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authorDavid Howells <dhowells@redhat.com>2021-10-31 12:58:05 +0000
committerDavid Howells <dhowells@redhat.com>2022-01-07 09:22:19 +0000
commit850cba069c266d6f31b81c5a199052a3482a63fc (patch)
tree9fa268c3d0607be533d62df8286402f89c79bac6 /fs/cachefiles/namei.c
parent01491a756578d8602dfdfc79f2638c519bfdadb7 (diff)
downloadlinux-850cba069c266d6f31b81c5a199052a3482a63fc.tar.bz2
cachefiles: Delete the cachefiles driver pending rewrite
Delete the code from the cachefiles driver to make it easier to rewrite and resubmit in a logical manner. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819577641.215744.12718114397770666596.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906883770.143852.4149714614981373410.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967076066.1823006.7175712134577687753.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021483619.640689.7586546280515844702.stgit@warthog.procyon.org.uk/ # v4
Diffstat (limited to 'fs/cachefiles/namei.c')
-rw-r--r--fs/cachefiles/namei.c1018
1 files changed, 0 insertions, 1018 deletions
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
deleted file mode 100644
index a9aca5ab5970..000000000000
--- a/fs/cachefiles/namei.c
+++ /dev/null
@@ -1,1018 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/* CacheFiles path walking and related routines
- *
- * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@redhat.com)
- */
-
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/file.h>
-#include <linux/fs.h>
-#include <linux/fsnotify.h>
-#include <linux/quotaops.h>
-#include <linux/xattr.h>
-#include <linux/mount.h>
-#include <linux/namei.h>
-#include <linux/security.h>
-#include <linux/slab.h>
-#include "internal.h"
-
-#define CACHEFILES_KEYBUF_SIZE 512
-
-/*
- * dump debugging info about an object
- */
-static noinline
-void __cachefiles_printk_object(struct cachefiles_object *object,
- const char *prefix)
-{
- struct fscache_cookie *cookie;
- const u8 *k;
- unsigned loop;
-
- pr_err("%sobject: OBJ%x\n", prefix, object->fscache.debug_id);
- pr_err("%sobjstate=%s fl=%lx wbusy=%x ev=%lx[%lx]\n",
- prefix, object->fscache.state->name,
- object->fscache.flags, work_busy(&object->fscache.work),
- object->fscache.events, object->fscache.event_mask);
- pr_err("%sops=%u inp=%u exc=%u\n",
- prefix, object->fscache.n_ops, object->fscache.n_in_progress,
- object->fscache.n_exclusive);
- pr_err("%sparent=%x\n",
- prefix, object->fscache.parent ? object->fscache.parent->debug_id : 0);
-
- spin_lock(&object->fscache.lock);
- cookie = object->fscache.cookie;
- if (cookie) {
- pr_err("%scookie=%x [pr=%x nd=%p fl=%lx]\n",
- prefix,
- cookie->debug_id,
- cookie->parent ? cookie->parent->debug_id : 0,
- cookie->netfs_data,
- cookie->flags);
- pr_err("%skey=[%u] '", prefix, cookie->key_len);
- k = (cookie->key_len <= sizeof(cookie->inline_key)) ?
