diff options
author | Evgeniy Polyakov <zbr@ioremap.net> | 2009-02-09 14:02:37 (GMT) |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-04-03 21:53:34 (GMT) |
commit | e3eec94dc91c39f2bd7939294b9cd4a65a82db44 (patch) | |
tree | 134242bfe68b79fae0126b2e37ff99034b4947b1 /drivers/staging/pohmelfs | |
parent | e2396ae53361340d945dd2a928173049f31fb1eb (diff) | |
download | linux-fsl-qoriq-e3eec94dc91c39f2bd7939294b9cd4a65a82db44.tar.xz |
Staging: pohmelfs: directory operations.
This patch implementes all supported directory operations
like directory reading, object lookup, creation, removal
and so on.
Currently object removal is not optimized at all.
Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/staging/pohmelfs')
-rw-r--r-- | drivers/staging/pohmelfs/dir.c | 1093 | ||||
-rw-r--r-- | drivers/staging/pohmelfs/path_entry.c | 114 |
2 files changed, 1207 insertions, 0 deletions
diff --git a/drivers/staging/pohmelfs/dir.c b/drivers/staging/pohmelfs/dir.c new file mode 100644 index 0000000..7a41183 --- /dev/null +++ b/drivers/staging/pohmelfs/dir.c @@ -0,0 +1,1093 @@ +/* + * 2007+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net> + * All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/kernel.h> +#include <linux/fs.h> +#include <linux/jhash.h> +#include <linux/namei.h> +#include <linux/pagemap.h> + +#include "netfs.h" + +static int pohmelfs_cmp_hash(struct pohmelfs_name *n, u32 hash) +{ + if (n->hash > hash) + return -1; + if (n->hash < hash) + return 1; + + return 0; +} + +static struct pohmelfs_name *pohmelfs_search_hash_unprecise(struct pohmelfs_inode *pi, u32 hash) +{ + struct rb_node *n = pi->hash_root.rb_node; + struct pohmelfs_name *tmp = NULL; + int cmp; + + while (n) { + tmp = rb_entry(n, struct pohmelfs_name, hash_node); + + cmp = pohmelfs_cmp_hash(tmp, hash); + if (cmp < 0) + n = n->rb_left; + else if (cmp > 0) + n = n->rb_right; + else + break; + + } + + return tmp; +} + +struct pohmelfs_name *pohmelfs_search_hash(struct pohmelfs_inode *pi, u32 hash) +{ + struct pohmelfs_name *tmp; + + tmp = pohmelfs_search_hash_unprecise(pi, hash); + if (tmp && (tmp->hash == hash)) + return tmp; + + return NULL; +} + +static void __pohmelfs_name_del(struct pohmelfs_inode *parent, struct pohmelfs_name *node) +{ + rb_erase(&node->hash_node, &parent->hash_root); +} + +/* + * Remove name cache entry from its caches and free it. + */ +static void pohmelfs_name_free(struct pohmelfs_inode *parent, struct pohmelfs_name *node) +{ + __pohmelfs_name_del(parent, node); + list_del(&node->sync_create_entry); + kfree(node); +} + +static struct pohmelfs_name *pohmelfs_insert_hash(struct pohmelfs_inode *pi, + struct pohmelfs_name *new) +{ + struct rb_node **n = &pi->hash_root.rb_node, *parent = NULL; + struct pohmelfs_name *ret = NULL, *tmp; + int cmp; + + while (*n) { + parent = *n; + + tmp = rb_entry(parent, struct pohmelfs_name, hash_node); + + cmp = pohmelfs_cmp_hash(tmp, new->hash); + if (cmp < 0) + n = &parent->rb_left; + else if (cmp > 0) + n = &parent->rb_right; + else { + ret = tmp; + break; + } + } + + if (ret) { + printk("%s: exist: parent: %llu, ino: %llu, hash: %x, len: %u, data: '%s', " + "new: ino: %llu, hash: %x, len: %u, data: '%s'.