[PATCH 5/17] [LogFS] dir.c

Joern Engel
2009-11-20T20:22:17Z

---
fs/logfs/dir.c | 818 +++++++++++++

diff --git a/fs/logfs/dir.c b/fs/logfs/dir.c
new file mode 100644
index 0000000..89104e6
--- /dev/null
+++ b/fs/logfs/dir.c
@@ -0,0 +1,818 @@
+/*
+ * fs/logfs/dir.c - directory-related code
+ *
+ * As should be obvious for Linux kernel code, license is GPLv2
+ *
+ * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org>
+ */
+#include "logfs.h"
+
+
+/*
+ * Atomic dir operations
+ *
+ * Directory operations are by default not atomic. Dentries and Inodes are
+ * created/removed/altered in seperate operations. Therefore we need to do
+ * a small amount of journaling.
+ *
+ * Create, link, mkdir, mknod and symlink all share the same function to do
+ * the work: __logfs_create. This function works in two atomic steps:
+ * 1. allocate inode (remember in journal)
+ * 2. allocate dentry (clear journal)
+ *
+ * As we can only get interrupted between the two, when the inode we just
+ * created is simply stored in the anchor. On next mount, if we were
+ * interrupted, we delete the inode. From a users point of view the
+ * operation never happened.
+ *
+ * Unlink and rmdir also share the same function: unlink. Again, this
+ * function works in two atomic steps
+ * 1. remove dentry (remember inode in journal)
+ * 2. unlink inode (clear journal)
+ *
+ * And again, on the next mount, if we were interrupted, we delete the inode.
+ * From a users point of view the operation succeeded.
+ *
+ * Rename is the real pain to deal with, harder than all the other methods
+ * combined. Depending on the circumstances we can run into three cases.
+ * A "target rename" where the target dentry already existed, a "local
+ * rename" where both parent directories are identical or a "cross-directory
+ * rename" in the remaining case.
+ *
+ * Local rename is atomic, as the old dentry is simply rewritten with a new
+ * name.
+ *
+ * Cross-directory rename works in two steps, similar to __logfs_create and
+ * logfs_unlink:
+ * 1. Write new dentry (remember old dentry in journal)
+ * 2. Remove old dentry (clear journal)
+ *
+ * Here we remember a dentry instead of an inode. On next mount, if we were
+ * interrupted, we delete the dentry. From a users point of view, the
+ * operation succeeded.
+ *
+ * Target rename works in three atomic steps:
+ * 1. Attach old inode to new dentry (remember old dentry and new inode)
+ * 2. Remove old dentry (still remember the new inode)
+ * 3. Remove victim inode
+ *
+ * Here we remember both an inode an a dentry. If we get interrupted
+ * between steps 1 and 2, we delete both the dentry and the inode. If
+ * we get interrupted between steps 2 and 3, we delete just the inode.
+ * In either case, the remaining objects are deleted on next mount. From
+ * a users point of view, the operation succeeded.
+ */
+
+static int write_dir(struct inode *dir, struct logfs_disk_dentry *dd,
+ loff_t pos)
+{
+ return logfs_inode_write(dir, dd, sizeof(*dd), pos, WF_LOCK, NULL);
+}
+
+static int write_inode(struct inode *inode)
+{
+ return __logfs_write_inode(inode, WF_LOCK);
+}
+
+static s64 dir_seek_data(struct inode *inode, s64 pos)
+{
+ s64 new_pos = logfs_seek_data(inode, pos);
+
+ return max(pos, new_pos - 1);
+}
+
+static int beyond_eof(struct inode *inode, loff_t bix)
+{
+ loff_t pos = bix << inode->i_sb->s_blocksize_bits;
+ return pos >= i_size_read(inode);
+}
+
+/*
+ * Prime value was chosen to be roughly 256 + 26. r5 hash uses 11,
+ * so short names (len <= 9) don't even occupy the complete 32bit name
+ * space. A prime >256 ensures short names quickly spread the 32bit
+ * name space. Add about 26 for the estimated amount of information
+ * of each character and pick a prime nearby, preferrably a bit-sparse
+ * one.
