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1085 lines
26 KiB
1085 lines
26 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
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* linux/fs/vfat/namei.c |
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* |
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* Written 1992,1993 by Werner Almesberger |
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* |
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* Windows95/Windows NT compatible extended MSDOS filesystem |
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* by Gordon Chaffee Copyright (C) 1995. Send bug reports for the |
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* VFAT filesystem to <[email protected]>. Specify |
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* what file operation caused you trouble and if you can duplicate |
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* the problem, send a script that demonstrates it. |
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* |
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* Short name translation 1999, 2001 by Wolfram Pienkoss <[email protected]> |
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* |
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* Support Multibyte characters and cleanup by |
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* OGAWA Hirofumi <[email protected]> |
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*/ |
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|
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#include <linux/module.h> |
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#include <linux/ctype.h> |
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#include <linux/slab.h> |
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#include <linux/namei.h> |
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#include <linux/kernel.h> |
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#include <linux/iversion.h> |
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#include "fat.h" |
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|
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static inline unsigned long vfat_d_version(struct dentry *dentry) |
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{ |
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return (unsigned long) dentry->d_fsdata; |
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} |
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|
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static inline void vfat_d_version_set(struct dentry *dentry, |
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unsigned long version) |
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{ |
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dentry->d_fsdata = (void *) version; |
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} |
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|
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/* |
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* If new entry was created in the parent, it could create the 8.3 |
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* alias (the shortname of logname). So, the parent may have the |
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* negative-dentry which matches the created 8.3 alias. |
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* |
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* If it happened, the negative dentry isn't actually negative |
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* anymore. So, drop it. |
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*/ |
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static int vfat_revalidate_shortname(struct dentry *dentry) |
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{ |
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int ret = 1; |
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spin_lock(&dentry->d_lock); |
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if (!inode_eq_iversion(d_inode(dentry->d_parent), vfat_d_version(dentry))) |
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ret = 0; |
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spin_unlock(&dentry->d_lock); |
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return ret; |
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} |
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|
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static int vfat_revalidate(struct dentry *dentry, unsigned int flags) |
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{ |
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if (flags & LOOKUP_RCU) |
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return -ECHILD; |
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|
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/* This is not negative dentry. Always valid. */ |
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if (d_really_is_positive(dentry)) |
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return 1; |
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return vfat_revalidate_shortname(dentry); |
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} |
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|
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static int vfat_revalidate_ci(struct dentry *dentry, unsigned int flags) |
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{ |
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if (flags & LOOKUP_RCU) |
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return -ECHILD; |
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|
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/* |
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* This is not negative dentry. Always valid. |
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* |
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* Note, rename() to existing directory entry will have ->d_inode, |
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* and will use existing name which isn't specified name by user. |
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* |
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* We may be able to drop this positive dentry here. But dropping |
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* positive dentry isn't good idea. So it's unsupported like |
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* rename("filename", "FILENAME") for now. |
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*/ |
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if (d_really_is_positive(dentry)) |
