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-rw-r--r--fs/fat/dir.c1271
1 files changed, 1271 insertions, 0 deletions
diff --git a/fs/fat/dir.c b/fs/fat/dir.c
new file mode 100644
index 00000000000..e5ae1b720dd
--- /dev/null
+++ b/fs/fat/dir.c
@@ -0,0 +1,1271 @@
+/*
+ * linux/fs/fat/dir.c
+ *
+ * directory handling functions for fat-based filesystems
+ *
+ * Written 1992,1993 by Werner Almesberger
+ *
+ * Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu>
+ *
+ * VFAT extensions by Gordon Chaffee <chaffee@plateau.cs.berkeley.edu>
+ * Merged with msdos fs by Henrik Storner <storner@osiris.ping.dk>
+ * Rewritten for constant inumbers. Plugged buffer overrun in readdir(). AV
+ * Short name translation 1999, 2001 by Wolfram Pienkoss <wp@bszh.de>
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/msdos_fs.h>
+#include <linux/dirent.h>
+#include <linux/smp_lock.h>
+#include <linux/buffer_head.h>
+#include <asm/uaccess.h>
+
+static inline loff_t fat_make_i_pos(struct super_block *sb,
+ struct buffer_head *bh,
+ struct msdos_dir_entry *de)
+{
+ return ((loff_t)bh->b_blocknr << MSDOS_SB(sb)->dir_per_block_bits)
+ | (de - (struct msdos_dir_entry *)bh->b_data);
+}
+
+/* Returns the inode number of the directory entry at offset pos. If bh is
+ non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
+ returned in bh.
+ AV. Most often we do it item-by-item. Makes sense to optimize.
+ AV. OK, there we go: if both bh and de are non-NULL we assume that we just
+ AV. want the next entry (took one explicit de=NULL in vfat/namei.c).
+ AV. It's done in fat_get_entry() (inlined), here the slow case lives.
+ AV. Additionally, when we return -1 (i.e. reached the end of directory)
+ AV. we make bh NULL.
+ */
+static int fat__get_entry(struct inode *dir, loff_t *pos,
+ struct buffer_head **bh, struct msdos_dir_entry **de)
+{
+ struct super_block *sb = dir->i_sb;
+ sector_t phys, iblock;
+ int offset;
+ int err;
+
+next:
+ if (*bh)
+ brelse(*bh);
+
+ *bh = NULL;
+ iblock = *pos >> sb->s_blocksize_bits;
+ err = fat_bmap(dir, iblock, &phys);
+ if (err || !phys)
+ return -1; /* beyond EOF or error */
+
+ *bh = sb_bread(sb, phys);
+ if (*bh == NULL) {
+ printk(KERN_ERR "FAT: Directory bread(block %llu) failed\n",
+ (unsigned long long)phys);
+ /* skip this block */
+ *pos = (iblock + 1) << sb->s_blocksize_bits;
+ goto next;
+ }
+
+ offset = *pos & (sb->s_blocksize - 1);
+ *pos += sizeof(struct msdos_dir_entry);
+ *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
+
+ return 0;
+}
+
+static inline int fat_get_entry(struct inode *dir, loff_t *pos,
+ struct buffer_head **bh,
+ struct msdos_dir_entry **de)
+{
+ /* Fast stuff first */
+ if (*bh && *de &&
+ (*de - (struct msdos_dir_entry *)(*bh)->b_data) < MSDOS_SB(dir->i_sb)->dir_per_block - 1) {
+ *pos += sizeof(struct msdos_dir_entry);
+ (*de)++;
+ return 0;
+ }
+ return fat__get_entry(dir, pos, bh, de);
+}
+
+/*
+ * Convert Unicode 16 to UTF8, translated Unicode, or ASCII.
+ * If uni_xlate is enabled and we can't get a 1:1 conversion, use a
+ * colon as an escape character since it is normally invalid on the vfat
+ * filesystem. The following four characters are the hexadecimal digits
+ * of Unicode value. This lets us do a full dump and restore of Unicode
+ * filenames. We could get into some trouble with long Unicode names,
+ * but ignore that right now.
+ * Ahem... Stack smashing in ring 0 isn't fun. Fixed.
