| Message ID | 1495398051-4604-5-git-send-email-richard@nod.at (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Richard, On Sun, May 21, 2017 at 10:20:49PM +0200, Richard Weinberger wrote: > The new feature UBIFS_FLG_PARENTPOINTER allows looking > up the parent. Usually the Linux VFS walks down the filesystem > and no parent pointers are needed. But when a filesystem > is exportable via NFS such a lookup is needed. > We can use a padding field in struct ubifs_ino_node to > maintain a pointer to the parent inode. > > Signed-off-by: Richard Weinberger <richard@nod.at> > --- > fs/ubifs/dir.c | 21 +++++++++++++++++++-- > fs/ubifs/journal.c | 5 ++++- > fs/ubifs/sb.c | 2 ++ > fs/ubifs/super.c | 1 + > fs/ubifs/ubifs-media.h | 12 +++++++++--- > fs/ubifs/ubifs.h | 4 ++++ > 6 files changed, 39 insertions(+), 6 deletions(-) > > diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c > index e79b529df9c3..a6eadb52a1a8 100644 > --- a/fs/ubifs/dir.c > +++ b/fs/ubifs/dir.c > @@ -171,6 +171,7 @@ struct inode *ubifs_new_inode(struct ubifs_info *c, struct inode *dir, > } > > inode->i_ino = ++c->highest_inum; > + ui->parent_inum = dir->i_ino; > /* > * The creation sequence number remains with this inode for its > * lifetime. All nodes for this inode have a greater sequence number, > @@ -1374,7 +1375,7 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, > if (unlink) > ubifs_assert(inode_is_locked(new_inode)); > > - if (old_dir != new_dir) { > + if (move) { > if (ubifs_crypt_is_encrypted(new_dir) && > !fscrypt_has_permitted_context(new_dir, old_inode)) > return -EPERM; > @@ -1528,8 +1529,12 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, > mark_inode_dirty(whiteout); > whiteout->i_state &= ~I_LINKABLE; > iput(whiteout); > + whiteout_ui->parent_inum = new_dir->i_ino; > } > > + if (move) > + old_inode_ui->parent_inum = new_dir->i_ino; > + > err = ubifs_jnl_rename(c, old_dir, old_inode, &old_nm, new_dir, > new_inode, &new_nm, whiteout, sync); I think that old_inode_ui->parent_inum could point old_dir, even though old_inode is a child of new_dir. this could happen that there is power-cut before old_inode is synced. so I guess that old_inode is needed to be written with rename's node group in ubifs_jnl_rename. is it right? > if (err) > @@ -1571,6 +1576,8 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, > inc_nlink(old_dir); > } > } > + if (move) > + old_inode_ui->parent_inum = old_dir->i_ino; > if (whiteout) { > drop_nlink(whiteout); > iput(whiteout); > @@ -1592,6 +1599,8 @@ static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry, > int sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir); > struct inode *fst_inode = d_inode(old_dentry); > struct inode *snd_inode = d_inode(new_dentry); > + struct ubifs_inode *fst_inode_ui = ubifs_inode(fst_inode); > + struct ubifs_inode *snd_inode_ui = ubifs_inode(snd_inode); > struct timespec time; > int err; > struct fscrypt_name fst_nm, snd_nm; > @@ -1623,7 +1632,10 @@ static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry, > old_dir->i_mtime = old_dir->i_ctime = time; > new_dir->i_mtime = new_dir->i_ctime = time; > > - if (old_dir != new_dir) { > + if (new_dir != old_dir) { > + fst_inode_ui->parent_inum = new_dir->i_ino; > + snd_inode_ui->parent_inum = old_dir->i_ino; > + > if (S_ISDIR(fst_inode->i_mode) && !S_ISDIR(snd_inode->i_mode)) { > inc_nlink(new_dir); > drop_nlink(old_dir); > @@ -1637,6 +1649,11 @@ static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry, > err = ubifs_jnl_xrename(c, old_dir, fst_inode, &fst_nm, new_dir, > snd_inode, &snd_nm, sync); > > + if (err && new_dir != old_dir) { > + fst_inode_ui->parent_inum = old_dir->i_ino; > + snd_inode_ui->parent_inum = new_dir->i_ino; > + } > + > unlock_4_inodes(old_dir, new_dir, NULL, NULL); > ubifs_release_budget(c, &req); > > diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c > index 294519b98874..8eaf8f2f1fe1 100644 > --- a/fs/ubifs/journal.c > +++ b/fs/ubifs/journal.c > @@ -66,7 +66,6 @@ > */ > static inline void zero_ino_node_unused(struct ubifs_ino_node *ino) > { > - memset(ino->padding1, 0, 4); > memset(ino->padding2, 0, 26); > } > > @@ -470,6 +469,10 @@ static void pack_inode(struct ubifs_info *c, struct ubifs_ino_node *ino, > ino->xattr_cnt = cpu_to_le32(ui->xattr_cnt); > ino->xattr_size = cpu_to_le32(ui->xattr_size); > ino->xattr_names = cpu_to_le32(ui->xattr_names); > + if (c->parent_pointer) > + ino->parent_inum = cpu_to_le32(ui->parent_inum); > + else > + ino->parent_inum = 0; > zero_ino_node_unused(ino); > > /* > diff --git a/fs/ubifs/sb.c b/fs/ubifs/sb.c > index 8c25081a5109..f2097c47f629 100644 > --- a/fs/ubifs/sb.c > +++ b/fs/ubifs/sb.c > @@ -166,6 +166,7 @@ static int create_default_filesystem(struct ubifs_info *c) > if (big_lpt) > sup_flags |= UBIFS_FLG_BIGLPT; > sup_flags |= UBIFS_FLG_DOUBLE_HASH; > + sup_flags |= UBIFS_FLG_PARENTPOINTER; > > sup->ch.node_type = UBIFS_SB_NODE; > sup->key_hash = UBIFS_KEY_HASH_R5; > @@ -639,6 +640,7 @@ int ubifs_read_superblock(struct ubifs_info *c) > c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP); > c->double_hash = !!(sup_flags & UBIFS_FLG_DOUBLE_HASH); > c->encrypted = !!(sup_flags & UBIFS_FLG_ENCRYPTION); > + c->parent_pointer = !!(sup_flags & UBIFS_FLG_PARENTPOINTER); > > if ((sup_flags & ~UBIFS_FLG_MASK) != 0) { > ubifs_err(c, "Unknown feature flags found: %#x", > diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c > index cf4cc99b75b5..7560071534bf 100644 > --- a/fs/ubifs/super.c > +++ b/fs/ubifs/super.c > @@ -154,6 +154,7 @@ struct inode *ubifs_iget(struct super_block *sb, unsigned long inum) > ui->synced_i_size = ui->ui_size = inode->i_size; > > ui->xattr = (ui->flags & UBIFS_XATTR_FL) ? 1 : 0; > + ui->parent_inum = le32_to_cpu(ino->parent_inum); > > err = validate_inode(c, inode); > if (err) > diff --git a/fs/ubifs/ubifs-media.h b/fs/ubifs/ubifs-media.h > index 5939776c7359..b3cb76cedf20 100644 > --- a/fs/ubifs/ubifs-media.h > +++ b/fs/ubifs/ubifs-media.h > @@ -427,15 +427,21 @@ enum { > * UBIFS_FLG_DOUBLE_HASH: store a 32bit cookie in directory entry nodes to > * support 64bit cookies for lookups by hash > * UBIFS_FLG_ENCRYPTION: this filesystem contains encrypted files > + * UBIFS_FLG_PARENTPOINTER: inode nodes maintain a pointer to the parent dir > */ > enum { > UBIFS_FLG_BIGLPT = 0x02, > UBIFS_FLG_SPACE_FIXUP = 0x04, > UBIFS_FLG_DOUBLE_HASH = 0x08, > UBIFS_FLG_ENCRYPTION = 0x10, > + UBIFS_FLG_PARENTPOINTER = 0x20, > }; > > -#define UBIFS_FLG_MASK (UBIFS_FLG_BIGLPT|UBIFS_FLG_SPACE_FIXUP|UBIFS_FLG_DOUBLE_HASH|UBIFS_FLG_ENCRYPTION) > +#define UBIFS_FLG_MASK (UBIFS_FLG_BIGLPT \ > + |UBIFS_FLG_SPACE_FIXUP \ > + |UBIFS_FLG_DOUBLE_HASH \ > + |UBIFS_FLG_ENCRYPTION \ > + |UBIFS_FLG_PARENTPOINTER) > > /** > * struct ubifs_ch - common header node. > @@ -494,7 +500,7 @@ union ubifs_dev_desc { > * @data_len: inode data length > * @xattr_cnt: count of extended attributes this inode has > * @xattr_size: summarized size of all extended attributes in bytes > - * @padding1: reserved for future, zeroes > + * @parent_inum: parent inode number > * @xattr_names: sum of lengths of all extended attribute names belonging to > * this inode > * @compr_type: compression type used for this inode > @@ -528,7 +534,7 @@ struct ubifs_ino_node { > __le32 data_len; > __le32 xattr_cnt; > __le32 xattr_size; > - __u8 padding1[4]; /* Watch 