+ */
+static u32 hash_32(const char *s, int len, u32 seed)
+{
+ u32 hash = seed;
+ int i;
+
+ for (i = 0; i < len; i++)
+ hash = hash * 293 + s[i];
+ return hash;
+}
+
+/*
+ * We have to satisfy several conflicting requirements here. Small
+ * directories should stay fairly compact and not require too many
+ * indirect blocks. The number of possible locations for a given hash
+ * should be small to make lookup() fast. And we should try hard not
+ * to overflow the 32bit name space or nfs and 32bit host systems will
+ * be unhappy.
+ *
+ * So we use the following scheme. First we reduce the hash to 0..15
+ * and try a direct block. If that is occupied we reduce the hash to
+ * 16..255 and try an indirect block. Same for 2x and 3x indirect
+ * blocks. Lastly we reduce the hash to 0x800_0000 .. 0xffff_ffff,
+ * but use buckets containing eight entries instead of a single one.
+ *
+ * Using 16 entries should allow for a reasonable amount of hash
+ * collisions, so the 32bit name space can be packed fairly tight
+ * before overflowing. Oh and currently we don't overflow but return
+ * and error.
+ *
+ * How likely are collisions? Doing the appropriate math is beyond me
+ * and the Bronstein textbook. But running a test program to brute
+ * force collisions for a couple of days showed that on average the
+ * first collision occurs after 598M entries, with 290M being the
+ * smallest result. Obviously 21 entries could already cause a
+ * collision if all entries are carefully chosen.
+ */
+static pgoff_t hash_index(u32 hash, int round)
+{
+ switch (round) {
+ case 0:
+ return hash % I0_BLOCKS;
+ case 1:
+ return I0_BLOCKS + hash % (I1_BLOCKS - I0_BLOCKS);
+ case 2:
+ return I1_BLOCKS + hash % (I2_BLOCKS - I1_BLOCKS);
+ case 3:
+ return I2_BLOCKS + hash % (I3_BLOCKS - I2_BLOCKS);
+ case 4 ... 19:
+ return I3_BLOCKS + 16 * (hash % (((1<<31) - I3_BLOCKS) / 16))
+ + round - 4;
+ }
+ BUG();
+}
+
+static struct page *logfs_get_dd_page(struct inode *dir, struct dentry *dentry)
+{
+ struct qstr *name = &dentry->d_name;
+ struct page *page;
+ struct logfs_disk_dentry *dd;
+ u32 hash = hash_32(name->name, name->len, 0);
+ pgoff_t index;
+ int round;
+
+ if (name->len > LOGFS_MAX_NAMELEN)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ for (round = 0; round < 20; round++) {
+ index = hash_index(hash, round);
+
+ if (beyond_eof(dir, index))
+ return NULL;
+ if (!logfs_exist_block(dir, index))
+ continue;
+ page = read_cache_page(dir->i_mapping, index,
+ (filler_t *)logfs_readpage, NULL);
+ if (IS_ERR(page))
+ return page;
+ dd = kmap_atomic(page, KM_USER0);
+ BUG_ON(dd->namelen == 0);
+
+ if (name->len != be16_to_cpu(dd->namelen) ||
+ memcmp(name->name, dd->name, name->len)) {
+ kunmap_atomic(dd, KM_USER0);
+ page_cache_release(page);
+ continue;
+ }
+
+ kunmap_atomic(dd, KM_USER0);
+ return page;
+ }
+ return NULL;
+}
+
+static int logfs_remove_inode(struct inode *inode)
+{
+ int ret;
+
+ inode->i_nlink--;
+ ret = write_inode(inode);
+ LOGFS_BUG_ON(ret, inode->i_sb);
+ return ret;
+}
+
+static void abort_transaction(struct inode *inode, struct logfs_transaction *ta)
+{
+ if (logfs_inode(inode)->li_block)
+ logfs_inode(inode)->li_block->ta = NULL;
+ kfree(ta);
+}
+
+static int logfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+ struct logfs_super *super = logfs_super(dir->i_sb);
