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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /fs/ubifs/xattr.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'fs/ubifs/xattr.c')
-rw-r--r--fs/ubifs/xattr.c745
1 files changed, 745 insertions, 0 deletions
diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c
new file mode 100644
index 000000000..349228dd1
--- /dev/null
+++ b/fs/ubifs/xattr.c
@@ -0,0 +1,745 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * This file is part of UBIFS.
+ *
+ * Copyright (C) 2006-2008 Nokia Corporation.
+ *
+ * Authors: Artem Bityutskiy (Битюцкий Артём)
+ * Adrian Hunter
+ */
+
+/*
+ * This file implements UBIFS extended attributes support.
+ *
+ * Extended attributes are implemented as regular inodes with attached data,
+ * which limits extended attribute size to UBIFS block size (4KiB). Names of
+ * extended attributes are described by extended attribute entries (xentries),
+ * which are almost identical to directory entries, but have different key type.
+ *
+ * In other words, the situation with extended attributes is very similar to
+ * directories. Indeed, any inode (but of course not xattr inodes) may have a
+ * number of associated xentries, just like directory inodes have associated
+ * directory entries. Extended attribute entries store the name of the extended
+ * attribute, the host inode number, and the extended attribute inode number.
+ * Similarly, direntries store the name, the parent and the target inode
+ * numbers. Thus, most of the common UBIFS mechanisms may be re-used for
+ * extended attributes.
+ *
+ * The number of extended attributes is not limited, but there is Linux
+ * limitation on the maximum possible size of the list of all extended
+ * attributes associated with an inode (%XATTR_LIST_MAX), so UBIFS makes sure
+ * the sum of all extended attribute names of the inode does not exceed that
+ * limit.
+ *
+ * Extended attributes are synchronous, which means they are written to the
+ * flash media synchronously and there is no write-back for extended attribute
+ * inodes. The extended attribute values are not stored in compressed form on
+ * the media.
+ *
+ * Since extended attributes are represented by regular inodes, they are cached
+ * in the VFS inode cache. The xentries are cached in the LNC cache (see
+ * tnc.c).
+ *
+ * ACL support is not implemented.
+ */
+
+#include "ubifs.h"
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/xattr.h>
+
+/*
+ * Extended attribute type constants.
+ *
+ * USER_XATTR: user extended attribute ("user.*")
+ * TRUSTED_XATTR: trusted extended attribute ("trusted.*)
+ * SECURITY_XATTR: security extended attribute ("security.*")
+ */
+enum {
+ USER_XATTR,
+ TRUSTED_XATTR,
+ SECURITY_XATTR,
+};
+
+static const struct inode_operations empty_iops;
+static const struct file_operations empty_fops;
+
+/**
+ * create_xattr - create an extended attribute.
+ * @c: UBIFS file-system description object
+ * @host: host inode
+ * @nm: extended attribute name
+ * @value: extended attribute value
+ * @size: size of extended attribute value
+ *
+ * This is a helper function which creates an extended attribute of name @nm
+ * and value @value for inode @host. The host inode is also updated on flash
+ * because the ctime and extended attribute accounting data changes. This
+ * function returns zero in case of success and a negative error code in case
+ * of failure.
+ */
+static int create_xattr(struct ubifs_info *c, struct inode *host,
+ const struct fscrypt_name *nm, const void *value, int size)
+{
+ int err, names_len;
+ struct inode *inode;
+ struct ubifs_inode *ui, *host_ui = ubifs_inode(host);
+ struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
+ .new_ino_d = ALIGN(size, 8), .dirtied_ino = 1,
+ .dirtied_ino_d = ALIGN(host_ui->data_len, 8) };
+
+ if (host_ui->xattr_cnt >= ubifs_xattr_max_cnt(c)) {
+ ubifs_err(c, "inode %lu already has too many xattrs (%d), cannot create more",
+ host->i_ino, host_ui->xattr_cnt);
+ return -ENOSPC;
+ }
+ /*
+ * Linux limits the maximum size of the extended attribute names list
+ * to %XATTR_LIST_MAX. This means we should not allow creating more
+ * extended attributes if the name list becomes larger. This limitation
+ * is artificial for UBIFS, though.
