[PATCH v2 38/53] cachefiles: Implement data storage object handling
David Howells
dhowells at redhat.com
Fri Oct 22 12:07:43 PDT 2021
Implement the handling of data storage objects, including the following
pieces:
(1) An S_KERNEL_FILE inode flag is provided that a kernel service,
e.g. cachefiles, can set to ward off other kernel services and drivers
(including itself) from using files it is actively using.
(2) Allocation of a cachefiles_object struct for storing state.
(3) Rendering the binary key into something that can be used as a
filename. A number of encoding are considered, including plain text,
hex rendering of arrays of le32 or be32 words or a base64 encoding.
(4) Lookup and creation of a file on disk, using a tmpfile if the file
isn't yet present. The file is then opened, sized for DIO and the
file handle is attached to the cachefiles_object struct. The inode is
marked S_KERNEL_FILE to indicate that it's in use by a kernel service.
(5) Reading and checking the xattr on a file to check coherency,
(6) Resizing an object, using truncate and/or fallocate to adjust the
object.
(7) Invalidation of an object, creating a tmpfile and switching the file
pointer in the cachefiles object.
(8) Committing a file to disk, including setting the coherency xattr on it
and, if necessary, creating a hard link to it.
Note that this would be a good place to use Omar Sandoval's vfs_link()
with AT_LINK_REPLACE[1] as I may have to unlink an old file before I
can link a tmpfile into place.
(9) Withdrawal of open objects when a cache is being withdrawn or a cookie
is relinquished. This involves committing or discarding the file.
(10) Culling a file at the behest of the daemon.
(11) A method by which the daemon can query to see if a file is in use by
the cache.
Changes
=======
ver #2)
- Disabled a debugging statement.
Signed-off-by: David Howells <dhowells at redhat.com>
Link: https://lore.kernel.org/r/163363935000.1980952.15279841414072653108.stgit@warthog.procyon.org.uk [1]
cc: linux-cachefs at redhat.com
---
fs/cachefiles/Makefile | 4
fs/cachefiles/bind.c | 32 ++
fs/cachefiles/daemon.c | 46 ++
fs/cachefiles/interface.c | 438 ++++++++++++++++++++++
fs/cachefiles/internal.h | 57 +++
fs/cachefiles/key.c | 142 +++++++
fs/cachefiles/main.c | 16 +
fs/cachefiles/namei.c | 739 +++++++++++++++++++++++++++++++++++++
fs/cachefiles/xattr.c | 181 +++++++++
include/linux/fs.h | 1
include/trace/events/cachefiles.h | 354 ++++++++++++++++++
include/trace/events/fscache.h | 4
12 files changed, 2010 insertions(+), 4 deletions(-)
create mode 100644 fs/cachefiles/key.c
create mode 100644 fs/cachefiles/xattr.c
diff --git a/fs/cachefiles/Makefile b/fs/cachefiles/Makefile
index 607f7c684a97..5dd99ca8df05 100644
--- a/fs/cachefiles/Makefile
+++ b/fs/cachefiles/Makefile
@@ -7,10 +7,12 @@ cachefiles-y := \
bind.o \
daemon.o \
interface.o \
+ key.o \
main.o \
namei.o \
security.o \
- volume.o
+ volume.o \
+ xattr.o
cachefiles-$(CONFIG_CACHEFILES_ERROR_INJECTION) += error_inject.o
diff --git a/fs/cachefiles/bind.c b/fs/cachefiles/bind.c
index 70924997b0cc..59c9d141f1fe 100644
--- a/fs/cachefiles/bind.c
+++ b/fs/cachefiles/bind.c
@@ -236,6 +236,36 @@ static int cachefiles_daemon_add_cache(struct cachefiles_cache *cache)
return ret;
}
+/*
+ * Mark all the objects as being out of service and queue them all for cleanup.
+ */
+static void cachefiles_withdraw_objects(struct cachefiles_cache *cache)
+{
+ struct cachefiles_object *object;
+ unsigned int count = 0;
+
+ _enter("");
+
+ spin_lock(&cache->object_list_lock);
+
+ while (!list_empty(&cache->object_list)) {
+ object = list_first_entry(&cache->object_list,
+ struct cachefiles_object, cache_link);
+ cachefiles_see_object(object, cachefiles_obj_see_withdrawal);
+ list_del_init(&object->cache_link);
+ fscache_withdraw_cookie(object->cookie);
+ count++;
+ if ((count & 63) == 0) {
+ spin_unlock(&cache->object_list_lock);
+ cond_resched();
+ spin_lock(&cache->object_list_lock);
+ }
+ }
+
+ spin_unlock(&cache->object_list_lock);
+ _leave(" [%u objs]", count);
+}
+
/*
* Withdraw volumes.
*/
@@ -276,7 +306,7 @@ static void cachefiles_withdraw_cache(struct cachefiles_cache *cache)
/* we now have to destroy all the active objects pertaining to this
* cache - which we do by passing them off to thread pool to be
* disposed of */
- // PLACEHOLDER: Withdraw objects
+ cachefiles_withdraw_objects(cache);
/* wait for all extant objects to finish their outstanding operations
* and go away */
diff --git a/fs/cachefiles/daemon.c b/fs/cachefiles/daemon.c
index c23d22a5d4a6..50ec292c7213 100644
--- a/fs/cachefiles/daemon.c
+++ b/fs/cachefiles/daemon.c
@@ -548,6 +548,10 @@ static int cachefiles_daemon_tag(struct cachefiles_cache *cache, char *args)
*/
static int cachefiles_daemon_cull(struct cachefiles_cache *cache, char *args)
{
+ struct path path;
+ const struct cred *saved_cred;
+ int ret;
+
_enter(",%s", args);
if (strchr(args, '/'))
@@ -563,7 +567,24 @@ static int cachefiles_daemon_cull(struct cachefiles_cache *cache, char *args)
return -EIO;
}
- return -EOPNOTSUPP; // PLACEHOLDER: Implement culling
+ /* extract the directory dentry from the cwd */
+ get_fs_pwd(current->fs, &path);
+
+ if (!d_can_lookup(path.dentry))
+ goto notdir;
+
+ cachefiles_begin_secure(cache, &saved_cred);
+ ret = cachefiles_cull(cache, path.dentry, args);
+ cachefiles_end_secure(cache, saved_cred);
+
+ path_put(&path);
+ _leave(" = %d", ret);
+ return ret;
+
+notdir:
+ path_put(&path);
+ pr_err("cull command requires dirfd to be a directory\n");
+ return -ENOTDIR;
inval:
pr_err("cull command requires dirfd and filename\n");
@@ -599,6 +620,10 @@ static int cachefiles_daemon_debug(struct cachefiles_cache *cache, char *args)
*/
static int cachefiles_daemon_inuse(struct cachefiles_cache *cache, char *args)
{
+ struct path path;
+ const struct cred *saved_cred;
+ int ret;
+
//_enter(",%s", args);
if (strchr(args, '/'))
@@ -614,7 +639,24 @@ static int cachefiles_daemon_inuse(struct cachefiles_cache *cache, char *args)
return -EIO;
}
- return -EOPNOTSUPP; // PLACEHOLDER: Implement check in use
+ /* extract the directory dentry from the cwd */
+ get_fs_pwd(current->fs, &path);
+
+ if (!d_can_lookup(path.dentry))
+ goto notdir;
+
+ cachefiles_begin_secure(cache, &saved_cred);
+ ret = cachefiles_check_in_use(cache, path.dentry, args);
+ cachefiles_end_secure(cache, saved_cred);
+
+ path_put(&path);
+ //_leave(" = %d", ret);
+ return ret;
+
+notdir:
+ path_put(&path);
+ pr_err("inuse command requires dirfd to be a directory\n");
+ return -ENOTDIR;
inval:
pr_err("inuse command requires dirfd and filename\n");
diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c
index 8624ee52b98b..b4a0bd2e803f 100644
--- a/fs/cachefiles/interface.c
+++ b/fs/cachefiles/interface.c
@@ -13,6 +13,310 @@
#include <trace/events/fscache.h>
#include "internal.h"
+static atomic_t cachefiles_object_debug_id;
+
+static int cachefiles_attr_changed(struct cachefiles_object *object);
+
+/*
+ * Allocate a cache object record.
+ */
+static
+struct cachefiles_object *cachefiles_alloc_object(struct fscache_cookie *cookie)
+{
+ struct fscache_volume *vcookie = cookie->volume;
+ struct cachefiles_object *object;
+ struct cachefiles_volume *volume = vcookie->cache_priv;
+ int n_accesses;
+
+ _enter("{%s},%x,", vcookie->key, cookie->debug_id);
+
+ object = kmem_cache_zalloc(cachefiles_object_jar, cachefiles_gfp);
+ if (!object)
+ return NULL;
+
+ atomic_set(&object->usage, 1);
+
+ spin_lock_init(&object->lock);
+ INIT_LIST_HEAD(&object->cache_link);
+ object->volume = volume;
+ object->debug_id = atomic_inc_return(&cachefiles_object_debug_id);
+ object->cookie = fscache_get_cookie(cookie, fscache_cookie_get_attach_object);
+
+ atomic_inc(&vcookie->cache->object_count);
+ trace_cachefiles_ref(object->debug_id, cookie->debug_id, 1,
+ cachefiles_obj_new);
+
+ /* Get a ref on the cookie and keep its n_accesses counter raised by 1
+ * to prevent wakeups from transitioning it to 0 until we're
+ * withdrawing caching services from it.
