cmservice.o \
dir.o \
dir_edit.o \
+ dir_silly.o \
dynroot.o \
file.o \
flock.o \
static int afs_readdir(struct file *file, struct dir_context *ctx);
static int afs_d_revalidate(struct dentry *dentry, unsigned int flags);
static int afs_d_delete(const struct dentry *dentry);
+static void afs_d_iput(struct dentry *dentry, struct inode *inode);
static int afs_lookup_one_filldir(struct dir_context *ctx, const char *name, int nlen,
loff_t fpos, u64 ino, unsigned dtype);
static int afs_lookup_filldir(struct dir_context *ctx, const char *name, int nlen,
.d_delete = afs_d_delete,
.d_release = afs_d_release,
.d_automount = afs_d_automount,
+ .d_iput = afs_d_iput,
};
struct afs_lookup_one_cookie {
return 1;
}
+/*
+ * Clean up sillyrename files on dentry removal.
+ */
+static void afs_d_iput(struct dentry *dentry, struct inode *inode)
+{
+ if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
+ afs_silly_iput(dentry, inode);
+ iput(inode);
+}
+
/*
* handle dentry release
*/
goto error_key;
}
+ if (vnode) {
+ ret = down_write_killable(&vnode->rmdir_lock);
+ if (ret < 0)
+ goto error_key;
+ }
+
ret = -ERESTARTSYS;
if (afs_begin_vnode_operation(&fc, dvnode, key)) {
while (afs_select_fileserver(&fc)) {
}
}
+ if (vnode)
+ up_write(&vnode->rmdir_lock);
error_key:
key_put(key);
error:
* However, if we didn't have a callback promise outstanding, or it was
* outstanding on a different server, then it won't break it either...
*/
-static int afs_dir_remove_link(struct dentry *dentry, struct key *key,
- unsigned long d_version_before,
- unsigned long d_version_after)
+int afs_dir_remove_link(struct dentry *dentry, struct key *key,
+ unsigned long d_version_before,
+ unsigned long d_version_after)
{
bool dir_valid;
int ret = 0;
struct afs_vnode *dvnode = AFS_FS_I(dir), *vnode = NULL;
struct key *key;
unsigned long d_version = (unsigned long)dentry->d_fsdata;
+ bool need_rehash = false;
u64 data_version = dvnode->status.data_version;
int ret;
goto error_key;
}
+ spin_lock(&dentry->d_lock);
+ if (vnode && d_count(dentry) > 1) {
+ spin_unlock(&dentry->d_lock);
+ /* Start asynchronous writeout of the inode */
+ write_inode_now(d_inode(dentry), 0);
+ ret = afs_sillyrename(dvnode, vnode, dentry, key);
+ goto error_key;
+ }
+ if (!d_unhashed(dentry)) {
+ /* Prevent a race with RCU lookup. */
+ __d_drop(dentry);
+ need_rehash = true;
+ }
+ spin_unlock(&dentry->d_lock);
+
ret = -ERESTARTSYS;
if (afs_begin_vnode_operation(&fc, dvnode, key)) {
while (afs_select_fileserver(&fc)) {
afs_edit_dir_for_unlink);
}
+ if (need_rehash && ret < 0 && ret != -ENOENT)
+ d_rehash(dentry);
+
error_key:
key_put(key);
error:
{
struct afs_fs_cursor fc;
struct afs_vnode *orig_dvnode, *new_dvnode, *vnode;
+ struct dentry *tmp = NULL, *rehash = NULL;
+ struct inode *new_inode;
struct key *key;
u64 orig_data_version, new_data_version;
bool new_negative = d_is_negative(new_dentry);
if (flags)
return -EINVAL;
+ /* Don't allow silly-rename files be moved around. */
+ if (old_dentry->d_flags & DCACHE_NFSFS_RENAMED)
+ return -EINVAL;
+
vnode = AFS_FS_I(d_inode(old_dentry));
orig_dvnode = AFS_FS_I(old_dir);
new_dvnode = AFS_FS_I(new_dir);
goto error;
}
+ /* For non-directories, check whether the target is busy and if so,
+ * make a copy of the dentry and then do a silly-rename. If the
+ * silly-rename succeeds, the copied dentry is hashed and becomes the
+ * new target.