- cookie->inline_key : cookie->key;
- for (loop = 0; loop < cookie->key_len; loop++)
- pr_cont("%02x", k[loop]);
- pr_cont("'\n");
- } else {
- pr_err("%scookie=NULL\n", prefix);
- }
- spin_unlock(&object->fscache.lock);
-}
-
-/*
- * dump debugging info about a pair of objects
- */
-static noinline void cachefiles_printk_object(struct cachefiles_object *object,
- struct cachefiles_object *xobject)
-{
- if (object)
- __cachefiles_printk_object(object, "");
- if (xobject)
- __cachefiles_printk_object(xobject, "x");
-}
-
-/*
- * mark the owner of a dentry, if there is one, to indicate that that dentry
- * has been preemptively deleted
- * - the caller must hold the i_mutex on the dentry's parent as required to
- * call vfs_unlink(), vfs_rmdir() or vfs_rename()
- */
-static void cachefiles_mark_object_buried(struct cachefiles_cache *cache,
- struct dentry *dentry,
- enum fscache_why_object_killed why)
-{
- struct cachefiles_object *object;
- struct rb_node *p;
-
- _enter(",'%pd'", dentry);
-
- write_lock(&cache->active_lock);
-
- p = cache->active_nodes.rb_node;
- while (p) {
- object = rb_entry(p, struct cachefiles_object, active_node);
- if (object->dentry > dentry)
- p = p->rb_left;
- else if (object->dentry < dentry)
- p = p->rb_right;
- else
- goto found_dentry;
- }
-
- write_unlock(&cache->active_lock);
- trace_cachefiles_mark_buried(NULL, dentry, why);
- _leave(" [no owner]");
- return;
-
- /* found the dentry for */
-found_dentry:
- kdebug("preemptive burial: OBJ%x [%s] %pd",
- object->fscache.debug_id,
- object->fscache.state->name,
- dentry);
-
- trace_cachefiles_mark_buried(object, dentry, why);
-
- if (fscache_object_is_live(&object->fscache)) {
- pr_err("\n");
- pr_err("Error: Can't preemptively bury live object\n");
- cachefiles_printk_object(object, NULL);
- } else {
- if (why != FSCACHE_OBJECT_IS_STALE)
- fscache_object_mark_killed(&object->fscache, why);
- }
-
- write_unlock(&cache->active_lock);
- _leave(" [owner marked]");
-}
-
-/*
- * record the fact that an object is now active
- */
-static int cachefiles_mark_object_active(struct cachefiles_cache *cache,
- struct cachefiles_object *object)
-{
- struct cachefiles_object *xobject;
- struct rb_node **_p, *_parent = NULL;
- struct dentry *dentry;
-
- _enter(",%x", object->fscache.debug_id);
-
-try_again:
- write_lock(&cache->active_lock);
-
- dentry = object->dentry;
- trace_cachefiles_mark_active(object, dentry);
-
- if (test_and_set_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags)) {
- pr_err("Error: Object already active\n");
- cachefiles_printk_object(object, NULL);
- BUG();
- }
-
- _p = &cache->active_nodes.rb_node;
- while (*_p) {
- _parent = *_p;
- xobject = rb_entry(_parent,
- struct cachefiles_object, active_node);
-
- ASSERT(xobject != object);
-
- if (xobject->dentry > dentry)
- _p = &(*_p)->rb_left;
- else if (xobject->dentry < dentry)
- _p = &(*_p)->rb_right;
- else
- goto wait_for_old_object;
- }
-
- rb_link_node(&object->active_node, _parent, _p);
- rb_insert_color(&object->active_node, &cache->active_nodes);
-
- write_unlock(&cache->active_lock);
- _leave(" = 0");
- return 0;
-
- /* an old object from a previous incarnation is hogging the slot - we
- * need to wait for it to be destroyed */
-wait_for_old_object:
- trace_cachefiles_wait_active(object, dentry, xobject);
- clear_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags);
-
- if (fscache_object_is_live(&xobject->fscache)) {
- pr_err("\n");