+ */
+ n_accesses = atomic_inc_return(&cookie->n_accesses);
+ trace_fscache_access(cookie->debug_id, refcount_read(&cookie->ref),
+ n_accesses, fscache_access_cache_pin);
+ set_bit(FSCACHE_COOKIE_NACC_ELEVATED, &cookie->flags);
+ return object;
+}
+
+/*
+ * Attempt to look up the nominated node in this cache
+ */
+static bool cachefiles_lookup_cookie(struct fscache_cookie *cookie)
+{
+ struct cachefiles_object *object;
+ struct cachefiles_cache *cache = cookie->volume->cache->cache_priv;
+ const struct cred *saved_cred;
+ bool success;
+
+ object = cachefiles_alloc_object(cookie);
+ if (!object)
+ goto fail;
+
+ _enter("{OBJ%x}", object->debug_id);
+
+ if (!cachefiles_cook_key(object))
+ goto fail_put;
+
+ cookie->cache_priv = object;
+
+ /* look up the key, creating any missing bits */
+ cachefiles_begin_secure(cache, &saved_cred);
+ success = cachefiles_look_up_object(object);
+ cachefiles_end_secure(cache, saved_cred);
+
+ if (!success)
+ goto fail_withdraw;
+
+ cachefiles_see_object(object, cachefiles_obj_see_lookup_cookie);
+
+ spin_lock(&cache->object_list_lock);
+ list_add(&object->cache_link, &cache->object_list);
+ spin_unlock(&cache->object_list_lock);
+ cachefiles_attr_changed(object);
+ _leave(" = t");
+ return true;
+
+fail_withdraw:
+ cachefiles_see_object(object, cachefiles_obj_see_lookup_failed);
+ clear_bit(FSCACHE_COOKIE_IS_CACHING, &object->flags);
+ fscache_set_cookie_stage(cookie, FSCACHE_COOKIE_STAGE_FAILED);
+ _debug("failed c=%08x o=%08x", cookie->debug_id, object->debug_id);
+ /* The caller holds an access count on the cookie, so we need them to
+ * drop it before we can withdraw the object.
+ */
+ return false;
+
+fail_put:
+ cachefiles_put_object(object, cachefiles_obj_put_alloc_fail);
+fail:
+ return false;
+}
+
+/*
+ * Note that an object has been seen.
+ */
+void cachefiles_see_object(struct cachefiles_object *object,
+ enum cachefiles_obj_ref_trace why)
+{
+ trace_cachefiles_ref(object->debug_id, object->cookie->debug_id,
+ atomic_read(&object->usage), why);
+}
+
+/*
+ * increment the usage count on an inode object (may fail if unmounting)
+ */
+struct cachefiles_object *cachefiles_grab_object(struct cachefiles_object *object,
+ enum cachefiles_obj_ref_trace why)
+{
+ int u;
+
+ u = atomic_inc_return(&object->usage);
+ trace_cachefiles_ref(object->debug_id, object->cookie->debug_id, u, why);
+ return object;
+}
+
+/*
+ * Shorten the backing object to discard any dirty data and free up
+ * any unused granules.
+ */
+static bool cachefiles_shorten_object(struct cachefiles_object *object,
+ struct file *file, loff_t new_size)
+{
+ struct cachefiles_cache *cache = object->volume->cache;
+ struct inode *inode = file_inode(file);
+ loff_t i_size, dio_size;
+ int ret;
+
+ dio_size = round_up(new_size, CACHEFILES_DIO_BLOCK_SIZE);
+ i_size = i_size_read(inode);
+
+ trace_cachefiles_trunc(object, inode, i_size, dio_size,
+ cachefiles_trunc_shrink);
+ ret = cachefiles_inject_remove_error();
+ if (ret == 0)
+ ret = vfs_truncate(&file->f_path, dio_size);
+ if (ret < 0) {
+ trace_cachefiles_io_error(object, file_inode(file), ret,
+ cachefiles_trace_trunc_error);
+ cachefiles_io_error_obj(object, "Trunc-to-size failed %d", ret);
+ cachefiles_remove_object_xattr(cache, object, file->f_path.dentry);
+ return false;
+ }
+
+ if (new_size < dio_size) {
+ trace_cachefiles_trunc(object, inode, dio_size, new_size,
+ cachefiles_trunc_dio_adjust);
+ ret = cachefiles_inject_write_error();
+ if (ret == 0)
+ ret = vfs_fallocate(file, FALLOC_FL_ZERO_RANGE,
+ new_size, dio_size);
+ if (ret < 0) {
+ trace_cachefiles_io_error(object, file_inode(file), ret,
+ cachefiles_trace_fallocate_error);
+ cachefiles_io_error_obj(object, "Trunc-to-dio-size failed %d", ret);
+ cachefiles_remove_object_xattr(cache, object, file->f_path.dentry);
+ return false;
+ }
+ }
+
+ return true;
+}
+
+/*
+ * Resize the backing object.
+ */
+static void cachefiles_resize_cookie(struct netfs_cache_resources *cres,
+ loff_t new_size)
+{
+ struct cachefiles_object *object = cachefiles_cres_object(cres);
+ struct cachefiles_cache *cache = object->volume->cache;
+ struct fscache_cookie *cookie = object->cookie;
+ const struct cred *saved_cred;
+ struct file *file = cachefiles_cres_file(cres);
+ loff_t old_size = cookie->object_size;
+
+ _enter("%llu->%llu", old_size, new_size);
+
+ if (new_size < old_size) {
+ cachefiles_begin_secure(cache, &saved_cred);
+ cachefiles_shorten_object(object, file, new_size);
+ cachefiles_end_secure(cache, saved_cred);
+ object->cookie->object_size = new_size;
+ return;
+ }
+
+ /* The file is being expanded. We don't need to do anything
+ * particularly. cookie->initial_size doesn't change and so the point
+ * at which we have to download before doesn't change.
+ */
+ cookie->object_size = new_size;
+}
+
+/*
+ * Commit changes to the object as we drop it.
+ */
+static void cachefiles_commit_object(struct cachefiles_object *object,
+ struct cachefiles_cache *cache)
+{
+ bool update = false;
+
+ if (test_and_clear_bit(FSCACHE_COOKIE_LOCAL_WRITE, &object->cookie->flags))
+ update = true;
+ if (test_and_clear_bit(FSCACHE_COOKIE_NEEDS_UPDATE, &object->cookie->flags))
+ update = true;
+ if (update)
+ cachefiles_set_object_xattr(object);
+
+ if (test_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags))
+ cachefiles_commit_tmpfile(cache, object);
+}
+
+/*
+ * Finalise and object and close the VFS structs that we have.
+ */
+static void cachefiles_clean_up_object(struct cachefiles_object *object,
+ struct cachefiles_cache *cache)
+{
+ if (test_bit(FSCACHE_COOKIE_RETIRED, &object->cookie->flags)) {
+ if (!test_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags)) {
+ cachefiles_see_object(object, cachefiles_obj_see_clean_delete);
+ _debug("- inval object OBJ%x", object->debug_id);
+ cachefiles_delete_object(object, FSCACHE_OBJECT_WAS_RETIRED);
+ } else {
+ cachefiles_see_object(object, cachefiles_obj_see_clean_drop_tmp);
+ _debug("- inval object OBJ%x tmpfile", object->debug_id);
+ }
+ } else {
+ cachefiles_see_object(object, cachefiles_obj_see_clean_commit);
+ cachefiles_commit_object(object, cache);
+ }
+
+ cachefiles_unmark_inode_in_use(object, object->file);
+ if (object->file) {
+ fput(object->file);
+ object->file = NULL;
+ }
+}
+
+/*
+ * Withdraw caching for a cookie.
