurora@gmail.com>
To: linux-fsdevel@vger.kernel.org, linux@vger.kernel.org
Cc: viro@zeniv.linux.org.uk, Valerie Aurora <vaurora@redhat.com>,
	Valerie Aurora <valerie.aurora@gmail.com>
Subject: [PATCH 12/74] whiteout: ext2 whiteout support
Date: Tue, 22 Mar 2011 18:58:48 -0700	[thread overview]
Message-ID: <1300845590-14184-13-git-send-email-valerie.aurora@gmail.com> (raw)
In-Reply-To: <1300845590-14184-1-git-send-email-valerie.aurora@gmail.com>

From: Valerie Aurora <vaurora@redhat.com>

Add support for whiteouts to ext2.

Signed-off-by: Valerie Aurora <valerie.aurora@gmail.com>
---
 fs/ext2/dir.c           |   65 +++++++++++++++++++++++++++++++++++++++++------
 fs/ext2/ext2.h          |    2 +
 fs/ext2/inode.c         |   11 ++++++--
 fs/ext2/namei.c         |   63 +++++++++++++++++++++++++++++++++++++++++++--
 fs/ext2/super.c         |    4 +++
 include/linux/ext2_fs.h |    4 +++
 6 files changed, 135 insertions(+), 14 deletions(-)

diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
index 74b23b0..6fa1217 100644
--- a/fs/ext2/dir.c
+++ b/fs/ext2/dir.c
@@ -211,7 +211,8 @@ fail:
 
 static inline int ext2_dirent_in_use(struct ext2_dir_entry_2 *de)
 {
-	return (de->inode);
+	return (de->inode ||
+		(de->file_type == EXT2_FT_WHT));
 }
 
 /*
@@ -260,6 +261,7 @@ static unsigned char ext2_filetype_table[EXT2_FT_MAX] = {
 	[EXT2_FT_FIFO]		= DT_FIFO,
 	[EXT2_FT_SOCK]		= DT_SOCK,
 	[EXT2_FT_SYMLINK]	= DT_LNK,
+	[EXT2_FT_WHT]		= DT_WHT,
 };
 
 #define S_SHIFT 12
@@ -458,6 +460,26 @@ static int ext2_prepare_chunk(struct page *page, loff_t pos, unsigned len)
 	return __block_write_begin(page, pos, len, ext2_get_block);
 }
 
+/* Special version for filetype based whiteout support */
+ino_t ext2_inode_by_dentry(struct inode *dir, struct dentry *dentry)
+{
+	ino_t res = 0;
+	struct ext2_dir_entry_2 *de;
+	struct page *page;
+
+	de = ext2_find_entry (dir, &dentry->d_name, &page);
+	if (de) {
+		res = le32_to_cpu(de->inode);
+		if (!res && de->file_type == EXT2_FT_WHT) {
+			spin_lock(&dentry->d_lock);
+			dentry->d_flags |= DCACHE_WHITEOUT;
+			spin_unlock(&dentry->d_lock);
+		}
+		ext2_put_page(page);
+	}
+	return res;
+}
+
 /* Releases the page */
 void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de,
 		   struct page *page, struct inode *inode, int update_times)
@@ -480,7 +502,9 @@ void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de,
 	mark_inode_dirty(dir);
 }
 
-int ext2_add_entry (struct dentry *dentry, struct inode *inode)
+int ext2_add_entry (struct dentry *dentry, struct inode *inode,
+		    ext2_dirent *de, struct page *page,
+		    int new_file_type)
 {
 	struct inode *dir = dentry->d_parent->d_inode;
 	const char *name = dentry->d_name.name;
@@ -488,8 +512,6 @@ int ext2_add_entry (struct dentry *dentry, struct inode *inode)
 	unsigned chunk_size = ext2_chunk_size(dir);
 	unsigned reclen = EXT2_DIR_REC_LEN(namelen);
 	unsigned short rec_len, name_len;
-	struct page *page = NULL;
-	ext2_dirent * de;
 	unsigned long npages = dir_pages(dir);
 	unsigned long n;
 	char *kaddr;
@@ -547,12 +569,27 @@ int ext2_add_entry (struct dentry *dentry, struct inode *inode)
 	return -EINVAL;
 