- pr_err("Error: Unexpected object collision\n");
- cachefiles_printk_object(object, xobject);
- }
- atomic_inc(&xobject->usage);
- write_unlock(&cache->active_lock);
-
- if (test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)) {
- wait_queue_head_t *wq;
-
- signed long timeout = 60 * HZ;
- wait_queue_entry_t wait;
- bool requeue;
-
- /* if the object we're waiting for is queued for processing,
- * then just put ourselves on the queue behind it */
- if (work_pending(&xobject->fscache.work)) {
- _debug("queue OBJ%x behind OBJ%x immediately",
- object->fscache.debug_id,
- xobject->fscache.debug_id);
- goto requeue;
- }
-
- /* otherwise we sleep until either the object we're waiting for
- * is done, or the fscache_object is congested */
- wq = bit_waitqueue(&xobject->flags, CACHEFILES_OBJECT_ACTIVE);
- init_wait(&wait);
- requeue = false;
- do {
- prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE);
- if (!test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags))
- break;
-
- requeue = fscache_object_sleep_till_congested(&timeout);
- } while (timeout > 0 && !requeue);
- finish_wait(wq, &wait);
-
- if (requeue &&
- test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)) {
- _debug("queue OBJ%x behind OBJ%x after wait",
- object->fscache.debug_id,
- xobject->fscache.debug_id);
- goto requeue;
- }
-
- if (timeout <= 0) {
- pr_err("\n");
- pr_err("Error: Overlong wait for old active object to go away\n");
- cachefiles_printk_object(object, xobject);
- goto requeue;
- }
- }
-
- ASSERT(!test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags));
-
- cache->cache.ops->put_object(&xobject->fscache,
- (enum fscache_obj_ref_trace)cachefiles_obj_put_wait_retry);
- goto try_again;
-
-requeue:
- cache->cache.ops->put_object(&xobject->fscache,
- (enum fscache_obj_ref_trace)cachefiles_obj_put_wait_timeo);
- _leave(" = -ETIMEDOUT");
- return -ETIMEDOUT;
-}
-
-/*
- * Mark an object as being inactive.
- */
-void cachefiles_mark_object_inactive(struct cachefiles_cache *cache,
- struct cachefiles_object *object,
- blkcnt_t i_blocks)
-{
- struct dentry *dentry = object->dentry;
- struct inode *inode = d_backing_inode(dentry);
-
- trace_cachefiles_mark_inactive(object, dentry, inode);
-
- write_lock(&cache->active_lock);
- rb_erase(&object->active_node, &cache->active_nodes);
- clear_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags);
- write_unlock(&cache->active_lock);
-
- wake_up_bit(&object->flags, CACHEFILES_OBJECT_ACTIVE);
-
- /* This object can now be culled, so we need to let the daemon know
- * that there is something it can remove if it needs to.
- */
- atomic_long_add(i_blocks, &cache->b_released);
- if (atomic_inc_return(&cache->f_released))
- cachefiles_state_changed(cache);
-}
-
-/*
- * delete an object representation from the cache
- * - file backed objects are unlinked
- * - directory backed objects are stuffed into the graveyard for userspace to
- * delete
- * - unlocks the directory mutex
- */
-static int cachefiles_bury_object(struct cachefiles_cache *cache,
- struct cachefiles_object *object,
- struct dentry *dir,
- struct dentry *rep,
- bool preemptive,
- enum fscache_why_object_killed why)
-{
- struct dentry *grave, *trap;
- struct path path, path_to_graveyard;
- char nbuffer[8 + 8 + 1];
- int ret;
-
- _enter(",'%pd','%pd'", dir, rep);
-
- /* non-directories can just be unlinked */
- if (!d_is_dir(rep)) {
- _debug("unlink stale object");
-
- path.mnt = cache->mnt;
- path.dentry = dir;
