#include #include #include #include #include "super.h" #include "mds_client.h" /* * Basic fh */ struct ceph_nfs_fh { u64 ino; } __attribute__ ((packed)); /* * Larger fh that includes parent ino. */ struct ceph_nfs_confh { u64 ino, parent_ino; } __attribute__ ((packed)); static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len, struct inode *parent_inode) { int type; struct ceph_nfs_fh *fh = (void *)rawfh; struct ceph_nfs_confh *cfh = (void *)rawfh; int connected_handle_length = sizeof(*cfh)/4; int handle_length = sizeof(*fh)/4; /* don't re-export snaps */ if (ceph_snap(inode) != CEPH_NOSNAP) return -EINVAL; if (parent_inode && (*max_len < connected_handle_length)) { *max_len = connected_handle_length; return FILEID_INVALID; } else if (*max_len < handle_length) { *max_len = handle_length; return FILEID_INVALID; } if (parent_inode) { dout("encode_fh %llx with parent %llx\n", ceph_ino(inode), ceph_ino(parent_inode)); cfh->ino = ceph_ino(inode); cfh->parent_ino = ceph_ino(parent_inode); *max_len = connected_handle_length; type = FILEID_INO32_GEN_PARENT; } else { dout("encode_fh %llx\n", ceph_ino(inode)); fh->ino = ceph_ino(inode); *max_len = handle_length; type = FILEID_INO32_GEN; } return type; } static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino) { struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc; struct inode *inode; struct ceph_vino vino; int err; vino.ino = ino; vino.snap = CEPH_NOSNAP; inode = ceph_find_inode(sb, vino); if (!inode) { struct ceph_mds_request *req; int mask; req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPINO, USE_ANY_MDS); if (IS_ERR(req)) return ERR_CAST(req); mask = CEPH_STAT_CAP_INODE; if (ceph_security_xattr_wanted(d_inode(sb->s_root))) mask |= CEPH_CAP_XATTR_SHARED; req->r_args.getattr.mask = cpu_to_le32(mask); req->r_ino1 = vino; req->r_num_caps = 1; err = ceph_mdsc_do_request(mdsc, NULL, req); inode = req->r_target_inode; if (inode) ihold(inode); ceph_mdsc_put_request(req); if (!inode) return ERR_PTR(-ESTALE); } return d_obtain_alias(inode); } /* * convert regular fh to dentry */ static struct dentry *ceph_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len, int fh_type) { struct ceph_nfs_fh *fh = (void *)fid->raw; if (fh_type != FILEID_INO32_GEN && fh_type != FILEID_INO32_GEN_PARENT) return NULL; if (fh_len < sizeof(*fh) / 4) return NULL; dout("fh_to_dentry %llx\n", fh->ino); return __fh_to_dentry(sb, fh->ino); } static struct dentry *__get_parent(struct super_block *sb, struct dentry *child, u64 ino) { struct ceph_mds_client *mdsc = ceph_sb_to_client(sb)->mdsc; struct ceph_mds_request *req; struct inode *inode; int mask; int err; req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPPARENT, USE_ANY_MDS); if (IS_ERR(req)) return ERR_CAST(req); if (child) { req->r_inode = d_inode(child); ihold(d_inode(child)); } else { req->r_ino1 = (struct ceph_vino) { .ino = ino, .snap = CEPH_NOSNAP, }; } mask = CEPH_STAT_CAP_INODE; if (ceph_security_xattr_wanted(d_inode(sb->s_root))) mask |= CEPH_CAP_XATTR_SHARED; req->r_args.getattr.mask = cpu_to_le32(mask); req->r_num_caps = 1; err = ceph_mdsc_do_request(mdsc, NULL, req); inode = req->r_target_inode; if (inode) ihold(inode); ceph_mdsc_put_request(req); if (!inode) return ERR_PTR(-ENOENT); return d_obtain_alias(inode); } static struct dentry *ceph_get_parent(struct dentry *child) { /* don't re-export snaps */ if (ceph_snap(d_inode(child)) != CEPH_NOSNAP) return ERR_PTR(-EINVAL); dout("get_parent %p ino %llx.