\n", + __func__, pi->ino, + ret->ino, ret->hash, ret->len, ret->data, + new->ino, new->hash, new->len, new->data); + ret->ino = new->ino; + return ret; + } + + rb_link_node(&new->hash_node, parent, n); + rb_insert_color(&new->hash_node, &pi->hash_root); + + return NULL; +} + +/* + * Free name cache for given inode. + */ +void pohmelfs_free_names(struct pohmelfs_inode *parent) +{ + struct rb_node *rb_node; + struct pohmelfs_name *n; + + for (rb_node = rb_first(&parent->hash_root); rb_node;) { + n = rb_entry(rb_node, struct pohmelfs_name, hash_node); + rb_node = rb_next(rb_node); + + pohmelfs_name_free(parent, n); + } +} + +static void pohmelfs_fix_offset(struct pohmelfs_inode *parent, struct pohmelfs_name *node) +{ + parent->total_len -= node->len; +} + +/* + * Free name cache entry helper. + */ +void pohmelfs_name_del(struct pohmelfs_inode *parent, struct pohmelfs_name *node) +{ + pohmelfs_fix_offset(parent, node); + pohmelfs_name_free(parent, node); +} + +/* + * Insert new name cache entry into all hash cache. + */ +static int pohmelfs_insert_name(struct pohmelfs_inode *parent, struct pohmelfs_name *n) +{ + struct pohmelfs_name *name; + + name = pohmelfs_insert_hash(parent, n); + if (name) + return -EEXIST; + + parent->total_len += n->len; + list_add_tail(&n->sync_create_entry, &parent->sync_create_list); + + return 0; +} + +/* + * Allocate new name cache entry. + */ +static struct pohmelfs_name *pohmelfs_name_alloc(unsigned int len) +{ + struct pohmelfs_name *n; + + n = kzalloc(sizeof(struct pohmelfs_name) + len, GFP_KERNEL); + if (!n) + return NULL; + + INIT_LIST_HEAD(&n->sync_create_entry); + + n->data = (char *)(n+1); + + return n; +} + +/* + * Add new name entry into directory's cache. + */ +static int pohmelfs_add_dir(struct pohmelfs_sb *psb, struct pohmelfs_inode *parent, + struct pohmelfs_inode *npi, struct qstr *str, unsigned int mode, int link) +{ + int err = -ENOMEM; + struct pohmelfs_name *n; + + n = pohmelfs_name_alloc(str->len + 1); + if (!n) + goto err_out_exit; + + n->ino = npi->ino; + n->mode = mode; + n->len = str->len; + n->hash = str->hash; + sprintf(n->data, "%s", str->name); + + mutex_lock(&parent->offset_lock); + err = pohmelfs_insert_name(parent, n); + mutex_unlock(&parent->offset_lock); + + if (err) { + if (err != -EEXIST) + goto err_out_free; + kfree(n); + } + + return 0; + +err_out_free: + kfree(n); +err_out_exit: + return err; +} + +/* + * Create new inode for given parameters (name, inode info, parent). + * This does not create object on the server, it will be synced there during writeback. + */ +struct pohmelfs_inode *pohmelfs_new_inode(struct pohmelfs_sb *psb, + struct pohmelfs_inode *parent, struct qstr *str, + struct netfs_inode_info *info, int link) +{ + struct inode *new = NULL; + struct pohmelfs_inode *npi; + int err = -EEXIST; + + dprintk("%s: creating inode: parent: %llu, ino: %llu, str: %p.\n", + __func__, (parent)?parent->ino:0, info->ino, str); + + err = -ENOMEM; + new = iget_locked(psb->sb, info->ino); + if (!new) + goto err_out_exit; + + npi = POHMELFS_I(new); + npi->ino = info->ino; + err = 0; + + if (new->i_state & I_NEW) { + dprintk("%s: filling VFS inode: %lu/%llu.\n", + __func__, new->i_ino, info->ino); + pohmelfs_fill_inode(new, info); + + if (S_ISDIR(info->mode)) { + struct qstr s; + + s.name = "."; + s.len = 1; + s.hash = jhash(s.name, s.len, 0); + + err = pohmelfs_add_dir(psb, npi, npi, &s, info->mode, 0); + if (err) + goto err_out_put; + + s.name = ".."; + s.len = 2; + s.hash = jhash(s.name, s.len, 0); + + err = pohmelfs_add_dir(psb, npi, (parent)?parent:npi, &s, + (parent)?parent->vfs_inode.i_mode:npi->vfs_inode.i_mode, 0); + if (err) + goto err_out_put; + } + } + + if (str) { + if (parent) { + err = pohmelfs_add_dir(psb, parent, npi, str, info->mode, link); + + dprintk("%s: %s inserted name: '%s', new_offset: %llu, ino: %llu, parent: %llu.\n", + __func__, (err)?"unsuccessfully":"successfully", + str->name, parent->total_len, info->ino, parent->ino); + + if (err && err != -EEXIST) + goto err_out_put; + } + } + + if (new->i_state & I_NEW) { + if (parent) + mark_inode_dirty(&parent->vfs_inode); + mark_inode_dirty(new); + } + + set_bit(NETFS_INODE_OWNED, &npi->state); + npi->lock_type = POHMELFS_WRITE_LOCK; + unlock_new_inode(new); + + return npi; + +err_out_put: + printk("%s: putting inode: %p, npi: %p, error: %d.