+ struct inode *inode = dentry->d_inode;
+ struct logfs_transaction *ta;
+ struct page *page;
+ pgoff_t index;
+ int ret;
+
+ ta = kzalloc(sizeof(*ta), GFP_KERNEL);
+ if (!ta)
+ return -ENOMEM;
+
+ ta->state = UNLINK_1;
+ ta->ino = inode->i_ino;
+
+ inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+
+ page = logfs_get_dd_page(dir, dentry);
+ if (!page)
+ return -ENOENT;
+ if (IS_ERR(page))
+ return PTR_ERR(page);
+ index = page->index;
+ page_cache_release(page);
+
+ mutex_lock(&super->s_dirop_mutex);
+ logfs_add_transaction(dir, ta);
+
+ ret = logfs_delete(dir, index, NULL);
+ if (!ret)
+ ret = write_inode(dir);
+
+ if (ret) {
+ abort_transaction(dir, ta);
+ printk(KERN_ERR"LOGFS: unable to delete inode\n");
+ goto out;
+ }
+
+ ta->state = UNLINK_2;
+ logfs_add_transaction(inode, ta);
+ ret = logfs_remove_inode(inode);
+out:
+ mutex_unlock(&super->s_dirop_mutex);
+ return ret;
+}
+
+static inline int logfs_empty_dir(struct inode *dir)
+{
+ u64 data;
+
+ data = logfs_seek_data(dir, 0) << dir->i_sb->s_blocksize_bits;
+ return data >= i_size_read(dir);
+}
+
+static int logfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+ struct inode *inode = dentry->d_inode;
+
+ if (!logfs_empty_dir(inode))
+ return -ENOTEMPTY;
+
+ return logfs_unlink(dir, dentry);
+}
+
+/* FIXME: readdir currently has it's own dir_walk code. I don't see a good
+ * way to combine the two copies */
+#define IMPLICIT_NODES 2
+static int __logfs_readdir(struct file *file, void *buf, filldir_t filldir)
+{
+ struct inode *dir = file->f_dentry->d_inode;
+ loff_t pos = file->f_pos - IMPLICIT_NODES;
+ struct page *page;
+ struct logfs_disk_dentry *dd;
+ int full;
+
+ BUG_ON(pos < 0);
+ for (;; pos++) {
+ if (beyond_eof(dir, pos))
+ break;
+ if (!logfs_exist_block(dir, pos)) {
+ /* deleted dentry */
+ pos = dir_seek_data(dir, pos);
+ continue;
+ }
+ page = read_cache_page(dir->i_mapping, pos,
+ (filler_t *)logfs_readpage, NULL);
+ if (IS_ERR(page))
+ return PTR_ERR(page);
+ dd = kmap_atomic(page, KM_USER0);
+ BUG_ON(dd->namelen == 0);
+
+ full = filldir(buf, (char *)dd->name, be16_to_cpu(dd->namelen),
+ pos, be64_to_cpu(dd->ino), dd->type);
+ kunmap_atomic(dd, KM_USER0);
+ page_cache_release(page);
+ if (full)
+ break;
+ }
+
+ file->f_pos = pos + IMPLICIT_NODES;
+ return 0;
+}
+
+static int logfs_readdir(struct file *file, void *buf, filldir_t filldir)
+{
+ struct inode *inode = file->f_dentry->d_inode;
+ ino_t pino = parent_ino(file->f_dentry);
+ int err;
+
+ if (file->f_pos < 0)
+ return -EINVAL;
+
+ if (file->f_pos == 0) {
+ if (filldir(buf, ".", 1, 1, inode->i_ino, DT_DIR) < 0)
+ return 0;
+ file->f_pos++;
+ }
+ if (file->f_pos == 1) {
+ if (filldir(buf, "..", 2, 2, pino, DT_DIR) < 0)
+ return 0;
+ file->f_pos++;
+ }
+
+ err = __logfs_readdir(file, buf, filldir);
+ return err;
+}
+
+static void logfs_set_name(struct logfs_disk_dentry *dd, struct qstr *name)
+{
+ dd->namelen = cpu_to_be16(name->len);
+ memcpy(dd->name, name->name, name->len);
+}
+
+static struct dentry *logfs_lookup(struct inode *dir, struct dentry *dentry,
+ struct nameidata *nd)
+{
+ struct page *page;
+ struct logfs_disk_dentry *dd;
+ pgoff_t index;
+ u64 ino = 0;
+ struct inode *inode;
+
+ page = logfs_get_dd_page(dir, dentry);