+ */
+static void cachefiles_withdraw_cookie(struct fscache_cookie *cookie)
+{
+ struct cachefiles_object *object = cookie->cache_priv;
+ struct cachefiles_cache *cache = object->volume->cache;
+ const struct cred *saved_cred;
+
+ _enter("o=%x", object->debug_id);
+ cachefiles_see_object(object, cachefiles_obj_see_withdraw_cookie);
+
+ if (!list_empty(&object->cache_link)) {
+ spin_lock(&cache->object_list_lock);
+ cachefiles_see_object(object, cachefiles_obj_see_withdrawal);
+ list_del_init(&object->cache_link);
+ spin_unlock(&cache->object_list_lock);
+ }
+
+ if (object->file) {
+ cachefiles_begin_secure(cache, &saved_cred);
+ cachefiles_clean_up_object(object, cache);
+ cachefiles_end_secure(cache, saved_cred);
+ }
+
+ cookie->cache_priv = NULL;
+ cachefiles_put_object(object, cachefiles_obj_put_detach);
+}
+
+/*
+ * dispose of a reference to an object
+ */
+void cachefiles_put_object(struct cachefiles_object *object,
+ enum cachefiles_obj_ref_trace why)
+{
+ unsigned int object_debug_id = object->debug_id;
+ unsigned int cookie_debug_id = object->cookie->debug_id;
+ struct fscache_cache *cache;
+ int u;
+
+ u = atomic_dec_return(&object->usage);
+ trace_cachefiles_ref(object_debug_id, cookie_debug_id, u, why);
+ if (u == 0) {
+ _debug("- kill object OBJ%x", object_debug_id);
+
+ ASSERTCMP(object->file, ==, NULL);
+
+ kfree(object->d_name);
+
+ cache = object->volume->cache->cache;
+ fscache_put_cookie(object->cookie, fscache_cookie_put_object);
+ object->cookie = NULL;
+ kmem_cache_free(cachefiles_object_jar, object);
+ if (atomic_dec_and_test(&cache->object_count))
+ wake_up_all(&cachefiles_clearance_wq);
+ }
+
+ _leave("");
+}
+
/*
* sync a cache
*/
@@ -37,8 +341,142 @@ void cachefiles_sync_cache(struct cachefiles_cache *cache)
ret);
}
+/*
+ * notification the attributes on an object have changed
+ * - called with reads/writes excluded by FS-Cache
+ */
+static int cachefiles_attr_changed(struct cachefiles_object *object)
+{
+ struct cachefiles_cache *cache = object->volume->cache;
+ const struct cred *saved_cred;
+ struct iattr newattrs;
+ struct file *file = object->file;
+ uint64_t ni_size;
+ loff_t oi_size;
+ int ret;
+
+ ni_size = object->cookie->object_size;
+ ni_size = round_up(ni_size, CACHEFILES_DIO_BLOCK_SIZE);
+
+ _enter("{OBJ%x},[%llu]",
+ object->debug_id, (unsigned long long) ni_size);
+
+ if (!file)
+ return -ENOBUFS;
+
+ oi_size = i_size_read(file_inode(file));
+ if (oi_size == ni_size)
+ return 0;
+
+ cachefiles_begin_secure(cache, &saved_cred);
+ inode_lock(file_inode(file));
+
+ /* if there's an extension to a partial page at the end of the backing
+ * file, we need to discard the partial page so that we pick up new
+ * data after it */
+ if (oi_size & ~PAGE_MASK && ni_size > oi_size) {
+ _debug("discard tail %llx", oi_size);
+ newattrs.ia_valid = ATTR_SIZE;
+ newattrs.ia_size = oi_size & PAGE_MASK;
+ ret = cachefiles_inject_remove_error();
+ if (ret == 0)
+ ret = notify_change(&init_user_ns, file->f_path.dentry,
+ &newattrs, NULL);
+ if (ret < 0)
+ goto truncate_failed;
+ }
+
+ newattrs.ia_valid = ATTR_SIZE;
+ newattrs.ia_size = ni_size;
+ ret = cachefiles_inject_write_error();
+ if (ret == 0)
+ ret = notify_change(&init_user_ns, file->f_path.dentry,
+ &newattrs, NULL);
+
+truncate_failed:
+ inode_unlock(file_inode(file));
+ cachefiles_end_secure(cache, saved_cred);
+
+ if (ret < 0)
+ trace_cachefiles_io_error(NULL, file_inode(file), ret,
+ cachefiles_trace_notify_change_error);
+ if (ret == -EIO) {
+ cachefiles_io_error_obj(object, "Size set failed");
+ ret = -ENOBUFS;
+ }
+
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * Invalidate the storage associated with a cookie.
+ */
+static bool cachefiles_invalidate_cookie(struct fscache_cookie *cookie)
+{
+ struct cachefiles_object *object = cookie->cache_priv;
+ struct file *new_file, *old_file;
+ bool old_tmpfile;
+
+ _enter("o=%x,[%llu]", object->debug_id, object->cookie->object_size);
+
+ old_tmpfile = test_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags);
+
+ if (!object->file) {
+ fscache_set_cookie_stage(cookie, FSCACHE_COOKIE_STAGE_ACTIVE);
+ _leave(" = t [light]");
+ return true;
+ }
+
+ new_file = cachefiles_create_tmpfile(object);
+ if (IS_ERR(new_file))
+ goto failed;
+
+ /* Substitute the VFS target */
+ _debug("sub");
+ spin_lock(&object->lock);
+
+ old_file = object->file;
+ object->file = new_file;
+ object->content_info = CACHEFILES_CONTENT_NO_DATA;
+ set_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags);
+ set_bit(FSCACHE_COOKIE_NEEDS_UPDATE, &object->cookie->flags);
+
+ spin_unlock(&object->lock);
+ _debug("subbed");
+
+ /* Allow I/O to take place again */
+ fscache_set_cookie_stage(cookie, FSCACHE_COOKIE_STAGE_ACTIVE);
+
+ if (old_file) {
+ if (!old_tmpfile) {
+ struct cachefiles_volume *volume = object->volume;
+ struct dentry *fan = volume->fanout[(u8)object->key_hash];
+
+ inode_lock_nested(d_inode(fan), I_MUTEX_PARENT);
+ cachefiles_bury_object(volume->cache, object, fan,
+ old_file->f_path.dentry,
+ FSCACHE_OBJECT_INVALIDATED);
+ }
+ fput(old_file);
+ }
+
+ _leave(" = t");
+ return true;
+
+failed:
+ fscache_set_cookie_stage(cookie, FSCACHE_COOKIE_STAGE_FAILED);
+ _leave(" = f");
+ return false;
+}
+
const struct fscache_cache_ops cachefiles_cache_ops = {
.name = "cachefiles",
.acquire_volume = cachefiles_acquire_volume,
.free_volume = cachefiles_free_volume,
+ .lookup_cookie = cachefiles_lookup_cookie,
+ .withdraw_cookie = cachefiles_withdraw_cookie,
+ .invalidate_cookie = cachefiles_invalidate_cookie,
+ .resize_cookie = cachefiles_resize_cookie,
+ .prepare_to_write = cachefiles_prepare_to_write,
};
diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h
index 828b888a8bf3..3fa23710fc6f 100644
--- a/fs/cachefiles/internal.h
+++ b/fs/cachefiles/internal.h
@@ -19,6 +19,8 @@
#include <linux/workqueue.h>
#include <linux/security.h>
+#define CACHEFILES_DIO_BLOCK_SIZE 4096
+
struct cachefiles_cache;
struct cachefiles_object;
@@ -27,6 +29,8 @@ extern unsigned cachefiles_debug;
#define CACHEFILES_DEBUG_KLEAVE 2
#define CACHEFILES_DEBUG_KDEBUG 4
+#define cachefiles_gfp (__GFP_RECLAIM | __GFP_NORETRY | __GFP_NOMEMALLOC)
+
enum cachefiles_content {
/* These values are saved on disk */
CACHEFILES_CONTENT_NO_DATA = 0, /* No content stored */
@@ -114,6 +118,18 @@ struct cachefiles_cache {
#include <trace/events/cachefiles.h>
+static inline
+struct file *cachefiles_cres_file(struct netfs_cache_resources *cres)
+{
+ return cres->cache_priv2;
+}
+
+static inline
+struct cachefiles_object *cachefiles_cres_object(struct netfs_cache_resources *cres)
+{
+ return fscache_cres_cookie(cres)->cache_priv;
+}
+
/*
* note change of state for daemon
*/
@@ -182,15 +198,45 @@ static inline int cachefiles_inject_remove_error(void)
* interface.c
*/
extern const struct fscache_cache_ops cachefiles_cache_ops;
+extern void cachefiles_see_object(struct cachefiles_object *object,
+ enum cachefiles_obj_ref_trace why);
+extern struct cachefiles_object *cachefiles_grab_object(struct cachefiles_object *object,
+ enum cachefiles_obj_ref_trace why);
+extern void cachefiles_put_object(struct cachefiles_object *object,
+ enum cachefiles_obj_ref_trace why);
extern void cachefiles_sync_cache(struct cachefiles_cache *cache);
+/*
+ * key.c
+ */
+extern bool cachefiles_cook_key(struct cachefiles_object *object);
+
/*
* namei.c
*/
+extern void cachefiles_unmark_inode_in_use(struct cachefiles_object *object,
+ struct file *file);
+extern int cachefiles_bury_object(struct cachefiles_cache *cache,
+ struct cachefiles_object *object,
+ struct dentry *dir,
+ struct dentry *rep,
+ enum fscache_why_object_killed why);
+extern int cachefiles_delete_object(struct cachefiles_object *object,
+ enum fscache_why_object_killed why);
+extern bool cachefiles_look_up_object(struct cachefiles_object *object);
extern struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
struct dentry *dir,
const char *name);
+extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
+ char *filename);
+
+extern int cachefiles_check_in_use(struct cachefiles_cache *cache,
+ struct dentry *dir, char *filename);
+extern struct file *cachefiles_create_tmpfile(struct cachefiles_object *object);
+extern bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache,
+ struct cachefiles_object *object);
+
/*
* security.c
*/
@@ -218,6 +264,17 @@ void cachefiles_acquire_volume(struct fscache_volume *volume);
void cachefiles_free_volume(struct fscache_volume *volume);
void cachefiles_withdraw_volume(struct cachefiles_volume *volume);
+/*
+ * xattr.c
+ */
+extern int cachefiles_set_object_xattr(struct cachefiles_object *object);
+extern int cachefiles_check_auxdata(struct cachefiles_object *object,
+ struct file *file);
+extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
+ struct cachefiles_object *object,
+ struct dentry *dentry);
+extern void cachefiles_prepare_to_write(struct fscache_cookie *cookie);
+
/*
* error handling
*/
diff --git a/fs/cachefiles/key.c b/fs/cachefiles/key.c
new file mode 100644
index 000000000000..10f2be29f892
--- /dev/null
+++ b/fs/cachefiles/key.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Key to pathname encoder
+ *
+ * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells at redhat.com)
+ */
+
+#include <linux/slab.h>
+#include "internal.h"
+
+static const char cachefiles_charmap[64] =
+ "0123456789" /* 0 - 9 */
+ "abcdefghijklmnopqrstuvwxyz" /* 10 - 35 */
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZ" /* 36 - 61 */
+ "_-" /* 62 - 63 */
+ ;
+
+static const char cachefiles_filecharmap[256] = {
+ /* we skip space and tab and control chars */
+ [33 ... 46] = 1, /* '!' -> '.' */
+ /* we skip '/' as it's significant to pathwalk */
+ [48 ... 127] = 1, /* '0' -> '~' */
+};
+
+static inline unsigned int how_many_hex_digits(unsigned int x)
+{
+ return x ? round_up(ilog2(x) + 1, 4) / 4 : 0;
+}
+
+/*
+ * turn the raw key into something cooked
+ * - the key may be up to NAME_MAX in length (including the length word)
+ * - "base64" encode the strange keys, mapping 3 bytes of raw to four of
+ * cooked
+ * - need to cut the cooked key into 252 char lengths (189 raw bytes)
+ */
+bool cachefiles_cook_key(struct cachefiles_object *object)
+{
+ const u8 *key = fscache_get_key(object->cookie), *kend;
+ unsigned char sum, ch;
+ unsigned int acc, i, n, nle, nbe, keylen = object->cookie->key_len;
+ unsigned int b64len, len, print, pad;
+ char *name, sep;
+
+ _enter(",%u,%*phN", keylen, keylen, key);
+
+ BUG_ON(keylen > NAME_MAX - 3);
+
+ sum = 0;
+ print = 1;
+ for (i = 0; i < keylen; i++) {
+ ch = key[i];
+ sum += ch;
+ print &= cachefiles_filecharmap[ch];
+ }
+ object->key_hash = sum;
+
+ /* If the path is usable ASCII, then we render it directly */
+ if (print) {
+ len = 1 + keylen + 1;
+ name = kmalloc(len, cachefiles_gfp);
+ if (!name)
+ return false;
+
+ name[0] = 'D'; /* Data object type, string encoding */
+ name[1 + keylen] = 0;
+ memcpy(name + 1, key, keylen);
+ goto success;
+ }
+
+ /* See if it makes sense to encode it as "hex,hex,hex" for each 32-bit
+ * chunk. We rely on the key having been padded out to a whole number
+ * of 32-bit words.