+ */
+static int uni16_to_x8(unsigned char *ascii, wchar_t *uni, int uni_xlate,
+ struct nls_table *nls)
+{
+ wchar_t *ip, ec;
+ unsigned char *op, nc;
+ int charlen;
+ int k;
+
+ ip = uni;
+ op = ascii;
+
+ while (*ip) {
+ ec = *ip++;
+ if ( (charlen = nls->uni2char(ec, op, NLS_MAX_CHARSET_SIZE)) > 0) {
+ op += charlen;
+ } else {
+ if (uni_xlate == 1) {
+ *op = ':';
+ for (k = 4; k > 0; k--) {
+ nc = ec & 0xF;
+ op[k] = nc > 9 ? nc + ('a' - 10)
+ : nc + '0';
+ ec >>= 4;
+ }
+ op += 5;
+ } else {
+ *op++ = '?';
+ }
+ }
+ /* We have some slack there, so it's OK */
+ if (op>ascii+256) {
+ op = ascii + 256;
+ break;
+ }
+ }
+ *op = 0;
+ return (op - ascii);
+}
+
+static inline int
+fat_short2uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
+{
+ int charlen;
+
+ charlen = t->char2uni(c, clen, uni);
+ if (charlen < 0) {
+ *uni = 0x003f; /* a question mark */
+ charlen = 1;
+ }
+ return charlen;
+}
+
+static inline int
+fat_short2lower_uni(struct nls_table *t, unsigned char *c, int clen, wchar_t *uni)
+{
+ int charlen;
+ wchar_t wc;
+
+ charlen = t->char2uni(c, clen, &wc);
+ if (charlen < 0) {
+ *uni = 0x003f; /* a question mark */
+ charlen = 1;
+ } else if (charlen <= 1) {
+ unsigned char nc = t->charset2lower[*c];
+
+ if (!nc)
+ nc = *c;
+
+ if ( (charlen = t->char2uni(&nc, 1, uni)) < 0) {
+ *uni = 0x003f; /* a question mark */
+ charlen = 1;
+ }
+ } else
+ *uni = wc;
+
+ return charlen;
+}
+
+static inline int
+fat_shortname2uni(struct nls_table *nls, unsigned char *buf, int buf_size,
+ wchar_t *uni_buf, unsigned short opt, int lower)
+{
+ int len = 0;
+
+ if (opt & VFAT_SFN_DISPLAY_LOWER)
+ len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
+ else if (opt & VFAT_SFN_DISPLAY_WIN95)
+ len = fat_short2uni(nls, buf, buf_size, uni_buf);
+ else if (opt & VFAT_SFN_DISPLAY_WINNT) {
+ if (lower)
+ len = fat_short2lower_uni(nls, buf, buf_size, uni_buf);
+ else
+ len = fat_short2uni(nls, buf, buf_size, uni_buf);
+ } else
+ len = fat_short2uni(nls, buf, buf_size, uni_buf);
+
+ return len;
+}
+
+/*
+ * Return values: negative -> error, 0 -> not found, positive -> found,
+ * value is the total amount of slots, including the shortname entry.
+ */
+int fat_search_long(struct inode *inode, const unsigned char *name,
+ int name_len, struct fat_slot_info *sinfo)
+{
+ struct super_block *sb = inode->i_sb;
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ struct buffer_head *bh = NULL;
+ struct msdos_dir_entry *de;
+ struct nls_table *nls_io = sbi->nls_io;
+ struct nls_table *nls_disk = sbi->nls_disk;
+ wchar_t bufuname[14];
+ unsigned char xlate_len, nr_slots;
+ wchar_t *unicode = NULL;
+ unsigned char work[8], bufname[260]; /* 256 + 4 */
+ int uni_xlate = sbi->options.unicode_xlate;
+ int utf8 = sbi->options.utf8;
+ int anycase = (sbi->options.name_check != 's');
+ unsigned short opt_shortname = sbi->options.shortname;
+ loff_t cpos = 0;
+ int chl, i, j, last_u, err;
+
+ err = -ENOENT;
+ while(1) {
+ if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
+ goto EODir;
+parse_record:
+ nr_slots = 0;
+ if (de->name[0] == DELETED_FLAG)
+ continue;
+ if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
+ continue;
+ if (de->attr != ATTR_EXT && IS_FREE(de->name))
+ continue;
+ if (de->attr == ATTR_EXT) {
+ struct msdos_dir_slot *ds;
+ unsigned char id;
+ unsigned char slot;
+ unsigned char slots;
+ unsigned char sum;
+ unsigned char alias_checksum;
+
+ if (!unicode) {
+ unicode = (wchar_t *)
+ __get_free_page(GFP_KERNEL);
+ if (!unicode) {
+ brelse(bh);
+ return -ENOMEM;
+ }
+ }
+parse_long:
+ slots = 0;
+ ds = (struct msdos_dir_slot *) de;
+ id = ds->id;
+ if (!(id & 0x40))
+ continue;
+ slots = id & ~0x40;
+ if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
+ continue;
+ nr_slots = slots;
+ alias_checksum = ds->alias_checksum;
+
+ slot = slots;
+ while (1) {
+ int offset;
+
+ slot--;
+ offset = slot * 13;
+ fat16_towchar(unicode + offset, ds->name0_4, 5);
+ fat16_towchar(unicode + offset + 5, ds->name5_10, 6);
+ fat16_towchar(unicode + offset + 11, ds->name11_12, 2);
+
+ if (ds->id & 0x40) {