- ret = security_path_unlink(&path, rep);
- if (ret < 0) {
- cachefiles_io_error(cache, "Unlink security error");
- } else {
- trace_cachefiles_unlink(object, rep, why);
- ret = vfs_unlink(&init_user_ns, d_inode(dir), rep,
- NULL);
-
- if (preemptive)
- cachefiles_mark_object_buried(cache, rep, why);
- }
-
- inode_unlock(d_inode(dir));
-
- if (ret == -EIO)
- cachefiles_io_error(cache, "Unlink failed");
-
- _leave(" = %d", ret);
- return ret;
- }
-
- /* directories have to be moved to the graveyard */
- _debug("move stale object to graveyard");
- inode_unlock(d_inode(dir));
-
-try_again:
- /* first step is to make up a grave dentry in the graveyard */
- sprintf(nbuffer, "%08x%08x",
- (uint32_t) ktime_get_real_seconds(),
- (uint32_t) atomic_inc_return(&cache->gravecounter));
-
- /* do the multiway lock magic */
- trap = lock_rename(cache->graveyard, dir);
-
- /* do some checks before getting the grave dentry */
- if (rep->d_parent != dir || IS_DEADDIR(d_inode(rep))) {
- /* the entry was probably culled when we dropped the parent dir
- * lock */
- unlock_rename(cache->graveyard, dir);
- _leave(" = 0 [culled?]");
- return 0;
- }
-
- if (!d_can_lookup(cache->graveyard)) {
- unlock_rename(cache->graveyard, dir);
- cachefiles_io_error(cache, "Graveyard no longer a directory");
- return -EIO;
- }
-
- if (trap == rep) {
- unlock_rename(cache->graveyard, dir);
- cachefiles_io_error(cache, "May not make directory loop");
- return -EIO;
- }
-
- if (d_mountpoint(rep)) {
- unlock_rename(cache->graveyard, dir);
- cachefiles_io_error(cache, "Mountpoint in cache");
- return -EIO;
- }
-
- grave = lookup_one_len(nbuffer, cache->graveyard, strlen(nbuffer));
- if (IS_ERR(grave)) {
- unlock_rename(cache->graveyard, dir);
-
- if (PTR_ERR(grave) == -ENOMEM) {
- _leave(" = -ENOMEM");
- return -ENOMEM;
- }
-
- cachefiles_io_error(cache, "Lookup error %ld",
- PTR_ERR(grave));
- return -EIO;
- }
-
- if (d_is_positive(grave)) {
- unlock_rename(cache->graveyard, dir);
- dput(grave);
- grave = NULL;
- cond_resched();
- goto try_again;
- }
-
- if (d_mountpoint(grave)) {
- unlock_rename(cache->graveyard, dir);
- dput(grave);
- cachefiles_io_error(cache, "Mountpoint in graveyard");
- return -EIO;
- }
-
- /* target should not be an ancestor of source */
- if (trap == grave) {
- unlock_rename(cache->graveyard, dir);
- dput(grave);
- cachefiles_io_error(cache, "May not make directory loop");
- return -EIO;
- }
-
- /* attempt the rename */
- path.mnt = cache->mnt;
- path.dentry = dir;
- path_to_graveyard.mnt = cache->mnt;
- path_to_graveyard.dentry = cache->graveyard;
- ret = security_path_rename(&path, rep, &path_to_graveyard, grave, 0);
- if (ret < 0) {
- cachefiles_io_error(cache, "Rename security error %d", ret);
- } else {
- struct renamedata rd = {
- .old_mnt_userns = &init_user_ns,
- .old_dir = d_inode(dir),
- .old_dentry = rep,
- .new_mnt_userns = &init_user_ns,
- .new_dir = d_inode(cache->graveyard),
- .new_dentry = grave,
- };
- trace_cachefiles_rename(object, rep, grave, why);
- ret = vfs_rename(&rd);
- if (ret != 0 && ret != -ENOMEM)
- cachefiles_io_error(cache,
- "Rename failed with error %d", ret);
-
- if (preemptive)
- cachefiles_mark_object_buried(cache, rep, why);
- }
-
- unlock_rename(cache->graveyard, dir);
- dput(grave);
- _leave(" = 0");
- return 0;
-}
-
-/*
- * delete an object representation from the cache
- */
-int cachefiles_delete_object(struct cachefiles_cache *cache,
- struct cachefiles_object *object)
-{
