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namei.c
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
*/
#include <linux/iversion.h>
#include <linux/namei.h>
#include <linux/slab.h>
#include <linux/buffer_head.h>
#include <linux/nls.h>
#include "exfat_raw.h"
#include "exfat_fs.h"
static inline unsigned long exfat_d_version(struct dentry *dentry)
{
return (unsigned long) dentry->d_fsdata;
}
static inline void exfat_d_version_set(struct dentry *dentry,
unsigned long version)
{
dentry->d_fsdata = (void *) version;
}
/*
* If new entry was created in the parent, it could create the 8.3 alias (the
* shortname of logname). So, the parent may have the negative-dentry which
* matches the created 8.3 alias.
*
* If it happened, the negative dentry isn't actually negative anymore. So,
* drop it.
*/
static int exfat_d_revalidate(struct dentry *dentry, unsigned int flags)
{
int ret;
if (flags & LOOKUP_RCU)
return -ECHILD;
/*
* This is not negative dentry. Always valid.
*
* Note, rename() to existing directory entry will have ->d_inode, and
* will use existing name which isn't specified name by user.
*
* We may be able to drop this positive dentry here. But dropping
* positive dentry isn't good idea. So it's unsupported like
* rename("filename", "FILENAME") for now.
*/
if (d_really_is_positive(dentry))
return 1;
/*
* Drop the negative dentry, in order to make sure to use the case
* sensitive name which is specified by user if this is for creation.
*/
if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
return 0;
spin_lock(&dentry->d_lock);
ret = inode_eq_iversion(d_inode(dentry->d_parent),
exfat_d_version(dentry));
spin_unlock(&dentry->d_lock);
return ret;
}
/* returns the length of a struct qstr, ignoring trailing dots */
static unsigned int exfat_striptail_len(unsigned int len, const char *name)
{
while (len && name[len - 1] == '.')
len--;
return len;
}
/*
* Compute the hash for the exfat name corresponding to the dentry. If the name
* is invalid, we leave the hash code unchanged so that the existing dentry can
* be used. The exfat fs routines will return ENOENT or EINVAL as appropriate.
*/
static int exfat_d_hash(const struct dentry *dentry, struct qstr *qstr)
{
struct super_block *sb = dentry->d_sb;
struct nls_table *t = EXFAT_SB(sb)->nls_io;
const unsigned char *name = qstr->name;
unsigned int len = exfat_striptail_len(qstr->len, qstr->name);
unsigned long hash = init_name_hash(dentry);
int i, charlen;
wchar_t c;
for (i = 0; i < len; i += charlen) {
charlen = t->char2uni(&name[i], len - i, &c);
if (charlen < 0)
return charlen;
hash = partial_name_hash(exfat_toupper(sb, c), hash);
}
qstr->hash = end_name_hash(hash);
return 0;
}
static int exfat_d_cmp(const struct dentry *dentry, unsigned int len,
const char *str, const struct qstr *name)
{
struct super_block *sb = dentry->d_sb;
struct nls_table *t = EXFAT_SB(sb)->nls_io;
unsigned int alen = exfat_striptail_len(name->len, name->name);
unsigned int blen = exfat_striptail_len(len, str);
wchar_t c1, c2;
int charlen, i;
if (alen != blen)
return 1;
for (i = 0; i < len; i += charlen) {
charlen = t->char2uni(&name->name[i], alen - i, &c1);
if (charlen < 0)
return 1;
if (charlen != t->char2uni(&str[i], blen - i, &c2))
return 1;
if (exfat_toupper(sb, c1) != exfat_toupper(sb, c2))
return 1;
}
return 0;
}
const struct dentry_operations exfat_dentry_ops = {
.d_revalidate = exfat_d_revalidate,
.d_hash = exfat_d_hash,
.d_compare = exfat_d_cmp,
};
static int exfat_utf8_d_hash(const struct dentry *dentry, struct qstr *qstr)
{
struct super_block *sb = dentry->d_sb;
const unsigned char *name = qstr->name;
unsigned int len = exfat_striptail_len(qstr->len, qstr->name);
unsigned long hash = init_name_hash(dentry);
int i, charlen;
unicode_t u;
for (i = 0; i < len; i += charlen) {
charlen = utf8_to_utf32(&name[i], len - i, &u);
if (charlen < 0)
return charlen;
/*
* Convert to UTF-16: code points above U+FFFF are encoded as
* surrogate pairs.
