2010-08-08 15:52:40

by Valerie Aurora

[permalink] [raw]
Subject: [PATCH 23/39] fallthru: ext2 fallthru support

Add support for fallthru directory entries to ext2.

Cc: Theodore Tso <[email protected]>
Cc: [email protected]
Signed-off-by: Valerie Aurora <[email protected]>
Signed-off-by: Jan Blunck <[email protected]>
---
fs/ext2/dir.c | 92 ++++++++++++++++++++++++++++++++++++++++++++--
fs/ext2/ext2.h | 1 +
fs/ext2/namei.c | 22 +++++++++++
fs/ext2/super.c | 2 +
include/linux/ext2_fs.h | 4 ++
5 files changed, 117 insertions(+), 4 deletions(-)

diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
index 030bd46..f19651e 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;
+ ino_t ino;
+ int err;
+
+ offset = (char *)de - kaddr;
+ err = generic_readdir_fallthru(filp->f_path.dentry, de->name,
+ de->name_len, &ino, &d_type);
+ if (!err) {
+ over = filldir(dirent, de->name, de->name_len,
+ (n<<PAGE_CACHE_SHIFT) | offset,
+ 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 89ab2f7..1504814 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 8f92dd0..af4052f 100644
--- a/fs/ext2/namei.c
+++ b/fs/ext2/namei.c
@@ -345,6 +345,7 @@ 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);
@@ -363,6 +364,26 @@ out:
return err;
}

+/*
+ * Create a fallthru entry.
+ */
+static int ext2_fallthru (struct inode *dir, struct dentry *dentry)
+{
+ int err;
+
+ dquot_initialize(dir);
+
+ 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 )
{
@@ -466,6 +487,7 @@ 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/fs/ext2/super.c b/fs/ext2/super.c
index 704521b..76eba1e 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -1095,6 +1095,8 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)

if (EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_WHITEOUT))
sb->s_flags |= MS_WHITEOUT;
+ if (EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_FALLTHRU))
+ sb->s_flags |= MS_FALLTHRU;

if (ext2_setup_super (sb, es, sb->s_flags & MS_RDONLY))
sb->s_flags |= MS_RDONLY;
diff --git a/include/linux/ext2_fs.h b/include/linux/ext2_fs.h
index b0fb356..1a6f929 100644
--- a/include/linux/ext2_fs.h
+++ b/include/linux/ext2_fs.h
@@ -505,11 +505,14 @@ struct ext2_super_block {
#define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008
#define EXT2_FEATURE_INCOMPAT_META_BG 0x0010
#define EXT2_FEATURE_INCOMPAT_WHITEOUT 0x0020
+/* ext3/4 incompat flags take up the intervening constants */
+#define EXT2_FEATURE_INCOMPAT_FALLTHRU 0x2000
#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_FALLTHRU| \
EXT2_FEATURE_INCOMPAT_META_BG)
#define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \
EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \
@@ -577,6 +580,7 @@ enum {
EXT2_FT_SOCK = 6,
EXT2_FT_SYMLINK = 7,
EXT2_FT_WHT = 8,
+ EXT2_FT_FALLTHRU = 9,
EXT2_FT_MAX
};

--
1.6.3.3


2010-08-13 13:52:02

by Miklos Szeredi

[permalink] [raw]
Subject: Re: [PATCH 23/39] fallthru: ext2 fallthru support

On Sun, 8 Aug 2010, Valerie Aurora wrote:
> Add support for fallthru directory entries to ext2.

This still doesn't work correctly, only now after unmounting/mounting
the top layer the directory appears empty:

uml:~# mount -oloop -r ext3.img /mnt/img/
uml:~# losetup /dev/loop2 ovl.img
uml:~# /host/store/git/e2fsprogs/misc/mke2fs -O whiteout,fallthru /dev/loop2
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
Stride=0 blocks, Stripe width=0 blocks
1280 inodes, 10240 blocks
512 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=10485760
2 block groups
8192 blocks per group, 8192 fragments per group
640 inodes per group
Superblock backups stored on blocks:
8193

Allocating group tables: done
Writing inode tables: done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 24 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
uml:~# mmount -b 8 -t ext2 /dev/loop2 /mnt/img/
uml:~# "ls" /mnt/img
lost+found union
uml:~# "ls" /mnt/img/union
1 2 3
uml:~# umount /mnt/img
uml:~# mmount -b 8 -t ext2 /dev/loop2 /mnt/img/
uml:~# ls -l /mnt/img/
total 13
drwx------ 2 root root 12288 Aug 13 13:42 lost+found
drwxr-xr-x 2 root root 1024 Aug 13 13:42 union
uml:~# ls -la /mnt/img/union/
total 2
drwxr-xr-x 2 root root 1024 Aug 13 13:42 .
drwxr-xr-x 4 root root 1024 Aug 13 13:42 ..
uml:~# grep /mnt/img /proc/self/mountinfo
21 12 7:0 / /mnt/img ro,relatime - ext3 /dev/loop0 ro,errors=continue,barrier=0,data=writeback
22 21 7:2 / /mnt/img rw,relatime,union - ext2 /dev/loop2 rw,errors=continue

Thanks,
Miklos

2010-08-17 21:08:47

by Valerie Aurora

[permalink] [raw]
Subject: Re: [PATCH 23/39] fallthru: ext2 fallthru support

On Fri, Aug 13, 2010 at 03:52:02PM +0200, Miklos Szeredi wrote:
> On Sun, 8 Aug 2010, Valerie Aurora wrote:
> > Add support for fallthru directory entries to ext2.
>
> This still doesn't work correctly, only now after unmounting/mounting
> the top layer the directory appears empty:

Thanks, I will look into this.

