v4.19.13 snapshot.
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
new file mode 100644
index 0000000..d6b81e3
--- /dev/null
+++ b/fs/fat/inode.c
@@ -0,0 +1,1965 @@
+/*
+ * linux/fs/fat/inode.c
+ *
+ * Written 1992,1993 by Werner Almesberger
+ * VFAT extensions by Gordon Chaffee, merged with msdos fs by Henrik Storner
+ * Rewritten for the constant inumbers support by Al Viro
+ *
+ * Fixes:
+ *
+ * Max Cohan: Fixed invalid FSINFO offset when info_sector is 0
+ */
+
+#include <linux/module.h>
+#include <linux/pagemap.h>
+#include <linux/mpage.h>
+#include <linux/vfs.h>
+#include <linux/seq_file.h>
+#include <linux/parser.h>
+#include <linux/uio.h>
+#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
+#include <asm/unaligned.h>
+#include <linux/iversion.h>
+#include "fat.h"
+
+#ifndef CONFIG_FAT_DEFAULT_IOCHARSET
+/* if user don't select VFAT, this is undefined. */
+#define CONFIG_FAT_DEFAULT_IOCHARSET ""
+#endif
+
+#define KB_IN_SECTORS 2
+
+/*
+ * A deserialized copy of the on-disk structure laid out in struct
+ * fat_boot_sector.
+ */
+struct fat_bios_param_block {
+ u16 fat_sector_size;
+ u8 fat_sec_per_clus;
+ u16 fat_reserved;
+ u8 fat_fats;
+ u16 fat_dir_entries;
+ u16 fat_sectors;
+ u16 fat_fat_length;
+ u32 fat_total_sect;
+
+ u8 fat16_state;
+ u32 fat16_vol_id;
+
+ u32 fat32_length;
+ u32 fat32_root_cluster;
+ u16 fat32_info_sector;
+ u8 fat32_state;
+ u32 fat32_vol_id;
+};
+
+static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
+static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
+
+static struct fat_floppy_defaults {
+ unsigned nr_sectors;
+ unsigned sec_per_clus;
+ unsigned dir_entries;
+ unsigned media;
+ unsigned fat_length;
+} floppy_defaults[] = {
+{
+ .nr_sectors = 160 * KB_IN_SECTORS,
+ .sec_per_clus = 1,
+ .dir_entries = 64,
+ .media = 0xFE,
+ .fat_length = 1,
+},
+{
+ .nr_sectors = 180 * KB_IN_SECTORS,
+ .sec_per_clus = 1,
+ .dir_entries = 64,
+ .media = 0xFC,
+ .fat_length = 2,
+},
+{
+ .nr_sectors = 320 * KB_IN_SECTORS,
+ .sec_per_clus = 2,
+ .dir_entries = 112,
+ .media = 0xFF,
+ .fat_length = 1,
+},
+{
+ .nr_sectors = 360 * KB_IN_SECTORS,
+ .sec_per_clus = 2,
+ .dir_entries = 112,
+ .media = 0xFD,
+ .fat_length = 2,
+},
+};
+
+int fat_add_cluster(struct inode *inode)
+{
+ int err, cluster;
+
+ err = fat_alloc_clusters(inode, &cluster, 1);
+ if (err)
+ return err;
+ /* FIXME: this cluster should be added after data of this
+ * cluster is writed */
+ err = fat_chain_add(inode, cluster, 1);
+ if (err)
+ fat_free_clusters(inode, cluster);
+ return err;
+}
+
+static inline int __fat_get_block(struct inode *inode, sector_t iblock,
+ unsigned long *max_blocks,
+ struct buffer_head *bh_result, int create)
+{
+ struct super_block *sb = inode->i_sb;
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ unsigned long mapped_blocks;
+ sector_t phys, last_block;
+ int err, offset;
+
+ err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false);
+ if (err)
+ return err;
+ if (phys) {
+ map_bh(bh_result, sb, phys);
+ *max_blocks = min(mapped_blocks, *max_blocks);
+ return 0;
+ }
+ if (!create)
+ return 0;
+
+ if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
+ fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)",
+ MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
+ return -EIO;
+ }
+
+ last_block = inode->i_blocks >> (sb->s_blocksize_bits - 9);
+ offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
+ /*
+ * allocate a cluster according to the following.