\n", __func__, new, npi, err); + iput(new); +err_out_exit: + return ERR_PTR(err); +} + +static int pohmelfs_remote_sync_complete(struct page **pages, unsigned int page_num, + void *private, int err) +{ + struct pohmelfs_inode *pi = private; + struct pohmelfs_sb *psb = POHMELFS_SB(pi->vfs_inode.i_sb); + + dprintk("%s: ino: %llu, err: %d.\n", __func__, pi->ino, err); + + if (err) + pi->error = err; + wake_up(&psb->wait); + pohmelfs_put_inode(pi); + + return err; +} + +/* + * Receive directory content from the server. + * This should be only done for objects, which were not created locally, + * and which were not synced previously. + */ +static int pohmelfs_sync_remote_dir(struct pohmelfs_inode *pi) +{ + struct inode *inode = &pi->vfs_inode; + struct pohmelfs_sb *psb = POHMELFS_SB(inode->i_sb); + long ret = msecs_to_jiffies(25000); + int err; + + dprintk("%s: dir: %llu, state: %lx: remote_synced: %d.\n", + __func__, pi->ino, pi->state, test_bit(NETFS_INODE_REMOTE_SYNCED, &pi->state)); + + if (test_bit(NETFS_INODE_REMOTE_DIR_SYNCED, &pi->state)) + return 0; + + if (!igrab(inode)) { + err = -ENOENT; + goto err_out_exit; + } + + err = pohmelfs_meta_command(pi, NETFS_READDIR, NETFS_TRANS_SINGLE_DST, + pohmelfs_remote_sync_complete, pi, 0); + if (err) + goto err_out_exit; + + pi->error = 0; + ret = wait_event_interruptible_timeout(psb->wait, + test_bit(NETFS_INODE_REMOTE_DIR_SYNCED, &pi->state) || pi->error, ret); + dprintk("%s: awake dir: %llu, ret: %ld, err: %d.\n", __func__, pi->ino, ret, pi->error); + if (ret <= 0) { + err = -ETIMEDOUT; + goto err_out_exit; + } + + if (pi->error) + return pi->error; + + return 0; + +err_out_exit: + clear_bit(NETFS_INODE_REMOTE_SYNCED, &pi->state); + + return err; +} + +static int pohmelfs_dir_open(struct inode *inode, struct file *file) +{ + file->private_data = NULL; + return 0; +} + +/* + * VFS readdir callback. Syncs directory content from server if needed, + * and provides direntry info to the userspace. + */ +static int pohmelfs_readdir(struct file *file, void *dirent, filldir_t filldir) +{ + struct inode *inode = file->f_path.dentry->d_inode; + struct pohmelfs_inode *pi = POHMELFS_I(inode); + struct pohmelfs_name *n; + struct rb_node *rb_node; + int err = 0, mode; + u64 len; + + dprintk("%s: parent: %llu, fpos: %llu, hash: %08lx.\n", + __func__, pi->ino, (u64)file->f_pos, + (unsigned long)file->private_data); + + err = pohmelfs_data_lock(pi, 0, ~0, POHMELFS_READ_LOCK); + if (err) + return err; + + err = pohmelfs_sync_remote_dir(pi); + if (err) + return err; + + if (file->private_data && (file->private_data == (void *)(unsigned long)file->f_pos)) + return 0; + + mutex_lock(&pi->offset_lock); + n = pohmelfs_search_hash_unprecise(pi, (unsigned long)file->private_data); + + while (n) { + mode = (n->mode >> 12) & 15; + + dprintk("%s: offset: %llu, parent ino: %llu, name: '%s', len: %u, ino: %llu, " + "mode: %o/%o, fpos: %llu, hash: %08x.\n", + __func__, file->f_pos, pi->ino, n->data, n->len, + n->ino, n->mode, mode, file->f_pos, n->hash); + + file->private_data = (void *)n->hash; + + len = n->len; + err = filldir(dirent, n->data, n->len, file->f_pos, n->ino, mode); + + if (err < 0) { + dprintk("%s: err: %d.