'zero_ino_node_unused()' if changing! */ > + __le32 parent_inum; > __le32 xattr_names; > __le16 compr_type; > __u8 padding2[26]; /* Watch 'zero_ino_node_unused()' if changing! */ > diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h > index f14dcc890e47..3c64481f4032 100644 > --- a/fs/ubifs/ubifs.h > +++ b/fs/ubifs/ubifs.h > @@ -353,6 +353,7 @@ struct ubifs_gced_idx_leb { > * currently stored on the flash; used only for regular file > * inodes > * @ui_size: inode size used by UBIFS when writing to flash > + * @parent_inum: inode number of the parent directory > * @flags: inode flags (@UBIFS_COMPR_FL, etc) > * @compr_type: default compression type used for this inode > * @last_page_read: page number of last page read (for bulk read) > @@ -404,6 +405,7 @@ struct ubifs_inode { > spinlock_t ui_lock; > loff_t synced_i_size; > loff_t ui_size; > + ino_t parent_inum; > int flags; > pgoff_t last_page_read; > pgoff_t read_in_a_row; > @@ -1012,6 +1014,7 @@ struct ubifs_debug_info; > * @space_fixup: flag indicating that free space in LEBs needs to be cleaned up > * @double_hash: flag indicating that we can do lookups by hash > * @encrypted: flag indicating that this file system contains encrypted files > + * @parent_pointer: flag indicating that inodes have pointers to the parent dir > * @no_chk_data_crc: do not check CRCs when reading data nodes (except during > * recovery) > * @bulk_read: enable bulk-reads > @@ -1255,6 +1258,7 @@ struct ubifs_info { > unsigned int space_fixup:1; > unsigned int double_hash:1; > unsigned int encrypted:1; > + unsigned int parent_pointer:1; > unsigned int no_chk_data_crc:1; > unsigned int bulk_read:1; > unsigned int default_compr:2; > -- > 2.12.0 > > > ______________________________________________________ > Linux MTD discussion mailing list > http://lists.infradead.org/mailman/listinfo/linux-mtd/
Hyunchul, Am 22.05.2017 um 06:30 schrieb Hyunchul Lee: >> + if (move) >> + old_inode_ui->parent_inum = new_dir->i_ino; >> + >> err = ubifs_jnl_rename(c, old_dir, old_inode, &old_nm, new_dir, >> new_inode, &new_nm, whiteout, sync); > > I think that old_inode_ui->parent_inum could point old_dir, even though old_inode > is a child of new_dir. this could happen that there is power-cut before > old_inode is synced. so I guess that old_inode is needed to be written with > rename's node group in ubifs_jnl_rename. is it right? I assumed that the journal does this already because we change old_inode->i_ctime in this function too. But checking the code showed the opposite. So, if we face a power-cut the rename can succeed but we lose the ctime change. This needs to be addressed before we can add the parent pointer. Thanks, //richard
Hi Richard, On Mon, May 22, 2017 at 10:45:08AM +0200, Richard Weinberger wrote: > Hyunchul, > > Am 22.05.2017 um 06:30 schrieb Hyunchul Lee: > >> + if (move) > >> + old_inode_ui->parent_inum = new_dir->i_ino; > >> + > >> err = ubifs_jnl_rename(c, old_dir, old_inode, &old_nm, new_dir, > >> new_inode, &new_nm, whiteout, sync); > > > > I think that old_inode_ui->parent_inum could point old_dir, even though old_inode > > is a child of new_dir. this could happen that there is power-cut before > > old_inode is synced. so I guess that old_inode is needed to be written with > > rename's node group in ubifs_jnl_rename. is it right? > > I assumed that the journal does this already because we change old_inode->i_ctime > in this function too. > But checking the code showed the opposite. > So, if we face a power-cut the rename can succeed but we lose the ctime change. > > This needs to be addressed before we can add the parent pointer. Is writing old_inode->i_ctime required? I guess that it is needed only when IS_SYNC(old_inode) is true, otherwise we don't need to guarantee that ctime is synced. > > Thanks, > //richard > > ______________________________________________________ > Linux MTD discussion mailing list > http://lists.infradead.org/mailman/listinfo/linux-mtd/