+ if (IS_ERR(page))
+ return ERR_CAST(page);
+ if (!page) {
+ d_add(dentry, NULL);
+ return NULL;
+ }
+ index = page->index;
+ dd = kmap_atomic(page, KM_USER0);
+ ino = be64_to_cpu(dd->ino);
+ kunmap_atomic(dd, KM_USER0);
+ page_cache_release(page);
+
+ inode = logfs_iget(dir->i_sb, ino);
+ if (IS_ERR(inode)) {
+ printk(KERN_ERR"LogFS: Cannot read inode #%llx for dentry (%lx, %lx)n",
+ ino, dir->i_ino, index);
+ return ERR_CAST(inode);
+ }
+ return d_splice_alias(inode, dentry);
+}
+
+static void grow_dir(struct inode *dir, loff_t index)
+{
+ index = (index + 1) << dir->i_sb->s_blocksize_bits;
+ if (i_size_read(dir) < index)
+ i_size_write(dir, index);
+}
+
+static int logfs_write_dir(struct inode *dir, struct dentry *dentry,
+ struct inode *inode)
+{
+ struct page *page;
+ struct logfs_disk_dentry *dd;
+ u32 hash = hash_32(dentry->d_name.name, dentry->d_name.len, 0);
+ pgoff_t index;
+ int round, err;
+
+ for (round = 0; round < 20; round++) {
+ index = hash_index(hash, round);
+
+ if (logfs_exist_block(dir, index))
+ continue;
+ page = find_or_create_page(dir->i_mapping, index, GFP_KERNEL);
+ if (!page)
+ return -ENOMEM;
+
+ dd = kmap_atomic(page, KM_USER0);
+ memset(dd, 0, sizeof(*dd));
+ dd->ino = cpu_to_be64(inode->i_ino);
+ dd->type = logfs_type(inode);
+ logfs_set_name(dd, &dentry->d_name);
+ kunmap_atomic(dd, KM_USER0);
+
+ err = logfs_write_buf(dir, page, WF_LOCK);
+ unlock_page(page);
+ page_cache_release(page);
+ if (!err)
+ grow_dir(dir, index);
+ return err;
+ }
+ /* FIXME: Is there a better return value? In most cases neither
+ * the filesystem nor the directory are full. But we have had
+ * too many collisions for this particular hash and no fallback.
+ */
+ return -ENOSPC;
+}
+
+static int __logfs_create(struct inode *dir, struct dentry *dentry,
+ struct inode *inode, const char *dest, long destlen)
+{
+ struct logfs_super *super = logfs_super(dir->i_sb);
+ struct logfs_inode *li = logfs_inode(inode);
+ struct logfs_transaction *ta;
+ int ret;
+
+ ta = kzalloc(sizeof(*ta), GFP_KERNEL);
+ if (!ta)
+ return -ENOMEM;
+
+ ta->state = CREATE_1;
+ ta->ino = inode->i_ino;
+ mutex_lock(&super->s_dirop_mutex);
+ logfs_add_transaction(inode, ta);
+
+ if (dest) {
+ /* symlink */
+ ret = logfs_inode_write(inode, dest, destlen, 0, WF_LOCK, NULL);
+ if (!ret)
+ ret = write_inode(inode);
+ } else {
+ /* creat/mkdir/mknod */
+ ret = write_inode(inode);
+ }
+ if (ret) {
+ abort_transaction(inode, ta);
+ li->li_flags |= LOGFS_IF_STILLBORN;
+ /* FIXME: truncate symlink */
+ inode->i_nlink--;
+ iput(inode);
+ goto out;
+ }
+
+ ta->state = CREATE_2;
+ logfs_add_transaction(dir, ta);
+ ret = logfs_write_dir(dir, dentry, inode);
+ /* sync directory */
+ if (!ret)
+ ret = write_inode(dir);
+
+ if (ret) {
+ logfs_del_transaction(dir, ta);
+ ta->state = CREATE_2;
+ logfs_add_transaction(inode, ta);
+ logfs_remove_inode(inode);
+ iput(inode);
+ goto out;
+ }
+ d_instantiate(dentry, inode);
+out:
+ mutex_unlock(&super->s_dirop_mutex);
+ return ret;
+}
+
+static int logfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+ struct inode *inode;
+
+ /*
+ * FIXME: why do we have to fill in S_IFDIR, while the mode is
+ * correct for mknod, creat, etc.? Smells like the vfs *should*
+ * do it for us but for some reason fails to do so.