+ */
+ names_len = host_ui->xattr_names + host_ui->xattr_cnt + fname_len(nm) + 1;
+ if (names_len > XATTR_LIST_MAX) {
+ ubifs_err(c, "cannot add one more xattr name to inode %lu, total names length would become %d, max. is %d",
+ host->i_ino, names_len, XATTR_LIST_MAX);
+ return -ENOSPC;
+ }
+
+ err = ubifs_budget_space(c, &req);
+ if (err)
+ return err;
+
+ inode = ubifs_new_inode(c, host, S_IFREG | S_IRWXUGO, true);
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ goto out_budg;
+ }
+
+ /* Re-define all operations to be "nothing" */
+ inode->i_mapping->a_ops = &empty_aops;
+ inode->i_op = &empty_iops;
+ inode->i_fop = &empty_fops;
+
+ inode->i_flags |= S_SYNC | S_NOATIME | S_NOCMTIME;
+ ui = ubifs_inode(inode);
+ ui->xattr = 1;
+ ui->flags |= UBIFS_XATTR_FL;
+ ui->data = kmemdup(value, size, GFP_NOFS);
+ if (!ui->data) {
+ err = -ENOMEM;
+ goto out_free;
+ }
+ inode->i_size = ui->ui_size = size;
+ ui->data_len = size;
+
+ mutex_lock(&host_ui->ui_mutex);
+ host->i_ctime = current_time(host);
+ host_ui->xattr_cnt += 1;
+ host_ui->xattr_size += CALC_DENT_SIZE(fname_len(nm));
+ host_ui->xattr_size += CALC_XATTR_BYTES(size);
+ host_ui->xattr_names += fname_len(nm);
+
+ /*
+ * We handle UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT here because we
+ * have to set the UBIFS_CRYPT_FL flag on the host inode.
+ * To avoid multiple updates of the same inode in the same operation,
+ * let's do it here.
+ */
+ if (strcmp(fname_name(nm), UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT) == 0)
+ host_ui->flags |= UBIFS_CRYPT_FL;
+
+ err = ubifs_jnl_update(c, host, nm, inode, 0, 1);
+ if (err)
+ goto out_cancel;
+ ubifs_set_inode_flags(host);
+ mutex_unlock(&host_ui->ui_mutex);
+
+ ubifs_release_budget(c, &req);
+ insert_inode_hash(inode);
+ iput(inode);
+ return 0;
+
+out_cancel:
+ host_ui->xattr_cnt -= 1;
+ host_ui->xattr_size -= CALC_DENT_SIZE(fname_len(nm));
+ host_ui->xattr_size -= CALC_XATTR_BYTES(size);
+ host_ui->xattr_names -= fname_len(nm);
+ host_ui->flags &= ~UBIFS_CRYPT_FL;
+ mutex_unlock(&host_ui->ui_mutex);
+out_free:
+ make_bad_inode(inode);
+ iput(inode);
+out_budg:
+ ubifs_release_budget(c, &req);
+ return err;
+}
+
+/**
+ * change_xattr - change an extended attribute.
+ * @c: UBIFS file-system description object
+ * @host: host inode
+ * @inode: extended attribute inode
+ * @value: extended attribute value
+ * @size: size of extended attribute value
+ *
+ * This helper function changes the value of extended attribute @inode with new
+ * data from @value. Returns zero in case of success and a negative error code
+ * in case of failure.
+ */
+static int change_xattr(struct ubifs_info *c, struct inode *host,
+ struct inode *inode, const void *value, int size)
+{
+ int err;
+ struct ubifs_inode *host_ui = ubifs_inode(host);
+ struct ubifs_inode *ui = ubifs_inode(inode);
+ void *buf = NULL;
+ int old_size;
+ struct ubifs_budget_req req = { .dirtied_ino = 2,
+ .dirtied_ino_d = ALIGN(size, 8) + ALIGN(host_ui->data_len, 8) };
+
+ ubifs_assert(c, ui->data_len == inode->i_size);
+ err = ubifs_budget_space(c, &req);
+ if (err)
+ return err;
+
+ buf = kmemdup(value, size, GFP_NOFS);
+ if (!buf) {
+ err = -ENOMEM;
+ goto out_free;
+ }
+ kfree(ui->data);
+ ui->data = buf;
+ inode->i_size = ui->ui_size = size;
+ old_size = ui->data_len;
+ ui->data_len = size;
+
+ mutex_lock(&host_ui->ui_mutex);
+ host->i_ctime = current_time(host);
+ host_ui->xattr_size -= CALC_XATTR_BYTES(old_size);
+ host_ui->xattr_size += CALC_XATTR_BYTES(size);
+
+ /*
+ * It is important to write the host inode after the xattr inode
+ * because if the host inode gets synchronized (via 'fsync()'), then
+ * the extended attribute inode gets synchronized, because it goes
+ * before the host inode in the write-buffer.