Hyunchul, Am 23.05.2017 um 01:50 schrieb Hyunchul Lee: >> I assumed that the journal does this already because we change old_inode->i_ctime >> in this function too. >> But checking the code showed the opposite. >> So, if we face a power-cut the rename can succeed but we lose the ctime change. >> >> This needs to be addressed before we can add the parent pointer. > > Is writing old_inode->i_ctime required? I guess that it is needed only when > IS_SYNC(old_inode) is true, otherwise we don't need to guarantee that ctime > is synced. Well, rename() has to be an atomic operation. When UBIFS updates ctime during this operation it has also to be atomic. Otherwise, after a power-cut, you can end-up with a renamed file but a not updated ctime. Userspace can depend on this. Think of a backup program that needs to detect changes. It won't notice the renamed file. AFAICT POSIX does not require ctime to be updated during rename() but suggests it. My point is, either we do it always or never. Just checked xfs and btrfs. Both seem to update ctime of old_inode during the rename transaction. UBIFS should do the same. Thanks, //richard
On Sun, May 21, 2017 at 10:20:49PM +0200, Richard Weinberger wrote: > The new feature UBIFS_FLG_PARENTPOINTER allows looking > up the parent. Usually the Linux VFS walks down the filesystem > and no parent pointers are needed. But when a filesystem > is exportable via NFS such a lookup is needed. > We can use a padding field in struct ubifs_ino_node to > maintain a pointer to the parent inode. Note that nfsd/exportfs will only do this for directories, and beacause we hardlinks for other objects that is an important distinction. I think the ubifs code should make sure to only maintain the parent pointers for directories, otherwise confusion and abuses will happen.
Christoph, Am 23.05.2017 um 10:37 schrieb Christoph Hellwig: > On Sun, May 21, 2017 at 10:20:49PM +0200, Richard Weinberger wrote: >> The new feature UBIFS_FLG_PARENTPOINTER allows looking >> up the parent. Usually the Linux VFS walks down the filesystem >> and no parent pointers are needed. But when a filesystem >> is exportable via NFS such a lookup is needed. >> We can use a padding field in struct ubifs_ino_node to >> maintain a pointer to the parent inode. > > Note that nfsd/exportfs will only do this for directories, and beacause > we hardlinks for other objects that is an important distinction. > > I think the ubifs code should make sure to only maintain the parent > pointers for directories, otherwise confusion and abuses will happen. Thanks for the info, I'll massage the code in that direction. Thanks, //richard
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index e79b529df9c3..a6eadb52a1a8 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -171,6 +171,7 @@ struct inode *ubifs_new_inode(struct ubifs_info *c, struct inode *dir, } inode->i_ino = ++c->highest_inum; + ui->parent_inum = dir->i_ino; /* * The creation sequence number remains with this inode for its * lifetime. All nodes for this inode have a greater sequence number, @@ -1374,7 +1375,7 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, if (unlink) ubifs_assert(inode_is_locked(new_inode)); - if (old_dir != new_dir) { + if (move) { if (ubifs_crypt_is_encrypted(new_dir) && !fscrypt_has_permitted_context(new_dir, old_inode)) return -EPERM; @@ -1528,8 +1529,12 