\n", __func__, err); + err = 0; + break; + } + + file->f_pos += len; + + rb_node = rb_next(&n->hash_node); + + if (!rb_node || (rb_node == &n->hash_node)) { + file->private_data = (void *)(unsigned long)file->f_pos; + break; + } + + n = rb_entry(rb_node, struct pohmelfs_name, hash_node); + } + mutex_unlock(&pi->offset_lock); + + return err; +} + +static loff_t pohmelfs_dir_lseek(struct file *file, loff_t offset, int origin) +{ + file->f_pos = offset; + file->private_data = NULL; + return offset; +} + +const struct file_operations pohmelfs_dir_fops = { + .open = pohmelfs_dir_open, + .read = generic_read_dir, + .llseek = pohmelfs_dir_lseek, + .readdir = pohmelfs_readdir, +}; + +/* + * Lookup single object on server. + */ +static int pohmelfs_lookup_single(struct pohmelfs_inode *parent, + struct qstr *str, u64 ino) +{ + struct pohmelfs_sb *psb = POHMELFS_SB(parent->vfs_inode.i_sb); + long ret = msecs_to_jiffies(5000); + int err; + + set_bit(NETFS_COMMAND_PENDING, &parent->state); + err = pohmelfs_meta_command_data(parent, parent->ino, NETFS_LOOKUP, + (char *)str->name, NETFS_TRANS_SINGLE_DST, NULL, NULL, ino); + if (err) + goto err_out_exit; + + err = 0; + ret = wait_event_interruptible_timeout(psb->wait, + !test_bit(NETFS_COMMAND_PENDING, &parent->state), ret); + if (ret == 0) + err = -ETIMEDOUT; + else if (signal_pending(current)) + err = -EINTR; + + if (err) + goto err_out_exit; + + return 0; + +err_out_exit: + clear_bit(NETFS_COMMAND_PENDING, &parent->state); + + printk("%s: failed: parent: %llu, ino: %llu, name: '%s', err: %d.\n", + __func__, parent->ino, ino, str->name, err); + + return err; +} + +/* + * VFS lookup callback. + * We first try to get inode number from local name cache, if we have one, + * then inode can be found in inode cache. If there is no inode or no object in + * local cache, try to lookup it on server. This only should be done for directories, + * which were not created locally, otherwise remote server does not know about dir at all, + * so no need to try to know that. + */ +struct dentry *pohmelfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) +{ + struct pohmelfs_inode *parent = POHMELFS_I(dir); + struct pohmelfs_name *n; + struct inode *inode = NULL; + unsigned long ino = 0; + int err, lock_type = POHMELFS_READ_LOCK, need_lock; + struct qstr str = dentry->d_name; + + if ((nd->intent.open.flags & O_ACCMODE) > 1) + lock_type = POHMELFS_WRITE_LOCK; + + need_lock = pohmelfs_need_lock(parent, lock_type); + + err = pohmelfs_data_lock(parent, 0, ~0, lock_type); + if (err) + goto out; + + str.hash = jhash(dentry->d_name.name, dentry->d_name.len, 0); + + mutex_lock(&parent->offset_lock); + n = pohmelfs_search_hash(parent, str.hash); + if (n) + ino = n->ino; + mutex_unlock(&parent->offset_lock); + + dprintk("%s: 1 ino: %lu, inode: %p, name: '%s', hash: %x, parent_state: %lx.\n", + __func__, ino, inode, str.name, str.hash, parent->state); + + if (ino) { + inode = ilookup(dir->i_sb, ino); + if (inode) + goto out; + } + + dprintk("%s: dir: %p, dir_ino: %llu, name: '%s', len: %u, dir_state: %lx, ino: %lu.\n", + __func__, dir, parent->ino, + str.name, str.len, parent->state, ino); + + if (!ino) { + if (!need_lock) + goto out; + } + + err = pohmelfs_lookup_single(parent, &str, ino); + if (err) + goto out; + + if (!ino) { + mutex_lock(&parent->offset_lock); + n = pohmelfs_search_hash(parent, str.hash); + if (n) + ino = n->ino; + mutex_unlock(&parent->offset_lock); + } + + if (ino) { + inode = ilookup(dir->i_sb, ino); + printk("%s: second lookup ino: %lu, inode: %p, name: '%s', hash: %x.\n", + __func__, ino, inode, str.name, str.hash); + if (!inode) { + printk("%s: No inode for ino: %lu, name: '%s', hash: %x.\n", + __func__, ino, str.name, str.hash); + //return NULL; + return ERR_PTR(-EACCES); + } + } else { + printk("%s: No inode number : name: '%s', hash: %x.