* exfat_toupper() works only for code points up to the U+FFFF.
*/
if (u > 0xFFFF) {
hash = partial_name_hash(exfat_high_surrogate(u), hash);
hash = partial_name_hash(exfat_low_surrogate(u), hash);
} else {
hash = partial_name_hash(exfat_toupper(sb, u), hash);
}
}
qstr->hash = end_name_hash(hash);
return 0;
}
static int exfat_utf8_d_cmp(const struct dentry *dentry, unsigned int len,
const char *str, const struct qstr *name)
{
struct super_block *sb = dentry->d_sb;
unsigned int alen = exfat_striptail_len(name->len, name->name);
unsigned int blen = exfat_striptail_len(len, str);
unicode_t u_a, u_b;
int charlen, i;
if (alen != blen)
return 1;
for (i = 0; i < alen; i += charlen) {
charlen = utf8_to_utf32(&name->name[i], alen - i, &u_a);
if (charlen < 0)
return 1;
if (charlen != utf8_to_utf32(&str[i], blen - i, &u_b))
return 1;
if (u_a <= 0xFFFF && u_b <= 0xFFFF) {
if (exfat_toupper(sb, u_a) != exfat_toupper(sb, u_b))
return 1;
} else if (u_a > 0xFFFF && u_b > 0xFFFF) {
if (exfat_low_surrogate(u_a) !=
exfat_low_surrogate(u_b) ||
exfat_high_surrogate(u_a) !=
exfat_high_surrogate(u_b))
return 1;
} else {
return 1;
}
}
return 0;
}
const struct dentry_operations exfat_utf8_dentry_ops = {
.d_revalidate = exfat_d_revalidate,
.d_hash = exfat_utf8_d_hash,
.d_compare = exfat_utf8_d_cmp,
};
/* used only in search empty_slot() */
#define CNT_UNUSED_NOHIT (-1)
#define CNT_UNUSED_HIT (-2)
/* search EMPTY CONTINUOUS "num_entries" entries */
static int exfat_search_empty_slot(struct super_block *sb,
struct exfat_hint_femp *hint_femp, struct exfat_chain *p_dir,
int num_entries)
{
int i, dentry, num_empty = 0;
int dentries_per_clu;
unsigned int type;
struct exfat_chain clu;
struct exfat_dentry *ep;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct buffer_head *bh;
dentries_per_clu = sbi->dentries_per_clu;
if (hint_femp->eidx != EXFAT_HINT_NONE) {
dentry = hint_femp->eidx;
if (num_entries <= hint_femp->count) {
hint_femp->eidx = EXFAT_HINT_NONE;
return dentry;
}
exfat_chain_dup(&clu, &hint_femp->cur);
} else {
exfat_chain_dup(&clu, p_dir);
dentry = 0;
}
while (clu.dir != EXFAT_EOF_CLUSTER) {
i = dentry & (dentries_per_clu - 1);
for (; i < dentries_per_clu; i++, dentry++) {
ep = exfat_get_dentry(sb, &clu, i, &bh, NULL);
if (!ep)
return -EIO;
type = exfat_get_entry_type(ep);
brelse(bh);
if (type == TYPE_UNUSED || type == TYPE_DELETED) {
num_empty++;
if (hint_femp->eidx == EXFAT_HINT_NONE) {
hint_femp->eidx = dentry;
hint_femp->count = CNT_UNUSED_NOHIT;
exfat_chain_set(&hint_femp->cur,
clu.dir, clu.size, clu.flags);
}
if (type == TYPE_UNUSED &&
hint_femp->count != CNT_UNUSED_HIT)
hint_femp->count = CNT_UNUSED_HIT;
} else {
if (hint_femp->eidx != EXFAT_HINT_NONE &&
hint_femp->count == CNT_UNUSED_HIT) {
/* unused empty group means
* an empty group which includes
* unused dentry
*/
exfat_fs_error(sb,
"found bogus dentry(%d) beyond unused empty group(%d) (start_clu : %u, cur_clu : %u)",
dentry, hint_femp->eidx,
p_dir->dir, clu.dir);
return -EIO;
}
num_empty = 0;
hint_femp->eidx = EXFAT_HINT_NONE;
}
if (num_empty >= num_entries) {
/* found and invalidate hint_femp */
hint_femp->eidx = EXFAT_HINT_NONE;
return (dentry - (num_entries - 1));
}
}
if (clu.flags == ALLOC_NO_FAT_CHAIN) {
if (--clu.size > 0)
clu.dir++;
else
clu.dir = EXFAT_EOF_CLUSTER;
} else {
if (exfat_get_next_cluster(sb, &clu.dir))
return -EIO;
}
}
return -ENOSPC;
}
static int exfat_check_max_dentries(struct inode *inode)
{
if (EXFAT_B_TO_DEN(i_size_read(inode)) >= MAX_EXFAT_DENTRIES) {
/*
* exFAT spec allows a dir to grow upto 8388608(256MB)
* dentries
*/
return -ENOSPC;
}
return 0;
}
/* find empty directory entry.