+ */
+ n = round_up(keylen, 4);
+ nbe = nle = 0;
+ for (i = 0; i < n; i += 4) {
+ u32 be = be32_to_cpu(*(__be32 *)(key + i));
+ u32 le = le32_to_cpu(*(__le32 *)(key + i));
+
+ nbe += 1 + how_many_hex_digits(be);
+ nle += 1 + how_many_hex_digits(le);
+ }
+
+ b64len = DIV_ROUND_UP(keylen, 3);
+ pad = b64len * 3 - keylen;
+ b64len = 2 + b64len * 4; /* Length if we base64-encode it */
+ _debug("len=%u nbe=%u nle=%u b64=%u", keylen, nbe, nle, b64len);
+ if (nbe < b64len || nle < b64len) {
+ unsigned int nlen = min(nbe, nle) + 1;
+ name = kmalloc(nlen, cachefiles_gfp);
+ if (!name)
+ return false;
+ sep = (nbe <= nle) ? 'S' : 'T'; /* Encoding indicator */
+ len = 0;
+ for (i = 0; i < n; i += 4) {
+ u32 x;
+ if (nbe <= nle)
+ x = be32_to_cpu(*(__be32 *)(key + i));
+ else
+ x = le32_to_cpu(*(__le32 *)(key + i));
+ name[len++] = sep;
+ if (x != 0)
+ len += snprintf(name + len, nlen - len, "%x", x);
+ sep = ',';
+ }
+ goto success;
+ }
+
+ /* We need to base64-encode it */
+ name = kmalloc(b64len + 1, cachefiles_gfp);
+ if (!name)
+ return false;
+
+ name[0] = 'E';
+ name[1] = '0' + pad;
+ len = 2;
+ kend = key + keylen;
+ do {
+ acc = *key++;
+ if (key < kend) {
+ acc |= *key++ << 8;
+ if (key < kend)
+ acc |= *key++ << 16;
+ }
+
+ name[len++] = cachefiles_charmap[acc & 63];
+ acc >>= 6;
+ name[len++] = cachefiles_charmap[acc & 63];
+ acc >>= 6;
+ name[len++] = cachefiles_charmap[acc & 63];
+ acc >>= 6;
+ name[len++] = cachefiles_charmap[acc & 63];
+ } while (key < kend);
+
+success:
+ name[len] = 0;
+ object->d_name = name;
+ object->d_name_len = len;
+ _leave(" = %s", object->d_name);
+ return true;
+}
diff --git a/fs/cachefiles/main.c b/fs/cachefiles/main.c
index 22581099236b..7a459074d715 100644
--- a/fs/cachefiles/main.c
+++ b/fs/cachefiles/main.c
@@ -31,6 +31,8 @@ MODULE_DESCRIPTION("Mounted-filesystem based cache");
MODULE_AUTHOR("Red Hat, Inc.");
MODULE_LICENSE("GPL");
+struct kmem_cache *cachefiles_object_jar;
+
static struct miscdevice cachefiles_dev = {
.minor = MISC_DYNAMIC_MINOR,
.name = "cachefiles",
@@ -52,9 +54,22 @@ static int __init cachefiles_init(void)
if (ret < 0)
goto error_dev;
+ /* create an object jar */
+ ret = -ENOMEM;
+ cachefiles_object_jar =
+ kmem_cache_create("cachefiles_object_jar",
+ sizeof(struct cachefiles_object),
+ 0, SLAB_HWCACHE_ALIGN, NULL);
+ if (!cachefiles_object_jar) {
+ pr_notice("Failed to allocate an object jar\n");
+ goto error_object_jar;
+ }
+
pr_info("Loaded\n");
return 0;
+error_object_jar:
+ misc_deregister(&cachefiles_dev);
error_dev:
cachefiles_unregister_error_injection();
error_einj:
@@ -71,6 +86,7 @@ static void __exit cachefiles_exit(void)
{
pr_info("Unloading\n");
+ kmem_cache_destroy(cachefiles_object_jar);
misc_deregister(&cachefiles_dev);
cachefiles_unregister_error_injection();
}
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index 69915dde0a83..ad87fb28b602 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -18,6 +18,431 @@
#include <linux/slab.h>
#include "internal.h"
+/*
+ * Mark the backing file as being a cache file if it's not already in use so.
+ */
+static bool cachefiles_mark_inode_in_use(struct cachefiles_object *object,
+ struct dentry *dentry)
+{
+ struct inode *inode = d_backing_inode(dentry);
+ bool can_use = false;
+
+ _enter(",%x", object->debug_id);
+
+ inode_lock(inode);
+
+ if (!(inode->i_flags & S_KERNEL_FILE)) {
+ inode->i_flags |= S_KERNEL_FILE;
+ trace_cachefiles_mark_active(object, inode);
+ can_use = true;
+ } else {
+ pr_notice("cachefiles: Inode already in use: %pD\n", object->file);
+ }
+
+ inode_unlock(inode);
+ return can_use;
+}
+
+/*
+ * Unmark a backing inode.
+ */
+void cachefiles_unmark_inode_in_use(struct cachefiles_object *object,
+ struct file *file)
+{
+ struct inode *inode = file_inode(file);
+
+ if (!inode)
+ return;
+
+ inode_lock(inode);
+ inode->i_flags &= ~S_KERNEL_FILE;
+ inode_unlock(inode);
+ trace_cachefiles_mark_inactive(object, inode);
+}
+
+/*
+ * Mark an object as being inactive.
+ */
+static void cachefiles_mark_object_inactive(struct cachefiles_object *object,
+ struct file *file)
+{
+ struct cachefiles_cache *cache = object->volume->cache;
+ blkcnt_t i_blocks = file_inode(file)->i_blocks;
+
+ /* 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
+ */
+int cachefiles_bury_object(struct cachefiles_cache *cache,
+ struct cachefiles_object *object,
+ struct dentry *dir,
+ struct dentry *rep,
+ 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);
+
+ if (rep->d_parent != dir) {
+ inode_unlock(d_inode(dir));
+ _leave(" = -ESTALE");
+ return -ESTALE;
+ }
+
+ /* 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);
+ dget(rep); /* Stop the dentry being negated if it's
+ * only pinned by a file struct.