+ unicode[offset + 13] = 0;
+ }
+ if (fat_get_entry(inode, &cpos, &bh, &de) < 0)
+ goto EODir;
+ if (slot == 0)
+ break;
+ ds = (struct msdos_dir_slot *) de;
+ if (ds->attr != ATTR_EXT)
+ goto parse_record;
+ if ((ds->id & ~0x40) != slot)
+ goto parse_long;
+ if (ds->alias_checksum != alias_checksum)
+ goto parse_long;
+ }
+ if (de->name[0] == DELETED_FLAG)
+ continue;
+ if (de->attr == ATTR_EXT)
+ goto parse_long;
+ if (IS_FREE(de->name) || (de->attr & ATTR_VOLUME))
+ continue;
+ for (sum = 0, i = 0; i < 11; i++)
+ sum = (((sum&1)<<7)|((sum&0xfe)>>1)) + de->name[i];
+ if (sum != alias_checksum)
+ nr_slots = 0;
+ }
+
+ memcpy(work, de->name, sizeof(de->name));
+ /* see namei.c, msdos_format_name */
+ if (work[0] == 0x05)
+ work[0] = 0xE5;
+ for (i = 0, j = 0, last_u = 0; i < 8;) {
+ if (!work[i]) break;
+ chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
+ &bufuname[j++], opt_shortname,
+ de->lcase & CASE_LOWER_BASE);
+ if (chl <= 1) {
+ if (work[i] != ' ')
+ last_u = j;
+ } else {
+ last_u = j;
+ }
+ i += chl;
+ }
+ j = last_u;
+ fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
+ for (i = 0; i < 3;) {
+ if (!de->ext[i]) break;
+ chl = fat_shortname2uni(nls_disk, &de->ext[i], 3 - i,
+ &bufuname[j++], opt_shortname,
+ de->lcase & CASE_LOWER_EXT);
+ if (chl <= 1) {
+ if (de->ext[i] != ' ')
+ last_u = j;
+ } else {
+ last_u = j;
+ }
+ i += chl;
+ }
+ if (!last_u)
+ continue;
+
+ bufuname[last_u] = 0x0000;
+ xlate_len = utf8
+ ?utf8_wcstombs(bufname, bufuname, sizeof(bufname))
+ :uni16_to_x8(bufname, bufuname, uni_xlate, nls_io);
+ if (xlate_len == name_len)
+ if ((!anycase && !memcmp(name, bufname, xlate_len)) ||
+ (anycase && !nls_strnicmp(nls_io, name, bufname,
+ xlate_len)))
+ goto Found;
+
+ if (nr_slots) {
+ xlate_len = utf8
+ ?utf8_wcstombs(bufname, unicode, sizeof(bufname))
+ :uni16_to_x8(bufname, unicode, uni_xlate, nls_io);
+ if (xlate_len != name_len)
+ continue;
+ if ((!anycase && !memcmp(name, bufname, xlate_len)) ||
+ (anycase && !nls_strnicmp(nls_io, name, bufname,
+ xlate_len)))
+ goto Found;
+ }
+ }
+
+Found:
+ nr_slots++; /* include the de */
+ sinfo->slot_off = cpos - nr_slots * sizeof(*de);
+ sinfo->nr_slots = nr_slots;
+ sinfo->de = de;
+ sinfo->bh = bh;
+ sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
+ err = 0;
+EODir:
+ if (unicode)
+ free_page((unsigned long)unicode);
+
+ return err;
+}
+
+EXPORT_SYMBOL(fat_search_long);
+
+struct fat_ioctl_filldir_callback {
+ struct dirent __user *dirent;
+ int result;
+ /* for dir ioctl */
+ const char *longname;
+ int long_len;
+ const char *shortname;
+ int short_len;
+};
+
+static int fat_readdirx(struct inode *inode, struct file *filp, void *dirent,
+ filldir_t filldir, int short_only, int both)
+{
+ struct super_block *sb = inode->i_sb;
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ struct buffer_head *bh;
+ struct msdos_dir_entry *de;
+ struct nls_table *nls_io = sbi->nls_io;
+ struct nls_table *nls_disk = sbi->nls_disk;
+ unsigned char long_slots;
+ const char *fill_name;
+ int fill_len;
+ wchar_t bufuname[14];
+ wchar_t *unicode = NULL;
+ unsigned char c, work[8], bufname[56], *ptname = bufname;
+ unsigned long lpos, dummy, *furrfu = &lpos;
+ int uni_xlate = sbi->options.unicode_xlate;
+ int isvfat = sbi->options.isvfat;
+ int utf8 = sbi->options.utf8;
+ int nocase = sbi->options.nocase;
+ unsigned short opt_shortname = sbi->options.shortname;
+ unsigned long inum;
+ int chi, chl, i, i2, j, last, last_u, dotoffset = 0;
+ loff_t cpos;
+ int ret = 0;
+
+ lock_kernel();
+
+ cpos = filp->f_pos;
+ /* Fake . and .. for the root directory. */
+ if (inode->i_ino == MSDOS_ROOT_INO) {
+ while (cpos < 2) {
+ if (filldir(dirent, "..", cpos+1, cpos, MSDOS_ROOT_INO, DT_DIR) < 0)
+ goto out;
+ cpos++;
+ filp->f_pos++;
+ }
+ if (cpos == 2) {
+ dummy = 2;
+ furrfu = &dummy;
+ cpos = 0;
+ }
+ }
+ if (cpos & (sizeof(struct msdos_dir_entry)-1)) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ bh = NULL;
+GetNew:
+ long_slots = 0;
+ if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
+ goto EODir;