\n", + __func__, str.name, str.hash); + } +out: + return d_splice_alias(inode, dentry); +} + +/* + * Create new object in local cache. Object will be synced to server + * during writeback for given inode. + */ +struct pohmelfs_inode *pohmelfs_create_entry_local(struct pohmelfs_sb *psb, + struct pohmelfs_inode *parent, struct qstr *str, u64 start, int mode) +{ + struct pohmelfs_inode *npi; + int err = -ENOMEM; + struct netfs_inode_info info; + + dprintk("%s: name: '%s', mode: %o, start: %llu.\n", + __func__, str->name, mode, start); + + info.mode = mode; + info.ino = start; + + if (!start) + info.ino = pohmelfs_new_ino(psb); + + info.nlink = S_ISDIR(mode)?2:1; + info.uid = current_fsuid(); + info.gid = current_fsgid(); + info.size = 0; + info.blocksize = 512; + info.blocks = 0; + info.rdev = 0; + info.version = 0; + + npi = pohmelfs_new_inode(psb, parent, str, &info, !!start); + if (IS_ERR(npi)) { + err = PTR_ERR(npi); + goto err_out_unlock; + } + + return npi; + +err_out_unlock: + dprintk("%s: err: %d.\n", __func__, err); + return ERR_PTR(err); +} + +/* + * Create local object and bind it to dentry. + */ +static int pohmelfs_create_entry(struct inode *dir, struct dentry *dentry, u64 start, int mode) +{ + struct pohmelfs_sb *psb = POHMELFS_SB(dir->i_sb); + struct pohmelfs_inode *npi, *parent; + struct qstr str = dentry->d_name; + int err; + + parent = POHMELFS_I(dir); + + err = pohmelfs_data_lock(parent, 0, ~0, POHMELFS_WRITE_LOCK); + if (err) + return err; + + str.hash = jhash(dentry->d_name.name, dentry->d_name.len, 0); + + npi = pohmelfs_create_entry_local(psb, parent, &str, start, mode); + if (IS_ERR(npi)) + return PTR_ERR(npi); + + d_instantiate(dentry, &npi->vfs_inode); + + dprintk("%s: parent: %llu, inode: %llu, name: '%s', parent_nlink: %d, nlink: %d.\n", + __func__, parent->ino, npi->ino, dentry->d_name.name, + (signed)dir->i_nlink, (signed)npi->vfs_inode.i_nlink); + + return 0; +} + +/* + * VFS create and mkdir callbacks. + */ +static int pohmelfs_create(struct inode *dir, struct dentry *dentry, int mode, + struct nameidata *nd) +{ + return pohmelfs_create_entry(dir, dentry, 0, mode); +} + +static int pohmelfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) +{ + int err; + + inode_inc_link_count(dir); + err = pohmelfs_create_entry(dir, dentry, 0, mode | S_IFDIR); + if (err) + inode_dec_link_count(dir); + + return err; +} + +static int pohmelfs_remove_entry(struct inode *dir, struct dentry *dentry) +{ + struct pohmelfs_sb *psb = POHMELFS_SB(dir->i_sb); + struct inode *inode = dentry->d_inode; + struct pohmelfs_inode *parent = POHMELFS_I(dir), *pi = POHMELFS_I(inode); + struct pohmelfs_name *n; + int err = -ENOENT; + struct qstr str = dentry->d_name; + + err = pohmelfs_data_lock(parent, 0, ~0, POHMELFS_WRITE_LOCK); + if (err) + return err; + + str.hash = jhash(dentry->d_name.name, dentry->d_name.len, 0); + + dprintk("%s: dir_ino: %llu, inode: %llu, name: '%s', nlink: %d.\n", + __func__, parent->ino, pi->ino, + str.name, (signed)inode->i_nlink); + + BUG_ON(!inode); + + mutex_lock(&parent->offset_lock); + n = pohmelfs_search_hash(parent, str.hash); + if (n) { + pohmelfs_fix_offset(parent, n); + if (test_bit(NETFS_INODE_REMOTE_SYNCED, &pi->state)) { + pohmelfs_remove_child(pi, n); + } + pohmelfs_name_free(parent, n); + err = 0; + } + mutex_unlock(&parent->offset_lock); + + if (!err) { + psb->avail_size += inode->i_size; + + pohmelfs_inode_del_inode(psb, pi); + + mark_inode_dirty(dir); + + inode->i_ctime = dir->i_ctime; + if (inode->i_nlink) + inode_dec_link_count(inode); + } + dprintk("%s: inode: %p, lock: %ld, unhashed: %d.