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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /fs/smb/client/namespace.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'fs/smb/client/namespace.c')
| -rw-r--r-- | fs/smb/client/namespace.c | 298 |
1 files changed, 298 insertions, 0 deletions
diff --git a/fs/smb/client/namespace.c b/fs/smb/client/namespace.c new file mode 100644 index 000000000..52a51b032 --- /dev/null +++ b/fs/smb/client/namespace.c @@ -0,0 +1,298 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Contains mounting routines used for handling traversal via SMB junctions. + * + * Copyright (c) 2007 Igor Mammedov + * Copyright (C) International Business Machines Corp., 2008 + * Author(s): Igor Mammedov (niallain@gmail.com) + * Steve French (sfrench@us.ibm.com) + * Copyright (c) 2023 Paulo Alcantara <palcantara@suse.de> + */ + +#include <linux/dcache.h> +#include <linux/mount.h> +#include <linux/namei.h> +#include <linux/slab.h> +#include <linux/vfs.h> +#include <linux/fs.h> +#include <linux/inet.h> +#include "cifsglob.h" +#include "cifsproto.h" +#include "cifsfs.h" +#include "cifs_debug.h" +#include "fs_context.h" + +static LIST_HEAD(cifs_automount_list); + +static void cifs_expire_automounts(struct work_struct *work); +static DECLARE_DELAYED_WORK(cifs_automount_task, + cifs_expire_automounts); +static int cifs_mountpoint_expiry_timeout = 500 * HZ; + +static void cifs_expire_automounts(struct work_struct *work) +{ + struct list_head *list = &cifs_automount_list; + + mark_mounts_for_expiry(list); + if (!list_empty(list)) + schedule_delayed_work(&cifs_automount_task, + cifs_mountpoint_expiry_timeout); +} + +void cifs_release_automount_timer(void) +{ + if (WARN_ON(!list_empty(&cifs_automount_list))) + return; + cancel_delayed_work_sync(&cifs_automount_task); +} + +/** + * cifs_build_devname - build a devicename from a UNC and optional prepath + * @nodename: pointer to UNC string + * @prepath: pointer to prefixpath (or NULL if there isn't one) + * + * Build a new cifs devicename after chasing a DFS referral. Allocate a buffer + * big enough to hold the final thing. Copy the UNC from the nodename, and + * concatenate the prepath onto the end of it if there is one. + * + * Returns pointer to the built string, or a ERR_PTR. Caller is responsible + * for freeing the returned string. + */ +char * +cifs_build_devname(char *nodename, const char *prepath) +{ + size_t pplen; + size_t unclen; + char *dev; + char *pos; + + /* skip over any preceding delimiters */ + nodename += strspn(nodename, "\\"); + if (!*nodename) + return ERR_PTR(-EINVAL); + + /* get length of UNC and set pos to last char */ + unclen = strlen(nodename); + pos = nodename + unclen - 1; + + /* trim off any trailing delimiters */ + while (*pos == '\\') { + --pos; + --unclen; + } + + /* allocate a buffer: + * +2 for preceding "//" + * +1 for delimiter between UNC and prepath + * +1 for trailing NULL + */ + pplen = prepath ? strlen(prepath) : 0; + dev = kmalloc(2 + unclen + 1 + pplen + 1, GFP_KERNEL); + if (!dev) + return ERR_PTR(-ENOMEM); + + pos = dev; + /* add the initial "//" */ + *pos = '/'; + ++pos; + *pos = '/'; + ++pos; + + /* copy in the UNC portion from referral */ + memcpy(pos, nodename, unclen); + pos += unclen; + + /* copy the prefixpath remainder (if there is one) */ + if (pplen) { + *pos = '/'; + ++pos; + memcpy(pos, prepath, pplen); + pos += pplen; + } + + /* NULL terminator */ + *pos = '\0'; + + convert_delimiter(dev, '/'); + return dev; +} + +static bool is_dfs_mount(struct dentry *dentry) +{ + struct cifs_sb_info *cifs_sb = CIFS_SB(dentry->d_sb); + struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb); + bool ret; + + spin_lock(&tcon->tc_lock); + ret = !!tcon->origin_fullpath; + spin_unlock(&tcon->tc_lock); + return ret; +} + +/* Return full path out of a dentry set for automount */ +static char *automount_fullpath(struct dentry *dentry, void *page) +{ + struct cifs_sb_info *cifs_sb = CIFS_SB(dentry->d_sb); + struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb); + size_t len; + char *s; + + spin_lock(&tcon->tc_lock); + if (!tcon->origin_fullpath) { + spin_unlock(&tcon->tc_lock); + return build_path_from_dentry_optional_prefix(dentry, + page, + true); + } + spin_unlock(&tcon->tc_lock); + + if (unlikely(!page)) + return ERR_PTR(-ENOMEM); + + s = dentry_path_raw(dentry, page, PATH_MAX); + if (IS_ERR(s)) + return s; + /* for root, we want "" */ + if (!s[1]) + s++; + + spin_lock(&tcon->tc_lock); + len = strlen(tcon->origin_fullpath); + if (s < (char *)page + len) { + spin_unlock(&tcon->tc_lock); + return ERR_PTR(-ENAMETOOLONG); + } + + s -= len; + memcpy(s, tcon->origin_fullpath, len); + spin_unlock(&tcon->tc_lock); + convert_delimiter(s, '/'); + + return s; +} + +static void fs_context_set_ids(struct smb3_fs_context *ctx) +{ + kuid_t uid = current_fsuid(); + kgid_t gid = current_fsgid(); + + if (ctx->multiuser) { + if (!ctx->uid_specified) + ctx->linux_uid = uid; + if (!ctx->gid_specified) + ctx->linux_gid = gid; + } + if (!ctx->cruid_specified) + ctx->cred_uid = uid; +} + +/* + * Create a vfsmount that we can automount + */ +static struct vfsmount *cifs_do_automount(struct path *path) +{ + int rc; + struct dentry *mntpt = path->dentry; + struct fs_context *fc; + void *page = NULL; + struct smb3_fs_context *ctx, *cur_ctx; + struct smb3_fs_context tmp; + char *full_path; + struct vfsmount *mnt; + struct cifs_sb_info *mntpt_sb; + struct cifs_ses *ses; + + if (IS_ROOT(mntpt)) + return ERR_PTR(-ESTALE); + + mntpt_sb = CIFS_SB(mntpt->d_sb); + ses = cifs_sb_master_tcon(mntpt_sb)->ses; + cur_ctx = mntpt_sb->ctx; + + /* + * At this point, the root session should be in the mntpt sb. We should + * bring the sb context passwords in sync with the root session's + * passwords. This would help prevent unnecessary retries and password + * swaps for automounts. + */ + mutex_lock(&ses->session_mutex); + rc = smb3_sync_session_ctx_passwords(mntpt_sb, ses); + mutex_unlock(&ses->session_mutex); + + if (rc) + return ERR_PTR(rc); + + fc = fs_context_for_submount(path->mnt->mnt_sb->s_type, mntpt); + if (IS_ERR(fc)) + return ERR_CAST(fc); + + ctx = smb3_fc2context(fc); + + page = alloc_dentry_path(); + full_path = automount_fullpath(mntpt, page); + if (IS_ERR(full_path)) { + mnt = ERR_CAST(full_path); + goto out; + } + + tmp = *cur_ctx; + tmp.source = NULL; + tmp.leaf_fullpath = NULL; + tmp.UNC = tmp.prepath = NULL; + tmp.dfs_root_ses = NULL; + fs_context_set_ids(&tmp); + + rc = smb3_fs_context_dup(ctx, &tmp); + if (rc) { + mnt = ERR_PTR(rc); + goto out; + } + + rc = smb3_parse_devname(full_path, ctx); + if (rc) { + mnt = ERR_PTR(rc); + goto out; + } + + ctx->source = smb3_fs_context_fullpath(ctx, '/'); + if (IS_ERR(ctx->source)) { + mnt = ERR_CAST(ctx->source); + ctx->source = NULL; + goto out; + } + ctx->dfs_automount = ctx->dfs_conn = is_dfs_mount(mntpt); + cifs_dbg(FYI, "%s: ctx: source=%s UNC=%s prepath=%s dfs_automount=%d\n", + __func__, ctx->source, ctx->UNC, ctx->prepath, ctx->dfs_automount); + + mnt = fc_mount(fc); +out: + put_fs_context(fc); + free_dentry_path(page); + return mnt; +} + +/* + * Attempt to automount the referral + */ +struct vfsmount *cifs_d_automount(struct path *path) +{ + struct vfsmount *newmnt; + + cifs_dbg(FYI, "%s: %pd\n", __func__, path->dentry); + + newmnt = cifs_do_automount(path); + if (IS_ERR(newmnt)) { + cifs_dbg(FYI, "leaving %s [automount failed]\n" , __func__); + return newmnt; + } + + mnt_set_expiry(newmnt, &cifs_automount_list); + schedule_delayed_work(&cifs_automount_task, + cifs_mountpoint_expiry_timeout); + cifs_dbg(FYI, "leaving %s [ok]\n" , __func__); + return newmnt; +} + +const struct inode_operations cifs_namespace_inode_operations = { + .fileattr_get = cifs_fileattr_get, +}; |
