diff options
Diffstat (limited to 'fs/cachefiles/xattr.c')
-rw-r--r-- | fs/cachefiles/xattr.c | 421 |
1 files changed, 178 insertions, 243 deletions
diff --git a/fs/cachefiles/xattr.c b/fs/cachefiles/xattr.c index 9e82de668595..83f41bd0c3a9 100644 --- a/fs/cachefiles/xattr.c +++ b/fs/cachefiles/xattr.c @@ -1,7 +1,7 @@ // SPDX-License-Identifier: GPL-2.0-or-later /* CacheFiles extended attribute management * - * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. + * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */ @@ -15,310 +15,245 @@ #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"; /* - * check the type label on an object - * - done using xattrs + * set the state xattr on a cache file */ -int cachefiles_check_object_type(struct cachefiles_object *object) +int cachefiles_set_object_xattr(struct cachefiles_object *object) { - struct dentry *dentry = object->dentry; - char type[3], xtype[3]; + struct cachefiles_xattr *buf; + struct dentry *dentry; + struct file *file = object->file; + unsigned int len = object->cookie->aux_len; int ret; - ASSERT(dentry); - ASSERT(d_backing_inode(dentry)); - - if (!object->fscache.cookie) - strcpy(type, "C3"); - else - snprintf(type, 3, "%02x", object->fscache.cookie->def->type); - - _enter("%x{%s}", object->fscache.debug_id, type); + if (!file) + return -ESTALE; + dentry = file->f_path.dentry; - /* attempt to install a type label directly */ - ret = vfs_setxattr(&init_user_ns, dentry, cachefiles_xattr_cache, type, - 2, XATTR_CREATE); - if (ret == 0) { - _debug("SET"); /* we succeeded */ - goto error; - } + _enter("%x,#%d", object->debug_id, len); - if (ret != -EEXIST) { - pr_err("Can't set xattr on %pd [%lu] (err %d)\n", - dentry, d_backing_inode(dentry)->i_ino, - -ret); - goto error; - } + buf = kmalloc(sizeof(struct cachefiles_xattr) + len, GFP_KERNEL); + if (!buf) + return -ENOMEM; - /* read the current type label */ - ret = vfs_getxattr(&init_user_ns, dentry, cachefiles_xattr_cache, xtype, - 3); + 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) { - if (ret == -ERANGE) - goto bad_type_length; - - pr_err("Can't read xattr on %pd [%lu] (err %d)\n", - dentry, d_backing_inode(dentry)->i_ino, - -ret); - goto error; + 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); } - /* check the type is what we're expecting */ - if (ret != 2) - goto bad_type_length; - - if (xtype[0] != type[0] || xtype[1] != type[1]) - goto bad_type; - - ret = 0; - -error: + kfree(buf); _leave(" = %d", ret); return ret; - -bad_type_length: - pr_err("Cache object %lu type xattr length incorrect\n", - d_backing_inode(dentry)->i_ino); - ret = -EIO; - goto error; - -bad_type: - xtype[2] = 0; - pr_err("Cache object %pd [%lu] type %s not %s\n", - dentry, d_backing_inode(dentry)->i_ino, - xtype, type); - ret = -EIO; - goto error; } /* - * set the state xattr on a cache file + * check the consistency between the backing cache and the FS-Cache cookie */ -int cachefiles_set_object_xattr(struct cachefiles_object *object, - struct cachefiles_xattr *auxdata) +int cachefiles_check_auxdata(struct cachefiles_object *object, struct file *file) { - struct dentry *dentry = object->dentry; - int ret; - - ASSERT(dentry); - - _enter("%p,#%d", object, auxdata->len); + 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; - /* attempt to install the cache metadata directly */ - _debug("SET #%u", auxdata->len); + tlen = sizeof(struct cachefiles_xattr) + len; + buf = kmalloc(tlen, GFP_KERNEL); + if (!buf) + return -ENOMEM; - clear_bit(FSCACHE_COOKIE_AUX_UPDATED, &object->fscache.cookie->flags); - ret = vfs_setxattr(&init_user_ns, dentry, cachefiles_xattr_cache, - &auxdata->type, auxdata->len, XATTR_CREATE); - if (ret < 0 && ret != -ENOMEM) - cachefiles_io_error_obj( - object, - "Failed to set xattr with error %d", ret); + 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; + } - _leave(" = %d", ret); + trace_cachefiles_coherency(object, file_inode(file)->i_ino, + buf->content, why); + kfree(buf); return ret; } /* - * update the state xattr on a cache file + * remove the object's xattr to mark it stale */ -int cachefiles_update_object_xattr(struct cachefiles_object *object, - struct cachefiles_xattr *auxdata) +int cachefiles_remove_object_xattr(struct cachefiles_cache *cache, + struct cachefiles_object *object, + struct dentry *dentry) { - struct dentry *dentry = object->dentry; int ret; - if (!dentry) - return -ESTALE; - - _enter("%x,#%d", object->fscache.debug_id, auxdata->len); - - /* attempt to install the cache metadata directly */ - _debug("SET #%u", auxdata->len); - - clear_bit(FSCACHE_COOKIE_AUX_UPDATED, &object->fscache.cookie->flags); - ret = vfs_setxattr(&init_user_ns, dentry, cachefiles_xattr_cache, - &auxdata->type, auxdata->len, XATTR_REPLACE); - if (ret < 0 && ret != -ENOMEM) - cachefiles_io_error_obj( - object, - "Failed to update xattr with error %d", 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; } /* - * check the consistency between the backing cache and the FS-Cache cookie + * Stick a marker on the cache object to indicate that it's dirty. */ -int cachefiles_check_auxdata(struct cachefiles_object *object) +void cachefiles_prepare_to_write(struct fscache_cookie *cookie) { - struct cachefiles_xattr *auxbuf; - enum fscache_checkaux validity; - struct dentry *dentry = object->dentry; - ssize_t xlen; - int ret; - - ASSERT(dentry); - ASSERT(d_backing_inode(dentry)); - ASSERT(object->fscache.cookie->def->check_aux); - - auxbuf = kmalloc(sizeof(struct cachefiles_xattr) + 512, GFP_KERNEL); - if (!auxbuf) - return -ENOMEM; + const struct cred *saved_cred; + struct cachefiles_object *object = cookie->cache_priv; + struct cachefiles_cache *cache = object->volume->cache; - xlen = vfs_getxattr(&init_user_ns, dentry, cachefiles_xattr_cache, - &auxbuf->type, 512 + 1); - ret = -ESTALE; - if (xlen < 1 || - auxbuf->type != object->fscache.cookie->def->type) - goto error; + _enter("c=%08x", object->cookie->debug_id); - xlen--; - validity = fscache_check_aux(&object->fscache, &auxbuf->data, xlen, - i_size_read(d_backing_inode(dentry))); - if (validity != FSCACHE_CHECKAUX_OKAY) - goto error; - - ret = 0; -error: - kfree(auxbuf); - return ret; + 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); + } } /* - * check the state xattr on a cache file - * - return -ESTALE if the object should be deleted + * Set the state xattr on a volume directory. */ -int cachefiles_check_object_xattr(struct cachefiles_object *object, - struct cachefiles_xattr *auxdata) +bool cachefiles_set_volume_xattr(struct cachefiles_volume *volume) { - struct cachefiles_xattr *auxbuf; - struct dentry *dentry = object->dentry; + unsigned int len = volume->vcookie->coherency_len; + const void *p = volume->vcookie->coherency; + struct dentry *dentry = volume->dentry; int ret; - _enter("%p,#%d", object, auxdata->len); - - ASSERT(dentry); - ASSERT(d_backing_inode(dentry)); - - auxbuf = kmalloc(sizeof(struct cachefiles_xattr) + 512, cachefiles_gfp); - if (!auxbuf) { - _leave(" = -ENOMEM"); - return -ENOMEM; - } + _enter("%x,#%d", volume->vcookie->debug_id, len); - /* read the current type label */ - ret = vfs_getxattr(&init_user_ns, dentry, cachefiles_xattr_cache, - &auxbuf->type, 