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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /fs/squashfs/export.c
downloadlinux-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/squashfs/export.c')
-rw-r--r--fs/squashfs/export.c180
1 files changed, 180 insertions, 0 deletions
diff --git a/fs/squashfs/export.c b/fs/squashfs/export.c
new file mode 100644
index 000000000..62972f0ff
--- /dev/null
+++ b/fs/squashfs/export.c
@@ -0,0 +1,180 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Squashfs - a compressed read only filesystem for Linux
+ *
+ * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
+ * Phillip Lougher <phillip@squashfs.org.uk>
+ *
+ * export.c
+ */
+
+/*
+ * This file implements code to make Squashfs filesystems exportable (NFS etc.)
+ *
+ * The export code uses an inode lookup table to map inode numbers passed in
+ * filehandles to an inode location on disk. This table is stored compressed
+ * into metadata blocks. A second index table is used to locate these. This
+ * second index table for speed of access (and because it is small) is read at
+ * mount time and cached in memory.
+ *
+ * The inode lookup table is used only by the export code, inode disk
+ * locations are directly encoded in directories, enabling direct access
+ * without an intermediate lookup for all operations except the export ops.
+ */
+
+#include <linux/fs.h>
+#include <linux/vfs.h>
+#include <linux/dcache.h>
+#include <linux/exportfs.h>
+#include <linux/slab.h>
+
+#include "squashfs_fs.h"
+#include "squashfs_fs_sb.h"
+#include "squashfs_fs_i.h"
+#include "squashfs.h"
+
+/*
+ * Look-up inode number (ino) in table, returning the inode location.
+ */
+static long long squashfs_inode_lookup(struct super_block *sb, int ino_num)
+{
+ struct squashfs_sb_info *msblk = sb->s_fs_info;
+ int blk = SQUASHFS_LOOKUP_BLOCK(ino_num - 1);
+ int offset = SQUASHFS_LOOKUP_BLOCK_OFFSET(ino_num - 1);
+ u64 start;
+ __le64 ino;
+ int err;
+
+ TRACE("Entered squashfs_inode_lookup, inode_number = %d\n", ino_num);
+
+ if (ino_num == 0 || (ino_num - 1) >= msblk->inodes)
+ return -EINVAL;
+
+ start = le64_to_cpu(msblk->inode_lookup_table[blk]);
+
+ err = squashfs_read_metadata(sb, &ino, &start, &offset, sizeof(ino));
+ if (err < 0)
+ return err;
+
+ TRACE("squashfs_inode_lookup, inode = 0x%llx\n",
+ (u64) le64_to_cpu(ino));
+
+ return le64_to_cpu(ino);
+}
+
+
+static struct dentry *squashfs_export_iget(struct super_block *sb,
+ unsigned int ino_num)
+{
+ long long ino;
+ struct dentry *dentry = ERR_PTR(-ENOENT);
+
+ TRACE("Entered squashfs_export_iget\n");
+
+ ino = squashfs_inode_lookup(sb, ino_num);
+ if (ino >= 0)
+ dentry = d_obtain_alias(squashfs_iget(sb, ino, ino_num));
+
+ return dentry;
+}
+
+
+static struct dentry *squashfs_fh_to_dentry(struct super_block *sb,
+ struct fid *fid, int fh_len, int fh_type)
+{
+ if ((fh_type != FILEID_INO32_GEN && fh_type != FILEID_INO32_GEN_PARENT)
+ || fh_len < 2)
+ return NULL;
+
+ return squashfs_export_iget(sb, fid->i32.ino);
+}
+
+
+static struct dentry *squashfs_fh_to_parent(struct super_block *sb,
+ struct fid *fid, int fh_len, int fh_type)
+{
+ if (fh_type != FILEID_INO32_GEN_PARENT || fh_len < 4)
+ return NULL;
+
+ return squashfs_export_iget(sb, fid->i32.parent_ino);
+}
+
+
+static struct dentry *squashfs_get_parent(struct dentry *child)
+{
+ struct inode *inode = d_inode(child);
+ unsigned int parent_ino = squashfs_i(inode)->parent;
+
+ return squashfs_export_iget(inode->i_sb, parent_ino);
+}
+
+
+/*
+ * Read uncompressed inode lookup table indexes off disk into memory
+ */
+__le64 *squashfs_read_inode_lookup_table(struct super_block *sb,
+ u64 lookup_table_start, u64 next_table, unsigned int inodes)
+{
+ unsigned int length = SQUASHFS_LOOKUP_BLOCK_BYTES(inodes);
+ unsigned int indexes = SQUASHFS_LOOKUP_BLOCKS(inodes);
+ int n;
+ __le64 *table;
+ u64 start, end;
+
+ TRACE("In read_inode_lookup_table, length %d\n", length);
+
+ /* Sanity check values */
+
+ /* there should always be at least one inode */
+ if (inodes == 0)
+ return ERR_PTR(-EINVAL);
+
+ /*
+ * The computed size of the lookup table (length bytes) should exactly
+ * match the table start and end points
+ */
+ if (length != (next_table - lookup_table_start))
+ return ERR_PTR(-EINVAL);
+
+ table = squashfs_read_table(sb, lookup_table_start, length);
+ if (IS_ERR(table))
+ return table;
+
+ /*
+ * table0], table[1], ... table[indexes - 1] store the locations
+ * of the compressed inode lookup blocks. Each entry should be
+ * less than the next (i.e. table[0] < table[1]), and the difference
+ * between them should be SQUASHFS_METADATA_SIZE or less.
+ * table[indexes - 1] should be less than lookup_table_start, and
+ * again the difference should be SQUASHFS_METADATA_SIZE or less
+ */
+ for (n = 0; n < (indexes - 1); n++) {
+ start = le64_to_cpu(table[n]);
+ end = le64_to_cpu(table[n + 1]);
+
+ if (start >= end
+ || (end - start) >
+ (SQUASHFS_METADATA_SIZE + SQUASHFS_BLOCK_OFFSET)) {
+ kfree(table);
+ return ERR_PTR(-EINVAL);
+ }
+ }
+
+ start = le64_to_cpu(table[indexes - 1]);
+ if (start >= lookup_table_start ||
+ (lookup_table_start - start) >
+ (SQUASHFS_METADATA_SIZE + SQUASHFS_BLOCK_OFFSET)) {
+ kfree(table);
+ return ERR_PTR(-EINVAL);
+ }
+
+ return table;
+}
+
+
+const struct export_operations squashfs_export_ops = {
+ .encode_fh = generic_encode_ino32_fh,
+ .fh_to_dentry = squashfs_fh_to_dentry,
+ .fh_to_parent = squashfs_fh_to_parent,
+ .get_parent = squashfs_get_parent
+};