* if there isn't any empty slot, expand cluster chain.
*/
static int exfat_find_empty_entry(struct inode *inode,
struct exfat_chain *p_dir, int num_entries)
{
int dentry;
unsigned int ret, last_clu;
sector_t sector;
loff_t size = 0;
struct exfat_chain clu;
struct exfat_dentry *ep = NULL;
struct super_block *sb = inode->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct exfat_inode_info *ei = EXFAT_I(inode);
struct exfat_hint_femp hint_femp;
hint_femp.eidx = EXFAT_HINT_NONE;
if (ei->hint_femp.eidx != EXFAT_HINT_NONE) {
memcpy(&hint_femp, &ei->hint_femp,
sizeof(struct exfat_hint_femp));
ei->hint_femp.eidx = EXFAT_HINT_NONE;
}
while ((dentry = exfat_search_empty_slot(sb, &hint_femp, p_dir,
num_entries)) < 0) {
if (dentry == -EIO)
break;
if (exfat_check_max_dentries(inode))
return -ENOSPC;
/* we trust p_dir->size regardless of FAT type */
if (exfat_find_last_cluster(sb, p_dir, &last_clu))
return -EIO;
/*
* Allocate new cluster to this directory
*/
exfat_chain_set(&clu, last_clu + 1, 0, p_dir->flags);
/* allocate a cluster */
ret = exfat_alloc_cluster(inode, 1, &clu);
if (ret)
return ret;
if (exfat_zeroed_cluster(inode, clu.dir))
return -EIO;
/* append to the FAT chain */
if (clu.flags != p_dir->flags) {
/* no-fat-chain bit is disabled,
* so fat-chain should be synced with alloc-bitmap
*/
exfat_chain_cont_cluster(sb, p_dir->dir, p_dir->size);
p_dir->flags = ALLOC_FAT_CHAIN;
hint_femp.cur.flags = ALLOC_FAT_CHAIN;
}
if (clu.flags == ALLOC_FAT_CHAIN)
if (exfat_ent_set(sb, last_clu, clu.dir))
return -EIO;
if (hint_femp.eidx == EXFAT_HINT_NONE) {
/* the special case that new dentry
* should be allocated from the start of new cluster
*/
hint_femp.eidx = EXFAT_B_TO_DEN_IDX(p_dir->size, sbi);
hint_femp.count = sbi->dentries_per_clu;
exfat_chain_set(&hint_femp.cur, clu.dir, 0, clu.flags);
}
hint_femp.cur.size++;
p_dir->size++;
size = EXFAT_CLU_TO_B(p_dir->size, sbi);
/* update the directory entry */
if (p_dir->dir != sbi->root_dir) {
struct buffer_head *bh;
ep = exfat_get_dentry(sb,
&(ei->dir), ei->entry + 1, &bh, §or);
if (!ep)
return -EIO;
ep->dentry.stream.valid_size = cpu_to_le64(size);
ep->dentry.stream.size = ep->dentry.stream.valid_size;
ep->dentry.stream.flags = p_dir->flags;
exfat_update_bh(sb, bh, IS_DIRSYNC(inode));
brelse(bh);
if (exfat_update_dir_chksum(inode, &(ei->dir),
ei->entry))
return -EIO;
}
/* directory inode should be updated in here */
i_size_write(inode, size);
EXFAT_I(inode)->i_size_ondisk += sbi->cluster_size;
EXFAT_I(inode)->i_size_aligned += sbi->cluster_size;
EXFAT_I(inode)->flags = p_dir->flags;
inode->i_blocks += 1 << sbi->sect_per_clus_bits;
}
return dentry;
}
/*
* Name Resolution Functions :
* Zero if it was successful; otherwise nonzero.