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return 1; |
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|
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/* |
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* This may be nfsd (or something), anyway, we can't see the |
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* intent of this. So, since this can be for creation, drop it. |
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*/ |
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if (!flags) |
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return 0; |
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|
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/* |
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* Drop the negative dentry, in order to make sure to use the |
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* case sensitive name which is specified by user if this is |
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* for creation. |
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*/ |
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if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET)) |
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return 0; |
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|
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return vfat_revalidate_shortname(dentry); |
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} |
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|
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/* returns the length of a struct qstr, ignoring trailing dots */ |
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static unsigned int __vfat_striptail_len(unsigned int len, const char *name) |
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{ |
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while (len && name[len - 1] == '.') |
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len--; |
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return len; |
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} |
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|
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static unsigned int vfat_striptail_len(const struct qstr *qstr) |
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{ |
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return __vfat_striptail_len(qstr->len, qstr->name); |
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} |
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|
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/* |
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* Compute the hash for the vfat name corresponding to the dentry. |
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* Note: if the name is invalid, we leave the hash code unchanged so |
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* that the existing dentry can be used. The vfat fs routines will |
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* return ENOENT or EINVAL as appropriate. |
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*/ |
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static int vfat_hash(const struct dentry *dentry, struct qstr *qstr) |
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{ |
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qstr->hash = full_name_hash(dentry, qstr->name, vfat_striptail_len(qstr)); |
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return 0; |
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} |
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|
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/* |
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* Compute the hash for the vfat name corresponding to the dentry. |
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* Note: if the name is invalid, we leave the hash code unchanged so |
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* that the existing dentry can be used. The vfat fs routines will |
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* return ENOENT or EINVAL as appropriate. |
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*/ |
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static int vfat_hashi(const struct dentry *dentry, struct qstr *qstr) |
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{ |
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struct nls_table *t = MSDOS_SB(dentry->d_sb)->nls_io; |
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const unsigned char *name; |
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unsigned int len; |
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unsigned long hash; |
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|
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name = qstr->name; |
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len = vfat_striptail_len(qstr); |
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|
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hash = init_name_hash(dentry); |
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while (len--) |
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hash = partial_name_hash(nls_tolower(t, *name++), hash); |
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qstr->hash = end_name_hash(hash); |
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|
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return 0; |
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} |
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|
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/* |
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* Case insensitive compare of two vfat names. |
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*/ |
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static int vfat_cmpi(const struct dentry *dentry, |
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unsigned int len, const char *str, const struct qstr *name) |
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{ |
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struct nls_table *t = MSDOS_SB(dentry->d_sb)->nls_io; |
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unsigned int alen, blen; |
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|
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/* A filename cannot end in '.' or we treat it like it has none */ |
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alen = vfat_striptail_len(name); |
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blen = __vfat_striptail_len(len, str); |
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if (alen == blen) { |