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, mark_inode_dirty(whiteout); whiteout->i_state &= ~I_LINKABLE; iput(whiteout); + whiteout_ui->parent_inum = new_dir->i_ino; } + if (move) + old_inode_ui->parent_inum = new_dir->i_ino; + err = ubifs_jnl_rename(c, old_dir, old_inode, &old_nm, new_dir, new_inode, &new_nm, whiteout, sync); if (err) @@ -1571,6 +1576,8 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, inc_nlink(old_dir); } } + if (move) + old_inode_ui->parent_inum = old_dir->i_ino; if (whiteout) { drop_nlink(whiteout); iput(whiteout); @@ -1592,6 +1599,8 @@ static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry, int sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir); struct inode *fst_inode = d_inode(old_dentry); struct inode *snd_inode = d_inode(new_dentry); + struct ubifs_inode *fst_inode_ui = ubifs_inode(fst_inode); + struct ubifs_inode *snd_inode_ui = ubifs_inode(snd_inode); struct timespec time; int err; struct fscrypt_name fst_nm, snd_nm; @@ -1623,7 +1632,10 @@ static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry, old_dir->i_mtime = old_dir->i_ctime = time; new_dir->i_mtime = new_dir->i_ctime = time; - if (old_dir != new_dir) { + if (new_dir != old_dir) { + fst_inode_ui->parent_inum = new_dir->i_ino; + snd_inode_ui->parent_inum = old_dir->i_ino; + if (S_ISDIR(fst_inode->i_mode) && !S_ISDIR(snd_inode->i_mode)) { inc_nlink(new_dir); drop_nlink(old_dir); @@ -1637,6 +1649,11 @@ static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry, err = ubifs_jnl_xrename(c, old_dir, fst_inode, &fst_nm, new_dir, snd_inode, &snd_nm, sync); + if (err && new_dir != old_dir) { + fst_inode_ui->parent_inum = old_dir->i_ino; + snd_inode_ui->parent_inum = new_dir->i_ino; + } + unlock_4_inodes(old_dir, new_dir, NULL, NULL); ubifs_release_budget(c, &req); diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c index 294519b98874..8eaf8f2f1fe1 100644 --- a/fs/ubifs/journal.c +++ b/fs/ubifs/journal.c @@ -66,7 +66,6 @@ */ static inline void zero_ino_node_unused(struct ubifs_ino_node *ino) { - memset(ino->padding1, 0, 4); memset(ino->padding2, 0, 26); } @@ -470,6 +469,10 @@ static void pack_inode(struct ubifs_info *c, struct ubifs_ino_node *ino, ino->xattr_cnt = cpu_to_le32(ui->xattr_cnt); ino->xattr_size = cpu_to_le32(ui->xattr_size); ino->xattr_names = cpu_to_le32(ui->xattr_names); + if (c->parent_pointer) + ino->parent_inum = cpu_to_le32(ui->parent_inum); + else + ino->parent_inum = 0; zero_ino_node_unused(ino); /* diff --git a/fs/ubifs/sb.c b/fs/ubifs/sb.c index 8c25081a5109..f2097c47f629 100644 --- a/fs/ubifs/sb.c +++ b/fs/ubifs/sb.c @@ -166,6 +166,7 @@ static int create_default_filesystem(struct ubifs_info *c) if (big_lpt) sup_flags |= UBIFS_FLG_BIGLPT; sup_flags |= UBIFS_FLG_DOUBLE_HASH; + sup_flags |= UBIFS_FLG_PARENTPOINTER; sup->ch.node_type = UBIFS_SB_NODE; sup->key_hash = UBIFS_KEY_HASH_R5; @@ -639,6 +640,7 @@ int ubifs_read_superblock(struct ubifs_info *c) c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP); c->double_hash = !!(sup_flags & UBIFS_FLG_DOUBLE_HASH); c->encrypted = !!(sup_flags & UBIFS_FLG_ENCRYPTION); + c->parent_pointer = !!(sup_flags & UBIFS_FLG_PARENTPOINTER); if ((sup_flags & ~UBIFS_FLG_MASK) != 0) { ubifs_err(c, "Unknown feature flags found: %#x", diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index cf4cc99b75b5..7560071534bf 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -154,6 +154,7 @@ struct inode *ubifs_iget(struct super_block *sb, unsigned long inum) ui->synced_i_size = ui->ui_size = inode->i_size; ui->xattr = (ui->flags & UBIFS_XATTR_FL) ? 