From 4352b8aee98005853aa63f57d6377282de17a33f Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 23 Aug 2026 13:28:57 -0700 Subject: Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux 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 ... --- drivers/mtd/mtdsuper.c | 179 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 179 insertions(+) create mode 100644 drivers/mtd/mtdsuper.c (limited to 'drivers/mtd/mtdsuper.c') diff --git a/drivers/mtd/mtdsuper.c b/drivers/mtd/mtdsuper.c new file mode 100644 index 000000000..c709ff7aa --- /dev/null +++ b/drivers/mtd/mtdsuper.c @@ -0,0 +1,179 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* MTD-based superblock management + * + * Copyright © 2001-2007 Red Hat, Inc. All Rights Reserved. + * Copyright © 2001-2010 David Woodhouse + * + * Written by: David Howells + * David Woodhouse + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "mtdcore.h" + +/* + * get a superblock on an MTD-backed filesystem + */ +static int mtd_get_sb(struct fs_context *fc, + struct mtd_info *mtd, + int (*fill_super)(struct super_block *, + struct fs_context *)) +{ + struct super_block *sb; + int ret; + + sb = sget_dev(fc, MKDEV(MTD_BLOCK_MAJOR, mtd->index)); + if (IS_ERR(sb)) + return PTR_ERR(sb); + + if (sb->s_root) { + /* new mountpoint for an already mounted superblock */ + pr_debug("MTDSB: Device %d (\"%s\") is already mounted\n", + mtd->index, mtd->name); + put_mtd_device(mtd); + } else { + /* fresh new superblock */ + pr_debug("MTDSB: New superblock for device %d (\"%s\")\n", + mtd->index, mtd->name); + + /* + * Would usually have been set with @sb_lock held but in + * contrast to sb->s_bdev that's checked with only + * @sb_lock held, nothing checks sb->s_mtd without also + * holding sb->s_umount and we're holding sb->s_umount + * here. + */ + sb->s_mtd = mtd; + sb->s_bdi = bdi_get(mtd_bdi); + + ret = fill_super(sb, fc); + if (ret < 0) + goto error_sb; + + sb->s_flags |= SB_ACTIVE; + } + + BUG_ON(fc->root); + fc->root = dget(sb->s_root); + return 0; + +error_sb: + deactivate_locked_super(sb); + return ret; +} + +/* + * get a superblock on an MTD-backed filesystem by MTD device number + */ +static int mtd_get_sb_by_nr(struct fs_context *fc, int mtdnr, + int (*fill_super)(struct super_block *, + struct fs_context *)) +{ + struct mtd_info *mtd; + + mtd = get_mtd_device(NULL, mtdnr); + if (IS_ERR(mtd)) { + errorf(fc, "MTDSB: Device #%u doesn't appear to exist\n", mtdnr); + return PTR_ERR(mtd); + } + + return mtd_get_sb(fc, mtd, fill_super); +} + +/** + * get_tree_mtd - Get a superblock based on a single MTD device + * @fc: The filesystem context holding the parameters + * @fill_super: Helper to initialise a new superblock + */ +int get_tree_mtd(struct fs_context *fc, + int (*fill_super)(struct super_block *sb, + struct fs_context *fc)) +{ +#ifdef CONFIG_BLOCK + dev_t dev; + int ret; +#endif + int mtdnr; + + if (!fc->source) + return invalf(fc, "No source specified"); + + pr_debug("MTDSB: dev_name \"%s\"\n", fc->source); + + /* the preferred way of mounting in future; especially when + * CONFIG_BLOCK=n - we specify the underlying MTD device by number or + * by name, so that we don't require block device support to be present + * in the kernel. + */ + if (fc->source[0] == 'm' && + fc->source[1] == 't' && + fc->source[2] == 'd') { + if (fc->source[3] == ':') { + struct mtd_info *mtd; + + /* mount by MTD device name */ + pr_debug("MTDSB: mtd:%%s, name \"%s\"\n", + fc->source + 4); + + mtd = get_mtd_device_nm(fc->source + 4); + if (!IS_ERR(mtd)) + return mtd_get_sb(fc, mtd, fill_super); + + errorf(fc, "MTD: MTD device with name \"%s\" not found", + fc->source + 4); + + } else if (isdigit(fc->source[3])) { + /* mount by MTD device number name */ + unsigned int mtdnr_val; + + if (kstrtouint(fc->source + 3, 0, &mtdnr_val) == 0) { + mtdnr = mtdnr_val; + /* It was a valid number */ + pr_debug("MTDSB: mtd%%d, mtdnr %u\n", mtdnr_val); + return mtd_get_sb_by_nr(fc, mtdnr, fill_super); + } + } + } + +#ifdef CONFIG_BLOCK + /* try the old way - the hack where we allowed users to mount + * /dev/mtdblock$(n) but didn't actually _use_ the blockdev + */ + ret = lookup_bdev(fc->source, &dev); + if (ret) { + errorf(fc, "MTD: Couldn't look up '%s': %d", fc->source, ret); + return ret; + } + pr_debug("MTDSB: lookup_bdev() returned 0\n"); + + if (MAJOR(dev) == MTD_BLOCK_MAJOR) + return mtd_get_sb_by_nr(fc, MINOR(dev), fill_super); + +#endif /* CONFIG_BLOCK */ + + if (!(fc->sb_flags & SB_SILENT)) + errorf(fc, "MTD: Attempt to mount non-MTD device \"%s\"", + fc->source); + return -EINVAL; +} +EXPORT_SYMBOL_GPL(get_tree_mtd); + +/* + * destroy an MTD-based superblock + */ +void kill_mtd_super(struct super_block *sb) +{ + generic_shutdown_super(sb); + put_mtd_device(sb->s_mtd); + sb->s_mtd = NULL; +} + +EXPORT_SYMBOL_GPL(kill_mtd_super); -- cgit v1.3.1