*/
static int __exfat_resolve_path(struct inode *inode, const unsigned char *path,
struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname,
int lookup)
{
int namelen;
int lossy = NLS_NAME_NO_LOSSY;
struct super_block *sb = inode->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct exfat_inode_info *ei = EXFAT_I(inode);
/* strip all trailing periods */
namelen = exfat_striptail_len(strlen(path), path);
if (!namelen)
return -ENOENT;
if (strlen(path) > (MAX_NAME_LENGTH * MAX_CHARSET_SIZE))
return -ENAMETOOLONG;
/*
* strip all leading spaces :
* "MS windows 7" supports leading spaces.
* So we should skip this preprocessing for compatibility.
*/
/* file name conversion :
* If lookup case, we allow bad-name for compatibility.
*/
namelen = exfat_nls_to_utf16(sb, path, namelen, p_uniname,
&lossy);
if (namelen < 0)
return namelen; /* return error value */
if ((lossy && !lookup) || !namelen)
return -EINVAL;
exfat_chain_set(p_dir, ei->start_clu,
EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags);
return 0;
}
static inline int exfat_resolve_path(struct inode *inode,
const unsigned char *path, struct exfat_chain *dir,
struct exfat_uni_name *uni)
{
return __exfat_resolve_path(inode, path, dir, uni, 0);
}
static inline int exfat_resolve_path_for_lookup(struct inode *inode,
const unsigned char *path, struct exfat_chain *dir,
struct exfat_uni_name *uni)
{
return __exfat_resolve_path(inode, path, dir, uni, 1);
}
static inline loff_t exfat_make_i_pos(struct exfat_dir_entry *info)
{
return ((loff_t) info->dir.dir << 32) | (info->entry & 0xffffffff);
}
static int exfat_add_entry(struct inode *inode, const char *path,
struct exfat_chain *p_dir, unsigned int type,
struct exfat_dir_entry *info)
{
int ret, dentry, num_entries;
struct super_block *sb = inode->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct exfat_uni_name uniname;
struct exfat_chain clu;
int clu_size = 0;
unsigned int start_clu = EXFAT_FREE_CLUSTER;
ret = exfat_resolve_path(inode, path, p_dir, &uniname);
if (ret)
goto out;
num_entries = exfat_calc_num_entries(&uniname);
if (num_entries < 0) {
ret = num_entries;
goto out;
}
/* exfat_find_empty_entry must be called before alloc_cluster() */
dentry = exfat_find_empty_entry(inode, p_dir, num_entries);
if (dentry < 0) {
ret = dentry; /* -EIO or -ENOSPC */
goto out;
}
if (type == TYPE_DIR) {
ret = exfat_alloc_new_dir(inode, &clu);
if (ret)
goto out;
start_clu = clu.dir;
clu_size = sbi->cluster_size;
}
/* update the directory entry */
/* fill the dos name directory entry information of the created file.
* the first cluster is not determined yet. (0)
*/
ret = exfat_init_dir_entry(inode, p_dir, dentry, type,
start_clu, clu_size);
if (ret)
goto out;
ret = exfat_init_ext_entry(inode, p_dir, dentry, num_entries, &uniname);
if (ret)
goto out;
memcpy(&info->dir, p_dir, sizeof(struct exfat_chain));
info->entry = dentry;
info->flags = ALLOC_NO_FAT_CHAIN;
info->type = type;
if (type == TYPE_FILE) {
info->attr = ATTR_ARCHIVE;
info->start_clu = EXFAT_EOF_CLUSTER;
info->size = 0;
info->num_subdirs = 0;
} else {
int count;
struct exfat_chain cdir;
info->attr = ATTR_SUBDIR;
info->start_clu = start_clu;
info->size = clu_size;
exfat_chain_set(&cdir, info->start_clu,
EXFAT_B_TO_CLU(info->size, sbi), info->flags);
count = exfat_count_dir_entries(sb, &cdir);
if (count < 0)
return -EIO;
info->num_subdirs = count + EXFAT_MIN_SUBDIR;
}