+ /* Check for long filename entry */
+ if (isvfat) {
+ if (de->name[0] == DELETED_FLAG)
+ goto RecEnd;
+ if (de->attr != ATTR_EXT && (de->attr & ATTR_VOLUME))
+ goto RecEnd;
+ if (de->attr != ATTR_EXT && IS_FREE(de->name))
+ goto RecEnd;
+ } else {
+ if ((de->attr & ATTR_VOLUME) || IS_FREE(de->name))
+ goto RecEnd;
+ }
+
+ if (isvfat && de->attr == ATTR_EXT) {
+ struct msdos_dir_slot *ds;
+ unsigned char id;
+ unsigned char slot;
+ unsigned char slots;
+ unsigned char sum;
+ unsigned char alias_checksum;
+
+ if (!unicode) {
+ unicode = (wchar_t *)__get_free_page(GFP_KERNEL);
+ if (!unicode) {
+ filp->f_pos = cpos;
+ brelse(bh);
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
+ParseLong:
+ slots = 0;
+ ds = (struct msdos_dir_slot *) de;
+ id = ds->id;
+ if (!(id & 0x40))
+ goto RecEnd;
+ slots = id & ~0x40;
+ if (slots > 20 || !slots) /* ceil(256 * 2 / 26) */
+ goto RecEnd;
+ long_slots = slots;
+ alias_checksum = ds->alias_checksum;
+
+ slot = slots;
+ while (1) {
+ int offset;
+
+ slot--;
+ offset = slot * 13;
+ fat16_towchar(unicode + offset, ds->name0_4, 5);
+ fat16_towchar(unicode + offset + 5, ds->name5_10, 6);
+ fat16_towchar(unicode + offset + 11, ds->name11_12, 2);
+
+ if (ds->id & 0x40) {
+ unicode[offset + 13] = 0;
+ }
+ if (fat_get_entry(inode, &cpos, &bh, &de) == -1)
+ goto EODir;
+ if (slot == 0)
+ break;
+ ds = (struct msdos_dir_slot *) de;
+ if (ds->attr != ATTR_EXT)
+ goto RecEnd; /* XXX */
+ if ((ds->id & ~0x40) != slot)
+ goto ParseLong;
+ if (ds->alias_checksum != alias_checksum)
+ goto ParseLong;
+ }
+ if (de->name[0] == DELETED_FLAG)
+ goto RecEnd;
+ if (de->attr == ATTR_EXT)
+ goto ParseLong;
+ if (IS_FREE(de->name) || (de->attr & ATTR_VOLUME))
+ goto RecEnd;
+ for (sum = 0, i = 0; i < 11; i++)
+ sum = (((sum&1)<<7)|((sum&0xfe)>>1)) + de->name[i];
+ if (sum != alias_checksum)
+ long_slots = 0;
+ }
+
+ if (sbi->options.dotsOK) {
+ ptname = bufname;
+ dotoffset = 0;
+ if (de->attr & ATTR_HIDDEN) {
+ *ptname++ = '.';
+ dotoffset = 1;
+ }
+ }
+
+ memcpy(work, de->name, sizeof(de->name));
+ /* see namei.c, msdos_format_name */
+ if (work[0] == 0x05)
+ work[0] = 0xE5;
+ for (i = 0, j = 0, last = 0, last_u = 0; i < 8;) {
+ if (!(c = work[i])) break;
+ chl = fat_shortname2uni(nls_disk, &work[i], 8 - i,
+ &bufuname[j++], opt_shortname,
+ de->lcase & CASE_LOWER_BASE);
+ if (chl <= 1) {
+ ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
+ if (c != ' ') {
+ last = i;
+ last_u = j;
+ }
+ } else {
+ last_u = j;
+ for (chi = 0; chi < chl && i < 8; chi++) {
+ ptname[i] = work[i];
+ i++; last = i;
+ }
+ }
+ }
+ i = last;
+ j = last_u;
+ fat_short2uni(nls_disk, ".", 1, &bufuname[j++]);
+ ptname[i++] = '.';
+ for (i2 = 0; i2 < 3;) {
+ if (!(c = de->ext[i2])) break;
+ chl = fat_shortname2uni(nls_disk, &de->ext[i2], 3 - i2,
+ &bufuname[j++], opt_shortname,
+ de->lcase & CASE_LOWER_EXT);
+ if (chl <= 1) {
+ i2++;
+ ptname[i++] = (!nocase && c>='A' && c<='Z') ? c+32 : c;
+ if (c != ' ') {
+ last = i;
+ last_u = j;
+ }
+ } else {
+ last_u = j;
+ for (chi = 0; chi < chl && i2 < 3; chi++) {
+ ptname[i++] = de->ext[i2++];
+ last = i;
+ }
+ }
+ }
+ if (!last)
+ goto RecEnd;
+
+ i = last + dotoffset;
+ j = last_u;
+
+ lpos = cpos - (long_slots+1)*sizeof(struct msdos_dir_entry);
+ if (!memcmp(de->name, MSDOS_DOT, MSDOS_NAME))
+ inum = inode->i_ino;
+ else if (!memcmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
+ inum = parent_ino(filp->f_dentry);
+ } else {
+ loff_t i_pos = fat_make_i_pos(sb, bh, de);
+ struct inode *tmp = fat_iget(sb, i_pos);
+ if (tmp) {
+ inum = tmp->i_ino;
+ iput(tmp);
+ } else
+ inum = iunique(sb, MSDOS_ROOT_INO);
+ }
+
+ if (isvfat) {
+ bufuname[j] = 0x0000;
+ i = utf8 ? utf8_wcstombs(bufname, bufuname, sizeof(bufname))
+ : uni16_to_x8(bufname, bufuname, uni_xlate, nls_io);
+ }
+
+ fill_name = bufname;
+ fill_len = i;
+ if (!short_only && long_slots) {
+ /* convert the unicode long name. 261 is maximum size
+ * of unicode buffer. (13 * slots + nul) */
+ void *longname = unicode + 261;
+ int buf_size = PAGE_SIZE - (261 * sizeof(unicode[0]));
+ int long_len = utf8