+ * 1) no more available blocks
+ * 2) not part of fallocate region
+ */
+ if (!offset && !(iblock < last_block)) {
+ /* TODO: multiple cluster allocation would be desirable. */
+ err = fat_add_cluster(inode);
+ if (err)
+ return err;
+ }
+ /* available blocks on this cluster */
+ mapped_blocks = sbi->sec_per_clus - offset;
+
+ *max_blocks = min(mapped_blocks, *max_blocks);
+ MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
+
+ err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false);
+ if (err)
+ return err;
+ if (!phys) {
+ fat_fs_error(sb,
+ "invalid FAT chain (i_pos %lld, last_block %llu)",
+ MSDOS_I(inode)->i_pos,
+ (unsigned long long)last_block);
+ return -EIO;
+ }
+
+ BUG_ON(*max_blocks != mapped_blocks);
+ set_buffer_new(bh_result);
+ map_bh(bh_result, sb, phys);
+
+ return 0;
+}
+
+static int fat_get_block(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh_result, int create)
+{
+ struct super_block *sb = inode->i_sb;
+ unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
+ int err;
+
+ err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
+ if (err)
+ return err;
+ bh_result->b_size = max_blocks << sb->s_blocksize_bits;
+ return 0;
+}
+
+static int fat_writepage(struct page *page, struct writeback_control *wbc)
+{
+ return block_write_full_page(page, fat_get_block, wbc);
+}
+
+static int fat_writepages(struct address_space *mapping,
+ struct writeback_control *wbc)
+{
+ return mpage_writepages(mapping, wbc, fat_get_block);
+}
+
+static int fat_readpage(struct file *file, struct page *page)
+{
+ return mpage_readpage(page, fat_get_block);
+}
+
+static int fat_readpages(struct file *file, struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages)
+{
+ return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
+}
+
+static void fat_write_failed(struct address_space *mapping, loff_t to)
+{
+ struct inode *inode = mapping->host;
+
+ if (to > inode->i_size) {
+ truncate_pagecache(inode, inode->i_size);
+ fat_truncate_blocks(inode, inode->i_size);
+ }
+}
+
+static int fat_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ int err;
+
+ *pagep = NULL;
+ err = cont_write_begin(file, mapping, pos, len, flags,
+ pagep, fsdata, fat_get_block,
+ &MSDOS_I(mapping->host)->mmu_private);
+ if (err < 0)
+ fat_write_failed(mapping, pos + len);
+ return err;
+}
+
+static int fat_write_end(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *pagep, void *fsdata)
+{
+ struct inode *inode = mapping->host;
+ int err;
+ err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
+ if (err < len)
+ fat_write_failed(mapping, pos + len);
+ if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
+ inode->i_mtime = inode->i_ctime = current_time(inode);
+ MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
+ mark_inode_dirty(inode);
+ }
+ return err;
+}
+
+static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
+{
+ struct file *file = iocb->ki_filp;
+ struct address_space *mapping = file->f_mapping;
+ struct inode *inode = mapping->host;
+ size_t count = iov_iter_count(iter);
+ loff_t offset = iocb->ki_pos;
+ ssize_t ret;
+
+ if (iov_iter_rw(iter) == WRITE) {
+ /*
+ * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
+ * so we need to update the ->mmu_private to block boundary.
+ *
+ * But we must fill the remaining area or hole by nul for
+ * updating ->mmu_private.
+ *
+ * Return 0, and fallback to normal buffered write.
+ */
+ loff_t size = offset + count;
+ if (MSDOS_I(inode)->mmu_private < size)
+ return 0;
+ }
+
+ /*
+ * FAT need to use the DIO_LOCKING for avoiding the race
+ * condition of fat_get_block() and ->truncate().
+ */
+ ret = blockdev_direct_IO(iocb, inode, iter, fat_get_block);
+ if (ret < 0 && iov_iter_rw(iter) == WRITE)
+ fat_write_failed(mapping, offset + count);
+
+ return ret;
+}
+
+static int fat_get_block_bmap(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh_result, int create)
+{
+ struct super_block *sb = inode->i_sb;
+ unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
+ int err;
+ sector_t bmap;
+ unsigned long mapped_blocks;
+
+ BUG_ON(create != 0);
+
+ err = fat_bmap(inode, iblock, &bmap, &mapped_blocks, create, true);
+ if (err)
+ return err;
+
+ if (bmap) {
+ map_bh(bh_result, sb, bmap);
+ max_blocks = min(mapped_blocks, max_blocks);
+ }
+
+ bh_result->b_size = max_blocks << sb->s_blocksize_bits;
+
+ return 0;
+}
+
+static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
+{
+ sector_t blocknr;
+
+ /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
+ down_read(&MSDOS_I(mapping->host)->truncate_lock);
+ blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap);
+ up_read(&MSDOS_I(mapping->host)->truncate_lock);
+
+ return blocknr;
+}
+
+/*
+ * fat_block_truncate_page() zeroes out a mapping from file offset `from'
+ * up to the end of the block which corresponds to `from'.