 got_it:
+	/*
+	 * Pre-existing entries with the same name are allowable
+	 * depending on the type of the entry being created.  Regular
+	 * entries replace whiteouts.  Whiteouts replace regular
+	 * entries.
+	 */
+	err = -EEXIST;
+	if (ext2_match(namelen, name, de)) {
+		if (new_file_type == EXT2_FT_WHT) {
+			if (de->file_type == EXT2_FT_WHT)
+				goto out_unlock;
+		} else if (de->file_type != EXT2_FT_WHT) {
+			goto out_unlock;
+		}
+	}
 	pos = page_offset(page) +
 		(char*)de - (char*)page_address(page);
 	err = ext2_prepare_chunk(page, pos, rec_len);
 	if (err)
 		goto out_unlock;
-	if (ext2_dirent_in_use(de)) {
+	if (ext2_dirent_in_use(de) && !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);
@@ -560,8 +597,13 @@ got_it:
 	}
 	de->name_len = namelen;
 	memcpy(de->name, name, namelen);
-	de->inode = cpu_to_le32(inode->i_ino);
-	ext2_set_de_type (de, inode);
+	if (inode) {
+		de->inode = cpu_to_le32(inode->i_ino);
+		ext2_set_de_type (de, inode);
+	} else {
+		de->inode = 0;
+		de->file_type = new_file_type;
+	}
 	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;
@@ -578,7 +620,14 @@ out_unlock:
 
 int ext2_add_link (struct dentry *dentry, struct inode *inode)
 {
-	return ext2_add_entry(dentry, inode);
+	ext2_dirent *de = NULL;
+	struct page *page = NULL;
+	return ext2_add_entry(dentry, inode, de, page, 0);
+}
+
+int ext2_whiteout_entry (struct dentry *dentry, ext2_dirent *de, struct page *page)
+{
+	return ext2_add_entry(dentry, NULL, de, page, EXT2_FT_WHT);
 }
 
 /*
diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
index 416daa6..799dedb 100644
--- a/fs/ext2/ext2.h
+++ b/fs/ext2/ext2.h
@@ -102,9 +102,11 @@ extern void ext2_rsv_window_add(struct super_block *sb, struct ext2_reserve_wind
 /* dir.c */
 extern int ext2_add_link (struct dentry *, struct inode *);
 extern ino_t ext2_inode_by_name(struct inode *, struct qstr *);
+extern ino_t ext2_inode_by_dentry(struct inode *, struct dentry *);
 extern int ext2_make_empty(struct inode *, struct inode *);
 extern struct ext2_dir_entry_2 * ext2_find_entry (struct inode *,struct qstr *, struct page **);
 extern int ext2_delete_entry (struct ext2_dir_entry_2 *, struct page *);
+extern int ext2_whiteout_entry (struct dentry *, struct ext2_dir_entry_2 *, struct page *);
 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/inode.c b/fs/ext2/inode.c
index 940c961..fb948f5 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -1258,7 +1258,8 @@ void ext2_set_inode_flags(struct inode *inode)
 {
 	unsigned int flags = EXT2_I(inode)->i_flags;
 
-	inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
+	inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|
+			    S_OPAQUE);
 	if (flags & EXT2_SYNC_FL)
 		inode->i_flags |= S_SYNC;
 	if (flags & EXT2_APPEND_FL)
@@ -1269,6 +1270,8 @@ void ext2_set_inode_flags(struct inode *inode)
 		inode->i_flags |= S_NOATIME;
 	if (flags & EXT2_DIRSYNC_FL)
 		inode->i_flags |= S_DIRSYNC;
+	if (flags & EXT2_OPAQUE_FL)
+		inode->i_flags |= S_OPAQUE;
 }
 
 /* Propagate flags from i_flags to EXT2_I(inode)->i_flags */
@@ -1276,8 +1279,8 @@ void ext2_get_inode_flags(struct ext2_inode_info *ei)
 {
 	unsigned int flags = ei->vfs_inode.i_flags;
 