- struct dentry *dir;
- int ret;
-
- _enter(",OBJ%x{%pd}", object->fscache.debug_id, object->dentry);
-
- ASSERT(object->dentry);
- ASSERT(d_backing_inode(object->dentry));
- ASSERT(object->dentry->d_parent);
-
- dir = dget_parent(object->dentry);
-
- inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
-
- if (test_bit(FSCACHE_OBJECT_KILLED_BY_CACHE, &object->fscache.flags)) {
- /* object allocation for the same key preemptively deleted this
- * object's file so that it could create its own file */
- _debug("object preemptively buried");
- inode_unlock(d_inode(dir));
- ret = 0;
- } else {
- /* we need to check that our parent is _still_ our parent - it
- * may have been renamed */
- if (dir == object->dentry->d_parent) {
- ret = cachefiles_bury_object(cache, object, dir,
- object->dentry, false,
- FSCACHE_OBJECT_WAS_RETIRED);
- } else {
- /* it got moved, presumably by cachefilesd culling it,
- * so it's no longer in the key path and we can ignore
- * it */
- inode_unlock(d_inode(dir));
- ret = 0;
- }
- }
-
- dput(dir);
- _leave(" = %d", ret);
- return ret;
-}
-
-/*
- * walk from the parent object to the child object through the backing
- * filesystem, creating directories as we go
- */
-int cachefiles_walk_to_object(struct cachefiles_object *parent,
- struct cachefiles_object *object,
- const char *key,
- struct cachefiles_xattr *auxdata)
-{
- struct cachefiles_cache *cache;
- struct dentry *dir, *next = NULL;
- struct inode *inode;
- struct path path;
- const char *name;
- int ret, nlen;
-
- _enter("OBJ%x{%pd},OBJ%x,%s,",
- parent->fscache.debug_id, parent->dentry,
- object->fscache.debug_id, key);
-
- cache = container_of(parent->fscache.cache,
- struct cachefiles_cache, cache);
- path.mnt = cache->mnt;
-
- ASSERT(parent->dentry);
- ASSERT(d_backing_inode(parent->dentry));
-
- if (!(d_is_dir(parent->dentry))) {
- // TODO: convert file to dir
- _leave("looking up in none directory");
- return -ENOBUFS;
- }
-
- dir = dget(parent->dentry);
-
-advance:
- /* attempt to transit the first directory component */
- name = key;
- nlen = strlen(key);
-
- /* key ends in a double NUL */
- key = key + nlen + 1;
- if (!*key)
- key = NULL;
-
-lookup_again:
- /* search the current directory for the element name */
- _debug("lookup '%s'", name);
-
- inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
-
- next = lookup_one_len(name, dir, nlen);
- if (IS_ERR(next)) {
- trace_cachefiles_lookup(object, next, NULL);
- goto lookup_error;
- }
-
- inode = d_backing_inode(next);
- trace_cachefiles_lookup(object, next, inode);
- _debug("next -> %pd %s", next, inode ? "positive" : "negative");
-
- if (!key)
- object->new = !inode;
-
- /* if this element of the path doesn't exist, then the lookup phase
- * failed, and we can release any readers in the certain knowledge that
- * there's nothing for them to actually read */
- if (d_is_negative(next))
- fscache_object_lookup_negative(&object->fscache);
-
- /* we need to create the object if it's negative */
- if (key || object->type == FSCACHE_COOKIE_TYPE_INDEX) {
- /* index objects and intervening tree levels must be subdirs */
- if (d_is_negative(next)) {
- ret = cachefiles_has_space(cache, 1, 0);
- if (ret < 0)
- goto no_space_error;
-
- path.dentry = dir;
- ret = security_path_mkdir(&path, next, 0);
- if (ret < 0)
- goto create_error;
- ret = vfs_mkdir(&init_user_ns, d_inode(dir), next, 0);
- if (!key)
- trace_cachefiles_mkdir(object, next, ret);
- if (ret < 0)
- goto create_error;