+ * This is required during truncate to physically zeroout the tail end
+ * of that block so it doesn't yield old data if the file is later grown.
+ * Also, avoid causing failure from fsx for cases of "data past EOF"
+ */
+int fat_block_truncate_page(struct inode *inode, loff_t from)
+{
+ return block_truncate_page(inode->i_mapping, from, fat_get_block);
+}
+
+static const struct address_space_operations fat_aops = {
+ .readpage = fat_readpage,
+ .readpages = fat_readpages,
+ .writepage = fat_writepage,
+ .writepages = fat_writepages,
+ .write_begin = fat_write_begin,
+ .write_end = fat_write_end,
+ .direct_IO = fat_direct_IO,
+ .bmap = _fat_bmap
+};
+
+/*
+ * New FAT inode stuff. We do the following:
+ * a) i_ino is constant and has nothing with on-disk location.
+ * b) FAT manages its own cache of directory entries.
+ * c) *This* cache is indexed by on-disk location.
+ * d) inode has an associated directory entry, all right, but
+ * it may be unhashed.
+ * e) currently entries are stored within struct inode. That should
+ * change.
+ * f) we deal with races in the following way:
+ * 1. readdir() and lookup() do FAT-dir-cache lookup.
+ * 2. rename() unhashes the F-d-c entry and rehashes it in
+ * a new place.
+ * 3. unlink() and rmdir() unhash F-d-c entry.
+ * 4. fat_write_inode() checks whether the thing is unhashed.
+ * If it is we silently return. If it isn't we do bread(),
+ * check if the location is still valid and retry if it
+ * isn't. Otherwise we do changes.
+ * 5. Spinlock is used to protect hash/unhash/location check/lookup
+ * 6. fat_evict_inode() unhashes the F-d-c entry.
+ * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
+ * and consider negative result as cache miss.
+ */
+
+static void fat_hash_init(struct super_block *sb)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ int i;
+
+ spin_lock_init(&sbi->inode_hash_lock);
+ for (i = 0; i < FAT_HASH_SIZE; i++)
+ INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
+}
+
+static inline unsigned long fat_hash(loff_t i_pos)
+{
+ return hash_32(i_pos, FAT_HASH_BITS);
+}
+
+static void dir_hash_init(struct super_block *sb)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ int i;
+
+ spin_lock_init(&sbi->dir_hash_lock);
+ for (i = 0; i < FAT_HASH_SIZE; i++)
+ INIT_HLIST_HEAD(&sbi->dir_hashtable[i]);
+}
+
+void fat_attach(struct inode *inode, loff_t i_pos)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
+
+ if (inode->i_ino != MSDOS_ROOT_INO) {
+ struct hlist_head *head = sbi->inode_hashtable
+ + fat_hash(i_pos);
+
+ spin_lock(&sbi->inode_hash_lock);
+ MSDOS_I(inode)->i_pos = i_pos;
+ hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
+ spin_unlock(&sbi->inode_hash_lock);
+ }
+
+ /* If NFS support is enabled, cache the mapping of start cluster
+ * to directory inode. This is used during reconnection of
+ * dentries to the filesystem root.