+ */
+ inode = logfs_new_inode(dir, S_IFDIR | mode);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ inode->i_op = &logfs_dir_iops;
+ inode->i_fop = &logfs_dir_fops;
+
+ return __logfs_create(dir, dentry, inode, NULL, 0);
+}
+
+static int logfs_create(struct inode *dir, struct dentry *dentry, int mode,
+ struct nameidata *nd)
+{
+ struct inode *inode;
+
+ inode = logfs_new_inode(dir, mode);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ inode->i_op = &logfs_reg_iops;
+ inode->i_fop = &logfs_reg_fops;
+ inode->i_mapping->a_ops = &logfs_reg_aops;
+
+ return __logfs_create(dir, dentry, inode, NULL, 0);
+}
+
+static int logfs_mknod(struct inode *dir, struct dentry *dentry, int mode,
+ dev_t rdev)
+{
+ struct inode *inode;
+
+ if (dentry->d_name.len > LOGFS_MAX_NAMELEN)
+ return -ENAMETOOLONG;
+
+ inode = logfs_new_inode(dir, mode);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ init_special_inode(inode, mode, rdev);
+
+ return __logfs_create(dir, dentry, inode, NULL, 0);
+}
+
+static int logfs_symlink(struct inode *dir, struct dentry *dentry,
+ const char *target)
+{
+ struct inode *inode;
+ size_t destlen = strlen(target) + 1;
+
+ if (destlen > dir->i_sb->s_blocksize)
+ return -ENAMETOOLONG;
+
+ inode = logfs_new_inode(dir, S_IFLNK | 0777);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ inode->i_op = &logfs_symlink_iops;
+ inode->i_mapping->a_ops = &logfs_reg_aops;
+
+ return __logfs_create(dir, dentry, inode, target, destlen);
+}
+
+static int logfs_permission(struct inode *inode, int mask)
+{
+ return generic_permission(inode, mask, NULL);
+}
+
+static int logfs_link(struct dentry *old_dentry, struct inode *dir,
+ struct dentry *dentry)
+{
+ struct inode *inode = old_dentry->d_inode;
+
+ if (inode->i_nlink >= LOGFS_LINK_MAX)
+ return -EMLINK;
+
+ inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+ atomic_inc(&inode->i_count);
+ inode->i_nlink++;
+ mark_inode_dirty_sync(inode);
+
+ return __logfs_create(dir, dentry, inode, NULL, 0);
+}
+
+static int logfs_get_dd(struct inode *dir, struct dentry *dentry,
+ struct logfs_disk_dentry *dd, loff_t *pos)
+{
+ struct page *page;
+ void *map;
+
+ page = logfs_get_dd_page(dir, dentry);
+ if (IS_ERR(page))
+ return PTR_ERR(page);
+ *pos = page->index;
+ map = kmap_atomic(page, KM_USER0);
+ memcpy(dd, map, sizeof(*dd));
+ kunmap_atomic(map, KM_USER0);
+ page_cache_release(page);
+ return 0;
+}
+
+static int logfs_delete_dd(struct inode *dir, loff_t pos)
+{
+ /*
+ * Getting called with pos somewhere beyond eof is either a goofup
+ * within this file or means someone maliciously edited the
+ * (crc-protected) journal.