-
- if (unlikely(d_unhashed(next))) {
- dput(next);
- inode_unlock(d_inode(dir));
- goto lookup_again;
- }
- ASSERT(d_backing_inode(next));
-
- _debug("mkdir -> %pd{ino=%lu}",
- next, d_backing_inode(next)->i_ino);
-
- } else if (!d_can_lookup(next)) {
- pr_err("inode %lu is not a directory\n",
- d_backing_inode(next)->i_ino);
- ret = -ENOBUFS;
- goto error;
- }
-
- } else {
- /* non-index objects start out life as files */
- if (d_is_negative(next)) {
- ret = cachefiles_has_space(cache, 1, 0);
- if (ret < 0)
- goto no_space_error;
-
- path.dentry = dir;
- ret = security_path_mknod(&path, next, S_IFREG, 0);
- if (ret < 0)
- goto create_error;
- ret = vfs_create(&init_user_ns, d_inode(dir), next,
- S_IFREG, true);
- trace_cachefiles_create(object, next, ret);
- if (ret < 0)
- goto create_error;
-
- ASSERT(d_backing_inode(next));
-
- _debug("create -> %pd{ino=%lu}",
- next, d_backing_inode(next)->i_ino);
-
- } else if (!d_can_lookup(next) &&
- !d_is_reg(next)
- ) {
- pr_err("inode %lu is not a file or directory\n",
- d_backing_inode(next)->i_ino);
- ret = -ENOBUFS;
- goto error;
- }
- }
-
- /* process the next component */
- if (key) {
- _debug("advance");
- inode_unlock(d_inode(dir));
- dput(dir);
- dir = next;
- next = NULL;
- goto advance;
- }
-
- /* we've found the object we were looking for */
- object->dentry = next;
-
- /* if we've found that the terminal object exists, then we need to
- * check its attributes and delete it if it's out of date */
- if (!object->new) {
- _debug("validate '%pd'", next);
-
- ret = cachefiles_check_object_xattr(object, auxdata);
- if (ret == -ESTALE) {
- /* delete the object (the deleter drops the directory
- * mutex) */
- object->dentry = NULL;
-
- ret = cachefiles_bury_object(cache, object, dir, next,
- true,
- FSCACHE_OBJECT_IS_STALE);
- dput(next);
- next = NULL;
-
- if (ret < 0)
- goto delete_error;
-
- _debug("redo lookup");
- fscache_object_retrying_stale(&object->fscache);
- goto lookup_again;
- }
- }
-
- /* note that we're now using this object */
- ret = cachefiles_mark_object_active(cache, object);
-
- inode_unlock(d_inode(dir));
- dput(dir);
- dir = NULL;
-
- if (ret == -ETIMEDOUT)
- goto mark_active_timed_out;
-
- _debug("=== OBTAINED_OBJECT ===");
-
- if (object->new) {
- /* attach data to a newly constructed terminal object */
- ret = cachefiles_set_object_xattr(object, auxdata);
- if (ret < 0)
- goto check_error;
- } else {
- /* always update the atime on an object we've just looked up
- * (this is used to keep track of culling, and atimes are only
- * updated by read, write and readdir but not lookup or
- * open) */
- path.dentry = next;
- touch_atime(&path);
- }
-
- /* open a file interface onto a data file */
- if (object->type != FSCACHE_COOKIE_TYPE_INDEX) {
- if (d_is_reg(object->dentry)) {
- const struct address_space_operations *aops;
-
- ret = -EPERM;
- aops = d_backing_inode(object->dentry)->i_mapping->a_ops;
- if (!aops->bmap)
- goto check_error;
- if (object->dentry->d_sb->s_blocksize > PAGE_SIZE)
- goto check_error;
-
- object->backer = object->dentry;
- } else {
- BUG(); // TODO: open file in data-class subdir
- }
- }
-
- object->new = 0;
- fscache_obtained_object(&object->fscache);
-
- _leave(" = 0 [%lu]", d_backing_inode(object->dentry)->i_ino);
- return 0;
-
-no_space_error:
- fscache_object_mark_killed(&object->fscache, FSCACHE_OBJECT_NO_SPACE);
-create_error:
- _debug("create error %d", ret);
- if (ret == -EIO)