+ */
+ ret = cachefiles_inject_remove_error();
+ if (ret == 0)
+ ret = vfs_unlink(&init_user_ns, d_inode(dir), rep, NULL);
+ dput(rep);
+ }
+
+ inode_unlock(d_inode(dir));
+
+ if (ret < 0) {
+ trace_cachefiles_vfs_error(object, d_inode(dir), ret,
+ cachefiles_trace_unlink_error);
+ 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);
+ trace_cachefiles_vfs_error(object, d_inode(cache->graveyard),
+ PTR_ERR(grave),
+ cachefiles_trace_lookup_error);
+
+ 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 = cachefiles_inject_read_error();
+ if (ret == 0)
+ ret = vfs_rename(&rd);
+ if (ret != 0)
+ trace_cachefiles_vfs_error(object, d_inode(dir),
+ PTR_ERR(grave),
+ cachefiles_trace_rename_error);
+ if (ret != 0 && ret != -ENOMEM)
+ cachefiles_io_error(cache,
+ "Rename failed with error %d", ret);
+ }
+
+ unlock_rename(cache->graveyard, dir);
+ dput(grave);
+ _leave(" = 0");
+ return 0;
+}
+
+static int cachefiles_unlink(struct cachefiles_object *object,
+ struct dentry *fan, struct dentry *dentry,
+ enum fscache_why_object_killed why)
+{
+ struct path path = {
+ .mnt = object->volume->cache->mnt,
+ .dentry = fan,
+ };
+ int ret;
+
+ trace_cachefiles_unlink(object, dentry, why);
+ ret = security_path_unlink(&path, dentry);
+ if (ret == 0)
+ ret = cachefiles_inject_remove_error();
+ if (ret == 0)
+ ret = vfs_unlink(&init_user_ns, d_backing_inode(fan), dentry, NULL);
+ if (ret != 0)
+ trace_cachefiles_vfs_error(object, d_backing_inode(fan), ret,
+ cachefiles_trace_unlink_error);
+ return ret;
+}
+
+/*
+ * Delete a cache file.
+ */
+int cachefiles_delete_object(struct cachefiles_object *object,
+ enum fscache_why_object_killed why)
+{
+ struct cachefiles_volume *volume = object->volume;
+ struct dentry *dentry = object->file->f_path.dentry;
+ struct dentry *fan = volume->fanout[(u8)object->key_hash];
+ int ret;
+
+ _enter(",OBJ%x{%pD}", object->debug_id, object->file);
+
+ /* Stop the dentry being negated if it's only pinned by a file struct. */
+ dget(dentry);
+
+ inode_lock_nested(d_backing_inode(fan), I_MUTEX_PARENT);
+ ret = cachefiles_unlink(object, fan, dentry, why);
+ inode_unlock(d_backing_inode(fan));
+ dput(dentry);
+
+ if (ret < 0)
+ trace_cachefiles_vfs_error(object, d_backing_inode(fan), ret,
+ cachefiles_trace_unlink_error);
+ if (ret < 0 && ret != -ENOENT)
+ cachefiles_io_error(volume->cache, "Unlink failed");
+ return ret;
+}
+
+/*
+ * Create a new file.
+ */
+static bool cachefiles_create_file(struct cachefiles_object *object)
+{
+ struct file *file;
+ int ret;
+
+ ret = cachefiles_has_space(object->volume->cache, 1, 0);
+ if (ret < 0)
+ return false;
+
+ file = cachefiles_create_tmpfile(object);
+ if (IS_ERR(file))
+ return false;
+
+ set_bit(FSCACHE_COOKIE_NEEDS_UPDATE, &object->cookie->flags);
+ set_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags);
+ _debug("create -> %pD{ino=%lu}", file, file_inode(file)->i_ino);
+ object->file = file;
+ return true;
+}
+
+/*
+ * Open an existing file, checking its attributes and replacing it if it is
+ * stale.
+ */
+static bool cachefiles_open_file(struct cachefiles_object *object,
+ struct dentry *dentry)
+{
+ struct cachefiles_cache *cache = object->volume->cache;
+ struct file *file;
+ struct path path;
+ int ret;
+
+ _enter("%pd", dentry);
+
+ if (!cachefiles_mark_inode_in_use(object, dentry))
+ return false;
+
+ /* We need to open a file interface onto a data file now as we can't do
+ * it on demand because writeback called from do_exit() sees
+ * current->fs == NULL - which breaks d_path() called from ext4 open.
+ */
+ path.mnt = cache->mnt;
+ path.dentry = dentry;
+ file = open_with_fake_path(&path, O_RDWR | O_LARGEFILE | O_DIRECT,
+ d_backing_inode(dentry), cache->cache_cred);
+ if (IS_ERR(file)) {
+ trace_cachefiles_vfs_error(object, d_backing_inode(dentry),
+ PTR_ERR(file),
+ cachefiles_trace_open_error);
+ goto error;
+ }
+
+ if (unlikely(!file->f_op->read_iter) ||
+ unlikely(!file->f_op->write_iter)) {
+ pr_notice("Cache does not support read_iter and write_iter\n");
+ goto error_fput;
+ }
+ _debug("file -> %pd positive", dentry);
+
+ ret = cachefiles_check_auxdata(object, file);
+ if (ret < 0)
+ goto check_failed;
+
+ object->file = file;
+
+ /* 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).
+ */
+ touch_atime(&file->f_path);
+ dput(dentry);
+ return true;
+
+check_failed:
+ fscache_cookie_lookup_negative(object->cookie);
+ cachefiles_unmark_inode_in_use(object, file);
+ cachefiles_mark_object_inactive(object, file);
+ if (ret == -ESTALE) {
+ fput(file);
+ dput(dentry);
+ return cachefiles_create_file(object);
+ }
+error_fput:
+ fput(file);
+error:
+ dput(dentry);
+ return false;
+}
+
+/*
+ * walk from the parent object to the child object through the backing
+ * filesystem, creating directories as we go
+ */
+bool cachefiles_look_up_object(struct cachefiles_object *object)
+{
+ struct cachefiles_volume *volume = object->volume;
+ struct dentry *dentry, *fan = volume->fanout[(u8)object->key_hash];
+ int ret;
+
+ _enter("OBJ%x,%s,", object->debug_id, object->d_name);
+
+ /* Look up path "cache/vol/fanout/file". */
+ ret = cachefiles_inject_read_error();
+ if (ret == 0)
+ dentry = lookup_positive_unlocked(object->d_name, fan,
+ object->d_name_len);
+ else
+ dentry = ERR_PTR(ret);
+ trace_cachefiles_lookup(object, dentry);
+ if (IS_ERR(dentry)) {
+ if (dentry == ERR_PTR(-ENOENT))
+ goto new_file;
+ if (dentry == ERR_PTR(-EIO))
+ cachefiles_io_error_obj(object, "Lookup failed");
+ return false;
+ }
+
+ if (!d_is_reg(dentry)) {
+ pr_err("%pd is not a file\n", dentry);
+ inode_lock_nested(d_inode(fan), I_MUTEX_PARENT);
+ ret = cachefiles_bury_object(volume->cache, object, fan, dentry,
+ FSCACHE_OBJECT_IS_WEIRD);
+ dput(dentry);
+ if (ret < 0)
+ return false;
+ goto new_file;
+ }
+
+ if (!cachefiles_open_file(object, dentry))
+ return false;
+
+ _leave(" = t [%lu]", file_inode(object->file)->i_ino);
+ return true;
+
+new_file:
+ fscache_cookie_lookup_negative(object->cookie);
+ return cachefiles_create_file(object);
+}
+
/*
* get a subdirectory
*/
@@ -131,3 +556,317 @@ struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
_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 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);
+ }
+
+ //_leave(" = %pd", victim);
+ return victim;
+
+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;
+ struct inode *inode;
+ int ret;
+
+ _enter(",%pd/,%s", dir, filename);
+
+ victim = cachefiles_check_active(cache, dir, filename);
+ if (IS_ERR(victim))
+ return PTR_ERR(victim);
+
+ /* check to see if someone is using this object */
+ inode = d_inode(victim);
+ inode_lock(inode);
+ if (inode->i_flags & S_KERNEL_FILE) {
+ ret = -EBUSY;
+ } else {
+ inode->i_flags |= S_KERNEL_FILE;
+ ret = 0;
+ }
+ inode_unlock(inode);
+ if (ret < 0)
+ goto error_unlock;
+
+ _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, NULL, 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,
+ 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;
+ int ret = 0;
+
+ //_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));
+ if (d_inode(victim)->i_flags & S_KERNEL_FILE)
+ ret = -EBUSY;
+ dput(victim);
+ //_leave(" = 0");
+ return ret;
+}
+
+/*
+ * Create a temporary file and leave it unattached and un-xattr'd until the
+ * time comes to discard the object from memory.