+ ? utf8_wcstombs(longname, unicode, buf_size)
+ : uni16_to_x8(longname, unicode, uni_xlate, nls_io);
+
+ if (!both) {
+ fill_name = longname;
+ fill_len = long_len;
+ } else {
+ /* hack for fat_ioctl_filldir() */
+ struct fat_ioctl_filldir_callback *p = dirent;
+
+ p->longname = longname;
+ p->long_len = long_len;
+ p->shortname = bufname;
+ p->short_len = i;
+ fill_name = NULL;
+ fill_len = 0;
+ }
+ }
+ if (filldir(dirent, fill_name, fill_len, *furrfu, inum,
+ (de->attr & ATTR_DIR) ? DT_DIR : DT_REG) < 0)
+ goto FillFailed;
+
+RecEnd:
+ furrfu = &lpos;
+ filp->f_pos = cpos;
+ goto GetNew;
+EODir:
+ filp->f_pos = cpos;
+FillFailed:
+ if (bh)
+ brelse(bh);
+ if (unicode)
+ free_page((unsigned long)unicode);
+out:
+ unlock_kernel();
+ return ret;
+}
+
+static int fat_readdir(struct file *filp, void *dirent, filldir_t filldir)
+{
+ struct inode *inode = filp->f_dentry->d_inode;
+ return fat_readdirx(inode, filp, dirent, filldir, 0, 0);
+}
+
+static int fat_ioctl_filldir(void *__buf, const char *name, int name_len,
+ loff_t offset, ino_t ino, unsigned int d_type)
+{
+ struct fat_ioctl_filldir_callback *buf = __buf;
+ struct dirent __user *d1 = buf->dirent;
+ struct dirent __user *d2 = d1 + 1;
+
+ if (buf->result)
+ return -EINVAL;
+ buf->result++;
+
+ if (name != NULL) {
+ /* dirent has only short name */
+ if (name_len >= sizeof(d1->d_name))
+ name_len = sizeof(d1->d_name) - 1;
+
+ if (put_user(0, d2->d_name) ||
+ put_user(0, &d2->d_reclen) ||
+ copy_to_user(d1->d_name, name, name_len) ||
+ put_user(0, d1->d_name + name_len) ||
+ put_user(name_len, &d1->d_reclen))
+ goto efault;
+ } else {
+ /* dirent has short and long name */
+ const char *longname = buf->longname;
+ int long_len = buf->long_len;
+ const char *shortname = buf->shortname;
+ int short_len = buf->short_len;
+
+ if (long_len >= sizeof(d1->d_name))
+ long_len = sizeof(d1->d_name) - 1;
+ if (short_len >= sizeof(d1->d_name))
+ short_len = sizeof(d1->d_name) - 1;
+
+ if (copy_to_user(d2->d_name, longname, long_len) ||
+ put_user(0, d2->d_name + long_len) ||
+ put_user(long_len, &d2->d_reclen) ||
+ put_user(ino, &d2->d_ino) ||
+ put_user(offset, &d2->d_off) ||
+ copy_to_user(d1->d_name, shortname, short_len) ||
+ put_user(0, d1->d_name + short_len) ||
+ put_user(short_len, &d1->d_reclen))
+ goto efault;
+ }
+ return 0;
+efault:
+ buf->result = -EFAULT;
+ return -EFAULT;
+}
+
+static int fat_dir_ioctl(struct inode * inode, struct file * filp,
+ unsigned int cmd, unsigned long arg)
+{
+ struct fat_ioctl_filldir_callback buf;
+ struct dirent __user *d1;
+ int ret, short_only, both;
+
+ switch (cmd) {
+ case VFAT_IOCTL_READDIR_SHORT:
+ short_only = 1;
+ both = 0;
+ break;
+ case VFAT_IOCTL_READDIR_BOTH:
+ short_only = 0;
+ both = 1;
+ break;
+ default:
+ return fat_generic_ioctl(inode, filp, cmd, arg);
+ }
+
+ d1 = (struct dirent __user *)arg;
+ if (!access_ok(VERIFY_WRITE, d1, sizeof(struct dirent[2])))
+ return -EFAULT;
+ /*
+ * Yes, we don't need this put_user() absolutely. However old
+ * code didn't return the right value. So, app use this value,
+ * in order to check whether it is EOF.
+ */
+ if (put_user(0, &d1->d_reclen))
+ return -EFAULT;
+
+ buf.dirent = d1;
+ buf.result = 0;
+ down(&inode->i_sem);
+ ret = -ENOENT;
+ if (!IS_DEADDIR(inode)) {
+ ret = fat_readdirx(inode, filp, &buf, fat_ioctl_filldir,
+ short_only, both);
+ }
+ up(&inode->i_sem);
+ if (ret >= 0)
+ ret = buf.result;
+ return ret;
+}
+
+struct file_operations fat_dir_operations = {
+ .read = generic_read_dir,
+ .readdir = fat_readdir,
+ .ioctl = fat_dir_ioctl,
+ .fsync = file_fsync,
+};
+
+static int fat_get_short_entry(struct inode *dir, loff_t *pos,
+ struct buffer_head **bh,
+ struct msdos_dir_entry **de)
+{
+ while (fat_get_entry(dir, pos, bh, de) >= 0) {
+ /* free entry or long name entry or volume label */
+ if (!IS_FREE((*de)->name) && !((*de)->attr & ATTR_VOLUME))
+ return 0;
+ }
+ return -ENOENT;
+}
+
+/*
+ * The ".." entry can not provide the "struct fat_slot_info" informations
+ * for inode. So, this function provide the some informations only.