- cachefiles_io_error(cache, "Create/mkdir failed");
- goto error;
-
-mark_active_timed_out:
- _debug("mark active timed out");
- goto release_dentry;
-
-check_error:
- _debug("check error %d", ret);
- cachefiles_mark_object_inactive(
- cache, object, d_backing_inode(object->dentry)->i_blocks);
-release_dentry:
- dput(object->dentry);
- object->dentry = NULL;
- goto error_out;
-
-delete_error:
- _debug("delete error %d", ret);
- goto error_out2;
-
-lookup_error:
- _debug("lookup error %ld", PTR_ERR(next));
- ret = PTR_ERR(next);
- if (ret == -EIO)
- cachefiles_io_error(cache, "Lookup failed");
- next = NULL;
-error:
- inode_unlock(d_inode(dir));
- dput(next);
-error_out2:
- dput(dir);
-error_out:
- _leave(" = error %d", -ret);
- return ret;
-}
-
-/*
- * get a subdirectory
- */
-struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
- struct dentry *dir,
- const char *dirname)
-{
- struct dentry *subdir;
- struct path path;
- int ret;
-
- _enter(",,%s", dirname);
-
- /* search the current directory for the element name */
- inode_lock(d_inode(dir));
-
-retry:
- subdir = lookup_one_len(dirname, dir, strlen(dirname));
- if (IS_ERR(subdir)) {
- if (PTR_ERR(subdir) == -ENOMEM)
- goto nomem_d_alloc;
- goto lookup_error;
- }
-
- _debug("subdir -> %pd %s",
- subdir, d_backing_inode(subdir) ? "positive" : "negative");
-
- /* we need to create the subdir if it doesn't exist yet */
- if (d_is_negative(subdir)) {
- ret = cachefiles_has_space(cache, 1, 0);
- if (ret < 0)
- goto mkdir_error;
-
- _debug("attempt mkdir");
-
- path.mnt = cache->mnt;
- path.dentry = dir;
- ret = security_path_mkdir(&path, subdir, 0700);
- if (ret < 0)
- goto mkdir_error;
- ret = vfs_mkdir(&init_user_ns, d_inode(dir), subdir, 0700);
- if (ret < 0)
- goto mkdir_error;
-
- if (unlikely(d_unhashed(subdir))) {
- dput(subdir);
- goto retry;
- }
- ASSERT(d_backing_inode(subdir));
-
- _debug("mkdir -> %pd{ino=%lu}",
- subdir, d_backing_inode(subdir)->i_ino);
- }
-
- inode_unlock(d_inode(dir));
-
- /* we need to make sure the subdir is a directory */
- ASSERT(d_backing_inode(subdir));
-
- if (!d_can_lookup(subdir)) {
- pr_err("%s is not a directory\n", dirname);
- ret = -EIO;
- goto check_error;
- }
-
- ret = -EPERM;
- if (!(d_backing_inode(subdir)->i_opflags & IOP_XATTR) ||
- !d_backing_inode(subdir)->i_op->lookup ||
- !d_backing_inode(subdir)->i_op->mkdir ||
- !d_backing_inode(subdir)->i_op->create ||
- !d_backing_inode(subdir)->i_op->rename ||
- !d_backing_inode(subdir)->i_op->rmdir ||
- !d_backing_inode(subdir)->i_op->unlink)
- goto check_error;
-
- _leave(" = [%lu]", d_backing_inode(subdir)->i_ino);
- return subdir;
-
-check_error:
- dput(subdir);
- _leave(" = %d [check]", ret);
- return ERR_PTR(ret);
-
-mkdir_error:
- inode_unlock(d_inode(dir));
- dput(subdir);
- pr_err("mkdir %s failed with error %d\n", dirname, ret);
- return ERR_PTR(ret);
-
-lookup_error:
- inode_unlock(d_inode(dir));
- ret = PTR_ERR(subdir);
- pr_err("Lookup %s failed with error %d\n", dirname, ret);
- return ERR_PTR(ret);
-
-nomem_d_alloc:
- inode_unlock(d_inode(dir));
- _leave(" = -ENOMEM");
- return ERR_PTR(-ENOMEM);
-}
-
-/*
- * find out if an object is in use or not
- * - if finds object and it's not in use:
- * - returns a pointer to the object and a reference on it
- * - returns with the directory locked
- */
-static struct dentry *cachefiles_check_active(struct cachefiles_cache *cache,
- struct dentry *dir,
- char *filename)
-{
- struct cachefiles_object *object;
- struct rb_node *_n;