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if (nls_strnicmp(t, name->name, str, alen) == 0) |
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return 0; |
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} |
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return 1; |
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} |
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|
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/* |
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* Case sensitive compare of two vfat names. |
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*/ |
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static int vfat_cmp(const struct dentry *dentry, |
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unsigned int len, const char *str, const struct qstr *name) |
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{ |
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unsigned int alen, blen; |
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|
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/* A filename cannot end in '.' or we treat it like it has none */ |
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alen = vfat_striptail_len(name); |
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blen = __vfat_striptail_len(len, str); |
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if (alen == blen) { |
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if (strncmp(name->name, str, alen) == 0) |
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return 0; |
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} |
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return 1; |
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} |
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|
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static const struct dentry_operations vfat_ci_dentry_ops = { |
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.d_revalidate = vfat_revalidate_ci, |
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.d_hash = vfat_hashi, |
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.d_compare = vfat_cmpi, |
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}; |
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|
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static const struct dentry_operations vfat_dentry_ops = { |
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.d_revalidate = vfat_revalidate, |
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.d_hash = vfat_hash, |
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.d_compare = vfat_cmp, |
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}; |
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|
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/* Characters that are undesirable in an MS-DOS file name */ |
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|
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static inline wchar_t vfat_bad_char(wchar_t w) |
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{ |
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return (w < 0x0020) |
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|| (w == '*') || (w == '?') || (w == '<') || (w == '>') |
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|| (w == '|') || (w == '"') || (w == ':') || (w == '/') |
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|| (w == '\\'); |
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} |
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static inline wchar_t vfat_replace_char(wchar_t w) |
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{ |
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return (w == '[') || (w == ']') || (w == ';') || (w == ',') |
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|| (w == '+') || (w == '='); |
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} |
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static wchar_t vfat_skip_char(wchar_t w) |
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{ |
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return (w == '.') || (w == ' '); |
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} |
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|
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static inline int vfat_is_used_badchars(const wchar_t *s, int len) |
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{ |
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int i; |
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|
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for (i = 0; i < len; i++) |
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if (vfat_bad_char(s[i])) |
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return -EINVAL; |
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|
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if (s[i - 1] == ' ') /* last character cannot be space */ |
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return -EINVAL; |
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|
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return 0; |
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} |
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|
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static int vfat_find_form(struct inode *dir, unsigned char *name) |
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{ |
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struct fat_slot_info sinfo; |
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int err = fat_scan(dir, name, &sinfo); |
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if (err) |
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return -ENOENT; |
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brelse(sinfo.bh); |
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return 0; |
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} |
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|
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/* |
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* 1) Valid characters for the 8.3 format alias are any combination of |
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* letters, uppercase alphabets, digits, any of the |
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* following special characters: |
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* $ % ' ` - @ { } ~ ! # ( ) & _ ^ |
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* In this case Longfilename is not stored in disk. |
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* |
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* WinNT's Extension: |