+ */
+int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh,
+ struct msdos_dir_entry **de, loff_t *i_pos)
+{
+ loff_t offset;
+
+ offset = 0;
+ *bh = NULL;
+ while (fat_get_short_entry(dir, &offset, bh, de) >= 0) {
+ if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME)) {
+ *i_pos = fat_make_i_pos(dir->i_sb, *bh, *de);
+ return 0;
+ }
+ }
+ return -ENOENT;
+}
+
+EXPORT_SYMBOL(fat_get_dotdot_entry);
+
+/* See if directory is empty */
+int fat_dir_empty(struct inode *dir)
+{
+ struct buffer_head *bh;
+ struct msdos_dir_entry *de;
+ loff_t cpos;
+ int result = 0;
+
+ bh = NULL;
+ cpos = 0;
+ while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
+ if (strncmp(de->name, MSDOS_DOT , MSDOS_NAME) &&
+ strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) {
+ result = -ENOTEMPTY;
+ break;
+ }
+ }
+ brelse(bh);
+ return result;
+}
+
+EXPORT_SYMBOL(fat_dir_empty);
+
+/*
+ * fat_subdirs counts the number of sub-directories of dir. It can be run
+ * on directories being created.
+ */
+int fat_subdirs(struct inode *dir)
+{
+ struct buffer_head *bh;
+ struct msdos_dir_entry *de;
+ loff_t cpos;
+ int count = 0;
+
+ bh = NULL;
+ cpos = 0;
+ while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) {
+ if (de->attr & ATTR_DIR)
+ count++;
+ }
+ brelse(bh);
+ return count;
+}
+
+/*
+ * Scans a directory for a given file (name points to its formatted name).
+ * Returns an error code or zero.
+ */
+int fat_scan(struct inode *dir, const unsigned char *name,
+ struct fat_slot_info *sinfo)
+{
+ struct super_block *sb = dir->i_sb;
+
+ sinfo->slot_off = 0;
+ sinfo->bh = NULL;
+ while (fat_get_short_entry(dir, &sinfo->slot_off, &sinfo->bh,
+ &sinfo->de) >= 0) {
+ if (!strncmp(sinfo->de->name, name, MSDOS_NAME)) {
+ sinfo->slot_off -= sizeof(*sinfo->de);
+ sinfo->nr_slots = 1;
+ sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
+ return 0;
+ }
+ }
+ return -ENOENT;
+}
+
+EXPORT_SYMBOL(fat_scan);
+
+static int __fat_remove_entries(struct inode *dir, loff_t pos, int nr_slots)
+{
+ struct super_block *sb = dir->i_sb;
+ struct buffer_head *bh;
+ struct msdos_dir_entry *de, *endp;
+ int err = 0, orig_slots;
+
+ while (nr_slots) {
+ bh = NULL;
+ if (fat_get_entry(dir, &pos, &bh, &de) < 0) {
+ err = -EIO;
+ break;
+ }
+
+ orig_slots = nr_slots;
+ endp = (struct msdos_dir_entry *)(bh->b_data + sb->s_blocksize);
+ while (nr_slots && de < endp) {
+ de->name[0] = DELETED_FLAG;
+ de++;
+ nr_slots--;
+ }
+ mark_buffer_dirty(bh);
+ if (IS_DIRSYNC(dir))
+ err = sync_dirty_buffer(bh);
+ brelse(bh);
+ if (err)
+ break;
+
+ /* pos is *next* de's position, so this does `- sizeof(de)' */
+ pos += ((orig_slots - nr_slots) * sizeof(*de)) - sizeof(*de);
+ }
+
+ return err;
+}
+
+int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo)
+{
+ struct msdos_dir_entry *de;
+ struct buffer_head *bh;
+ int err = 0, nr_slots;
+
+ /*
+ * First stage: Remove the shortname. By this, the directory
+ * entry is removed.
+ */
+ nr_slots = sinfo->nr_slots;
+ de = sinfo->de;
+ sinfo->de = NULL;
+ bh = sinfo->bh;
+ sinfo->bh = NULL;
+ while (nr_slots && de >= (struct msdos_dir_entry *)bh->b_data) {
+ de->name[0] = DELETED_FLAG;
+ de--;
+ nr_slots--;
+ }
+ mark_buffer_dirty(bh);
+ if (IS_DIRSYNC(dir))
+ err = sync_dirty_buffer(bh);
+ brelse(bh);
+ if (err)
+ return err;
+ dir->i_version++;
+
+ if (nr_slots) {
+ /*
+ * Second stage: remove the remaining longname slots.