memset(&info->crtime, 0, sizeof(info->crtime));
memset(&info->mtime, 0, sizeof(info->mtime));
memset(&info->atime, 0, sizeof(info->atime));
out:
return ret;
}
static int exfat_create(struct inode *dir, struct dentry *dentry, umode_t mode,
bool excl)
{
struct super_block *sb = dir->i_sb;
struct inode *inode;
struct exfat_chain cdir;
struct exfat_dir_entry info;
loff_t i_pos;
int err;
mutex_lock(&EXFAT_SB(sb)->s_lock);
exfat_set_vol_flags(sb, VOL_DIRTY);
err = exfat_add_entry(dir, dentry->d_name.name, &cdir, TYPE_FILE,
&info);
exfat_set_vol_flags(sb, VOL_CLEAN);
if (err)
goto unlock;
inode_inc_iversion(dir);
dir->i_ctime = dir->i_mtime = current_time(dir);
if (IS_DIRSYNC(dir))
exfat_sync_inode(dir);
else
mark_inode_dirty(dir);
i_pos = exfat_make_i_pos(&info);
inode = exfat_build_inode(sb, &info, i_pos);
if (IS_ERR(inode))
goto unlock;
inode_inc_iversion(inode);
inode->i_mtime = inode->i_atime = inode->i_ctime =
EXFAT_I(inode)->i_crtime = current_time(inode);
/* timestamp is already written, so mark_inode_dirty() is unneeded. */
d_instantiate(dentry, inode);
unlock:
mutex_unlock(&EXFAT_SB(sb)->s_lock);
return err;
}
/* lookup a file */
static int exfat_find(struct inode *dir, struct qstr *qname,
struct exfat_dir_entry *info)
{
int ret, dentry, num_entries, count;
struct exfat_chain cdir;
struct exfat_uni_name uni_name;
struct exfat_dentry *ep, *ep2;
struct exfat_entry_set_cache *es = NULL;
struct super_block *sb = dir->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct exfat_inode_info *ei = EXFAT_I(dir);
if (qname->len == 0)
return -ENOENT;
/* check the validity of directory name in the given pathname */
ret = exfat_resolve_path_for_lookup(dir, qname->name, &cdir, &uni_name);
if (ret)
return ret;
num_entries = exfat_calc_num_entries(&uni_name);
if (num_entries < 0)
return num_entries;
/* check the validation of hint_stat and initialize it if required */
if (ei->version != (inode_peek_iversion_raw(dir) & 0xffffffff)) {
ei->hint_stat.clu = cdir.dir;
ei->hint_stat.eidx = 0;
ei->version = (inode_peek_iversion_raw(dir) & 0xffffffff);
ei->hint_femp.eidx = EXFAT_HINT_NONE;
}
/* search the file name for directories */
dentry = exfat_find_dir_entry(sb, ei, &cdir, &uni_name,
num_entries, TYPE_ALL);
if ((dentry < 0) && (dentry != -EEXIST))
return dentry; /* -error value */
memcpy(&info->dir, &cdir.dir, sizeof(struct exfat_chain));
info->entry = dentry;
info->num_subdirs = 0;
/* root directory itself */
if (unlikely(dentry == -EEXIST)) {
int num_clu = 0;
info->type = TYPE_DIR;
info->attr = ATTR_SUBDIR;
info->flags = ALLOC_FAT_CHAIN;
info->start_clu = sbi->root_dir;
memset(&info->crtime, 0, sizeof(info->crtime));
memset(&info->mtime, 0, sizeof(info->mtime));
memset(&info->atime, 0, sizeof(info->atime));
exfat_chain_set(&cdir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
if (exfat_count_num_clusters(sb, &cdir, &num_clu))
return -EIO;
info->size = num_clu << sbi->cluster_size_bits;
count = exfat_count_dir_entries(sb, &cdir);
if (count < 0)
return -EIO;
info->num_subdirs = count;
} else {
es = exfat_get_dentry_set(sb, &cdir, dentry, ES_2_ENTRIES, &ep);
if (!es)
return -EIO;
ep2 = ep + 1;
info->type = exfat_get_entry_type(ep);
info->attr = le16_to_cpu(ep->dentry.file.attr);
info->size = le64_to_cpu(ep2->dentry.stream.valid_size);
if ((info->type == TYPE_FILE) && (info->size == 0)) {
info->flags = ALLOC_NO_FAT_CHAIN;
info->start_clu = EXFAT_EOF_CLUSTER;
} else {