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* File name and extension name is contain uppercase/lowercase |
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* only. And it is expressed by CASE_LOWER_BASE and CASE_LOWER_EXT. |
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* |
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* 2) File name is 8.3 format, but it contain the uppercase and |
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* lowercase char, muliti bytes char, etc. In this case numtail is not |
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* added, but Longfilename is stored. |
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* |
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* 3) When the one except for the above, or the following special |
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* character are contained: |
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* . [ ] ; , + = |
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* numtail is added, and Longfilename must be stored in disk . |
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*/ |
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struct shortname_info { |
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unsigned char lower:1, |
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upper:1, |
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valid:1; |
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}; |
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#define INIT_SHORTNAME_INFO(x) do { \ |
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(x)->lower = 1; \ |
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(x)->upper = 1; \ |
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(x)->valid = 1; \ |
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} while (0) |
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|
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static inline int to_shortname_char(struct nls_table *nls, |
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unsigned char *buf, int buf_size, |
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wchar_t *src, struct shortname_info *info) |
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{ |
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int len; |
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|
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if (vfat_skip_char(*src)) { |
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info->valid = 0; |
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return 0; |
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} |
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if (vfat_replace_char(*src)) { |
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info->valid = 0; |
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buf[0] = '_'; |
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return 1; |
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} |
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|
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len = nls->uni2char(*src, buf, buf_size); |
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if (len <= 0) { |
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info->valid = 0; |
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buf[0] = '_'; |
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len = 1; |
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} else if (len == 1) { |
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unsigned char prev = buf[0]; |
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|
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if (buf[0] >= 0x7F) { |
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info->lower = 0; |
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info->upper = 0; |
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} |
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buf[0] = nls_toupper(nls, buf[0]); |
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if (isalpha(buf[0])) { |
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if (buf[0] == prev) |
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info->lower = 0; |
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else |
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info->upper = 0; |
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} |
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} else { |
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info->lower = 0; |
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info->upper = 0; |
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} |
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|
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return len; |
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} |
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|
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/* |
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* Given a valid longname, create a unique shortname. Make sure the |
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* shortname does not exist |
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* Returns negative number on error, 0 for a normal |
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* return, and 1 for valid shortname |
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*/ |
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static int vfat_create_shortname(struct inode *dir, struct nls_table *nls, |
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wchar_t *uname, int ulen, |
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unsigned char *name_res, unsigned char *lcase) |
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{ |
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struct fat_mount_options *opts = &MSDOS_SB(dir->i_sb)->options; |
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wchar_t *ip, *ext_start, *end, *name_start; |
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unsigned char base[9], ext[4], buf[5], *p; |
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unsigned char charbuf[NLS_MAX_CHARSET_SIZE]; |
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int chl, chi; |
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int sz = 0, extlen, baselen, i, numtail_baselen, numtail2_baselen; |
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int is_shortname; |
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struct shortname_info base_info, ext_info; |
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|
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is_shortname = 1; |