+ */
+ if (d_is_positive(new_dentry) && !d_is_dir(new_dentry)) {
+ /* To prevent any new references to the target during the
+ * rename, we unhash the dentry in advance.
+ */
+ if (!d_unhashed(new_dentry)) {
+ d_drop(new_dentry);
+ rehash = new_dentry;
+ }
+
+ if (d_count(new_dentry) > 2) {
+ /* copy the target dentry's name */
+ ret = -ENOMEM;
+ tmp = d_alloc(new_dentry->d_parent,
+ &new_dentry->d_name);
+ if (!tmp)
+ goto error_rehash;
+
+ ret = afs_sillyrename(new_dvnode,
+ AFS_FS_I(d_inode(new_dentry)),
+ new_dentry, key);
+ if (ret)
+ goto error_rehash;
+
+ new_dentry = tmp;
+ rehash = NULL;
+ new_negative = true;
+ orig_data_version = orig_dvnode->status.data_version;
+ new_data_version = new_dvnode->status.data_version;
+ }
+ }
+
ret = -ERESTARTSYS;
if (afs_begin_vnode_operation(&fc, orig_dvnode, key)) {
if (orig_dvnode != new_dvnode) {
if (mutex_lock_interruptible_nested(&new_dvnode->io_lock, 1) < 0) {
afs_end_vnode_operation(&fc);
- goto error_key;
+ goto error_rehash;
}
}
while (afs_select_fileserver(&fc)) {
mutex_unlock(&new_dvnode->io_lock);
ret = afs_end_vnode_operation(&fc);
if (ret < 0)
- goto error_key;
+ goto error_rehash;
}
if (ret == 0) {
+ if (rehash)
+ d_rehash(rehash);
if (test_bit(AFS_VNODE_DIR_VALID, &orig_dvnode->flags))
afs_edit_dir_remove(orig_dvnode, &old_dentry->d_name,
- afs_edit_dir_for_rename);
+ afs_edit_dir_for_rename_0);
if (!new_negative &&
test_bit(AFS_VNODE_DIR_VALID, &new_dvnode->flags))
afs_edit_dir_remove(new_dvnode, &new_dentry->d_name,
- afs_edit_dir_for_rename);
+ afs_edit_dir_for_rename_1);
if (test_bit(AFS_VNODE_DIR_VALID, &new_dvnode->flags))
afs_edit_dir_add(new_dvnode, &new_dentry->d_name,
- &vnode->fid, afs_edit_dir_for_rename);
+ &vnode->fid, afs_edit_dir_for_rename_2);
+
+ new_inode = d_inode(new_dentry);
+ if (new_inode) {
+ spin_lock(&new_inode->i_lock);
+ if (new_inode->i_nlink > 0)
+ drop_nlink(new_inode);
+ spin_unlock(&new_inode->i_lock);
+ }
+ d_move(old_dentry, new_dentry);
+ goto error_tmp;
}
-error_key:
+error_rehash:
+ if (rehash)
+ d_rehash(rehash);
+error_tmp:
+ if (tmp)
+ dput(tmp);
key_put(key);
error:
_leave(" = %d", ret);
--- /dev/null
+/* AFS silly rename handling
+ *
+ * Copyright (C) 2019 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ * - Derived from NFS's sillyrename.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/fsnotify.h>
+#include "internal.h"
+
+/*
+ * Actually perform the silly rename step.
