| 1 | |
| 2 | |
| 3 | * eCryptfs: Linux filesystem encryption layer
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| 4 | *
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| 5 | * Copyright (C) 1997-2003 Erez Zadok
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| 6 | * Copyright (C) 2001-2003 Stony Brook University
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| 7 | * Copyright (C) 2004-2006 International Business Machines Corp.
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| 8 | * Author(s): Michael A. Halcrow <[email protected]>
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| 9 |
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| 10 |
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| 11 | #include <linux/dcache.h>
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| 12 | #include <linux/namei.h>
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| 13 | #include <linux/mount.h>
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| 14 | #include <linux/fs_stack.h>
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| 15 | #include <linux/slab.h>
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| 16 | #include "ecryptfs_kernel.h"
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| 17 |
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| 18 | |
| 19 | * ecryptfs_d_revalidate - revalidate an ecryptfs dentry
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| 20 | * @dir: inode of expected parent
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| 21 | * @name: expected name
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| 22 | * @dentry: dentry to revalidate
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| 23 | * @flags: lookup flags
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| 24 | *
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| 25 | * Called when the VFS needs to revalidate a dentry. This
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| 26 | * is called whenever a name lookup finds a dentry in the
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| 27 | * dcache. Most filesystems leave this as NULL, because all their
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| 28 | * dentries in the dcache are valid.
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| 29 | *
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| 30 | * Returns 1 if valid, 0 otherwise.
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| 31 | *
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| 32 |
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| 33 | static int ecryptfs_d_revalidate(struct inode *dir, const struct qstr *name,
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| 34 | struct dentry *dentry, unsigned int flags)
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| 35 | {
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| 36 | struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
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| 37 | int rc = 1;
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| 38 |
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| 39 | if (flags & LOOKUP_RCU)
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| 40 | return -ECHILD;
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| 41 |
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| 42 | if (lower_dentry->d_flags & DCACHE_OP_REVALIDATE) {
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| 43 | struct inode *lower_dir = ecryptfs_inode_to_lower(dir);
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| 44 | struct name_snapshot n;
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| 45 |
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| 46 | take_dentry_name_snapshot(&n, lower_dentry);
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| 47 | rc = lower_dentry->d_op->d_revalidate(lower_dir, &n.name,
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| 48 | lower_dentry, flags);
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| 49 | release_dentry_name_snapshot(&n);
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| 50 | }
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| 51 |
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| 52 | if (d_really_is_positive(dentry)) {
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| 53 | struct inode *inode = d_inode(dentry);
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| 54 |
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| 55 | fsstack_copy_attr_all(inode, ecryptfs_inode_to_lower(inode));
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| 56 | if (!inode->i_nlink)
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| 57 | return 0;
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| 58 | }
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| 59 | return rc;
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| 60 | }
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| 61 |
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| 62 | |
| 63 | * ecryptfs_d_release
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| 64 | * @dentry: The ecryptfs dentry
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| 65 | *
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| 66 | * Called when a dentry is really deallocated.
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| 67 |
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| 68 | static void ecryptfs_d_release(struct dentry *dentry)
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| 69 | {
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| 70 | dput(dentry->d_fsdata);
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| 71 | }
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| 72 |
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| 73 | const struct dentry_operations ecryptfs_dops = {
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| 74 | .d_revalidate = ecryptfs_d_revalidate,
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| 75 | .d_release = ecryptfs_d_release,
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| 76 | };
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