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INIT_SHORTNAME_INFO(&base_info); |
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INIT_SHORTNAME_INFO(&ext_info); |
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|
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/* Now, we need to create a shortname from the long name */ |
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ext_start = end = &uname[ulen]; |
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while (--ext_start >= uname) { |
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if (*ext_start == 0x002E) { /* is `.' */ |
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if (ext_start == end - 1) { |
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sz = ulen; |
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ext_start = NULL; |
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} |
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break; |
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} |
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} |
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|
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if (ext_start == uname - 1) { |
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sz = ulen; |
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ext_start = NULL; |
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} else if (ext_start) { |
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/* |
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* Names which start with a dot could be just |
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* an extension eg. "...test". In this case Win95 |
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* uses the extension as the name and sets no extension. |
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*/ |
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name_start = &uname[0]; |
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while (name_start < ext_start) { |
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if (!vfat_skip_char(*name_start)) |
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break; |
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name_start++; |
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} |
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if (name_start != ext_start) { |
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sz = ext_start - uname; |
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ext_start++; |
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} else { |
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sz = ulen; |
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ext_start = NULL; |
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} |
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} |
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|
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numtail_baselen = 6; |
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numtail2_baselen = 2; |
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for (baselen = i = 0, p = base, ip = uname; i < sz; i++, ip++) { |
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chl = to_shortname_char(nls, charbuf, sizeof(charbuf), |
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ip, &base_info); |
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if (chl == 0) |
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continue; |
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|
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if (baselen < 2 && (baselen + chl) > 2) |
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numtail2_baselen = baselen; |
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if (baselen < 6 && (baselen + chl) > 6) |
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numtail_baselen = baselen; |
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for (chi = 0; chi < chl; chi++) { |
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*p++ = charbuf[chi]; |
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baselen++; |
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if (baselen >= 8) |
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break; |
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} |
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if (baselen >= 8) { |
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if ((chi < chl - 1) || (ip + 1) - uname < sz) |
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is_shortname = 0; |
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break; |
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} |
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} |
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if (baselen == 0) { |
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return -EINVAL; |
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} |
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|
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extlen = 0; |
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if (ext_start) { |
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for (p = ext, ip = ext_start; extlen < 3 && ip < end; ip++) { |
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chl = to_shortname_char(nls, charbuf, sizeof(charbuf), |
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ip, &ext_info); |
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if (chl == 0) |
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continue; |
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|
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if ((extlen + chl) > 3) { |
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is_shortname = 0; |
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break; |
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} |
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for (chi = 0; chi < chl; chi++) { |
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*p++ = charbuf[chi]; |
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extlen++; |
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} |
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if (extlen >= 3) { |
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if (ip + 1 != end) |
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is_shortname = 0; |
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break; |
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} |
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} |
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} |
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ext[extlen] = '\0'; |