+ */
+static int afs_do_silly_rename(struct afs_vnode *dvnode, struct afs_vnode *vnode,
+ struct dentry *old, struct dentry *new,
+ struct key *key)
+{
+ struct afs_fs_cursor fc;
+ u64 dir_data_version = dvnode->status.data_version;
+ int ret = -ERESTARTSYS;
+
+ _enter("%pd,%pd", old, new);
+
+ trace_afs_silly_rename(vnode, false);
+ if (afs_begin_vnode_operation(&fc, dvnode, key)) {
+ while (afs_select_fileserver(&fc)) {
+ fc.cb_break = afs_calc_vnode_cb_break(dvnode);
+ afs_fs_rename(&fc, old->d_name.name,
+ dvnode, new->d_name.name,
+ dir_data_version, dir_data_version);
+ }
+
+ afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
+ ret = afs_end_vnode_operation(&fc);
+ }
+
+ if (ret == 0) {
+ spin_lock(&old->d_lock);
+ old->d_flags |= DCACHE_NFSFS_RENAMED;
+ spin_unlock(&old->d_lock);
+ if (dvnode->silly_key != key) {
+ key_put(dvnode->silly_key);
+ dvnode->silly_key = key_get(key);
+ }
+
+ if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
+ afs_edit_dir_remove(dvnode, &old->d_name,
+ afs_edit_dir_for_silly_0);
+ if (test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
+ afs_edit_dir_add(dvnode, &new->d_name,
+ &vnode->fid, afs_edit_dir_for_silly_1);
+
+ /* vfs_unlink and the like do not issue this when a file is
+ * sillyrenamed, so do it here.
+ */
+ fsnotify_nameremove(old, 0);
+ }
+
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/**
+ * afs_sillyrename - Perform a silly-rename of a dentry
+ *
+ * AFS is stateless and the server doesn't know when the client is holding a
+ * file open. To prevent application problems when a file is unlinked while
+ * it's still open, the client performs a "silly-rename". That is, it renames
+ * the file to a hidden file in the same directory, and only performs the
+ * unlink once the last reference to it is put.
+ *
+ * The final cleanup is done during dentry_iput.
+ */
+int afs_sillyrename(struct afs_vnode *dvnode, struct afs_vnode *vnode,
+ struct dentry *dentry, struct key *key)
+{
+ static unsigned int sillycounter;
+ struct dentry *sdentry = NULL;
+ unsigned char silly[16];
+ int ret = -EBUSY;
+
+ _enter("");
+
+ /* We don't allow a dentry to be silly-renamed twice. */
+ if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
+ return -EBUSY;
+
+ sdentry = NULL;
+ do {
+ int slen;
+
+ dput(sdentry);
+ sillycounter++;
+
+ /* Create a silly name. Note that the ".__afs" prefix is
+ * understood by the salvager and must not be changed.
+ */
+ slen = scnprintf(silly, sizeof(silly), ".__afs%04X", sillycounter);
+ sdentry = lookup_one_len(silly, dentry->d_parent, slen);
+
+ /* N.B. Better to return EBUSY here ... it could be dangerous
+ * to delete the file while it's in use.
+ */
+ if (IS_ERR(sdentry))
+ goto out;
+ } while (!d_is_negative(sdentry));
+
+ ihold(&vnode->vfs_inode);
+
+ ret = afs_do_silly_rename(dvnode, vnode, dentry, sdentry, key);
+ switch (ret) {
+ case 0:
+ /* The rename succeeded. */
+ d_move(dentry, sdentry);
+ break;
+ case -ERESTARTSYS:
+ /* The result of the rename is unknown. Play it safe by forcing
+ * a new lookup.
+ */
+ d_drop(dentry);
+ d_drop(sdentry);
+ }
+
+ iput(&vnode->vfs_inode);
+ dput(sdentry);
+out:
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * Tell the server to remove a sillyrename file.