\n", + __func__, pi, inode->i_state & I_LOCK, hlist_unhashed(&inode->i_hash)); + + return err; +} + +/* + * Unlink and rmdir VFS callbacks. + */ +static int pohmelfs_unlink(struct inode *dir, struct dentry *dentry) +{ + return pohmelfs_remove_entry(dir, dentry); +} + +static int pohmelfs_rmdir(struct inode *dir, struct dentry *dentry) +{ + int err; + struct inode *inode = dentry->d_inode; + + dprintk("%s: parent: %llu, inode: %llu, name: '%s', parent_nlink: %d, nlink: %d.\n", + __func__, POHMELFS_I(dir)->ino, POHMELFS_I(inode)->ino, + dentry->d_name.name, (signed)dir->i_nlink, (signed)inode->i_nlink); + + err = pohmelfs_remove_entry(dir, dentry); + if (!err) { + inode_dec_link_count(dir); + inode_dec_link_count(inode); + } + + return err; +} + +/* + * Link creation is synchronous. + * I'm lazy. + * Earth is somewhat round. + */ +static int pohmelfs_create_link(struct pohmelfs_inode *parent, struct qstr *obj, + struct pohmelfs_inode *target, struct qstr *tstr) +{ + struct super_block *sb = parent->vfs_inode.i_sb; + struct pohmelfs_sb *psb = POHMELFS_SB(sb); + struct netfs_cmd *cmd; + struct netfs_trans *t; + void *data; + int err, parent_len, target_len = 0, cur_len, path_size = 0; + + err = pohmelfs_data_lock(parent, 0, ~0, POHMELFS_WRITE_LOCK); + if (err) + return err; + + err = sb->s_op->write_inode(&parent->vfs_inode, 0); + if (err) + goto err_out_exit; + + if (tstr) + target_len = tstr->len; + + parent_len = pohmelfs_path_length(parent); + if (target) + target_len += pohmelfs_path_length(target); + + if (parent_len < 0) { + err = parent_len; + goto err_out_exit; + } + + if (target_len < 0) { + err = target_len; + goto err_out_exit; + } + + t = netfs_trans_alloc(psb, parent_len + target_len + obj->len + 2, 0, 0); + if (!t) { + err = -ENOMEM; + goto err_out_exit; + } + cur_len = netfs_trans_cur_len(t); + + cmd = netfs_trans_current(t); + if (IS_ERR(cmd)) { + err = PTR_ERR(cmd); + goto err_out_free; + } + + data = (void *)(cmd + 1); + cur_len -= sizeof(struct netfs_cmd); + + err = pohmelfs_construct_path_string(parent, data, parent_len); + if (err > 0) { + /* Do not place null-byte before the slash */ + path_size = err - 1; + cur_len -= path_size; + + err = snprintf(data + path_size, cur_len, "/%s|", obj->name); + + path_size += err; + cur_len -= err; + + cmd->ext = path_size - 1; /* No | symbol */ + + if (target) { + err = pohmelfs_construct_path_string(target, data + path_size, target_len); + if (err > 0) { + path_size += err; + cur_len -= err; + } + } + } + + if (err < 0) + goto err_out_free; + + cmd->start = 0; + + if (!target && tstr) { + if (tstr->len > cur_len - 1) { + err = -ENAMETOOLONG; + goto err_out_free; + } + + err = snprintf(data + path_size, cur_len, "%s", tstr->name) + 1; /* 0-byte */ + path_size += err; + cur_len -= err; + cmd->start = 1; + } + + dprintk("%s: parent: %llu, obj: '%s', target_inode: %llu, target_str: '%s', full: '%s'.\n", + __func__, parent->ino, obj->name, (target)?target->ino:0, (tstr)?tstr->name:NULL, + (char *)data); + + cmd->cmd = NETFS_LINK; + cmd->size = path_size; + cmd->id = parent->ino; + + netfs_convert_cmd(cmd); + + netfs_trans_update(cmd, t, path_size); + + err = netfs_trans_finish(t, psb); + if (err) + goto err_out_exit; + + return 0; + +err_out_free: + t->result = err; + netfs_trans_put(t); +err_out_exit: + return err; +} + +/* + * VFS hard and soft link callbacks. + */ +static int pohmelfs_link(struct dentry *old_dentry, struct inode *dir, + struct dentry *dentry) +{ + struct inode *inode = old_dentry->d_inode; + struct pohmelfs_inode *pi = POHMELFS_I(inode); + int err; + struct qstr str = dentry->d_name; + + str.hash = jhash(dentry->d_name.name, dentry->d_name.len, 0); + + err = inode->i_sb->s_op->write_inode(inode, 0); + if (err) + return err; + + err = pohmelfs_create_link(POHMELFS_I(dir), &str, pi, NULL); + if (err) + return err; + + return