+ */
+ if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
+ struct hlist_head *d_head = sbi->dir_hashtable;
+ d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart);
+
+ spin_lock(&sbi->dir_hash_lock);
+ hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head);
+ spin_unlock(&sbi->dir_hash_lock);
+ }
+}
+EXPORT_SYMBOL_GPL(fat_attach);
+
+void fat_detach(struct inode *inode)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
+ spin_lock(&sbi->inode_hash_lock);
+ MSDOS_I(inode)->i_pos = 0;
+ hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
+ spin_unlock(&sbi->inode_hash_lock);
+
+ if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
+ spin_lock(&sbi->dir_hash_lock);
+ hlist_del_init(&MSDOS_I(inode)->i_dir_hash);
+ spin_unlock(&sbi->dir_hash_lock);
+ }
+}
+EXPORT_SYMBOL_GPL(fat_detach);
+
+struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
+ struct msdos_inode_info *i;
+ struct inode *inode = NULL;
+
+ spin_lock(&sbi->inode_hash_lock);
+ hlist_for_each_entry(i, head, i_fat_hash) {
+ BUG_ON(i->vfs_inode.i_sb != sb);
+ if (i->i_pos != i_pos)
+ continue;
+ inode = igrab(&i->vfs_inode);
+ if (inode)
+ break;
+ }
+ spin_unlock(&sbi->inode_hash_lock);
+ return inode;
+}
+
+static int is_exec(unsigned char *extension)
+{
+ unsigned char exe_extensions[] = "EXECOMBAT", *walk;
+
+ for (walk = exe_extensions; *walk; walk += 3)
+ if (!strncmp(extension, walk, 3))
+ return 1;
+ return 0;
+}
+
+static int fat_calc_dir_size(struct inode *inode)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
+ int ret, fclus, dclus;
+
+ inode->i_size = 0;
+ if (MSDOS_I(inode)->i_start == 0)
+ return 0;
+
+ ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
+ if (ret < 0)
+ return ret;
+ inode->i_size = (fclus + 1) << sbi->cluster_bits;
+
+ return 0;
+}
+
+static int fat_validate_dir(struct inode *dir)
+{
+ struct super_block *sb = dir->i_sb;
+
+ if (dir->i_nlink < 2) {
+ /* Directory should have "."/".." entries at least. */
+ fat_fs_error(sb, "corrupted directory (invalid entries)");
+ return -EIO;
+ }
+ if (MSDOS_I(dir)->i_start == 0 ||
+ MSDOS_I(dir)->i_start == MSDOS_SB(sb)->root_cluster) {
+ /* Directory should point valid cluster. */
+ fat_fs_error(sb, "corrupted directory (invalid i_start)");
+ return -EIO;
+ }
+ return 0;
+}
+
+/* doesn't deal with root inode */
+int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
+ int error;
+
+ MSDOS_I(inode)->i_pos = 0;
+ inode->i_uid = sbi->options.fs_uid;
+ inode->i_gid = sbi->options.fs_gid;
+ inode_inc_iversion(inode);
+ inode->i_generation = get_seconds();
+
+ if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
+ inode->i_generation &= ~1;
+ inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
+ inode->i_op = sbi->dir_ops;
+ inode->i_fop = &fat_dir_operations;
+
+ MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
+ MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
+ error = fat_calc_dir_size(inode);
+ if (error < 0)
+ return error;
+ MSDOS_I(inode)->mmu_private = inode->i_size;
+
+ set_nlink(inode, fat_subdirs(inode));
+
+ error = fat_validate_dir(inode);
+ if (error < 0)
+ return error;
+ } else { /* not a directory */
+ inode->i_generation |= 1;
+ inode->i_mode = fat_make_mode(sbi, de->attr,
+ ((sbi->options.showexec && !is_exec(de->name + 8))
+ ? S_IRUGO|S_IWUGO : S_IRWXUGO));
+ MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
+
+ MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
+ inode->i_size = le32_to_cpu(de->size);
+ inode->i_op = &fat_file_inode_operations;
+ inode->i_fop = &fat_file_operations;
+ inode->i_mapping->a_ops = &fat_aops;
+ MSDOS_I(inode)->mmu_private = inode->i_size;
+ }
+ if (de->attr & ATTR_SYS) {
+ if (sbi->options.sys_immutable)
+ inode->i_flags |= S_IMMUTABLE;
+ }
+ fat_save_attrs(inode, de->attr);
+
+ inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