info->flags = ep2->dentry.stream.flags;
info->start_clu =
le32_to_cpu(ep2->dentry.stream.start_clu);
}
if (ei->start_clu == EXFAT_FREE_CLUSTER) {
exfat_fs_error(sb,
"non-zero size file starts with zero cluster (size : %llu, p_dir : %u, entry : 0x%08x)",
i_size_read(dir), ei->dir.dir, ei->entry);
return -EIO;
}
exfat_get_entry_time(sbi, &info->crtime,
ep->dentry.file.create_tz,
ep->dentry.file.create_time,
ep->dentry.file.create_date,
ep->dentry.file.create_time_ms);
exfat_get_entry_time(sbi, &info->mtime,
ep->dentry.file.modify_tz,
ep->dentry.file.modify_time,
ep->dentry.file.modify_date,
ep->dentry.file.modify_time_ms);
exfat_get_entry_time(sbi, &info->atime,
ep->dentry.file.access_tz,
ep->dentry.file.access_time,
ep->dentry.file.access_date,
0);
kfree(es);
if (info->type == TYPE_DIR) {
exfat_chain_set(&cdir, info->start_clu,
EXFAT_B_TO_CLU(info->size, sbi), info->flags);
count = exfat_count_dir_entries(sb, &cdir);
if (count < 0)
return -EIO;
info->num_subdirs = count + EXFAT_MIN_SUBDIR;
}
}
return 0;
}
static int exfat_d_anon_disconn(struct dentry *dentry)
{
return IS_ROOT(dentry) && (dentry->d_flags & DCACHE_DISCONNECTED);
}
static struct dentry *exfat_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
struct super_block *sb = dir->i_sb;
struct inode *inode;
struct dentry *alias;
struct exfat_dir_entry info;
int err;
loff_t i_pos;
mode_t i_mode;
mutex_lock(&EXFAT_SB(sb)->s_lock);
err = exfat_find(dir, &dentry->d_name, &info);
if (err) {
if (err == -ENOENT) {
inode = NULL;
goto out;
}
goto unlock;
}
i_pos = exfat_make_i_pos(&info);
inode = exfat_build_inode(sb, &info, i_pos);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto unlock;
}
i_mode = inode->i_mode;
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 &&
!exfat_d_anon_disconn(alias)) {
/*
* Unhashed alias is able to exist because of revalidate()
* called by lookup_fast. You can easily make this status
* by calling create and lookup concurrently
* In such case, we reuse an alias instead of new dentry
*/
if (d_unhashed(alias)) {
WARN_ON(alias->d_name.hash_len !=
dentry->d_name.hash_len);
exfat_msg(sb, KERN_INFO,
"rehashed a dentry(%p) in read lookup", alias);
d_drop(dentry);
d_rehash(alias);
} else if (!S_ISDIR(i_mode)) {
/*
* 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.
*/
d_move(alias, dentry);
}
iput(inode);
mutex_unlock(&EXFAT_SB(sb)->s_lock);
return alias;
}
dput(alias);
out:
mutex_unlock(&EXFAT_SB(sb)->s_lock);
if (!inode)
exfat_d_version_set(dentry, inode_query_iversion(dir));
return d_splice_alias(inode, dentry);
unlock:
mutex_unlock(&EXFAT_SB(sb)->s_lock);
return ERR_PTR(err);
}
/* remove an entry, BUT don't truncate */
static int exfat_unlink(struct inode *dir, struct dentry *dentry)
{
struct exfat_chain cdir;
struct exfat_dentry *ep;
struct super_block *sb = dir->i_sb;
struct inode *inode = dentry->d_inode;
struct exfat_inode_info *ei = EXFAT_I(inode);
struct buffer_head *bh;
sector_t sector;
int num_entries, entry, err = 0;
mutex_lock(&EXFAT_SB(sb)->s_lock);
exfat_chain_dup(&cdir, &ei->dir);
entry = ei->entry;
if (ei->dir.dir == DIR_DELETED) {
exfat_msg(sb, KERN_ERR, "abnormal access to deleted dentry");
err = -ENOENT;
goto unlock;
}
ep = exfat_get_dentry(sb, &cdir, entry, &bh, §or);
if (!ep) {
err = -EIO;
goto unlock;
}
num_entries = exfat_count_ext_entries(sb, &cdir, entry, ep);
if (num_entries < 0) {
err = -EIO;
brelse(bh);
goto unlock;
}
num_entries++;