-	ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL|
-			EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL);
+	ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL|EXT2_IMMUTABLE_FL|
+			 EXT2_NOATIME_FL|EXT2_DIRSYNC_FL|EXT2_OPAQUE_FL);
 	if (flags & S_SYNC)
 		ei->i_flags |= EXT2_SYNC_FL;
 	if (flags & S_APPEND)
@@ -1288,6 +1291,8 @@ void ext2_get_inode_flags(struct ext2_inode_info *ei)
 		ei->i_flags |= EXT2_NOATIME_FL;
 	if (flags & S_DIRSYNC)
 		ei->i_flags |= EXT2_DIRSYNC_FL;
+	if (flags & S_OPAQUE)
+		ei->i_flags |= EXT2_OPAQUE_FL;
 }
 
 struct inode *ext2_iget (struct super_block *sb, unsigned long ino)
diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c
index 71efb0e..08ad675 100644
--- a/fs/ext2/namei.c
+++ b/fs/ext2/namei.c
@@ -55,15 +55,16 @@ static inline int ext2_add_nondir(struct dentry *dentry, struct inode *inode)
  * Methods themselves.
  */
 
-static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
+static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry,
+				  struct nameidata *nd)
 {
 	struct inode * inode;
 	ino_t ino;
-	
+
 	if (dentry->d_name.len > EXT2_NAME_LEN)
 		return ERR_PTR(-ENAMETOOLONG);
 
-	ino = ext2_inode_by_name(dir, &dentry->d_name);
+	ino = ext2_inode_by_dentry(dir, dentry);
 	inode = NULL;
 	if (ino) {
 		inode = ext2_iget(dir->i_sb, ino);
@@ -307,6 +308,61 @@ static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
 	return err;
 }
 
+/*
+ * Create a whiteout for the dentry
+ */
+static int ext2_whiteout(struct inode *dir, struct dentry *dentry,
+			 struct dentry *new_dentry)
+{
+	struct inode * inode = dentry->d_inode;
+	struct ext2_dir_entry_2 * de = NULL;
+	struct page * page;
+	int err = -ENOTEMPTY;
+
+	if (!EXT2_HAS_INCOMPAT_FEATURE(dir->i_sb,
+				       EXT2_FEATURE_INCOMPAT_FILETYPE)) {
+		ext2_error (dir->i_sb, "ext2_whiteout",
+			    "can't set whiteout filetype");
+		err = -EPERM;
+		goto out;
+	}
+
+	dquot_initialize(dir);
+
+	if (inode) {
+		if (S_ISDIR(inode->i_mode) && !ext2_empty_dir(inode))
+			goto out;
+
+		err = -ENOENT;
+		de = ext2_find_entry(dir, &dentry->d_name, &page);
+		if (!de)
+			goto out;
+		lock_page(page);
+	}
+
+	err = ext2_whiteout_entry(dentry, de, page);
+	if (err)
+		goto out;
+
+	spin_lock(&new_dentry->d_lock);
+	new_dentry->d_flags |= DCACHE_WHITEOUT;
+	spin_unlock(&new_dentry->d_lock);
+	d_add(new_dentry, NULL);
+
+	if (inode) {
+		inode->i_ctime = dir->i_ctime;
+		inode_dec_link_count(inode);
+		if (S_ISDIR(inode->i_mode)) {
+			inode->i_size = 0;
+			inode_dec_link_count(inode);
+			inode_dec_link_count(dir);
+		}
+	}
+	err = 0;
+out:
+	return err;
+}
+
 static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
 	struct inode * new_dir,	struct dentry * new_dentry )
 {
@@ -409,6 +465,7 @@ const struct inode_operations ext2_dir_inode_operations = {
 	.mkdir		= ext2_mkdir,
 	.rmdir		= ext2_rmdir,
 	.mknod		= ext2_mknod,
+	.whiteout	= ext2_whiteout,
 	.rename		= ext2_rename,
 #ifdef CONFIG_EXT2_FS_XATTR
 	.setxattr	= generic_setxattr,
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 1ec6026..b941b99 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -1080,6 +1080,10 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 	if (EXT2_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_HAS_JOURNAL))
 		ext2_msg(sb, KERN_WARNING,
 			"warning: mounting ext3 filesystem as ext2");
+
+	if (EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_WHITEOUT))
+		sb->s_flags |= MS_WHITEOUT;
+
 	if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
 		sb->s_flags |= MS_RDONLY;
 	ext2_write_super(sb);
diff --git a/include/linux/ext2_fs.h b/include/linux/ext2_fs.h
index 2dfa707..b0fb356 100644
--- a/include/linux/ext2_fs.h
+++ b/include/linux/ext2_fs.h
@@ -189,6 +189,7 @@ struct ext2_group_desc
 #define EXT2_NOTAIL_FL			FS_NOTAIL_FL	/* file tail should not be merged */
 #define EXT2_DIRSYNC_FL			FS_DIRSYNC_FL	/* dirsync behaviour (directories only) */
 #define EXT2_TOPDIR_FL			FS_TOPDIR_FL	/* Top of directory hierarchies*/
+#define EXT2_OPAQUE_FL			FS_OPAQUE_FL	/* Dir is opaque */
 #define EXT2_RESERVED_FL		FS_RESERVED_FL	/* reserved for ext2 lib */
 