+ */
+struct file *cachefiles_create_tmpfile(struct cachefiles_object *object)
+{
+ struct cachefiles_volume *volume = object->volume;
+ struct cachefiles_cache *cache = volume->cache;
+ const struct cred *saved_cred;
+ struct dentry *fan = volume->fanout[(u8)object->key_hash];
+ struct file *file;
+ struct path path;
+ uint64_t ni_size = object->cookie->object_size;
+ long ret;
+
+ ni_size = round_up(ni_size, CACHEFILES_DIO_BLOCK_SIZE);
+
+ cachefiles_begin_secure(cache, &saved_cred);
+
+ path.mnt = cache->mnt;
+ ret = cachefiles_inject_write_error();
+ if (ret == 0)
+ path.dentry = vfs_tmpfile(&init_user_ns, fan, S_IFREG, O_RDWR);
+ else
+ path.dentry = ERR_PTR(ret);
+ if (IS_ERR(path.dentry)) {
+ trace_cachefiles_vfs_error(object, d_inode(fan), PTR_ERR(path.dentry),
+ cachefiles_trace_tmpfile_error);
+ if (PTR_ERR(path.dentry) == -EIO)
+ cachefiles_io_error_obj(object, "Failed to create tmpfile");
+ file = ERR_CAST(path.dentry);
+ goto out;
+ }
+
+ trace_cachefiles_tmpfile(object, d_backing_inode(path.dentry));
+
+ if (!cachefiles_mark_inode_in_use(object, path.dentry)) {
+ file = ERR_PTR(-EBUSY);
+ goto out_dput;
+ }
+
+ if (ni_size > 0) {
+ trace_cachefiles_trunc(object, d_backing_inode(path.dentry), 0, ni_size,
+ cachefiles_trunc_expand_tmpfile);
+ ret = cachefiles_inject_write_error();
+ if (ret == 0)
+ ret = vfs_truncate(&path, ni_size);
+ if (ret < 0) {
+ trace_cachefiles_vfs_error(
+ object, d_backing_inode(path.dentry), ret,
+ cachefiles_trace_trunc_error);
+ file = ERR_PTR(ret);
+ goto out_dput;
+ }
+ }
+
+ file = open_with_fake_path(&path, O_RDWR | O_LARGEFILE | O_DIRECT,
+ d_backing_inode(path.dentry), cache->cache_cred);
+ if (IS_ERR(file)) {
+ trace_cachefiles_vfs_error(object, d_backing_inode(path.dentry),
+ PTR_ERR(file),
+ cachefiles_trace_open_error);
+ goto out_dput;
+ }
+ if (unlikely(!file->f_op->read_iter) ||
+ unlikely(!file->f_op->write_iter)) {
+ fput(file);
+ pr_notice("Cache does not support read_iter and write_iter\n");
+ file = ERR_PTR(-EINVAL);
+ }
+
+out_dput:
+ dput(path.dentry);
+out:
+ cachefiles_end_secure(cache, saved_cred);
+ return file;
+}
+
+/*
+ * Attempt to link a temporary file into its rightful place in the cache.
+ */
+bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache,
+ struct cachefiles_object *object)
+{
+ struct cachefiles_volume *volume = object->volume;
+ struct dentry *dentry, *fan = volume->fanout[(u8)object->key_hash];
+ bool success = false;
+ int ret;
+
+ _enter(",%pD", object->file);
+
+ inode_lock_nested(d_inode(fan), I_MUTEX_PARENT);
+ ret = cachefiles_inject_read_error();
+ if (ret == 0)
+ dentry = lookup_one_len(object->d_name, fan, object->d_name_len);
+ else
+ dentry = ERR_PTR(ret);
+ if (IS_ERR(dentry)) {
+ trace_cachefiles_vfs_error(object, d_inode(fan), PTR_ERR(dentry),
+ cachefiles_trace_lookup_error);
+ _debug("lookup fail %ld", PTR_ERR(dentry));
+ goto out_unlock;
+ }
+
+ if (!d_is_negative(dentry)) {
+ if (d_backing_inode(dentry) == file_inode(object->file)) {
+ success = true;
+ goto out_dput;
+ }
+
+ ret = cachefiles_unlink(object, fan, dentry, FSCACHE_OBJECT_IS_STALE);
+ if (ret < 0) {
+ trace_cachefiles_vfs_error(object, d_inode(fan), ret,
+ cachefiles_trace_unlink_error);
+ goto out_dput;
+ }
+
+ dput(dentry);
+ ret = cachefiles_inject_read_error();
+ if (ret == 0)
+ dentry = lookup_one_len(object->d_name, fan, object->d_name_len);
+ else
+ dentry = ERR_PTR(ret);
+ if (IS_ERR(dentry)) {
+ trace_cachefiles_vfs_error(object, d_inode(fan), PTR_ERR(dentry),
+ cachefiles_trace_lookup_error);
+ _debug("lookup fail %ld", PTR_ERR(dentry));
+ goto out_unlock;
+ }
+ }
+
+ ret = cachefiles_inject_read_error();
+ if (ret == 0)
+ ret = vfs_link(object->file->f_path.dentry, &init_user_ns,
+ d_inode(fan), dentry, NULL);
+ if (ret < 0) {
+ trace_cachefiles_vfs_error(object, d_inode(fan), PTR_ERR(dentry),
+ cachefiles_trace_link_error);
+ _debug("link fail %d", ret);
+ } else {
+ trace_cachefiles_link(object, file_inode(object->file));
+ spin_lock(&object->lock);
+ /* TODO: Do we want to switch the file pointer to the new dentry? */
+ clear_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags);
+ spin_unlock(&object->lock);
+ success = true;
+ }
+
+out_dput:
+ dput(dentry);
+out_unlock:
+ inode_unlock(d_inode(fan));
+ _leave(" = %u", success);
+ return success;
+}
diff --git a/fs/cachefiles/xattr.c b/fs/cachefiles/xattr.c
new file mode 100644
index 000000000000..0601c46a22ef
--- /dev/null
+++ b/fs/cachefiles/xattr.c
@@ -0,0 +1,181 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* CacheFiles extended attribute management
+ *
+ * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells at 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/slab.h>
+#include "internal.h"
+
+#define CACHEFILES_COOKIE_TYPE_DATA 1
+
+struct cachefiles_xattr {
+ __be64 object_size; /* Actual size of the object */
+ __be64 zero_point; /* Size after which server has no data not written by us */
+ __u8 type; /* Type of object */
+ __u8 content; /* Content presence (enum cachefiles_content) */
+ __u8 data[]; /* netfs coherency data */
+} __packed;
+
+static const char cachefiles_xattr_cache[] =
+ XATTR_USER_PREFIX "CacheFiles.cache";
+
+/*
+ * set the state xattr on a cache file
+ */
+int cachefiles_set_object_xattr(struct cachefiles_object *object)
+{
+ struct cachefiles_xattr *buf;
+ struct dentry *dentry;
+ struct file *file = object->file;
+ unsigned int len = object->cookie->aux_len;
+ int ret;
+
+ if (!file)
+ return -ESTALE;
+ dentry = file->f_path.dentry;
+
+ _enter("%x,#%d", object->debug_id, len);
+
+ buf = kmalloc(sizeof(struct cachefiles_xattr) + len, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ buf->object_size = cpu_to_be64(object->cookie->object_size);
+ buf->zero_point = 0;
+ buf->type = CACHEFILES_COOKIE_TYPE_DATA;
+ buf->content = object->content_info;
+ if (test_bit(FSCACHE_COOKIE_LOCAL_WRITE, &object->cookie->flags))
+ buf->content = CACHEFILES_CONTENT_DIRTY;
+ if (len > 0)
+ memcpy(buf->data, fscache_get_aux(object->cookie), len);
+
+ ret = cachefiles_inject_write_error();
+ if (ret == 0)
+ ret = vfs_setxattr(&init_user_ns, dentry, cachefiles_xattr_cache,
+ buf, sizeof(struct cachefiles_xattr) + len, 0);
+ if (ret < 0) {
+ trace_cachefiles_vfs_error(object, file_inode(file), ret,
+ cachefiles_trace_setxattr_error);
+ trace_cachefiles_coherency(object, file_inode(file)->i_ino,
+ buf->content,
+ cachefiles_coherency_set_fail);
+ if (ret != -ENOMEM)
+ cachefiles_io_error_obj(
+ object,
+ "Failed to set xattr with error %d", ret);
+ } else {
+ trace_cachefiles_coherency(object, file_inode(file)->i_ino,
+ buf->content,
+ cachefiles_coherency_set_ok);
+ }
+
+ kfree(buf);
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * check the consistency between the backing cache and the FS-Cache cookie
+ */
+int cachefiles_check_auxdata(struct cachefiles_object *object, struct file *file)
+{
+ struct cachefiles_xattr *buf;
+ struct dentry *dentry = file->f_path.dentry;
+ unsigned int len = object->cookie->aux_len, tlen;
+ const void *p = fscache_get_aux(object->cookie);
+ enum cachefiles_coherency_trace why;
+ ssize_t xlen;
+ int ret = -ESTALE;
+
+ tlen = sizeof(struct cachefiles_xattr) + len;
+ buf = kmalloc(tlen, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ xlen = cachefiles_inject_read_error();
+ if (xlen == 0)
+ xlen = vfs_getxattr(&init_user_ns, dentry, cachefiles_xattr_cache, buf, tlen);
+ if (xlen != tlen) {
+ if (xlen < 0)
+ trace_cachefiles_vfs_error(object, file_inode(file), xlen,
+ cachefiles_trace_getxattr_error);
+ if (xlen == -EIO)
+ cachefiles_io_error_obj(
+ object,
+ "Failed to read aux with error %zd", xlen);
+ why = cachefiles_coherency_check_xattr;
+ } else if (buf->type != CACHEFILES_COOKIE_TYPE_DATA) {
+ why = cachefiles_coherency_check_type;
+ } else if (memcmp(buf->data, p, len) != 0) {
+ why = cachefiles_coherency_check_aux;
+ } else if (be64_to_cpu(buf->object_size) != object->cookie->object_size) {
+ why = cachefiles_coherency_check_objsize;
+ } else if (buf->content == CACHEFILES_CONTENT_DIRTY) {
+ // TODO: Begin conflict resolution
+ pr_warn("Dirty object in cache\n");
+ why = cachefiles_coherency_check_dirty;
+ } else {
+ why = cachefiles_coherency_check_ok;
+ ret = 0;
+ }
+
+ trace_cachefiles_coherency(object, file_inode(file)->i_ino,
+ buf->content, why);
+ kfree(buf);
+ return ret;
+}
+
+/*
+ * remove the object's xattr to mark it stale
+ */
+int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
+ struct cachefiles_object *object,
+ struct dentry *dentry)
+{
+ int ret;
+
+ ret = cachefiles_inject_remove_error();
+ if (ret == 0)
+ ret = vfs_removexattr(&init_user_ns, dentry, cachefiles_xattr_cache);
+ if (ret < 0) {
+ trace_cachefiles_vfs_error(object, d_inode(dentry), ret,
+ cachefiles_trace_remxattr_error);
+ if (ret == -ENOENT || ret == -ENODATA)
+ ret = 0;
+ else if (ret != -ENOMEM)
+ cachefiles_io_error(cache,
+ "Can't remove xattr from %lu"
+ " (error %d)",
+ d_backing_inode(dentry)->i_ino, -ret);
+ }
+
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * Stick a marker on the cache object to indicate that it's dirty.