+ */
+ err = ubifs_jnl_change_xattr(c, inode, host);
+ if (err)
+ goto out_cancel;
+ mutex_unlock(&host_ui->ui_mutex);
+
+ ubifs_release_budget(c, &req);
+ return 0;
+
+out_cancel:
+ host_ui->xattr_size -= CALC_XATTR_BYTES(size);
+ host_ui->xattr_size += CALC_XATTR_BYTES(old_size);
+ mutex_unlock(&host_ui->ui_mutex);
+ make_bad_inode(inode);
+out_free:
+ ubifs_release_budget(c, &req);
+ return err;
+}
+
+static struct inode *iget_xattr(struct ubifs_info *c, ino_t inum)
+{
+ struct inode *inode;
+
+ inode = ubifs_iget(c->vfs_sb, inum);
+ if (IS_ERR(inode)) {
+ ubifs_err(c, "dead extended attribute entry, error %d",
+ (int)PTR_ERR(inode));
+ return inode;
+ }
+ if (ubifs_inode(inode)->xattr)
+ return inode;
+ ubifs_err(c, "corrupt extended attribute entry");
+ iput(inode);
+ return ERR_PTR(-EINVAL);
+}
+
+int ubifs_xattr_set(struct inode *host, const char *name, const void *value,
+ size_t size, int flags, bool check_lock)
+{
+ struct inode *inode;
+ struct ubifs_info *c = host->i_sb->s_fs_info;
+ struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))};
+ struct ubifs_dent_node *xent;
+ union ubifs_key key;
+ int err;
+
+ if (check_lock)
+ ubifs_assert(c, inode_is_locked(host));
+
+ if (size > UBIFS_MAX_INO_DATA)
+ return -ERANGE;
+
+ if (fname_len(&nm) > UBIFS_MAX_NLEN)
+ return -ENAMETOOLONG;
+
+ xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
+ if (!xent)
+ return -ENOMEM;
+
+ down_write(&ubifs_inode(host)->xattr_sem);
+ /*
+ * The extended attribute entries are stored in LNC, so multiple
+ * look-ups do not involve reading the flash.
+ */
+ xent_key_init(c, &key, host->i_ino, &nm);
+ err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
+ if (err) {
+ if (err != -ENOENT)
+ goto out_free;
+
+ if (flags & XATTR_REPLACE)
+ /* We are asked not to create the xattr */
+ err = -ENODATA;
+ else
+ err = create_xattr(c, host, &nm, value, size);
+ goto out_free;
+ }
+
+ if (flags & XATTR_CREATE) {
+ /* We are asked not to replace the xattr */
+ err = -EEXIST;
+ goto out_free;
+ }
+
+ inode = iget_xattr(c, le64_to_cpu(xent->inum));
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ goto out_free;
+ }
+
+ err = change_xattr(c, host, inode, value, size);
+ iput(inode);
+
+out_free:
+ up_write(&ubifs_inode(host)->xattr_sem);
+ kfree(xent);
+ return err;
+}
+
+ssize_t ubifs_xattr_get(struct inode *host, const char *name, void *buf,
+ size_t size)
+{
+ struct inode *inode;
+ struct ubifs_info *c = host->i_sb->s_fs_info;
+ struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))};
+ struct ubifs_inode *ui;
+ struct ubifs_dent_node *xent;
+ union ubifs_key key;
+ int err;
+
+ if (fname_len(&nm) > UBIFS_MAX_NLEN)
+ return -ENAMETOOLONG;
+
+ xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
+ if (!xent)
+ return -ENOMEM;
+
+ down_read(&ubifs_inode(host)->xattr_sem);
+ xent_key_init(c, &key, host->i_ino, &nm);