 #define EXT2_FL_USER_VISIBLE		FS_FL_USER_VISIBLE	/* User visible flags */
@@ -503,10 +504,12 @@ struct ext2_super_block {
 #define EXT3_FEATURE_INCOMPAT_RECOVER		0x0004
 #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008
 #define EXT2_FEATURE_INCOMPAT_META_BG		0x0010
+#define EXT2_FEATURE_INCOMPAT_WHITEOUT		0x0020
 #define EXT2_FEATURE_INCOMPAT_ANY		0xffffffff
 
 #define EXT2_FEATURE_COMPAT_SUPP	EXT2_FEATURE_COMPAT_EXT_ATTR
 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT2_FEATURE_INCOMPAT_FILETYPE| \
+					 EXT2_FEATURE_INCOMPAT_WHITEOUT| \
 					 EXT2_FEATURE_INCOMPAT_META_BG)
 #define EXT2_FEATURE_RO_COMPAT_SUPP	(EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
 					 EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
@@ -573,6 +576,7 @@ enum {
 	EXT2_FT_FIFO		= 5,
 	EXT2_FT_SOCK		= 6,
 	EXT2_FT_SYMLINK		= 7,
+	EXT2_FT_WHT		= 8,
 	EXT2_FT_MAX
 };
 
-- 
1.7.0.4


  parent reply	other threads:[~2011-03-23  2:00 UTC|newest]