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base[baselen] = '\0'; |
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|
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/* Yes, it can happen. ".\xe5" would do it. */ |
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if (base[0] == DELETED_FLAG) |
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base[0] = 0x05; |
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|
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/* OK, at this point we know that base is not longer than 8 symbols, |
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* ext is not longer than 3, base is nonempty, both don't contain |
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* any bad symbols (lowercase transformed to uppercase). |
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*/ |
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|
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memset(name_res, ' ', MSDOS_NAME); |
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memcpy(name_res, base, baselen); |
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memcpy(name_res + 8, ext, extlen); |
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*lcase = 0; |
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if (is_shortname && base_info.valid && ext_info.valid) { |
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if (vfat_find_form(dir, name_res) == 0) |
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return -EEXIST; |
|
|
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if (opts->shortname & VFAT_SFN_CREATE_WIN95) { |
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return (base_info.upper && ext_info.upper); |
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} else if (opts->shortname & VFAT_SFN_CREATE_WINNT) { |
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if ((base_info.upper || base_info.lower) && |
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(ext_info.upper || ext_info.lower)) { |
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if (!base_info.upper && base_info.lower) |
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*lcase |= CASE_LOWER_BASE; |
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if (!ext_info.upper && ext_info.lower) |
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*lcase |= CASE_LOWER_EXT; |
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return 1; |
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} |
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return 0; |
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} else { |
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BUG(); |
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} |
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} |
|
|
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if (opts->numtail == 0) |
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if (vfat_find_form(dir, name_res) < 0) |
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return 0; |
|
|
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/* |
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* Try to find a unique extension. This used to |
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* iterate through all possibilities sequentially, |
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* but that gave extremely bad performance. Windows |
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* only tries a few cases before using random |
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* values for part of the base. |
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*/ |
|
|
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if (baselen > 6) { |
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baselen = numtail_baselen; |
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name_res[7] = ' '; |
|
} |
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name_res[baselen] = '~'; |
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for (i = 1; i < 10; i++) { |
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name_res[baselen + 1] = i + '0'; |
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if (vfat_find_form(dir, name_res) < 0) |
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return 0; |
|
} |
|
|
|
i = jiffies; |
|
sz = (jiffies >> 16) & 0x7; |
|
if (baselen > 2) { |
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baselen = numtail2_baselen; |
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name_res[7] = ' '; |
|
} |
|
name_res[baselen + 4] = '~'; |
|
name_res[baselen + 5] = '1' + sz; |
|
while (1) { |
|
snprintf(buf, sizeof(buf), "%04X", i & 0xffff); |
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memcpy(&name_res[baselen], buf, 4); |
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if (vfat_find_form(dir, name_res) < 0) |
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break; |
|
i -= 11; |
|
} |
|
return 0; |
|
} |
|
|
|
/* Translate a string, including coded sequences into Unicode */ |
|
static int |
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xlate_to_uni(const unsigned char *name, int len, unsigned char *outname, |
|
int *longlen, int *outlen, int escape, int utf8, |
|
struct nls_table *nls) |
|
{ |
|
const unsigned char *ip; |
|
unsigned char *op; |
|
int i, fill; |
|
int charlen; |
|
|
|
if (utf8) { |
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*outlen = utf8s_to_utf16s(name, len, UTF16_HOST_ENDIAN, |
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(wchar_t *) outname, FAT_LFN_LEN + 2); |
|
if (*outlen < 0) |
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return *outlen; |
|
else if (*outlen > FAT_LFN_LEN) |
|
return -ENAMETOOLONG; |
|
|
|
op = &outname[*outlen * sizeof(wchar_t)]; |
|
} else { |
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for (i = 0, ip = name, op = outname, *outlen = 0; |
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i < len && *outlen < FAT_LFN_LEN; |
|
*outlen += 1) { |
|
if (escape && (*ip == ':')) { |
|
u8 uc[2]; |
|
|
|
if (i > len - 5) |
|
return -EINVAL; |
|
|
|
if (hex2bin(uc, ip + 1, 2) < 0) |
|
return -EINVAL; |
|
|
|
*(wchar_t *)op = uc[0] << 8 | uc[1]; |
|
|
|
op += 2; |
|
ip += 5; |
|
i += 5; |
|
} else { |
|
charlen = nls->char2uni(ip, len - i, |
|
(wchar_t *)op); |
|
if (charlen < 0) |
|
return -EINVAL; |
|
ip += charlen; |
|
i += charlen; |
|
op += 2; |
|
} |
|
} |
|
if (i < len) |
|
return -ENAMETOOLONG; |
|
} |
|
|
|
*longlen = *outlen; |
|
if (*outlen % 13) { |
|
*op++ = 0; |
|
*op++ = 0; |
|
*outlen += 1; |
|
if (*outlen % 13) { |
|
fill = 13 - (*outlen % 13); |
|
for (i = 0; i < fill; i++) { |
|
*op++ = 0xff; |
|
*op++ = 0xff; |
|
} |
|
*outlen += fill; |
|