+ err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
+ if (err) {
+ if (err == -ENOENT)
+ err = -ENODATA;
+ goto out_cleanup;
+ }
+
+ inode = iget_xattr(c, le64_to_cpu(xent->inum));
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ goto out_cleanup;
+ }
+
+ ui = ubifs_inode(inode);
+ ubifs_assert(c, inode->i_size == ui->data_len);
+ ubifs_assert(c, ubifs_inode(host)->xattr_size > ui->data_len);
+
+ if (buf) {
+ /* If @buf is %NULL we are supposed to return the length */
+ if (ui->data_len > size) {
+ err = -ERANGE;
+ goto out_iput;
+ }
+
+ memcpy(buf, ui->data, ui->data_len);
+ }
+ err = ui->data_len;
+
+out_iput:
+ iput(inode);
+out_cleanup:
+ up_read(&ubifs_inode(host)->xattr_sem);
+ kfree(xent);
+ return err;
+}
+
+static bool xattr_visible(const char *name)
+{
+ /* File encryption related xattrs are for internal use only */
+ if (strcmp(name, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT) == 0)
+ return false;
+
+ /* Show trusted namespace only for "power" users */
+ if (strncmp(name, XATTR_TRUSTED_PREFIX,
+ XATTR_TRUSTED_PREFIX_LEN) == 0 && !capable(CAP_SYS_ADMIN))
+ return false;
+
+ return true;
+}
+
+ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size)
+{
+ union ubifs_key key;
+ struct inode *host = d_inode(dentry);
+ struct ubifs_info *c = host->i_sb->s_fs_info;
+ struct ubifs_inode *host_ui = ubifs_inode(host);
+ struct ubifs_dent_node *xent, *pxent = NULL;
+ int err, len, written = 0;
+ struct fscrypt_name nm = {0};
+
+ dbg_gen("ino %lu ('%pd'), buffer size %zd", host->i_ino,
+ dentry, size);
+
+ down_read(&host_ui->xattr_sem);
+ len = host_ui->xattr_names + host_ui->xattr_cnt;
+ if (!buffer) {
+ /*
+ * We should return the minimum buffer size which will fit a
+ * null-terminated list of all the extended attribute names.
+ */
+ err = len;
+ goto out_err;
+ }
+
+ if (len > size) {
+ err = -ERANGE;
+ goto out_err;
+ }
+
+ lowest_xent_key(c, &key, host->i_ino);
+ while (1) {
+ xent = ubifs_tnc_next_ent(c, &key, &nm);
+ if (IS_ERR(xent)) {
+ err = PTR_ERR(xent);
+ break;
+ }
+
+ fname_name(&nm) = xent->name;
+ fname_len(&nm) = le16_to_cpu(xent->nlen);
+
+ if (xattr_visible(xent->name)) {
+ memcpy(buffer + written, fname_name(&nm), fname_len(&nm) + 1);
+ written += fname_len(&nm) + 1;
+ }
+
+ kfree(pxent);
+ pxent = xent;
+ key_read(c, &xent->key, &key);
+ }
+ kfree(pxent);
+ up_read(&host_ui->xattr_sem);
+
+ if (err != -ENOENT) {
+ ubifs_err(c, "cannot find next direntry, error %d", err);
+ return err;
+ }
+
+ ubifs_assert(c, written <= size);
+ return written;
+
+out_err:
+ up_read(&host_ui->xattr_sem);
+ return err;
+}
+
+static int remove_xattr(struct ubifs_info *c, struct inode *host,
+ struct inode *inode, const struct fscrypt_name *nm)
+{
+ int err;
+ struct ubifs_inode *host_ui = ubifs_inode(host);
+ struct ubifs_inode *ui = ubifs_inode(inode);
+ struct ubifs_budget_req req = { .dirtied_ino = 2, .mod_dent = 1,