pohmelfs_create_entry(dir, dentry, pi->ino, inode->i_mode); +} + +static int pohmelfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname) +{ + struct qstr sym_str; + struct qstr str = dentry->d_name; + struct inode *inode; + int err; + + str.hash = jhash(dentry->d_name.name, dentry->d_name.len, 0); + + sym_str.name = symname; + sym_str.len = strlen(symname); + + err = pohmelfs_create_link(POHMELFS_I(dir), &str, NULL, &sym_str); + if (err) + goto err_out_exit; + + err = pohmelfs_create_entry(dir, dentry, 0, S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO); + if (err) + goto err_out_exit; + + inode = dentry->d_inode; + + err = page_symlink(inode, symname, sym_str.len + 1); + if (err) + goto err_out_put; + + return 0; + +err_out_put: + iput(inode); +err_out_exit: + return err; +} + +static int pohmelfs_send_rename(struct pohmelfs_inode *pi, struct pohmelfs_inode *parent, + struct qstr *str) +{ + int path_len, err, total_len = 0, inode_len, parent_len; + char *path; + struct netfs_trans *t; + struct netfs_cmd *cmd; + struct pohmelfs_sb *psb = POHMELFS_SB(pi->vfs_inode.i_sb); + + parent_len = pohmelfs_path_length(parent); + inode_len = pohmelfs_path_length(pi); + + if (parent_len < 0 || inode_len < 0) + return -EINVAL; + + path_len = parent_len + inode_len + str->len + 3; + + t = netfs_trans_alloc(psb, path_len, 0, 0); + if (!t) + return -ENOMEM; + + cmd = netfs_trans_current(t); + path = (char *)(cmd + 1); + + err = pohmelfs_construct_path_string(pi, path, inode_len); + if (err < 0) + goto err_out_unlock; + + cmd->ext = err; + + path += err; + total_len += err; + path_len -= err; + + *path = '|'; + path++; + total_len++; + path_len--; + + err = pohmelfs_construct_path_string(parent, path, parent_len); + if (err < 0) + goto err_out_unlock; + + /* + * Do not place a null-byte before the final slash and the name. + */ + err--; + path += err; + total_len += err; + path_len -= err; + + err = snprintf(path, path_len - 1, "/%s", str->name); + + total_len += err + 1; /* 0 symbol */ + path_len -= err + 1; + + cmd->cmd = NETFS_RENAME; + cmd->id = pi->ino; + cmd->start = parent->ino; + cmd->size = total_len; + + netfs_convert_cmd(cmd); + + netfs_trans_update(cmd, t, total_len); + + return netfs_trans_finish(t, psb); + +err_out_unlock: + netfs_trans_free(t); + return err; +} + +static int pohmelfs_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry) +{ + struct inode *inode = old_dentry->d_inode; + struct pohmelfs_inode *old_parent, *pi, *new_parent; + struct qstr str = new_dentry->d_name; + struct pohmelfs_name *n; + unsigned int old_hash; + int err = -ENOENT; + + pi = POHMELFS_I(inode); + old_parent = POHMELFS_I(old_dir); + + if (new_dir) { + new_dir->i_sb->s_op->write_inode(new_dir, 0); + } + + old_hash = jhash(old_dentry->d_name.name, old_dentry->d_name.len, 0); + str.hash = jhash(new_dentry->d_name.name, new_dentry->d_name.len, 0); + + str.len = new_dentry->d_name.len; + str.name = new_dentry->d_name.name; + str.hash = jhash(new_dentry->d_name.name, new_dentry->d_name.len, 0); + + if (new_dir) { + new_parent = POHMELFS_I(new_dir); + err = -ENOTEMPTY; + + if (S_ISDIR(inode->i_mode) && + new_parent->total_len <= 3) + goto err_out_exit; + } else { + new_parent = old_parent; + } + + dprintk("%s: ino: %llu, parent: %llu, name: '%s' -> parent: %llu, name: '%s', i_size: %llu.