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 <[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 | 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
In message <[email protected]>, Valerie Aurora writes:
> 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 <[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 | 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)))
Extra set of () unnecessary here and in several places below.
> 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);
So, why 123 and not at least some other unused number below 10: at least
that way it's in the ext2 "reserved" range should something go horribly
wrong (like a power failure right shortly thereafter).
BTW, this yet-unimplemented functionality should be mentioned under
"limitations" or something in the current design doc. I also think the
design doc should list all short-term and long-term things that need to be
implemented, and in what order.
> + 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
>
> --
> 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
Erez.