1 : 0; + ui->parent_inum = le32_to_cpu(ino->parent_inum); err = validate_inode(c, inode); if (err) diff --git a/fs/ubifs/ubifs-media.h b/fs/ubifs/ubifs-media.h index 5939776c7359..b3cb76cedf20 100644 --- a/fs/ubifs/ubifs-media.h +++ b/fs/ubifs/ubifs-media.h @@ -427,15 +427,21 @@ enum { * UBIFS_FLG_DOUBLE_HASH: store a 32bit cookie in directory entry nodes to * support 64bit cookies for lookups by hash * UBIFS_FLG_ENCRYPTION: this filesystem contains encrypted files + * UBIFS_FLG_PARENTPOINTER: inode nodes maintain a pointer to the parent dir */ enum { UBIFS_FLG_BIGLPT = 0x02, UBIFS_FLG_SPACE_FIXUP = 0x04, UBIFS_FLG_DOUBLE_HASH = 0x08, UBIFS_FLG_ENCRYPTION = 0x10, + UBIFS_FLG_PARENTPOINTER = 0x20, }; -#define UBIFS_FLG_MASK (UBIFS_FLG_BIGLPT|UBIFS_FLG_SPACE_FIXUP|UBIFS_FLG_DOUBLE_HASH|UBIFS_FLG_ENCRYPTION) +#define UBIFS_FLG_MASK (UBIFS_FLG_BIGLPT \ + |UBIFS_FLG_SPACE_FIXUP \ + |UBIFS_FLG_DOUBLE_HASH \ + |UBIFS_FLG_ENCRYPTION \ + |UBIFS_FLG_PARENTPOINTER) /** * struct ubifs_ch - common header node. @@ -494,7 +500,7 @@ union ubifs_dev_desc { * @data_len: inode data length * @xattr_cnt: count of extended attributes this inode has * @xattr_size: summarized size of all extended attributes in bytes - * @padding1: reserved for future, zeroes + * @parent_inum: parent inode number * @xattr_names: sum of lengths of all extended attribute names belonging to * this inode * @compr_type: compression type used for this inode @@ -528,7 +534,7 @@ struct ubifs_ino_node { __le32 data_len; __le32 xattr_cnt; __le32 xattr_size; - __u8 padding1[4]; /* Watch 'zero_ino_node_unused()' if changing! */ + __le32 parent_inum; __le32 xattr_names; __le16 compr_type; __u8 padding2[26]; /* Watch 'zero_ino_node_unused()' if changing! */ diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h index f14dcc890e47..3c64481f4032 100644 --- a/fs/ubifs/ubifs.h +++ b/fs/ubifs/ubifs.h @@ -353,6 +353,7 @@ struct ubifs_gced_idx_leb { * currently stored on the flash; used only for regular file * inodes * @ui_size: inode size used by UBIFS when writing to flash + * @parent_inum: inode number of the parent directory * @flags: inode flags (@UBIFS_COMPR_FL, etc) * @compr_type: default compression type used for this inode * @last_page_read: page number of last page read (for bulk read) @@ -404,6 +405,7 @@ struct ubifs_inode { spinlock_t ui_lock; loff_t synced_i_size; loff_t ui_size; + ino_t parent_inum; int flags; pgoff_t last_page_read; pgoff_t read_in_a_row; @@ -1012,6 +1014,7 @@ struct ubifs_debug_info; * @space_fixup: flag indicating that free space in LEBs needs to be cleaned up * @double_hash: flag indicating that we can do lookups by hash * @encrypted: flag indicating that this file system contains encrypted files + * @parent_pointer: flag indicating that inodes have pointers to the parent dir * @no_chk_data_crc: do not check CRCs when reading data nodes (except during * recovery) * @bulk_read: enable bulk-reads @@ -1255,6 +1258,7 @@ struct ubifs_info { unsigned int space_fixup:1; unsigned int double_hash:1; unsigned int encrypted:1; + unsigned int parent_pointer:1; unsigned int no_chk_data_crc:1; unsigned int bulk_read:1; unsigned int default_compr:2;
The new feature UBIFS_FLG_PARENTPOINTER allows looking up the parent. Usually the Linux VFS walks down the filesystem and no parent pointers are needed. But when a filesystem is exportable via NFS such a lookup is needed. We can use a padding field in struct ubifs_ino_node to maintain a pointer to the parent inode. Signed-off-by: Richard Weinberger <richard@nod.at> --- fs/ubifs/dir.c | 21 +++++++++++++++++++-- fs/ubifs/journal.c | 5 ++++- fs/ubifs/sb.c | 2 ++ fs/ubifs/super.c | 1 + fs/ubifs/ubifs-media.h | 12 +++++++++--- fs/ubifs/ubifs.h | 4 ++++ 6 files changed, 39 insertions(+), 6 deletions(-)