%llx\n", child, ceph_vinop(d_inode(child))); return __get_parent(child->d_sb, child, 0); } /* * convert regular fh to parent */ static struct dentry *ceph_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len, int fh_type) { struct ceph_nfs_confh *cfh = (void *)fid->raw; struct dentry *dentry; if (fh_type != FILEID_INO32_GEN_PARENT) return NULL; if (fh_len < sizeof(*cfh) / 4) return NULL; dout("fh_to_parent %llx\n", cfh->parent_ino); dentry = __get_parent(sb, NULL, cfh->ino); if (unlikely(dentry == ERR_PTR(-ENOENT))) dentry = __fh_to_dentry(sb, cfh->parent_ino); return dentry; } static int ceph_get_name(struct dentry *parent, char *name, struct dentry *child) { struct ceph_mds_client *mdsc; struct ceph_mds_request *req; int err; mdsc = ceph_inode_to_client(d_inode(child))->mdsc; req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LOOKUPNAME, USE_ANY_MDS); if (IS_ERR(req)) return PTR_ERR(req); inode_lock(d_inode(parent)); req->r_inode = d_inode(child); ihold(d_inode(child)); req->r_ino2 = ceph_vino(d_inode(parent)); req->r_locked_dir = d_inode(parent); req->r_num_caps = 2; err = ceph_mdsc_do_request(mdsc, NULL, req); inode_unlock(d_inode(parent)); if (!err) { struct ceph_mds_reply_info_parsed *rinfo = &req->r_reply_info; memcpy(name, rinfo->dname, rinfo->dname_len); name[rinfo->dname_len] = 0; dout("get_name %p ino %llx.%llx name %s\n", child, ceph_vinop(d_inode(child)), name); } else { dout("get_name %p ino %llx.%llx err %d\n", child, ceph_vinop(d_inode(child)), err); } ceph_mdsc_put_request(req); return err; } const struct export_operations ceph_export_ops = { .encode_fh = ceph_encode_fh, .fh_to_dentry = ceph_fh_to_dentry, .fh_to_parent = ceph_fh_to_parent, .get_parent = ceph_get_parent, .get_name = ceph_get_name, }; 785.h?id=966d2b04e070bc040319aaebfec09e0144dc3341'>patch) tree4b96156e3d1dd4dfd6039b7c219c9dc4616da52d /sound/pci/oxygen/wm8785.h parent1b1bc42c1692e9b62756323c675a44cb1a1f9dbd (diff)
percpu-refcount: fix reference leak during percpu-atomic transition
percpu_ref_tryget() and percpu_ref_tryget_live() should return "true" IFF they acquire a reference. But the return value from atomic_long_inc_not_zero() is a long and may have high bits set, e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines is bool so the reference may actually be acquired but the routines return "false" which results in a reference leak since the caller assumes it does not need to do a corresponding percpu_ref_put(). This was seen when performing CPU hotplug during I/O, as hangs in blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start) raced with percpu_ref_tryget (blk_mq_timeout_work). Sample stack trace: __switch_to+0x2c0/0x450 __schedule+0x2f8/0x970 schedule+0x48/0xc0 blk_mq_freeze_queue_wait+0x94/0x120 blk_mq_queue_reinit_work+0xb8/0x180 blk_mq_queue_reinit_prepare+0x84/0xa0 cpuhp_invoke_callback+0x17c/0x600 cpuhp_up_callbacks+0x58/0x150 _cpu_up+0xf0/0x1c0 do_cpu_up+0x120/0x150 cpu_subsys_online+0x64/0xe0 device_online+0xb4/0x120 online_store+0xb4/0xc0 dev_attr_store+0x68/0xa0 sysfs_kf_write+0x80/0xb0 kernfs_fop_write+0x17c/0x250 __vfs_write+0x6c/0x1e0 vfs_write+0xd0/0x270 SyS_write+0x6c/0x110 system_call+0x38/0xe0 Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS, and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests. However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0 and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set. The fix is to make the tryget routines use an actual boolean internally instead of the atomic long result truncated to a int. Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751 Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Reviewed-by: Jens Axboe <axboe@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints") Cc: stable@vger.kernel.org # v3.18+
Diffstat (limited to 'sound/pci/oxygen/wm8785.h')