+ .dirtied_ino_d = ALIGN(host_ui->data_len, 8) };
+
+ ubifs_assert(c, ui->data_len == inode->i_size);
+
+ err = ubifs_budget_space(c, &req);
+ if (err)
+ return err;
+
+ mutex_lock(&host_ui->ui_mutex);
+ host->i_ctime = current_time(host);
+ host_ui->xattr_cnt -= 1;
+ host_ui->xattr_size -= CALC_DENT_SIZE(fname_len(nm));
+ host_ui->xattr_size -= CALC_XATTR_BYTES(ui->data_len);
+ host_ui->xattr_names -= fname_len(nm);
+
+ err = ubifs_jnl_delete_xattr(c, host, inode, nm);
+ if (err)
+ goto out_cancel;
+ mutex_unlock(&host_ui->ui_mutex);
+
+ ubifs_release_budget(c, &req);
+ return 0;
+
+out_cancel:
+ host_ui->xattr_cnt += 1;
+ host_ui->xattr_size += CALC_DENT_SIZE(fname_len(nm));
+ host_ui->xattr_size += CALC_XATTR_BYTES(ui->data_len);
+ host_ui->xattr_names += fname_len(nm);
+ mutex_unlock(&host_ui->ui_mutex);
+ ubifs_release_budget(c, &req);
+ make_bad_inode(inode);
+ return err;
+}
+
+int ubifs_purge_xattrs(struct inode *host)
+{
+ union ubifs_key key;
+ struct ubifs_info *c = host->i_sb->s_fs_info;
+ struct ubifs_dent_node *xent, *pxent = NULL;
+ struct inode *xino;
+ struct fscrypt_name nm = {0};
+ int err;
+
+ if (ubifs_inode(host)->xattr_cnt <= ubifs_xattr_max_cnt(c))
+ return 0;
+
+ ubifs_warn(c, "inode %lu has too many xattrs, doing a non-atomic deletion",
+ host->i_ino);
+
+ down_write(&ubifs_inode(host)->xattr_sem);
+ lowest_xent_key(c, &key, host->i_ino);
+ while (1) {
+ xent = ubifs_tnc_next_ent(c, &key, &nm);
+ if (IS_ERR(xent)) {
+ err = PTR_ERR(xent);
+ break;
+ }
+
+ fname_name(&nm) = xent->name;
+ fname_len(&nm) = le16_to_cpu(xent->nlen);
+
+ xino = ubifs_iget(c->vfs_sb, le64_to_cpu(xent->inum));
+ if (IS_ERR(xino)) {
+ err = PTR_ERR(xino);
+ ubifs_err(c, "dead directory entry '%s', error %d",
+ xent->name, err);
+ ubifs_ro_mode(c, err);
+ kfree(pxent);
+ kfree(xent);
+ goto out_err;
+ }
+
+ ubifs_assert(c, ubifs_inode(xino)->xattr);
+
+ clear_nlink(xino);
+ err = remove_xattr(c, host, xino, &nm);
+ if (err) {
+ kfree(pxent);
+ kfree(xent);
+ iput(xino);
+ ubifs_err(c, "cannot remove xattr, error %d", err);
+ goto out_err;
+ }
+
+ iput(xino);
+
+ kfree(pxent);
+ pxent = xent;
+ key_read(c, &xent->key, &key);
+ }
+ kfree(pxent);
+ up_write(&ubifs_inode(host)->xattr_sem);
+
+ if (err != -ENOENT) {
+ ubifs_err(c, "cannot find next direntry, error %d", err);
+ return err;
+ }
+
+ return 0;
+
+out_err:
+ up_write(&ubifs_inode(host)->xattr_sem);
+ return err;
+}
+
+/**
+ * ubifs_evict_xattr_inode - Evict an xattr inode.
+ * @c: UBIFS file-system description object
+ * @xattr_inum: xattr inode number
+ *
+ * When an inode that hosts xattrs is being removed we have to make sure
+ * that cached inodes of the xattrs also get removed from the inode cache
+ * otherwise we'd waste memory. This function looks up an inode from the
+ * inode cache and clears the link counter such that iput() will evict
+ * the inode.