+ */
+static int afs_do_silly_unlink(struct afs_vnode *dvnode, struct afs_vnode *vnode,
+ struct dentry *dentry, struct key *key)
+{
+ struct afs_fs_cursor fc;
+ u64 dir_data_version = dvnode->status.data_version;
+ int ret = -ERESTARTSYS;
+
+ _enter("");
+
+ trace_afs_silly_rename(vnode, true);
+ if (afs_begin_vnode_operation(&fc, dvnode, key)) {
+ while (afs_select_fileserver(&fc)) {
+ fc.cb_break = afs_calc_vnode_cb_break(dvnode);
+
+ if (test_bit(AFS_SERVER_FL_IS_YFS, &fc.cbi->server->flags) &&
+ !test_bit(AFS_SERVER_FL_NO_RM2, &fc.cbi->server->flags)) {
+ yfs_fs_remove_file2(&fc, vnode, dentry->d_name.name,
+ dir_data_version);
+ if (fc.ac.error != -ECONNABORTED ||
+ fc.ac.abort_code != RXGEN_OPCODE)
+ continue;
+ set_bit(AFS_SERVER_FL_NO_RM2, &fc.cbi->server->flags);
+ }
+
+ afs_fs_remove(&fc, vnode, dentry->d_name.name, false,
+ dir_data_version);
+ }
+
+ afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
+ ret = afs_end_vnode_operation(&fc);
+ if (ret == 0) {
+ drop_nlink(&vnode->vfs_inode);
+ if (vnode->vfs_inode.i_nlink == 0) {
+ set_bit(AFS_VNODE_DELETED, &vnode->flags);
+ clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
+ }
+ }
+ if (ret == 0 &&
+ test_bit(AFS_VNODE_DIR_VALID, &dvnode->flags))
+ afs_edit_dir_remove(dvnode, &dentry->d_name,
+ afs_edit_dir_for_unlink);
+ }
+
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * Remove sillyrename file on iput.
+ */
+int afs_silly_iput(struct dentry *dentry, struct inode *inode)
+{
+ struct afs_vnode *dvnode = AFS_FS_I(d_inode(dentry->d_parent));
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+ struct dentry *alias;
+ int ret;
+
+ DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+
+ _enter("%p{%pd},%llx", dentry, dentry, vnode->fid.vnode);
+
+ down_read(&dvnode->rmdir_lock);
+
+ alias = d_alloc_parallel(dentry->d_parent, &dentry->d_name, &wq);
+ if (IS_ERR(alias)) {
+ up_read(&dvnode->rmdir_lock);
+ return 0;
+ }
+
+ if (!d_in_lookup(alias)) {
+ /* We raced with lookup... See if we need to transfer the
+ * sillyrename information to the aliased dentry.
+ */
+ ret = 0;
+ spin_lock(&alias->d_lock);
+ if (d_really_is_positive(alias) &&
+ !(alias->d_flags & DCACHE_NFSFS_RENAMED)) {
+ alias->d_flags |= DCACHE_NFSFS_RENAMED;
+ ret = 1;
+ }
+ spin_unlock(&alias->d_lock);
+ up_read(&dvnode->rmdir_lock);
+ dput(alias);
+ return ret;
+ }
+
+ /* Stop lock-release from complaining. */
+ spin_lock(&vnode->lock);
+ vnode->lock_state = AFS_VNODE_LOCK_DELETED;
+ trace_afs_flock_ev(vnode, NULL, afs_flock_silly_delete, 0);
+ spin_unlock(&vnode->lock);
+
+ afs_do_silly_unlink(dvnode, vnode, dentry, dvnode->silly_key);
+ up_read(&dvnode->rmdir_lock);
+ d_lookup_done(alias);
+ dput(alias);
+ return 1;
+}
/* attempt to release the server lock; if it fails, we just
* wait 5 minutes and it'll expire anyway */
ret = afs_release_lock(vnode, vnode->lock_key);
- if (ret < 0) {
+ if (ret < 0 && vnode->lock_state != AFS_VNODE_LOCK_DELETED) {
trace_afs_flock_ev(vnode, NULL, afs_flock_release_fail,
ret);
printk(KERN_WARNING "AFS:"
#endif
afs_put_permits(rcu_access_pointer(vnode->permit_cache));
+ key_put(vnode->silly_key);
+ vnode->silly_key = NULL;
key_put(vnode->lock_key);