+ * (This directory entry is already removed, and so return
+ * the success)
+ */
+ err = __fat_remove_entries(dir, sinfo->slot_off, nr_slots);
+ if (err) {
+ printk(KERN_WARNING
+ "FAT: Couldn't remove the long name slots\n");
+ }
+ }
+
+ dir->i_mtime = dir->i_atime = CURRENT_TIME_SEC;
+ if (IS_DIRSYNC(dir))
+ (void)fat_sync_inode(dir);
+ else
+ mark_inode_dirty(dir);
+
+ return 0;
+}
+
+EXPORT_SYMBOL(fat_remove_entries);
+
+static int fat_zeroed_cluster(struct inode *dir, sector_t blknr, int nr_used,
+ struct buffer_head **bhs, int nr_bhs)
+{
+ struct super_block *sb = dir->i_sb;
+ sector_t last_blknr = blknr + MSDOS_SB(sb)->sec_per_clus;
+ int err, i, n;
+
+ /* Zeroing the unused blocks on this cluster */
+ blknr += nr_used;
+ n = nr_used;
+ while (blknr < last_blknr) {
+ bhs[n] = sb_getblk(sb, blknr);
+ if (!bhs[n]) {
+ err = -ENOMEM;
+ goto error;
+ }
+ memset(bhs[n]->b_data, 0, sb->s_blocksize);
+ set_buffer_uptodate(bhs[n]);
+ mark_buffer_dirty(bhs[n]);
+
+ n++;
+ blknr++;
+ if (n == nr_bhs) {
+ if (IS_DIRSYNC(dir)) {
+ err = fat_sync_bhs(bhs, n);
+ if (err)
+ goto error;
+ }
+ for (i = 0; i < n; i++)
+ brelse(bhs[i]);
+ n = 0;
+ }
+ }
+ if (IS_DIRSYNC(dir)) {
+ err = fat_sync_bhs(bhs, n);
+ if (err)
+ goto error;
+ }
+ for (i = 0; i < n; i++)
+ brelse(bhs[i]);
+
+ return 0;
+
+error:
+ for (i = 0; i < n; i++)
+ bforget(bhs[i]);
+ return err;
+}
+
+int fat_alloc_new_dir(struct inode *dir, struct timespec *ts)
+{
+ struct super_block *sb = dir->i_sb;
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ struct buffer_head *bhs[MAX_BUF_PER_PAGE];
+ struct msdos_dir_entry *de;
+ sector_t blknr;
+ __le16 date, time;
+ int err, cluster;
+
+ err = fat_alloc_clusters(dir, &cluster, 1);
+ if (err)
+ goto error;
+
+ blknr = fat_clus_to_blknr(sbi, cluster);
+ bhs[0] = sb_getblk(sb, blknr);
+ if (!bhs[0]) {
+ err = -ENOMEM;
+ goto error_free;
+ }
+
+ fat_date_unix2dos(ts->tv_sec, &time, &date);
+
+ de = (struct msdos_dir_entry *)bhs[0]->b_data;
+ /* filling the new directory slots ("." and ".." entries) */
+ memcpy(de[0].name, MSDOS_DOT, MSDOS_NAME);
+ memcpy(de[1].name, MSDOS_DOTDOT, MSDOS_NAME);
+ de->attr = de[1].attr = ATTR_DIR;
+ de[0].lcase = de[1].lcase = 0;
+ de[0].time = de[1].time = time;
+ de[0].date = de[1].date = date;
+ de[0].ctime_cs = de[1].ctime_cs = 0;
+ if (sbi->options.isvfat) {
+ /* extra timestamps */
+ de[0].ctime = de[1].ctime = time;
+ de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = date;
+ } else {
+ de[0].ctime = de[1].ctime = 0;
+ de[0].adate = de[0].cdate = de[1].adate = de[1].cdate = 0;
+ }
+ de[0].start = cpu_to_le16(cluster);
+ de[0].starthi = cpu_to_le16(cluster >> 16);
+ de[1].start = cpu_to_le16(MSDOS_I(dir)->i_logstart);
+ de[1].starthi = cpu_to_le16(MSDOS_I(dir)->i_logstart >> 16);
+ de[0].size = de[1].size = 0;
+ memset(de + 2, 0, sb->s_blocksize - 2 * sizeof(*de));
+ set_buffer_uptodate(bhs[0]);
+ mark_buffer_dirty(bhs[0]);
+
+ err = fat_zeroed_cluster(dir, blknr, 1, bhs, MAX_BUF_PER_PAGE);
+ if (err)
+ goto error_free;
+
+ return cluster;
+
+error_free:
+ fat_free_clusters(dir, cluster);
+error:
+ return err;
+}
+
+EXPORT_SYMBOL(fat_alloc_new_dir);
+
+static int fat_add_new_entries(struct inode *dir, void *slots, int nr_slots,
+ int *nr_cluster, struct msdos_dir_entry **de,
+ struct buffer_head **bh, loff_t *i_pos)
+{
+ struct super_block *sb = dir->i_sb;
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ struct buffer_head *bhs[MAX_BUF_PER_PAGE];
+ sector_t blknr, start_blknr, last_blknr;
+ unsigned long size, copy;
+ int err, i, n, offset, cluster[2];
+
+ /*
+ * The minimum cluster size is 512bytes, and maximum entry
+ * size is 32*slots (672bytes). So, iff the cluster size is
+ * 512bytes, we may need two clusters.
+ */
+ size = nr_slots * sizeof(struct msdos_dir_entry);
+ *nr_cluster = (size + (sbi->cluster_size - 1)) >> sbi->cluster_bits;
+ BUG_ON(*nr_cluster > 2);
+
+ err = fat_alloc_clusters(dir, cluster, *nr_cluster);
+ if (err)
+ goto error;
+
+ /*
+ * First stage: Fill the directory entry. NOTE: This cluster
+ * is not referenced from any inode yet, so updates order is
+ * not important.