Thread overview: 56+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-23  1:58 [PATCH 00/74] Union mounts version something or other Valerie Aurora
2011-03-23  1:58 ` [PATCH 01/74] VFS: Comment follow_mount() and friends Valerie Aurora
2011-03-23  1:58 ` [PATCH 02/74] VFS: Make lookup_hash() return a struct path Valerie Aurora
2011-03-23  1:58 ` [PATCH 03/74] autofs4: Save autofs trigger's vfsmount in super block info Valerie Aurora
2011-03-23  1:58 ` [PATCH 04/74] Documentation: Fix trivial typo in filesystems/sharedsubtree.txt Valerie Aurora
2011-03-23  1:58 ` [PATCH 05/74] whiteout/NFSD: Don't return information about whiteouts to userspace Valerie Aurora
2011-03-23  1:58 ` [PATCH 06/74] whiteout: Define opaque inode flags and operations Valerie Aurora
2011-03-23  1:58 ` [PATCH 07/74] whiteout: Add vfs_whiteout() and whiteout inode operation Valerie Aurora
2011-03-23  1:58 ` [PATCH 08/74] whiteout: Allow removal of a directory with whiteouts Valerie Aurora
2011-03-23  1:58 ` [PATCH 09/74] whiteout: tmpfs whiteout support Valerie Aurora
2011-03-23  1:58 ` [PATCH 10/74] ext2: Add ext2_dirent_in_use() Valerie Aurora
2011-03-23  1:58 ` [PATCH 11/74] ext2: Split ext2_add_entry() from ext2_add_link() Valerie Aurora
2011-03-23  1:58 ` Valerie Aurora [this message]
2011-03-23  1:58 ` [PATCH 13/74] whiteout: jffs2 whiteout support Valerie Aurora
2011-03-23  1:58 ` [PATCH 14/74] fallthru: Basic fallthru definitions Valerie Aurora
2011-03-23  1:58 ` [PATCH 15/74] fallthru: ext2 fallthru support Valerie Aurora
2011-03-23  1:58 ` [PATCH 16/74] fallthru: tmpfs " Valerie Aurora
2011-03-23  1:58 ` [PATCH 17/74] fallthru: jffs2 " Valerie Aurora
2011-03-23  1:58 ` [PATCH 18/74] VFS: Add hard read-only users count to superblock Valerie Aurora
2011-03-23  1:58 ` [PATCH 19/74] VFS: Make clone_mnt()/copy_tree()/collect_mounts() return errors Valerie Aurora
2011-03-23  1:58 ` [PATCH 20/74] VFS: Add CL_NO_SHARED flag to clone_mnt()/copy_tree() Valerie Aurora
2011-03-23  1:58 ` [PATCH 21/74] VFS: Add CL_NO_SLAVE " Valerie Aurora
2011-03-23  1:58 ` [PATCH 22/74] VFS: Add CL_MAKE_HARD_READONLY " Valerie Aurora
2011-03-23  1:58 ` [PATCH 23/74] union-mount: Union mounts documentation Valerie Aurora
2011-03-23  1:59 ` [PATCH 24/74] union-mount: Introduce MNT_UNION and MS_UNION flags Valerie Aurora
2011-03-23  1:59 ` [PATCH 25/74] union-mount: Add CONFIG_UNION_MOUNT option Valerie Aurora
2011-03-23  1:59 ` [PATCH 26/74] union-mount: Create union_stack structure Valerie Aurora
2011-03-23  1:59 ` [PATCH 27/74] union-mount: Add two superblock fields for union mounts Valerie Aurora
2011-03-23  1:59 ` [PATCH 28/74] union-mount: Add union_alloc() Valerie Aurora
2011-03-23  1:59 ` [PATCH 29/74] union-mount: Add union_find_dir() Valerie Aurora
2011-03-23  1:59 ` [PATCH 30/74] union-mount: Create d_free_unions() Valerie Aurora
2011-03-23  1:59 ` [PATCH 31/74] union-mount: Free union stack on removal of topmost dentry from dcache Valerie Aurora
2011-03-23  1:59 ` [PATCH 32/74] union-mount: Create union_add_dir() Valerie Aurora
2011-03-23  1:59 ` [PATCH 33/74] union-mount: Add union_create_topmost_dir() Valerie Aurora
2011-03-23  1:59 ` [PATCH 34/74] union-mount: Create IS_MNT_UNION() Valerie Aurora
2011-03-23  1:59 ` [PATCH 35/74] union-mount: Create needs_lookup_union() Valerie Aurora
2011-03-23  1:59 ` [PATCH 36/74] union-mount: Create check_topmost_union_mnt() Valerie Aurora
2011-03-23  1:59 ` [PATCH 37/74] union-mount: Add clone_union_tree() and put_union_sb() Valerie Aurora
2011-03-23  1:59 ` [PATCH 38/74] union-mount: Create build_root_union() Valerie Aurora
2011-03-23  1:59 ` [PATCH 39/74] union-mount: Create prepare_mnt_union() and cleanup_mnt_union() Valerie Aurora
2011-03-23  1:59 ` [PATCH 40/74] union-mount: Prevent improper union-related remounts Valerie Aurora
2011-03-23  1:59 ` [PATCH 41/74] union-mount: Prevent topmost file system from being mounted elsewhere Valerie Aurora
2011-03-23  1:59 ` [PATCH 42/74] union-mount: Prevent bind mounts of union mounts Valerie Aurora
2011-03-23  1:59 ` [PATCH 43/74] union-mount: Implement union mount Valerie Aurora
2011-03-23  1:59 ` [PATCH 44/74] union-mount: Temporarily disable some syscalls Valerie Aurora
2011-03-23  2:12 ` [PATCH 00/74] Union mounts version something or other Valerie Aurora
2011-03-24 13:43   ` Union mounts comparison with overlay file system prototype? Ric Wheeler
2011-03-25 11:38     ` Szeredi Miklos
2011-03-25 12:12       ` Ric Wheeler
2011-03-23  8:38 ` [PATCH 00/74] Union mounts version something or other Sedat Dilek
2011-03-24 22:40   ` Ben Hutchings
2011-03-25  2:32     ` Sedat Dilek
2011-03-30 14:30 ` David Howells
2011-04-01 16:48   ` Valerie Aurora
2011-04-21 13:09   ` David Howells
2011-04-24 21:48     ` Valerie Aurora

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