brelse(bh);
exfat_set_vol_flags(sb, VOL_DIRTY);
/* update the directory entry */
if (exfat_remove_entries(dir, &cdir, entry, 0, num_entries)) {
err = -EIO;
goto unlock;
}
/* This doesn't modify ei */
ei->dir.dir = DIR_DELETED;
exfat_set_vol_flags(sb, VOL_CLEAN);
inode_inc_iversion(dir);
dir->i_mtime = dir->i_atime = current_time(dir);
if (IS_DIRSYNC(dir))
exfat_sync_inode(dir);
else
mark_inode_dirty(dir);
clear_nlink(inode);
inode->i_mtime = inode->i_atime = current_time(inode);
exfat_unhash_inode(inode);
exfat_d_version_set(dentry, inode_query_iversion(dir));
unlock:
mutex_unlock(&EXFAT_SB(sb)->s_lock);
return err;
}
static int exfat_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
struct super_block *sb = dir->i_sb;
struct inode *inode;
struct exfat_dir_entry info;
struct exfat_chain cdir;
loff_t i_pos;
int err;
mutex_lock(&EXFAT_SB(sb)->s_lock);
exfat_set_vol_flags(sb, VOL_DIRTY);
err = exfat_add_entry(dir, dentry->d_name.name, &cdir, TYPE_DIR,
&info);
exfat_set_vol_flags(sb, VOL_CLEAN);
if (err)
goto unlock;
inode_inc_iversion(dir);
dir->i_ctime = dir->i_mtime = current_time(dir);
if (IS_DIRSYNC(dir))
exfat_sync_inode(dir);
else
mark_inode_dirty(dir);
inc_nlink(dir);
i_pos = exfat_make_i_pos(&info);
inode = exfat_build_inode(sb, &info, i_pos);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto unlock;
}
inode_inc_iversion(inode);
inode->i_mtime = inode->i_atime = inode->i_ctime =
EXFAT_I(inode)->i_crtime = current_time(inode);
/* timestamp is already written, so mark_inode_dirty() is unneeded. */
d_instantiate(dentry, inode);
unlock:
mutex_unlock(&EXFAT_SB(sb)->s_lock);
return err;
}
static int exfat_check_dir_empty(struct super_block *sb,
struct exfat_chain *p_dir)
{
int i, dentries_per_clu;
unsigned int type;
struct exfat_chain clu;
struct exfat_dentry *ep;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct buffer_head *bh;
dentries_per_clu = sbi->dentries_per_clu;
exfat_chain_dup(&clu, p_dir);
while (clu.dir != EXFAT_EOF_CLUSTER) {
for (i = 0; i < dentries_per_clu; i++) {
ep = exfat_get_dentry(sb, &clu, i, &bh, NULL);
if (!ep)
return -EIO;
type = exfat_get_entry_type(ep);
brelse(bh);
if (type == TYPE_UNUSED)
return 0;
if (type != TYPE_FILE && type != TYPE_DIR)
continue;
return -ENOTEMPTY;
}
if (clu.flags == ALLOC_NO_FAT_CHAIN) {
if (--clu.size > 0)
clu.dir++;
else
clu.dir = EXFAT_EOF_CLUSTER;
} else {
if (exfat_get_next_cluster(sb, &(clu.dir)))
return -EIO;
}
}
return 0;
}
static int exfat_rmdir(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
struct exfat_dentry *ep;
struct exfat_chain cdir, clu_to_free;
struct super_block *sb = inode->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct exfat_inode_info *ei = EXFAT_I(inode);
struct buffer_head *bh;
sector_t sector;
int num_entries, entry, err;
mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
exfat_chain_dup(&cdir, &ei->dir);
entry = ei->entry;
if (ei->dir.dir == DIR_DELETED) {
exfat_msg(sb, KERN_ERR, "abnormal access to deleted dentry");
err = -ENOENT;
goto unlock;
}
exfat_set_vol_flags(sb, VOL_DIRTY);
exfat_chain_set(&clu_to_free, ei->start_clu,
EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi), ei->flags);
err = exfat_check_dir_empty(sb, &clu_to_free);
if (err) {
if (err == -EIO)
exfat_msg(sb, KERN_ERR,
"failed to exfat_check_dir_empty : err(%d)",
err);
goto unlock;
}
ep = exfat_get_dentry(sb, &cdir, entry, &bh, §or);
if (!ep) {
err = -EIO;
goto unlock;
}