+ & ~((loff_t)sbi->cluster_size - 1)) >> 9;
+
+ fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
+ if (sbi->options.isvfat) {
+ fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
+ de->cdate, de->ctime_cs);
+ fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
+ } else
+ inode->i_ctime = inode->i_atime = inode->i_mtime;
+
+ return 0;
+}
+
+static inline void fat_lock_build_inode(struct msdos_sb_info *sbi)
+{
+ if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
+ mutex_lock(&sbi->nfs_build_inode_lock);
+}
+
+static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi)
+{
+ if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
+ mutex_unlock(&sbi->nfs_build_inode_lock);
+}
+
+struct inode *fat_build_inode(struct super_block *sb,
+ struct msdos_dir_entry *de, loff_t i_pos)
+{
+ struct inode *inode;
+ int err;
+
+ fat_lock_build_inode(MSDOS_SB(sb));
+ inode = fat_iget(sb, i_pos);
+ if (inode)
+ goto out;
+ inode = new_inode(sb);
+ if (!inode) {
+ inode = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+ inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
+ inode_set_iversion(inode, 1);
+ err = fat_fill_inode(inode, de);
+ if (err) {
+ iput(inode);
+ inode = ERR_PTR(err);
+ goto out;
+ }
+ fat_attach(inode, i_pos);
+ insert_inode_hash(inode);
+out:
+ fat_unlock_build_inode(MSDOS_SB(sb));
+ return inode;
+}
+
+EXPORT_SYMBOL_GPL(fat_build_inode);
+
+static int __fat_write_inode(struct inode *inode, int wait);
+
+static void fat_free_eofblocks(struct inode *inode)
+{
+ /* Release unwritten fallocated blocks on inode eviction. */
+ if ((inode->i_blocks << 9) >
+ round_up(MSDOS_I(inode)->mmu_private,
+ MSDOS_SB(inode->i_sb)->cluster_size)) {
+ int err;
+
+ fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private);
+ /* Fallocate results in updating the i_start/iogstart
+ * for the zero byte file. So, make it return to
+ * original state during evict and commit it to avoid
+ * any corruption on the next access to the cluster
+ * chain for the file.
+ */
+ err = __fat_write_inode(inode, inode_needs_sync(inode));
+ if (err) {
+ fat_msg(inode->i_sb, KERN_WARNING, "Failed to "
+ "update on disk inode for unused "
+ "fallocated blocks, inode could be "
+ "corrupted. Please run fsck");
+ }
+
+ }
+}
+
+static void fat_evict_inode(struct inode *inode)
+{
+ truncate_inode_pages_final(&inode->i_data);
+ if (!inode->i_nlink) {
+ inode->i_size = 0;
+ fat_truncate_blocks(inode, 0);
+ } else
+ fat_free_eofblocks(inode);
+
+ invalidate_inode_buffers(inode);
+ clear_inode(inode);
+ fat_cache_inval_inode(inode);
+ fat_detach(inode);
+}
+
+static void fat_set_state(struct super_block *sb,
+ unsigned int set, unsigned int force)
+{
+ struct buffer_head *bh;
+ struct fat_boot_sector *b;
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+
+ /* do not change any thing if mounted read only */
+ if (sb_rdonly(sb) && !force)
+ return;
+
+ /* do not change state if fs was dirty */
+ if (sbi->dirty) {
+ /* warn only on set (mount). */
+ if (set)
+ fat_msg(sb, KERN_WARNING, "Volume was not properly "
+ "unmounted. Some data may be corrupt. "
+ "Please run fsck.");
+ return;
+ }
+
+ bh = sb_bread(sb, 0);
+ if (bh == NULL) {
+ fat_msg(sb, KERN_ERR, "unable to read boot sector "
+ "to mark fs as dirty");
+ return;
+ }
+
+ b = (struct fat_boot_sector *) bh->b_data;
+
+ if (sbi->fat_bits == 32) {
+ if (set)
+ b->fat32.state |= FAT_STATE_DIRTY;
+ else
+ b->fat32.state &= ~FAT_STATE_DIRTY;
+ } else /* fat 16 and 12 */ {
+ if (set)
+ b->fat16.state |= FAT_STATE_DIRTY;
+ else
+ b->fat16.state &= ~FAT_STATE_DIRTY;
+ }
+
+ mark_buffer_dirty(bh);
+ sync_dirty_buffer(bh);
+ brelse(bh);
+}
+
+static void fat_reset_iocharset(struct fat_mount_options *opts)
+{
+ if (opts->iocharset != fat_default_iocharset) {
+ /* Note: opts->iocharset can be NULL here */