+ */
+void cachefiles_prepare_to_write(struct fscache_cookie *cookie)
+{
+ const struct cred *saved_cred;
+ struct cachefiles_object *object = cookie->cache_priv;
+ struct cachefiles_cache *cache = object->volume->cache;
+
+ _enter("c=%08x", object->cookie->debug_id);
+
+ if (!test_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags)) {
+ cachefiles_begin_secure(cache, &saved_cred);
+ cachefiles_set_object_xattr(object);
+ cachefiles_end_secure(cache, saved_cred);
+ }
+}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 908ea452a2cf..336739fed3e9 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2250,6 +2250,7 @@ struct super_operations {
#define S_ENCRYPTED (1 << 14) /* Encrypted file (using fs/crypto/) */
#define S_CASEFOLD (1 << 15) /* Casefolded file */
#define S_VERITY (1 << 16) /* Verity file (using fs/verity/) */
+#define S_KERNEL_FILE (1 << 17) /* File is in use by the kernel (eg. fs/cachefiles) */
/*
* Note that nosuid etc flags are inode-specific: setting some file-system
diff --git a/include/trace/events/cachefiles.h b/include/trace/events/cachefiles.h
index 9bd5a8a60801..5412991ab5e1 100644
--- a/include/trace/events/cachefiles.h
+++ b/include/trace/events/cachefiles.h
@@ -18,6 +18,60 @@
#ifndef __CACHEFILES_DECLARE_TRACE_ENUMS_ONCE_ONLY
#define __CACHEFILES_DECLARE_TRACE_ENUMS_ONCE_ONLY
+enum cachefiles_obj_ref_trace {
+ cachefiles_obj_get_ioreq,
+ cachefiles_obj_new,
+ cachefiles_obj_put_alloc_fail,
+ cachefiles_obj_put_detach,
+ cachefiles_obj_put_ioreq,
+ cachefiles_obj_see_clean_commit,
+ cachefiles_obj_see_clean_delete,
+ cachefiles_obj_see_clean_drop_tmp,
+ cachefiles_obj_see_lookup_cookie,
+ cachefiles_obj_see_lookup_failed,
+ cachefiles_obj_see_withdraw_cookie,
+ cachefiles_obj_see_withdrawal,
+};
+
+enum fscache_why_object_killed {
+ FSCACHE_OBJECT_IS_STALE,
+ FSCACHE_OBJECT_IS_WEIRD,
+ FSCACHE_OBJECT_INVALIDATED,
+ FSCACHE_OBJECT_NO_SPACE,
+ FSCACHE_OBJECT_WAS_RETIRED,
+ FSCACHE_OBJECT_WAS_CULLED,
+};
+
+enum cachefiles_coherency_trace {
+ cachefiles_coherency_check_aux,
+ cachefiles_coherency_check_content,
+ cachefiles_coherency_check_dirty,
+ cachefiles_coherency_check_len,
+ cachefiles_coherency_check_objsize,
+ cachefiles_coherency_check_ok,
+ cachefiles_coherency_check_type,
+ cachefiles_coherency_check_xattr,
+ cachefiles_coherency_set_fail,
+ cachefiles_coherency_set_ok,
+};
+
+enum cachefiles_trunc_trace {
+ cachefiles_trunc_dio_adjust,
+ cachefiles_trunc_expand_tmpfile,
+ cachefiles_trunc_shrink,
+};
+
+enum cachefiles_prepare_read_trace {
+ cachefiles_trace_read_after_eof,
+ cachefiles_trace_read_found_hole,
+ cachefiles_trace_read_found_part,
+ cachefiles_trace_read_have_data,
+ cachefiles_trace_read_no_data,
+ cachefiles_trace_read_no_file,
+ cachefiles_trace_read_seek_error,
+ cachefiles_trace_read_seek_nxio,
+};
+
enum cachefiles_error_trace {
cachefiles_trace_fallocate_error,
cachefiles_trace_getxattr_error,
@@ -43,6 +97,55 @@ enum cachefiles_error_trace {
/*
* Define enum -> string mappings for display.
*/
+#define cachefiles_obj_kill_traces \
+ EM(FSCACHE_OBJECT_IS_STALE, "stale") \
+ EM(FSCACHE_OBJECT_IS_WEIRD, "weird") \
+ EM(FSCACHE_OBJECT_INVALIDATED, "inval") \
+ EM(FSCACHE_OBJECT_NO_SPACE, "no_space") \
+ EM(FSCACHE_OBJECT_WAS_RETIRED, "was_retired") \
+ E_(FSCACHE_OBJECT_WAS_CULLED, "was_culled")
+
+#define cachefiles_obj_ref_traces \
+ EM(cachefiles_obj_get_ioreq, "GET ioreq") \
+ EM(cachefiles_obj_new, "NEW obj") \
+ EM(cachefiles_obj_put_alloc_fail, "PUT alloc_fail") \
+ EM(cachefiles_obj_put_detach, "PUT detach") \
+ EM(cachefiles_obj_put_ioreq, "PUT ioreq") \
+ EM(cachefiles_obj_see_clean_commit, "SEE clean_commit") \
+ EM(cachefiles_obj_see_clean_delete, "SEE clean_delete") \
+ EM(cachefiles_obj_see_clean_drop_tmp, "SEE clean_drop_tmp") \
+ EM(cachefiles_obj_see_lookup_cookie, "SEE lookup_cookie") \
+ EM(cachefiles_obj_see_lookup_failed, "SEE lookup_failed") \
+ EM(cachefiles_obj_see_withdraw_cookie, "SEE withdraw_cookie") \
+ E_(cachefiles_obj_see_withdrawal, "SEE withdrawal")
+
+#define cachefiles_coherency_traces \
+ EM(cachefiles_coherency_check_aux, "BAD aux ") \
+ EM(cachefiles_coherency_check_content, "BAD cont") \
+ EM(cachefiles_coherency_check_dirty, "BAD dirt") \
+ EM(cachefiles_coherency_check_len, "BAD len ") \
+ EM(cachefiles_coherency_check_objsize, "BAD osiz") \
+ EM(cachefiles_coherency_check_ok, "OK ") \
+ EM(cachefiles_coherency_check_type, "BAD type") \
+ EM(cachefiles_coherency_check_xattr, "BAD xatt") \
+ EM(cachefiles_coherency_set_fail, "SET fail") \
+ E_(cachefiles_coherency_set_ok, "SET ok ")
+
+#define cachefiles_trunc_traces \
+ EM(cachefiles_trunc_dio_adjust, "DIOADJ") \
+ EM(cachefiles_trunc_expand_tmpfile, "EXPTMP") \
+ E_(cachefiles_trunc_shrink, "SHRINK")
+
+#define cachefiles_prepare_read_traces \
+ EM(cachefiles_trace_read_after_eof, "after-eof ") \
+ EM(cachefiles_trace_read_found_hole, "found-hole") \
+ EM(cachefiles_trace_read_found_part, "found-part") \
+ EM(cachefiles_trace_read_have_data, "have-data ") \
+ EM(cachefiles_trace_read_no_data, "no-data ") \
+ EM(cachefiles_trace_read_no_file, "no-file ") \
+ EM(cachefiles_trace_read_seek_error, "seek-error") \
+ E_(cachefiles_trace_read_seek_nxio, "seek-enxio")
+
#define cachefiles_error_traces \
EM(cachefiles_trace_fallocate_error, "fallocate") \
EM(cachefiles_trace_getxattr_error, "getxattr") \
@@ -71,6 +174,11 @@ enum cachefiles_error_trace {
#define EM(a, b) TRACE_DEFINE_ENUM(a);
#define E_(a, b) TRACE_DEFINE_ENUM(a);
+cachefiles_obj_kill_traces;
+cachefiles_obj_ref_traces;
+cachefiles_coherency_traces;
+cachefiles_trunc_traces;
+cachefiles_prepare_read_traces;
cachefiles_error_traces;
/*
@@ -83,6 +191,252 @@ cachefiles_error_traces;
#define E_(a, b) { a, b }
+TRACE_EVENT(cachefiles_ref,
+ TP_PROTO(unsigned int object_debug_id,
+ unsigned int cookie_debug_id,
+ int usage,
+ enum cachefiles_obj_ref_trace why),
+
+ TP_ARGS(object_debug_id, cookie_debug_id, usage, why),
+
+ /* Note that obj may be NULL */
+ TP_STRUCT__entry(
+ __field(unsigned int, obj )
+ __field(unsigned int, cookie )
+ __field(enum cachefiles_obj_ref_trace, why )
+ __field(int, usage )
+ ),
+
+ TP_fast_assign(
+ __entry->obj = object_debug_id;
+ __entry->cookie = cookie_debug_id;
+ __entry->usage = usage;
+ __entry->why = why;
+ ),
+
+ TP_printk("c=%08x o=%08x u=%d %s",
+ __entry->cookie, __entry->obj, __entry->usage,
+ __print_symbolic(__entry->why, cachefiles_obj_ref_traces))
+ );
+
+TRACE_EVENT(cachefiles_lookup,
+ TP_PROTO(struct cachefiles_object *obj,
+ struct dentry *de),
+
+ TP_ARGS(obj, de),
+
+ TP_STRUCT__entry(
+ __field(unsigned int, obj )
+ __field(short, error )
+ __field(unsigned long, ino )
+ ),
+
+ TP_fast_assign(
+ __entry->obj = obj->debug_id;
+ __entry->ino = (!IS_ERR(de) && d_backing_inode(de) ?