vnode->lock_key = NULL;
_leave("");
struct afs_permits __rcu *permit_cache; /* cache of permits so far obtained */
struct mutex io_lock; /* Lock for serialising I/O on this mutex */
struct rw_semaphore validate_lock; /* lock for validating this vnode */
+ struct rw_semaphore rmdir_lock; /* Lock for rmdir vs sillyrename */
+ struct key *silly_key; /* Silly rename key */
spinlock_t wb_lock; /* lock for wb_keys */
spinlock_t lock; /* waitqueue/flags lock */
unsigned long flags;
extern const struct dentry_operations afs_fs_dentry_operations;
extern void afs_d_release(struct dentry *);
+extern int afs_dir_remove_link(struct dentry *, struct key *, unsigned long, unsigned long);
/*
* dir_edit.c
enum afs_edit_dir_reason);
extern void afs_edit_dir_remove(struct afs_vnode *, struct qstr *, enum afs_edit_dir_reason);
+/*
+ * dir_silly.c
+ */
+extern int afs_sillyrename(struct afs_vnode *, struct afs_vnode *,
+ struct dentry *, struct key *);
+extern int afs_silly_iput(struct dentry *, struct inode *);
+
/*
* dynroot.c
*/
.init_fs_context = afs_init_fs_context,
.parameters = &afs_fs_parameters,
.kill_sb = afs_kill_super,
- .fs_flags = 0,
+ .fs_flags = FS_RENAME_DOES_D_MOVE,
};
MODULE_ALIAS_FS("afs");
vnode->cb_type = 0;
vnode->lock_state = AFS_VNODE_LOCK_NONE;
+ init_rwsem(&vnode->rmdir_lock);
+
_leave(" = %p", &vnode->vfs_inode);
return &vnode->vfs_inode;
}
afs_edit_dir_for_create,
afs_edit_dir_for_link,
afs_edit_dir_for_mkdir,
- afs_edit_dir_for_rename,
+ afs_edit_dir_for_rename_0,
+ afs_edit_dir_for_rename_1,
+ afs_edit_dir_for_rename_2,
afs_edit_dir_for_rmdir,
+ afs_edit_dir_for_silly_0,
+ afs_edit_dir_for_silly_1,
afs_edit_dir_for_symlink,
afs_edit_dir_for_unlink,
};
afs_flock_fail_perm,
afs_flock_no_lockers,
afs_flock_release_fail,
+ afs_flock_silly_delete,
afs_flock_timestamp,
afs_flock_try_to_lock,
afs_flock_vfs_lock,
EM(afs_edit_dir_for_create, "Create") \
EM(afs_edit_dir_for_link, "Link ") \
EM(afs_edit_dir_for_mkdir, "MkDir ") \
- EM(afs_edit_dir_for_rename, "Rename") \
+ EM(afs_edit_dir_for_rename_0, "Renam0") \
+ EM(afs_edit_dir_for_rename_1, "Renam1") \
+ EM(afs_edit_dir_for_rename_2, "Renam2") \
EM(afs_edit_dir_for_rmdir, "RmDir ") \
+ EM(afs_edit_dir_for_silly_0, "S_Ren0") \
+ EM(afs_edit_dir_for_silly_1, "S_Ren1") \
EM(afs_edit_dir_for_symlink, "Symlnk") \
E_(afs_edit_dir_for_unlink, "Unlink")
EM(afs_flock_fail_perm, "ErrPerm ") \
EM(afs_flock_no_lockers, "NoLocker") \
EM(afs_flock_release_fail, "Rel_Fail") \
+ EM(afs_flock_silly_delete, "SillyDel") \
EM(afs_flock_timestamp, "Timestmp") \
EM(afs_flock_try_to_lock, "TryToLck") \
EM(afs_flock_vfs_lock, "VFSLock ") \
__entry->fid.vid, __entry->fid.vnode, __entry->fid.unique)
);
+TRACE_EVENT(afs_silly_rename,
+ TP_PROTO(struct afs_vnode *vnode, bool done),
+
+ TP_ARGS(vnode, done),
+
+ TP_STRUCT__entry(
+ __field_struct(struct afs_fid, fid )
+ __field(bool, done )
+ ),
+
+ TP_fast_assign(
+ __entry->fid = vnode->fid;
+ __entry->done = done;
+ ),
+
+ TP_printk("%llx:%llx:%x done=%u",
+ __entry->fid.vid, __entry->fid.vnode, __entry->fid.unique,
+ __entry->done)
+ );
+
#endif /* _TRACE_AFS_H */
/* This part must be outside protection */
projects / linux-2.6-block.git / commitdiff