-VAL

> uml:~# mount -oloop -r ext3.img /mnt/img/
> uml:~# losetup /dev/loop2 ovl.img
> uml:~# /host/store/git/e2fsprogs/misc/mke2fs -O whiteout,fallthru /dev/loop2
> mke2fs 1.41.12 (17-May-2010)
> Filesystem label=
> OS type: Linux
> Block size=1024 (log=0)
> Fragment size=1024 (log=0)
> Stride=0 blocks, Stripe width=0 blocks
> 1280 inodes, 10240 blocks
> 512 blocks (5.00%) reserved for the super user
> First data block=1
> Maximum filesystem blocks=10485760
> 2 block groups
> 8192 blocks per group, 8192 fragments per group
> 640 inodes per group
> Superblock backups stored on blocks:
> 8193
>
> Allocating group tables: done
> Writing inode tables: done
> Writing superblocks and filesystem accounting information: done
>
> This filesystem will be automatically checked every 24 mounts or
> 180 days, whichever comes first. Use tune2fs -c or -i to override.
> uml:~# mmount -b 8 -t ext2 /dev/loop2 /mnt/img/
> uml:~# "ls" /mnt/img
> lost+found union
> uml:~# "ls" /mnt/img/union
> 1 2 3
> uml:~# umount /mnt/img
> uml:~# mmount -b 8 -t ext2 /dev/loop2 /mnt/img/
> uml:~# ls -l /mnt/img/
> total 13
> drwx------ 2 root root 12288 Aug 13 13:42 lost+found
> drwxr-xr-x 2 root root 1024 Aug 13 13:42 union
> uml:~# ls -la /mnt/img/union/
> total 2
> drwxr-xr-x 2 root root 1024 Aug 13 13:42 .
> drwxr-xr-x 4 root root 1024 Aug 13 13:42 ..
> uml:~# grep /mnt/img /proc/self/mountinfo
> 21 12 7:0 / /mnt/img ro,relatime - ext3 /dev/loop0 ro,errors=continue,barrier=0,data=writeback
> 22 21 7:2 / /mnt/img rw,relatime,union - ext2 /dev/loop2 rw,errors=continue
>
> Thanks,
> Miklos
> --
> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html

2010-08-17 22:29:03

by Valerie Aurora

[permalink] [raw]
Subject: Re: [PATCH 23/39] fallthru: ext2 fallthru support

On Fri, Aug 13, 2010 at 03:52:02PM +0200, Miklos Szeredi wrote:
> On Sun, 8 Aug 2010, Valerie Aurora wrote:
> > Add support for fallthru directory entries to ext2.
>
> This still doesn't work correctly, only now after unmounting/mounting
> the top layer the directory appears empty:

Thanks, I will look into this.

-VAL

> uml:~# mount -oloop -r ext3.img /mnt/img/
> uml:~# losetup /dev/loop2 ovl.img
> uml:~# /host/store/git/e2fsprogs/misc/mke2fs -O whiteout,fallthru /dev/loop2
> mke2fs 1.41.12 (17-May-2010)
> Filesystem label=
> OS type: Linux
> Block size=1024 (log=0)
> Fragment size=1024 (log=0)
> Stride=0 blocks, Stripe width=0 blocks
> 1280 inodes, 10240 blocks
> 512 blocks (5.00%) reserved for the super user
> First data block=1
> Maximum filesystem blocks=10485760
> 2 block groups
> 8192 blocks per group, 8192 fragments per group
> 640 inodes per group
> Superblock backups stored on blocks:
> 8193
>
> Allocating group tables: done
> Writing inode tables: done
> Writing superblocks and filesystem accounting information: done
>
> This filesystem will be automatically checked every 24 mounts or
> 180 days, whichever comes first. Use tune2fs -c or -i to override.
> uml:~# mmount -b 8 -t ext2 /dev/loop2 /mnt/img/
> uml:~# "ls" /mnt/img
> lost+found union
> uml:~# "ls" /mnt/img/union
> 1 2 3
> uml:~# umount /mnt/img
> uml:~# mmount -b 8 -t ext2 /dev/loop2 /mnt/img/
> uml:~# ls -l /mnt/img/
> total 13
> drwx------ 2 root root 12288 Aug 13 13:42 lost+found
> drwxr-xr-x 2 root root 1024 Aug 13 13:42 union
> uml:~# ls -la /mnt/img/union/
> total 2
> drwxr-xr-x 2 root root 1024 Aug 13 13:42 .
> drwxr-xr-x 4 root root 1024 Aug 13 13:42 ..
> uml:~# grep /mnt/img /proc/self/mountinfo
> 21 12 7:0 / /mnt/img ro,relatime - ext3 /dev/loop0 ro,errors=continue,barrier=0,data=writeback
> 22 21 7:2 / /mnt/img rw,relatime,union - ext2 /dev/loop2 rw,errors=continue
>
> Thanks,
> Miklos
> --
> To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html