- struct dentry *victim;
- int ret;
-
- //_enter(",%pd/,%s",
- // dir, filename);
-
- /* look up the victim */
- inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
-
- victim = lookup_one_len(filename, dir, strlen(filename));
- if (IS_ERR(victim))
- goto lookup_error;
-
- //_debug("victim -> %pd %s",
- // victim, d_backing_inode(victim) ? "positive" : "negative");
-
- /* if the object is no longer there then we probably retired the object
- * at the netfs's request whilst the cull was in progress
- */
- if (d_is_negative(victim)) {
- inode_unlock(d_inode(dir));
- dput(victim);
- _leave(" = -ENOENT [absent]");
- return ERR_PTR(-ENOENT);
- }
-
- /* check to see if we're using this object */
- read_lock(&cache->active_lock);
-
- _n = cache->active_nodes.rb_node;
-
- while (_n) {
- object = rb_entry(_n, struct cachefiles_object, active_node);
-
- if (object->dentry > victim)
- _n = _n->rb_left;
- else if (object->dentry < victim)
- _n = _n->rb_right;
- else
- goto object_in_use;
- }
-
- read_unlock(&cache->active_lock);
-
- //_leave(" = %pd", victim);
- return victim;
-
-object_in_use:
- read_unlock(&cache->active_lock);
- inode_unlock(d_inode(dir));
- dput(victim);
- //_leave(" = -EBUSY [in use]");
- return ERR_PTR(-EBUSY);
-
-lookup_error:
- inode_unlock(d_inode(dir));
- ret = PTR_ERR(victim);
- if (ret == -ENOENT) {
- /* file or dir now absent - probably retired by netfs */
- _leave(" = -ESTALE [absent]");
- return ERR_PTR(-ESTALE);
- }
-
- if (ret == -EIO) {
- cachefiles_io_error(cache, "Lookup failed");
- } else if (ret != -ENOMEM) {
- pr_err("Internal error: %d\n", ret);
- ret = -EIO;
- }
-
- _leave(" = %d", ret);
- return ERR_PTR(ret);
-}
-
-/*
- * cull an object if it's not in use
- * - called only by cache manager daemon
- */
-int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
- char *filename)
-{
- struct dentry *victim;
- int ret;
-
- _enter(",%pd/,%s", dir, filename);
-
- victim = cachefiles_check_active(cache, dir, filename);
- if (IS_ERR(victim))
- return PTR_ERR(victim);
-
- _debug("victim -> %pd %s",
- victim, d_backing_inode(victim) ? "positive" : "negative");
-
- /* okay... the victim is not being used so we can cull it
- * - start by marking it as stale
- */
- _debug("victim is cullable");
-
- ret = cachefiles_remove_object_xattr(cache, victim);
- if (ret < 0)
- goto error_unlock;
-
- /* actually remove the victim (drops the dir mutex) */
- _debug("bury");
-
- ret = cachefiles_bury_object(cache, NULL, dir, victim, false,
- FSCACHE_OBJECT_WAS_CULLED);
- if (ret < 0)
- goto error;
-
- dput(victim);
- _leave(" = 0");
- return 0;
-
-error_unlock:
- inode_unlock(d_inode(dir));
-error:
- dput(victim);
- if (ret == -ENOENT) {
- /* file or dir now absent - probably retired by netfs */
- _leave(" = -ESTALE [absent]");
- return -ESTALE;
- }
-
- if (ret != -ENOMEM) {
- pr_err("Internal error: %d\n", ret);
- ret = -EIO;
- }
-
- _leave(" = %d", ret);
- return ret;
-}
-
-/*
- * find out if an object is in use or not
- * - called only by cache manager daemon
- * - returns -EBUSY or 0 to indicate whether an object is in use or not
- */
-int cachefiles_check_in_use(struct cachefiles_cache *cache, struct dentry *dir,
- char *filename)
-{
- struct dentry *victim;
-
- //_enter(",%pd/,%s",
- // dir, filename);
-
- victim = cachefiles_check_active(cache, dir, filename);
- if (IS_ERR(victim))
- return PTR_ERR(victim);
-
- inode_unlock(d_inode(dir));
- dput(victim);
- //_leave(" = 0");
- return 0;
-}