512 + 1); + ret = cachefiles_inject_write_error(); + if (ret == 0) + ret = vfs_setxattr(&init_user_ns, dentry, cachefiles_xattr_cache, + p, len, 0); if (ret < 0) { - if (ret == -ENODATA) - goto stale; /* no attribute - power went off - * mid-cull? */ - - if (ret == -ERANGE) - goto bad_type_length; - - cachefiles_io_error_obj(object, - "Can't read xattr on %lu (err %d)", - d_backing_inode(dentry)->i_ino, -ret); - goto error; + trace_cachefiles_vfs_error(NULL, d_inode(dentry), ret, + cachefiles_trace_setxattr_error); + trace_cachefiles_vol_coherency(volume, d_inode(dentry)->i_ino, + cachefiles_coherency_vol_set_fail); + if (ret != -ENOMEM) + cachefiles_io_error( + volume->cache, "Failed to set xattr with error %d", ret); + } else { + trace_cachefiles_vol_coherency(volume, d_inode(dentry)->i_ino, + cachefiles_coherency_vol_set_ok); } - /* check the on-disk object */ - if (ret < 1) - goto bad_type_length; - - if (auxbuf->type != auxdata->type) - goto stale; - - auxbuf->len = ret; - - /* consult the netfs */ - if (object->fscache.cookie->def->check_aux) { - enum fscache_checkaux result; - unsigned int dlen; - - dlen = auxbuf->len - 1; - - _debug("checkaux %s #%u", - object->fscache.cookie->def->name, dlen); - - result = fscache_check_aux(&object->fscache, - &auxbuf->data, dlen, - i_size_read(d_backing_inode(dentry))); - - switch (result) { - /* entry okay as is */ - case FSCACHE_CHECKAUX_OKAY: - goto okay; - - /* entry requires update */ - case FSCACHE_CHECKAUX_NEEDS_UPDATE: - break; - - /* entry requires deletion */ - case FSCACHE_CHECKAUX_OBSOLETE: - goto stale; - - default: - BUG(); - } - - /* update the current label */ - ret = vfs_setxattr(&init_user_ns, dentry, - cachefiles_xattr_cache, &auxdata->type, - auxdata->len, XATTR_REPLACE); - if (ret < 0) { - cachefiles_io_error_obj(object, - "Can't update xattr on %lu" - " (error %d)", - d_backing_inode(dentry)->i_ino, -ret); - goto error; - } - } - -okay: - ret = 0; - -error: - kfree(auxbuf); _leave(" = %d", ret); - return ret; - -bad_type_length: - pr_err("Cache object %lu xattr length incorrect\n", - d_backing_inode(dentry)->i_ino); - ret = -EIO; - goto error; - -stale: - ret = -ESTALE; - goto error; + return ret == 0; } /* - * remove the object's xattr to mark it stale + * Check the consistency between the backing cache and the volume cookie. */ -int cachefiles_remove_object_xattr(struct cachefiles_cache *cache, - struct dentry *dentry) +int cachefiles_check_volume_xattr(struct cachefiles_volume *volume) { - int ret; + struct cachefiles_xattr *buf; + struct dentry *dentry = volume->dentry; + unsigned int len = volume->vcookie->coherency_len; + const void *p = volume->vcookie->coherency; + enum cachefiles_coherency_trace why; + ssize_t xlen; + int ret = -ESTALE; - ret = vfs_removexattr(&init_user_ns, dentry, cachefiles_xattr_cache); - if (ret < 0) { - 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); + _enter(""); + + buf = kmalloc(len, 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, len); + if (xlen != len) { + if (xlen < 0) { + trace_cachefiles_vfs_error(NULL, d_inode(dentry), xlen, + cachefiles_trace_getxattr_error); + if (xlen == -EIO) + cachefiles_io_error( + volume->cache, + "Failed to read xattr with error %zd", xlen); + } + why = cachefiles_coherency_vol_check_xattr; + } else if (memcmp(buf->data, p, len) != 0) { + why = cachefiles_coherency_vol_check_cmp; + } else { + why = cachefiles_coherency_vol_check_ok; + ret = 0; } + trace_cachefiles_vol_coherency(volume, d_inode(dentry)->i_ino, why); + kfree(buf); _leave(" = %d", ret); return ret; } |