} |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int vfat_build_slots(struct inode *dir, const unsigned char *name, |
|
int len, int is_dir, int cluster, |
|
struct timespec64 *ts, |
|
struct msdos_dir_slot *slots, int *nr_slots) |
|
{ |
|
struct msdos_sb_info *sbi = MSDOS_SB(dir->i_sb); |
|
struct fat_mount_options *opts = &sbi->options; |
|
struct msdos_dir_slot *ps; |
|
struct msdos_dir_entry *de; |
|
unsigned char cksum, lcase; |
|
unsigned char msdos_name[MSDOS_NAME]; |
|
wchar_t *uname; |
|
__le16 time, date; |
|
u8 time_cs; |
|
int err, ulen, usize, i; |
|
loff_t offset; |
|
|
|
*nr_slots = 0; |
|
|
|
uname = __getname(); |
|
if (!uname) |
|
return -ENOMEM; |
|
|
|
err = xlate_to_uni(name, len, (unsigned char *)uname, &ulen, &usize, |
|
opts->unicode_xlate, opts->utf8, sbi->nls_io); |
|
if (err) |
|
goto out_free; |
|
|
|
err = vfat_is_used_badchars(uname, ulen); |
|
if (err) |
|
goto out_free; |
|
|
|
err = vfat_create_shortname(dir, sbi->nls_disk, uname, ulen, |
|
msdos_name, &lcase); |
|
if (err < 0) |
|
goto out_free; |
|
else if (err == 1) { |
|
de = (struct msdos_dir_entry *)slots; |
|
err = 0; |
|
goto shortname; |
|
} |
|
|
|
/* build the entry of long file name */ |
|
cksum = fat_checksum(msdos_name); |
|
|
|
*nr_slots = usize / 13; |
|
for (ps = slots, i = *nr_slots; i > 0; i--, ps++) { |
|
ps->id = i; |
|
ps->attr = ATTR_EXT; |
|
ps->reserved = 0; |
|
ps->alias_checksum = cksum; |
|
ps->start = 0; |
|
offset = (i - 1) * 13; |
|
fatwchar_to16(ps->name0_4, uname + offset, 5); |
|
fatwchar_to16(ps->name5_10, uname + offset + 5, 6); |
|
fatwchar_to16(ps->name11_12, uname + offset + 11, 2); |
|
} |
|
slots[0].id |= 0x40; |
|
de = (struct msdos_dir_entry *)ps; |
|
|
|
shortname: |
|
/* build the entry of 8.3 alias name */ |
|
(*nr_slots)++; |
|
memcpy(de->name, msdos_name, MSDOS_NAME); |
|
de->attr = is_dir ? ATTR_DIR : ATTR_ARCH; |
|
de->lcase = lcase; |
|
fat_time_unix2fat(sbi, ts, &time, &date, &time_cs); |
|
de->time = de->ctime = time; |
|
de->date = de->cdate = de->adate = date; |
|
de->ctime_cs = time_cs; |
|
fat_set_start(de, cluster); |
|
de->size = 0; |
|
out_free: |
|
__putname(uname); |
|
return err; |
|
} |
|
|
|
static int vfat_add_entry(struct inode *dir, const struct qstr *qname, |
|
int is_dir, int cluster, struct timespec64 *ts, |
|
struct fat_slot_info *sinfo) |
|
{ |
|
struct msdos_dir_slot *slots; |
|
unsigned int len; |
|
int err, nr_slots; |
|
|
|
len = vfat_striptail_len(qname); |
|
if (len == 0) |
|
return -ENOENT; |
|
|
|
slots = kmalloc_array(MSDOS_SLOTS, sizeof(*slots), GFP_NOFS); |
|
if (slots == NULL) |
|
return -ENOMEM; |
|
|
|
err = vfat_build_slots(dir, qname->name, len, is_dir, cluster, ts, |
|
slots, &nr_slots); |
|
if (err) |
|
goto cleanup; |
|
|
|
err = fat_add_entries(dir, slots, nr_slots, sinfo); |
|
if (err) |
|
goto cleanup; |
|
|
|
/* update timestamp */ |
|
fat_truncate_time(dir, ts, S_CTIME|S_MTIME); |
|
if (IS_DIRSYNC(dir)) |
|
(void)fat_sync_inode(dir); |
|
else |
|
mark_inode_dirty(dir); |
|
cleanup: |
|
kfree(slots); |
|
return err; |
|
} |
|
|
|
static int vfat_find(struct inode *dir, const struct qstr *qname, |
|
struct fat_slot_info *sinfo) |
|
{ |
|
unsigned int len = vfat_striptail_len(qname); |
|
if (len == 0) |
|
return -ENOENT; |
|
return fat_search_long(dir, qname->name, len, sinfo); |
|
} |
|
|
|
static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry, |
|
unsigned int flags) |
|
{ |
|
struct super_block *sb = dir->i_sb; |
|
struct fat_slot_info sinfo; |
|
struct inode *inode; |
|
struct dentry *alias; |
|
int err; |
|
|
|
mutex_lock(&MSDOS_SB(sb)->s_lock); |
|
|
|
err = vfat_find(dir, &dentry->d_name, &sinfo); |
|
if (err) { |
|
if (err == -ENOENT) { |
|
inode = NULL; |
|
goto out; |
|
} |
|
goto error; |
|
} |
|
|
|
inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); |
|
brelse(sinfo.bh); |
|
if (IS_ERR(inode)) { |
|
err = PTR_ERR(inode); |
|
goto error; |
|
} |
|
|
|
alias = d_find_alias(inode); |
|
/* |
|
* Checking "alias->d_parent == dentry->d_parent" to make sure |
|
* FS is not corrupted (especially double linked dir). |
|
*/ |
|
if (alias && alias->d_parent == dentry->d_parent) { |
|
/* |
|
* This inode has non anonymous-DCACHE_DISCONNECTED |
|
* dentry. This means, the user did ->lookup() by an |
|
* another name (longname vs 8.3 alias of it) in past. |
|
* |
|
* Switch to new one for reason of locality if possible. |
|
*/ |
|
if (!S_ISDIR(inode->i_mode)) |
|
d_move(alias, dentry); |
|
iput(inode); |
|
mutex_unlock(&MSDOS_SB(sb)->s_lock); |
|
return alias; |
|
} else |
|
dput(alias); |
|
|
|
out: |
|
mutex_unlock(&MSDOS_SB(sb)->s_lock); |
|
if (!inode) |
|
vfat_d_version_set(dentry, inode_query_iversion(dir)); |
|
return d_splice_alias(inode, dentry); |
|
error: |
|
mutex_unlock(&MSDOS_SB(sb)->s_lock); |
|
return ERR_PTR(err); |
|
} |
|
|
|
static int vfat_create(struct user_namespace *mnt_userns, struct inode *dir, |
|
struct dentry *dentry, umode_t mode, bool excl) |
|
{ |
|
struct super_block *sb = dir->i_sb; |
|
struct inode *inode; |
|
struct fat_slot_info sinfo; |
|
struct timespec64 ts; |
|
int err; |
|
|
|
mutex_lock(&MSDOS_SB(sb)->s_lock); |
|
|
|
ts = current_time(dir); |
|
err = vfat_add_entry(dir, &dentry->d_name, 0, 0, &ts, &sinfo); |
|
if (err) |
|
goto out; |
|
inode_inc_iversion(dir); |
|
|
|
inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); |
|
brelse(sinfo.bh); |
|
if (IS_ERR(inode)) { |
|
err = PTR_ERR(inode); |
|
goto out; |
|
} |
|
inode_inc_iversion(inode); |
|
fat_truncate_time(inode, &ts, S_ATIME|S_CTIME|S_MTIME); |
|
/* timestamp is already written, so mark_inode_dirty() is unneeded. */ |
|
|
|
d_instantiate(dentry, inode); |
|
out: |
|
mutex_unlock(&MSDOS_SB(sb)->s_lock); |
|
return err; |
|
} |
|
|
|
static int vfat_rmdir(struct inode *dir, struct dentry *dentry) |
|
{ |
|
struct inode *inode = d_inode(dentry); |
|
struct super_block *sb = dir->i_sb; |
|
struct fat_slot_info sinfo; |
|
int err; |
|
|
|
mutex_lock(&MSDOS_SB(sb)->s_lock); |
|
|
|
err = fat_dir_empty(inode); |
|
if (err) |
|
goto out; |
|
err = vfat_find(dir, &dentry->d_name, &sinfo); |
|
if (err) |
|
goto out; |
|
|
|
err = fat_remove_entries(dir, &sinfo); /* and releases bh */ |
|
if (err) |
|
goto out; |
|
drop_nlink(dir); |
|
|
|
clear_nlink(inode); |
|
fat_truncate_time(inode, NULL, S_ATIME|S_MTIME); |
|
fat_detach(inode); |
|
vfat_d_version_set(dentry, inode_query_iversion(dir)); |
|
out: |
|
mutex_unlock(&MSDOS_SB(sb)->s_lock); |
|
|
|
return err; |
|
} |
|
|
|
static int vfat_unlink(struct inode *dir, struct dentry *dentry) |
|
{ |
|
struct inode *inode = d_inode(dentry); |
|
struct super_block *sb = dir->i_sb; |
|
struct fat_slot_info sinfo; |
|
int err; |
|
|
|
mutex_lock(&MSDOS_SB(sb)->s_lock); |
|
|
|