+ */
+void ubifs_evict_xattr_inode(struct ubifs_info *c, ino_t xattr_inum)
+{
+ struct inode *inode;
+
+ inode = ilookup(c->vfs_sb, xattr_inum);
+ if (inode) {
+ clear_nlink(inode);
+ iput(inode);
+ }
+}
+
+static int ubifs_xattr_remove(struct inode *host, const char *name)
+{
+ struct inode *inode;
+ struct ubifs_info *c = host->i_sb->s_fs_info;
+ struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))};
+ struct ubifs_dent_node *xent;
+ union ubifs_key key;
+ int err;
+
+ ubifs_assert(c, inode_is_locked(host));
+
+ if (fname_len(&nm) > UBIFS_MAX_NLEN)
+ return -ENAMETOOLONG;
+
+ xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
+ if (!xent)
+ return -ENOMEM;
+
+ down_write(&ubifs_inode(host)->xattr_sem);
+ xent_key_init(c, &key, host->i_ino, &nm);
+ err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
+ if (err) {
+ if (err == -ENOENT)
+ err = -ENODATA;
+ goto out_free;
+ }
+
+ inode = iget_xattr(c, le64_to_cpu(xent->inum));
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ goto out_free;
+ }
+
+ ubifs_assert(c, inode->i_nlink == 1);
+ clear_nlink(inode);
+ err = remove_xattr(c, host, inode, &nm);
+ if (err)
+ set_nlink(inode, 1);
+
+ /* If @i_nlink is 0, 'iput()' will delete the inode */
+ iput(inode);
+
+out_free:
+ up_write(&ubifs_inode(host)->xattr_sem);
+ kfree(xent);
+ return err;
+}
+
+#ifdef CONFIG_UBIFS_FS_SECURITY
+static int init_xattrs(struct inode *inode, const struct xattr *xattr_array,
+ void *fs_info)
+{
+ const struct xattr *xattr;
+ char *name;
+ int err = 0;
+
+ for (xattr = xattr_array; xattr->name != NULL; xattr++) {
+ name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
+ strlen(xattr->name) + 1, GFP_NOFS);
+ if (!name) {
+ err = -ENOMEM;
+ break;
+ }
+ strcpy(name, XATTR_SECURITY_PREFIX);
+ strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
+ /*
+ * creating a new inode without holding the inode rwsem,
+ * no need to check whether inode is locked.
+ */
+ err = ubifs_xattr_set(inode, name, xattr->value,
+ xattr->value_len, 0, false);
+ kfree(name);
+ if (err < 0)
+ break;
+ }
+
+ return err;
+}
+
+int ubifs_init_security(struct inode *dentry, struct inode *inode,
+ const struct qstr *qstr)
+{
+ int err;
+
+ err = security_inode_init_security(inode, dentry, qstr,
+ &init_xattrs, NULL);
+ if (err) {
+ struct ubifs_info *c = dentry->i_sb->s_fs_info;
+ ubifs_err(c, "cannot initialize security for inode %lu, error %d",
+ inode->i_ino, err);
+ }
+ return err;
+}
+#endif
+
+static int xattr_get(const struct xattr_handler *handler,
+ struct dentry *dentry, struct inode *inode,
+ const char *name, void *buffer, size_t size)
+{
+ dbg_gen("xattr '%s', ino %lu ('%pd'), buf size %zd", name,
+ inode->i_ino, dentry, size);
+
+ name = xattr_full_name(handler, name);
+ return ubifs_xattr_get(inode, name, buffer, size);
+}
+
+static int xattr_set(const struct xattr_handler *handler,
+ struct mnt_idmap *idmap,
+ struct dentry *dentry, struct inode *inode,
+ const char *name, const void *value,
+ size_t size, int flags)
+{
+ dbg_gen("xattr '%s', host ino %lu ('%pd'), size %zd",
+ name, inode->i_ino, dentry, size);
+
+ name = xattr_full_name(handler, name);
+
+ if (value)
+ return ubifs_xattr_set(inode, name, value, size, flags, true);
+ else
+ return ubifs_xattr_remove(inode, name);
+}
+
+static const struct xattr_handler ubifs_user_xattr_handler = {
+ .prefix = XATTR_USER_PREFIX,
+ .get = xattr_get,
+ .set = xattr_set,
+};
+
+static const struct xattr_handler ubifs_trusted_xattr_handler = {
+ .prefix = XATTR_TRUSTED_PREFIX,
+ .get = xattr_get,
+ .set = xattr_set,
+};
+
+#ifdef CONFIG_UBIFS_FS_SECURITY
+static const struct xattr_handler ubifs_security_xattr_handler = {
+ .prefix = XATTR_SECURITY_PREFIX,
+ .get = xattr_get,
+ .set = xattr_set,
+};
+#endif
+
+const struct xattr_handler *ubifs_xattr_handlers[] = {
+ &ubifs_user_xattr_handler,
+ &ubifs_trusted_xattr_handler,
+#ifdef CONFIG_UBIFS_FS_SECURITY
+ &ubifs_security_xattr_handler,
+#endif
+ NULL
+};