+ */
+ i = n = copy = 0;
+ do {
+ start_blknr = blknr = fat_clus_to_blknr(sbi, cluster[i]);
+ last_blknr = start_blknr + sbi->sec_per_clus;
+ while (blknr < last_blknr) {
+ bhs[n] = sb_getblk(sb, blknr);
+ if (!bhs[n]) {
+ err = -ENOMEM;
+ goto error_nomem;
+ }
+
+ /* fill the directory entry */
+ copy = min(size, sb->s_blocksize);
+ memcpy(bhs[n]->b_data, slots, copy);
+ slots += copy;
+ size -= copy;
+ set_buffer_uptodate(bhs[n]);
+ mark_buffer_dirty(bhs[n]);
+ if (!size)
+ break;
+ n++;
+ blknr++;
+ }
+ } while (++i < *nr_cluster);
+
+ memset(bhs[n]->b_data + copy, 0, sb->s_blocksize - copy);
+ offset = copy - sizeof(struct msdos_dir_entry);
+ get_bh(bhs[n]);
+ *bh = bhs[n];
+ *de = (struct msdos_dir_entry *)((*bh)->b_data + offset);
+ *i_pos = fat_make_i_pos(sb, *bh, *de);
+
+ /* Second stage: clear the rest of cluster, and write outs */
+ err = fat_zeroed_cluster(dir, start_blknr, ++n, bhs, MAX_BUF_PER_PAGE);
+ if (err)
+ goto error_free;
+
+ return cluster[0];
+
+error_free:
+ brelse(*bh);
+ *bh = NULL;
+ n = 0;
+error_nomem:
+ for (i = 0; i < n; i++)
+ bforget(bhs[i]);
+ fat_free_clusters(dir, cluster[0]);
+error:
+ return err;
+}
+
+int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
+ struct fat_slot_info *sinfo)
+{
+ struct super_block *sb = dir->i_sb;
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ struct buffer_head *bh, *prev, *bhs[3]; /* 32*slots (672bytes) */
+ struct msdos_dir_entry *de;
+ int err, free_slots, i, nr_bhs;
+ loff_t pos, i_pos;
+
+ sinfo->nr_slots = nr_slots;
+
+ /* First stage: search free direcotry entries */
+ free_slots = nr_bhs = 0;
+ bh = prev = NULL;
+ pos = 0;
+ err = -ENOSPC;
+ while (fat_get_entry(dir, &pos, &bh, &de) > -1) {
+ /* check the maximum size of directory */
+ if (pos >= FAT_MAX_DIR_SIZE)
+ goto error;
+
+ if (IS_FREE(de->name)) {
+ if (prev != bh) {
+ get_bh(bh);
+ bhs[nr_bhs] = prev = bh;
+ nr_bhs++;
+ }
+ free_slots++;
+ if (free_slots == nr_slots)
+ goto found;
+ } else {
+ for (i = 0; i < nr_bhs; i++)
+ brelse(bhs[i]);
+ prev = NULL;
+ free_slots = nr_bhs = 0;
+ }
+ }
+ if (dir->i_ino == MSDOS_ROOT_INO) {
+ if (sbi->fat_bits != 32)
+ goto error;
+ } else if (MSDOS_I(dir)->i_start == 0) {
+ printk(KERN_ERR "FAT: Corrupted directory (i_pos %lld)\n",
+ MSDOS_I(dir)->i_pos);
+ err = -EIO;
+ goto error;
+ }
+
+found:
+ err = 0;
+ pos -= free_slots * sizeof(*de);
+ nr_slots -= free_slots;
+ if (free_slots) {
+ /*
+ * Second stage: filling the free entries with new entries.
+ * NOTE: If this slots has shortname, first, we write
+ * the long name slots, then write the short name.
+ */
+ int size = free_slots * sizeof(*de);
+ int offset = pos & (sb->s_blocksize - 1);
+ int long_bhs = nr_bhs - (nr_slots == 0);
+
+ /* Fill the long name slots. */
+ for (i = 0; i < long_bhs; i++) {
+ int copy = min_t(int, sb->s_blocksize - offset, size);
+ memcpy(bhs[i]->b_data + offset, slots, copy);
+ mark_buffer_dirty(bhs[i]);
+ offset = 0;
+ slots += copy;
+ size -= copy;
+ }
+ if (long_bhs && IS_DIRSYNC(dir))
+ err = fat_sync_bhs(bhs, long_bhs);
+ if (!err && i < nr_bhs) {
+ /* Fill the short name slot. */
+ int copy = min_t(int, sb->s_blocksize - offset, size);
+ memcpy(bhs[i]->b_data + offset, slots, copy);
+ mark_buffer_dirty(bhs[i]);
+ if (IS_DIRSYNC(dir))
+ err = sync_dirty_buffer(bhs[i]);
+ }
+ for (i = 0; i < nr_bhs; i++)
+ brelse(bhs[i]);
+ if (err)
+ goto error_remove;
+ }
+
+ if (nr_slots) {
+ int cluster, nr_cluster;
+
+ /*
+ * Third stage: allocate the cluster for new entries.
+ * And initialize the cluster with new entries, then
+ * add the cluster to dir.
+ */
+ cluster = fat_add_new_entries(dir, slots, nr_slots, &nr_cluster,
+ &de, &bh, &i_pos);
+ if (cluster < 0) {
+ err = cluster;
+ goto error_remove;
+ }
+ err = fat_chain_add(dir, cluster, nr_cluster);
+ if (err) {
+ fat_free_clusters(dir, cluster);
+ goto error_remove;
+ }
+ if (dir->i_size & (sbi->cluster_size - 1)) {
+ fat_fs_panic(sb, "Odd directory size");
+ dir->i_size = (dir->i_size + sbi->cluster_size - 1)
+ & ~((loff_t)sbi->cluster_size - 1);
+ }
+ dir->i_size += nr_cluster << sbi->cluster_bits;
+ MSDOS_I(dir)->mmu_private += nr_cluster << sbi->cluster_bits;
+ }
+ sinfo->slot_off = pos;
+ sinfo->de = de;
+ sinfo->bh = bh;
+ sinfo->i_pos = fat_make_i_pos(sb, sinfo->bh, sinfo->de);
+
+ return 0;
+
+error:
+ brelse(bh);
+ for (i = 0; i < nr_bhs; i++)
+ brelse(bhs[i]);
+ return err;
+
+error_remove:
+ brelse(bh);
+ if (free_slots)
+ __fat_remove_entries(dir, pos, free_slots);
+ return err;
+}
+
+EXPORT_SYMBOL(fat_add_entries);
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-11-24 08:03:53 +0000