+ */
+ BUG_ON(beyond_eof(dir, pos));
+ dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+ log_dir(" Delete dentry (%lx, %llx)\n", dir->i_ino, pos);
+ return logfs_delete(dir, pos, NULL);
+}
+
+/*
+ * Cross-directory rename, target does not exist. Just a little nasty.
+ * Create a new dentry in the target dir, then remove the old dentry,
+ * all the while taking care to remember our operation in the journal.
+ */
+static int logfs_rename_cross(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry)
+{
+ struct logfs_super *super = logfs_super(old_dir->i_sb);
+ struct logfs_disk_dentry dd;
+ struct logfs_transaction *ta;
+ loff_t pos;
+ int err;
+
+ /* 1. locate source dd */
+ err = logfs_get_dd(old_dir, old_dentry, &dd, &pos);
+ if (err)
+ return err;
+
+ ta = kzalloc(sizeof(*ta), GFP_KERNEL);
+ if (!ta)
+ return -ENOMEM;
+
+ ta->state = CROSS_RENAME_1;
+ ta->dir = old_dir->i_ino;
+ ta->pos = pos;
+
+ /* 2. write target dd */
+ mutex_lock(&super->s_dirop_mutex);
+ logfs_add_transaction(new_dir, ta);
+ err = logfs_write_dir(new_dir, new_dentry, old_dentry->d_inode);
+ if (!err)
+ err = write_inode(new_dir);
+
+ if (err) {
+ super->s_rename_dir = 0;
+ super->s_rename_pos = 0;
+ abort_transaction(new_dir, ta);
+ goto out;
+ }
+
+ /* 3. remove source dd */
+ ta->state = CROSS_RENAME_2;
+ logfs_add_transaction(old_dir, ta);
+ err = logfs_delete_dd(old_dir, pos);
+ if (!err)
+ err = write_inode(old_dir);
+ LOGFS_BUG_ON(err, old_dir->i_sb);
+out:
+ mutex_unlock(&super->s_dirop_mutex);
+ return err;
+}
+
+static int logfs_replace_inode(struct inode *dir, struct dentry *dentry,
+ struct logfs_disk_dentry *dd, struct inode *inode)
+{
+ loff_t pos;
+ int err;
+
+ err = logfs_get_dd(dir, dentry, dd, &pos);
+ if (err)
+ return err;
+ dd->ino = cpu_to_be64(inode->i_ino);
+ dd->type = logfs_type(inode);
+
+ err = write_dir(dir, dd, pos);
+ if (err)
+ return err;
+ log_dir("Replace dentry (%lx, %llx) %s -> %llx\n", dir->i_ino, pos,
+ dd->name, be64_to_cpu(dd->ino));
+ return write_inode(dir);
+}
+
+/* Target dentry exists - the worst case. We need to attach the source
+ * inode to the target dentry, then remove the orphaned target inode and
+ * source dentry.