+ d_backing_inode(de)->i_ino : 0);
+ __entry->error = IS_ERR(de) ? PTR_ERR(de) : 0;
+ ),
+
+ TP_printk("o=%08x i=%lx e=%d",
+ __entry->obj, __entry->ino, __entry->error)
+ );
+
+TRACE_EVENT(cachefiles_tmpfile,
+ TP_PROTO(struct cachefiles_object *obj, struct inode *backer),
+
+ TP_ARGS(obj, backer),
+
+ TP_STRUCT__entry(
+ __field(unsigned int, obj )
+ __field(unsigned int, backer )
+ ),
+
+ TP_fast_assign(
+ __entry->obj = obj->debug_id;
+ __entry->backer = backer->i_ino;
+ ),
+
+ TP_printk("o=%08x b=%08x",
+ __entry->obj,
+ __entry->backer)
+ );
+
+TRACE_EVENT(cachefiles_link,
+ TP_PROTO(struct cachefiles_object *obj, struct inode *backer),
+
+ TP_ARGS(obj, backer),
+
+ TP_STRUCT__entry(
+ __field(unsigned int, obj )
+ __field(unsigned int, backer )
+ ),
+
+ TP_fast_assign(
+ __entry->obj = obj->debug_id;
+ __entry->backer = backer->i_ino;
+ ),
+
+ TP_printk("o=%08x b=%08x",
+ __entry->obj,
+ __entry->backer)
+ );
+
+TRACE_EVENT(cachefiles_unlink,
+ TP_PROTO(struct cachefiles_object *obj,
+ struct dentry *de,
+ enum fscache_why_object_killed why),
+
+ TP_ARGS(obj, de, why),
+
+ /* Note that obj may be NULL */
+ TP_STRUCT__entry(
+ __field(unsigned int, obj )
+ __field(struct dentry *, de )
+ __field(enum fscache_why_object_killed, why )
+ ),
+
+ TP_fast_assign(
+ __entry->obj = obj ? obj->debug_id : UINT_MAX;
+ __entry->de = de;
+ __entry->why = why;
+ ),
+
+ TP_printk("o=%08x d=%p w=%s",
+ __entry->obj, __entry->de,
+ __print_symbolic(__entry->why, cachefiles_obj_kill_traces))
+ );
+
+TRACE_EVENT(cachefiles_rename,
+ TP_PROTO(struct cachefiles_object *obj,
+ struct dentry *de,
+ struct dentry *to,
+ enum fscache_why_object_killed why),
+
+ TP_ARGS(obj, de, to, why),
+
+ /* Note that obj may be NULL */
+ TP_STRUCT__entry(
+ __field(unsigned int, obj )
+ __field(struct dentry *, de )
+ __field(struct dentry *, to )
+ __field(enum fscache_why_object_killed, why )
+ ),
+
+ TP_fast_assign(
+ __entry->obj = obj ? obj->debug_id : UINT_MAX;
+ __entry->de = de;
+ __entry->to = to;
+ __entry->why = why;
+ ),
+
+ TP_printk("o=%08x d=%p t=%p w=%s",
+ __entry->obj, __entry->de, __entry->to,
+ __print_symbolic(__entry->why, cachefiles_obj_kill_traces))
+ );
+
+TRACE_EVENT(cachefiles_mark_active,
+ TP_PROTO(struct cachefiles_object *obj,
+ struct inode *inode),
+
+ TP_ARGS(obj, inode),
+
+ /* Note that obj may be NULL */
+ TP_STRUCT__entry(
+ __field(unsigned int, obj )
+ __field(ino_t, inode )
+ ),
+
+ TP_fast_assign(
+ __entry->obj = obj->debug_id;
+ __entry->inode = inode->i_ino;
+ ),
+
+ TP_printk("o=%08x i=%lx",
+ __entry->obj, __entry->inode)
+ );
+
+TRACE_EVENT(cachefiles_mark_inactive,
+ TP_PROTO(struct cachefiles_object *obj,
+ struct inode *inode),
+
+ TP_ARGS(obj, inode),
+
+ /* Note that obj may be NULL */
+ TP_STRUCT__entry(
+ __field(unsigned int, obj )
+ __field(ino_t, inode )
+ ),
+
+ TP_fast_assign(
+ __entry->obj = obj->debug_id;
+ __entry->inode = inode->i_ino;
+ ),
+
+ TP_printk("o=%08x i=%lx",
+ __entry->obj, __entry->inode)
+ );
+
+TRACE_EVENT(cachefiles_coherency,
+ TP_PROTO(struct cachefiles_object *obj,
+ ino_t ino,
+ enum cachefiles_content content,
+ enum cachefiles_coherency_trace why),
+
+ TP_ARGS(obj, ino, content, why),
+
+ /* Note that obj may be NULL */
+ TP_STRUCT__entry(
+ __field(unsigned int, obj )
+ __field(enum cachefiles_coherency_trace, why )
+ __field(enum cachefiles_content, content )
+ __field(u64, ino )
+ ),
+
+ TP_fast_assign(
+ __entry->obj = obj->debug_id;
+ __entry->why = why;
+ __entry->content = content;
+ __entry->ino = ino;
+ ),
+
+ TP_printk("o=%08x %s i=%llx c=%u",
+ __entry->obj,
+ __print_symbolic(__entry->why, cachefiles_coherency_traces),
+ __entry->ino,
+ __entry->content)
+ );
+
+TRACE_EVENT(cachefiles_trunc,
+ TP_PROTO(struct cachefiles_object *obj, struct inode *backer,
+ loff_t from, loff_t to, enum cachefiles_trunc_trace why),
+
+ TP_ARGS(obj, backer, from, to, why),
+
+ TP_STRUCT__entry(
+ __field(unsigned int, obj )
+ __field(unsigned int, backer )
+ __field(enum cachefiles_trunc_trace, why )
+ __field(loff_t, from )
+ __field(loff_t, to )
+ ),
+
+ TP_fast_assign(
+ __entry->obj = obj->debug_id;
+ __entry->backer = backer->i_ino;
+ __entry->from = from;
+ __entry->to = to;
+ __entry->why = why;
+ ),
+
+ TP_printk("o=%08x b=%08x %s l=%llx->%llx",
+ __entry->obj,
+ __entry->backer,
+ __print_symbolic(__entry->why, cachefiles_trunc_traces),
+ __entry->from,
+ __entry->to)
+ );
+
TRACE_EVENT(cachefiles_vfs_error,
TP_PROTO(struct cachefiles_object *obj, struct inode *backer,
int error, enum cachefiles_error_trace where),
diff --git a/include/trace/events/fscache.h b/include/trace/events/fscache.h
index b01784370963..3ebb874b5f0f 100644
--- a/include/trace/events/fscache.h
+++ b/include/trace/events/fscache.h
@@ -48,6 +48,7 @@ enum fscache_volume_trace {
enum fscache_cookie_trace {
fscache_cookie_collision,
fscache_cookie_discard,
+ fscache_cookie_get_attach_object,
fscache_cookie_get_end_access,
fscache_cookie_get_hash_collision,
fscache_cookie_get_inval_work,
@@ -56,6 +57,7 @@ enum fscache_cookie_trace {
fscache_cookie_new_acquire,
fscache_cookie_put_hash_collision,
fscache_cookie_put_lru,
+ fscache_cookie_put_object,
fscache_cookie_put_over_queued,
fscache_cookie_put_relinquish,
fscache_cookie_put_withdrawn,
@@ -119,6 +121,7 @@ enum fscache_access_trace {
#define fscache_cookie_traces \
EM(fscache_cookie_collision, "*COLLIDE*") \
EM(fscache_cookie_discard, "DISCARD ") \
+ EM(fscache_cookie_get_attach_object, "GET attch") \
EM(fscache_cookie_get_hash_collision, "GET hcoll") \
EM(fscache_cookie_get_end_access, "GQ endac") \
EM(fscache_cookie_get_inval_work, "GQ inval") \
@@ -127,6 +130,7 @@ enum fscache_access_trace {
EM(fscache_cookie_new_acquire, "NEW acq ") \
EM(fscache_cookie_put_hash_collision, "PUT hcoll") \
EM(fscache_cookie_put_lru, "PUT lru ") \
+ EM(fscache_cookie_put_object, "PUT obj ") \
EM(fscache_cookie_put_over_queued, "PQ overq") \
EM(fscache_cookie_put_relinquish, "PUT relnq") \
EM(fscache_cookie_put_withdrawn, "PUT wthdn") \
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