err = vfat_find(dir, &dentry->d_name, &sinfo); |
|
if (err) |
|
goto out; |
|
|
|
err = fat_remove_entries(dir, &sinfo); /* and releases bh */ |
|
if (err) |
|
goto out; |
|
clear_nlink(inode); |
|
fat_truncate_time(inode, NULL, S_ATIME|S_MTIME); |
|
fat_detach(inode); |
|
vfat_d_version_set(dentry, inode_query_iversion(dir)); |
|
out: |
|
mutex_unlock(&MSDOS_SB(sb)->s_lock); |
|
|
|
return err; |
|
} |
|
|
|
static int vfat_mkdir(struct user_namespace *mnt_userns, struct inode *dir, |
|
struct dentry *dentry, umode_t mode) |
|
{ |
|
struct super_block *sb = dir->i_sb; |
|
struct inode *inode; |
|
struct fat_slot_info sinfo; |
|
struct timespec64 ts; |
|
int err, cluster; |
|
|
|
mutex_lock(&MSDOS_SB(sb)->s_lock); |
|
|
|
ts = current_time(dir); |
|
cluster = fat_alloc_new_dir(dir, &ts); |
|
if (cluster < 0) { |
|
err = cluster; |
|
goto out; |
|
} |
|
err = vfat_add_entry(dir, &dentry->d_name, 1, cluster, &ts, &sinfo); |
|
if (err) |
|
goto out_free; |
|
inode_inc_iversion(dir); |
|
inc_nlink(dir); |
|
|
|
inode = fat_build_inode(sb, sinfo.de, sinfo.i_pos); |
|
brelse(sinfo.bh); |
|
if (IS_ERR(inode)) { |
|
err = PTR_ERR(inode); |
|
/* the directory was completed, just return a error */ |
|
goto out; |
|
} |
|
inode_inc_iversion(inode); |
|
set_nlink(inode, 2); |
|
fat_truncate_time(inode, &ts, S_ATIME|S_CTIME|S_MTIME); |
|
/* timestamp is already written, so mark_inode_dirty() is unneeded. */ |
|
|
|
d_instantiate(dentry, inode); |
|
|
|
mutex_unlock(&MSDOS_SB(sb)->s_lock); |
|
return 0; |
|
|
|
out_free: |
|
fat_free_clusters(dir, cluster); |
|
out: |
|
mutex_unlock(&MSDOS_SB(sb)->s_lock); |
|
return err; |
|
} |
|
|
|
static int vfat_rename(struct user_namespace *mnt_userns, struct inode *old_dir, |
|
struct dentry *old_dentry, struct inode *new_dir, |
|
struct dentry *new_dentry, unsigned int flags) |
|
{ |
|
struct buffer_head *dotdot_bh; |
|
struct msdos_dir_entry *dotdot_de; |
|
struct inode *old_inode, *new_inode; |
|
struct fat_slot_info old_sinfo, sinfo; |
|
struct timespec64 ts; |
|
loff_t new_i_pos; |
|
int err, is_dir, update_dotdot, corrupt = 0; |
|
struct super_block *sb = old_dir->i_sb; |
|
|
|
if (flags & ~RENAME_NOREPLACE) |
|
return -EINVAL; |
|
|
|
old_sinfo.bh = sinfo.bh = dotdot_bh = NULL; |
|
old_inode = d_inode(old_dentry); |
|
new_inode = d_inode(new_dentry); |
|
mutex_lock(&MSDOS_SB(sb)->s_lock); |
|
err = vfat_find(old_dir, &old_dentry->d_name, &old_sinfo); |
|
if (err) |
|
goto out; |
|
|
|
is_dir = S_ISDIR(old_inode->i_mode); |
|
update_dotdot = (is_dir && old_dir != new_dir); |
|
if (update_dotdot) { |
|
if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de)) { |
|
err = -EIO; |
|
goto out; |
|
} |
|
} |
|
|
|
ts = current_time(old_dir); |
|
if (new_inode) { |
|
if (is_dir) { |
|
err = fat_dir_empty(new_inode); |
|
if (err) |
|
goto out; |
|
} |
|
new_i_pos = MSDOS_I(new_inode)->i_pos; |
|
fat_detach(new_inode); |
|
} else { |
|
err = vfat_add_entry(new_dir, &new_dentry->d_name, is_dir, 0, |
|
&ts, &sinfo); |
|
if (err) |
|
goto out; |
|
new_i_pos = sinfo.i_pos; |
|
} |
|
inode_inc_iversion(new_dir); |
|
|
|
fat_detach(old_inode); |
|
fat_attach(old_inode, new_i_pos); |
|
if (IS_DIRSYNC(new_dir)) { |
|
err = fat_sync_inode(old_inode); |
|
if (err) |
|
goto error_inode; |
|
} else |
|
mark_inode_dirty(old_inode); |
|
|
|
if (update_dotdot) { |
|
fat_set_start(dotdot_de, MSDOS_I(new_dir)->i_logstart); |
|
mark_buffer_dirty_inode(dotdot_bh, old_inode); |
|
if (IS_DIRSYNC(new_dir)) { |
|
err = sync_dirty_buffer(dotdot_bh); |
|
if (err) |
|
goto error_dotdot; |
|
} |
|
drop_nlink(old_dir); |
|
if (!new_inode) |
|
inc_nlink(new_dir); |
|
} |
|
|
|
err = fat_remove_entries(old_dir, &old_sinfo); /* and releases bh */ |
|
old_sinfo.bh = NULL; |
|
if (err) |
|
goto error_dotdot; |
|
inode_inc_iversion(old_dir); |
|
fat_truncate_time(old_dir, &ts, S_CTIME|S_MTIME); |
|
if (IS_DIRSYNC(old_dir)) |
|
(void)fat_sync_inode(old_dir); |
|
else |
|
mark_inode_dirty(old_dir); |
|
|
|
if (new_inode) { |
|
drop_nlink(new_inode); |
|
if (is_dir) |
|
drop_nlink(new_inode); |
|
fat_truncate_time(new_inode, &ts, S_CTIME); |
|
} |
|
out: |
|
brelse(sinfo.bh); |
|
brelse(dotdot_bh); |
|
brelse(old_sinfo.bh); |
|
mutex_unlock(&MSDOS_SB(sb)->s_lock); |
|
|
|
return err; |
|
|
|
error_dotdot: |
|
/* data cluster is shared, serious corruption */ |
|
corrupt = 1; |
|
|
|
if (update_dotdot) { |
|
fat_set_start(dotdot_de, MSDOS_I(old_dir)->i_logstart); |
|
mark_buffer_dirty_inode(dotdot_bh, old_inode); |
|
corrupt |= sync_dirty_buffer(dotdot_bh); |
|
} |
|
error_inode: |
|
fat_detach(old_inode); |
|
fat_attach(old_inode, old_sinfo.i_pos); |
|
if (new_inode) { |
|
fat_attach(new_inode, new_i_pos); |
|
if (corrupt) |
|
corrupt |= fat_sync_inode(new_inode); |
|
} else { |
|
/* |
|
* If new entry was not sharing the data cluster, it |
|
* shouldn't be serious corruption. |
|
*/ |
|
int err2 = fat_remove_entries(new_dir, &sinfo); |
|
if (corrupt) |
|
corrupt |= err2; |
|
sinfo.bh = NULL; |
|
} |
|
if (corrupt < 0) { |
|
fat_fs_error(new_dir->i_sb, |
|
"%s: Filesystem corrupted (i_pos %lld)", |
|
__func__, sinfo.i_pos); |
|
} |
|
goto out; |
|
} |
|
|
|
static const struct inode_operations vfat_dir_inode_operations = { |
|
.create = vfat_create, |
|
.lookup = vfat_lookup, |
|
.unlink = vfat_unlink, |
|
.mkdir = vfat_mkdir, |
|
.rmdir = vfat_rmdir, |
|
.rename = vfat_rename, |
|
.setattr = fat_setattr, |
|
.getattr = fat_getattr, |
|
.update_time = fat_update_time, |
|
}; |
|
|
|
static void setup(struct super_block *sb) |
|
{ |
|
MSDOS_SB(sb)->dir_ops = &vfat_dir_inode_operations; |
|
if (MSDOS_SB(sb)->options.name_check != 's') |
|
sb->s_d_op = &vfat_ci_dentry_ops; |
|
else |
|
sb->s_d_op = &vfat_dentry_ops; |
|
} |
|
|
|
static int vfat_fill_super(struct super_block *sb, void *data, int silent) |
|
{ |
|
return fat_fill_super(sb, data, silent, 1, setup); |
|
} |
|
|
|
static struct dentry *vfat_mount(struct file_system_type *fs_type, |
|
int flags, const char *dev_name, |
|
void *data) |
|
{ |
|
return mount_bdev(fs_type, flags, dev_name, data, vfat_fill_super); |
|
} |
|
|
|
static struct file_system_type vfat_fs_type = { |
|
.owner = THIS_MODULE, |
|
.name = "vfat", |
|
.mount = vfat_mount, |
|
.kill_sb = kill_block_super, |
|
.fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP, |
|
}; |
|
MODULE_ALIAS_FS("vfat"); |
|
|
|
static int __init init_vfat_fs(void) |
|
{ |
|
return register_filesystem(&vfat_fs_type); |
|
} |
|
|
|
static void __exit exit_vfat_fs(void) |
|
{ |
|
unregister_filesystem(&vfat_fs_type); |
|
} |
|
|
|
MODULE_LICENSE("GPL"); |
|
MODULE_DESCRIPTION("VFAT filesystem support"); |
|
MODULE_AUTHOR("Gordon Chaffee"); |
|
|
|
module_init(init_vfat_fs) |
|
module_exit(exit_vfat_fs)
|
|
|