+ */
+static int logfs_rename_target(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry)
+{
+ struct logfs_super *super = logfs_super(old_dir->i_sb);
+ struct inode *old_inode = old_dentry->d_inode;
+ struct inode *new_inode = new_dentry->d_inode;
+ int isdir = S_ISDIR(old_inode->i_mode);
+ struct logfs_disk_dentry dd;
+ struct logfs_transaction *ta;
+ loff_t pos;
+ int err;
+
+ BUG_ON(isdir != S_ISDIR(new_inode->i_mode));
+ if (isdir) {
+ if (!logfs_empty_dir(new_inode))
+ return -ENOTEMPTY;
+ }
+
+ /* 1. locate source dd */
+ err = logfs_get_dd(old_dir, old_dentry, &dd, &pos);
+ if (err)
+ return err;
+
+ ta = kzalloc(sizeof(*ta), GFP_KERNEL);
+ if (!ta)
+ return -ENOMEM;
+
+ ta->state = TARGET_RENAME_1;
+ ta->dir = old_dir->i_ino;
+ ta->pos = pos;
+ ta->ino = new_inode->i_ino;
+
+ /* 2. attach source inode to target dd */
+ mutex_lock(&super->s_dirop_mutex);
+ logfs_add_transaction(new_dir, ta);
+ err = logfs_replace_inode(new_dir, new_dentry, &dd, old_inode);
+ if (err) {
+ super->s_rename_dir = 0;
+ super->s_rename_pos = 0;
+ super->s_victim_ino = 0;
+ abort_transaction(new_dir, ta);
+ goto out;
+ }
+
+ /* 3. remove source dd */
+ ta->state = TARGET_RENAME_2;
+ logfs_add_transaction(old_dir, ta);
+ err = logfs_delete_dd(old_dir, pos);
+ if (!err)
+ err = write_inode(old_dir);
+ LOGFS_BUG_ON(err, old_dir->i_sb);
+
+ /* 4. remove target inode */
+ ta->state = TARGET_RENAME_3;
+ logfs_add_transaction(new_inode, ta);
+ err = logfs_remove_inode(new_inode);
+
+out:
+ mutex_unlock(&super->s_dirop_mutex);
+ return err;
+}
+
+static int logfs_rename(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry)
+{
+ if (new_dentry->d_inode)
+ return logfs_rename_target(old_dir, old_dentry,
+ new_dir, new_dentry);
+ return logfs_rename_cross(old_dir, old_dentry, new_dir, new_dentry);
+}
+
+/* No locking done here, as this is called before .get_sb() returns. */
+int logfs_replay_journal(struct super_block *sb)
+{
+ struct logfs_super *super = logfs_super(sb);
+ struct inode *inode;
+ u64 ino, pos;
+ int err;
+
+ if (super->s_victim_ino) {
+ /* delete victim inode */
+ ino = super->s_victim_ino;
+ printk(KERN_INFO"LogFS: delete unmapped inode #%llx\n", ino);
+ inode = logfs_iget(sb, ino);
+ if (IS_ERR(inode))
+ goto fail;
+
+ LOGFS_BUG_ON(i_size_read(inode) > 0, sb);
+ super->s_victim_ino = 0;
+ err = logfs_remove_inode(inode);
+ iput(inode);
+ if (err) {
+ super->s_victim_ino = ino;
+ goto fail;
+ }
+ }
+ if (super->s_rename_dir) {
+ /* delete old dd from rename */
+ ino = super->s_rename_dir;
+ pos = super->s_rename_pos;
+ printk(KERN_INFO"LogFS: delete unbacked dentry (%llx, %llx)\n",
+ ino, pos);
+ inode = logfs_iget(sb, ino);
+ if (IS_ERR(inode))
+ goto fail;
+
+ super->s_rename_dir = 0;
+ super->s_rename_pos = 0;
+ err = logfs_delete_dd(inode, pos);
+ iput(inode);
+ if (err) {
+ super->s_rename_dir = ino;
+ super->s_rename_pos = pos;
+ goto fail;
+ }
+ }
+ return 0;
+fail:
+ LOGFS_BUG(sb);
+ return -EIO;
+}
+
+const struct inode_operations logfs_symlink_iops = {
+ .readlink = generic_readlink,
+ .follow_link = page_follow_link_light,
+};
+
+const struct inode_operations logfs_dir_iops = {
+ .create = logfs_create,
+ .link = logfs_link,
+ .lookup = logfs_lookup,
+ .mkdir = logfs_mkdir,
+ .mknod = logfs_mknod,
+ .rename = logfs_rename,
+ .rmdir = logfs_rmdir,
+ .permission = logfs_permission,
+ .symlink = logfs_symlink,
+ .unlink = logfs_unlink,
+};
+const struct file_operations logfs_dir_fops = {
+ .fsync = logfs_fsync,
+ .ioctl = logfs_ioctl,
+ .readdir = logfs_readdir,
+ .read = generic_read_dir,
+};