\n", + __func__, pi->ino, old_parent->ino, old_dentry->d_name.name, + new_parent->ino, new_dentry->d_name.name, inode->i_size); + + if (test_bit(NETFS_INODE_REMOTE_SYNCED, &pi->state) && + test_bit(NETFS_INODE_OWNED, &pi->state)) { + err = pohmelfs_send_rename(pi, new_parent, &str); + if (err) + goto err_out_exit; + } + + n = pohmelfs_name_alloc(str.len + 1); + if (!n) + goto err_out_exit; + + mutex_lock(&new_parent->offset_lock); + n->ino = pi->ino; + n->mode = inode->i_mode; + n->len = str.len; + n->hash = str.hash; + sprintf(n->data, "%s", str.name); + + err = pohmelfs_insert_name(new_parent, n); + mutex_unlock(&new_parent->offset_lock); + + if (err) + goto err_out_exit; + + mutex_lock(&old_parent->offset_lock); + n = pohmelfs_search_hash(old_parent, old_hash); + if (n) + pohmelfs_name_del(old_parent, n); + mutex_unlock(&old_parent->offset_lock); + + mark_inode_dirty(inode); + mark_inode_dirty(&new_parent->vfs_inode); + + WARN_ON_ONCE(list_empty(&inode->i_dentry)); + + return 0; + +err_out_exit: + + clear_bit(NETFS_INODE_REMOTE_SYNCED, &pi->state); + + mutex_unlock(&inode->i_mutex); + return err; +} + +/* + * POHMELFS directory inode operations. + */ +const struct inode_operations pohmelfs_dir_inode_ops = { + .link = pohmelfs_link, + .symlink = pohmelfs_symlink, + .unlink = pohmelfs_unlink, + .mkdir = pohmelfs_mkdir, + .rmdir = pohmelfs_rmdir, + .create = pohmelfs_create, + .lookup = pohmelfs_lookup, + .setattr = pohmelfs_setattr, + .rename = pohmelfs_rename, +}; diff --git a/drivers/staging/pohmelfs/path_entry.c b/drivers/staging/pohmelfs/path_entry.c new file mode 100644 index 0000000..9270e54 --- /dev/null +++ b/drivers/staging/pohmelfs/path_entry.c @@ -0,0 +1,114 @@ +/* + * 2007+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net> + * All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/fs.h> +#include <linux/ktime.h> +#include <linux/fs.h> +#include <linux/pagemap.h> +#include <linux/writeback.h> +#include <linux/mount.h> +#include <linux/mm.h> + +#include "netfs.h" + +#define UNHASHED_OBSCURE_STRING_SIZE sizeof(" (deleted)") + +/* + * Create path from root for given inode. + * Path is formed as set of stuctures, containing name of the object + * and its inode data (mode, permissions and so on). + */ +int pohmelfs_construct_path_string(struct pohmelfs_inode *pi, void *data, int len) +{ + struct path path; + struct dentry *d; + char *ptr; + int err = 0, strlen, reduce = 0; + + d = d_find_alias(&pi->vfs_inode); + if (!d) { + printk("%s: no alias, list_empty: %d.\n", __func__, list_empty(&pi->vfs_inode.i_dentry)); + return -ENOENT; + } + + read_lock(¤t->fs->lock); + path.mnt = mntget(current->fs->root.mnt); + read_unlock(¤t->fs->lock); + + path.dentry = d; + + if (!IS_ROOT(d) && d_unhashed(d)) + reduce = 1; + + ptr = d_path(&path, data, len); + if (IS_ERR(ptr)) { + err = PTR_ERR(ptr); + goto out; + } + + if (reduce && len >= UNHASHED_OBSCURE_STRING_SIZE) { + char *end = data + len - UNHASHED_OBSCURE_STRING_SIZE; + *end = '\0'; + } + + strlen = len - (ptr - (char *)data); + memmove(data, ptr, strlen); + ptr = data; + + err = strlen; + + dprintk("%s: dname: '%s', len: %u, maxlen: %u, name: '%s', strlen: %d.\n", + __func__, d->d_name.name, d->d_name.len, len, ptr, strlen); + +out: + dput(d); + mntput(path.mnt); + + return err; +} + +int pohmelfs_path_length(struct pohmelfs_inode *pi) +{ + struct dentry *d, *root, *first; + int len = 1; /* Root slash */ + + first = d = d_find_alias(&pi->vfs_inode); + if (!d) { + dprintk("%s: ino: %llu, mode: %o.\n", __func__, pi->ino, pi->vfs_inode.i_mode); + return -ENOENT; + } + + read_lock(¤t->fs->lock); + root = dget(current->fs->root.dentry); + read_unlock(¤t->fs->lock); + + spin_lock(&dcache_lock); + + if (!IS_ROOT(d) && d_unhashed(d)) + len += UNHASHED_OBSCURE_STRING_SIZE; /* Obscure " (deleted)" string */ + + while (d && d != root && !IS_ROOT(d)) { + len += d->d_name.len + 1; /* Plus slash */ + d = d->d_parent; + } + spin_unlock(&dcache_lock); + + dput(root); + dput(first); + + return len + 1; /* Including zero-byte */ +} |