+ kfree(opts->iocharset);
+ opts->iocharset = fat_default_iocharset;
+ }
+}
+
+static void delayed_free(struct rcu_head *p)
+{
+ struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu);
+ unload_nls(sbi->nls_disk);
+ unload_nls(sbi->nls_io);
+ fat_reset_iocharset(&sbi->options);
+ kfree(sbi);
+}
+
+static void fat_put_super(struct super_block *sb)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+
+ fat_set_state(sb, 0, 0);
+
+ iput(sbi->fsinfo_inode);
+ iput(sbi->fat_inode);
+
+ call_rcu(&sbi->rcu, delayed_free);
+}
+
+static struct kmem_cache *fat_inode_cachep;
+
+static struct inode *fat_alloc_inode(struct super_block *sb)
+{
+ struct msdos_inode_info *ei;
+ ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
+ if (!ei)
+ return NULL;
+
+ init_rwsem(&ei->truncate_lock);
+ return &ei->vfs_inode;
+}
+
+static void fat_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
+}
+
+static void fat_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, fat_i_callback);
+}
+
+static void init_once(void *foo)
+{
+ struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
+
+ spin_lock_init(&ei->cache_lru_lock);
+ ei->nr_caches = 0;
+ ei->cache_valid_id = FAT_CACHE_VALID + 1;
+ INIT_LIST_HEAD(&ei->cache_lru);
+ INIT_HLIST_NODE(&ei->i_fat_hash);
+ INIT_HLIST_NODE(&ei->i_dir_hash);
+ inode_init_once(&ei->vfs_inode);
+}
+
+static int __init fat_init_inodecache(void)
+{
+ fat_inode_cachep = kmem_cache_create("fat_inode_cache",
+ sizeof(struct msdos_inode_info),
+ 0, (SLAB_RECLAIM_ACCOUNT|
+ SLAB_MEM_SPREAD|SLAB_ACCOUNT),
+ init_once);
+ if (fat_inode_cachep == NULL)
+ return -ENOMEM;
+ return 0;
+}
+
+static void __exit fat_destroy_inodecache(void)
+{
+ /*
+ * Make sure all delayed rcu free inodes are flushed before we
+ * destroy cache.
+ */
+ rcu_barrier();
+ kmem_cache_destroy(fat_inode_cachep);
+}
+
+static int fat_remount(struct super_block *sb, int *flags, char *data)
+{
+ bool new_rdonly;
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ *flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME);
+
+ sync_filesystem(sb);
+
+ /* make sure we update state on remount. */
+ new_rdonly = *flags & SB_RDONLY;
+ if (new_rdonly != sb_rdonly(sb)) {
+ if (new_rdonly)
+ fat_set_state(sb, 0, 0);
+ else
+ fat_set_state(sb, 1, 1);
+ }
+ return 0;
+}
+
+static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+ struct super_block *sb = dentry->d_sb;
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
+
+ /* If the count of free cluster is still unknown, counts it here. */
+ if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
+ int err = fat_count_free_clusters(dentry->d_sb);
+ if (err)
+ return err;
+ }
+
+ buf->f_type = dentry->d_sb->s_magic;
+ buf->f_bsize = sbi->cluster_size;
+ buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
+ buf->f_bfree = sbi->free_clusters;
+ buf->f_bavail = sbi->free_clusters;
+ buf->f_fsid.val[0] = (u32)id;
+ buf->f_fsid.val[1] = (u32)(id >> 32);
+ buf->f_namelen =
+ (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
+
+ return 0;
+}
+
+static int __fat_write_inode(struct inode *inode, int wait)
+{
+ struct super_block *sb = inode->i_sb;
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ struct buffer_head *bh;
+ struct msdos_dir_entry *raw_entry;
+ loff_t i_pos;
+ sector_t blocknr;
+ int err, offset;
+
+ if (inode->i_ino == MSDOS_ROOT_INO)
+ return 0;
+
+retry:
+ i_pos = fat_i_pos_read(sbi, inode);
+ if (!i_pos)
+ return 0;
+
+ fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset);
+ bh = sb_bread(sb, blocknr);
+ if (!bh) {
+ fat_msg(sb, KERN_ERR, "unable to read inode block "
+ "for updating (i_pos %lld)", i_pos);
+ return -EIO;
+ }
+ spin_lock(&sbi->inode_hash_lock);
+ if (i_pos != MSDOS_I(inode)->i_pos) {
+ spin_unlock(&sbi->inode_hash_lock);
+ brelse(bh);
+ goto retry;
+ }
+
+ raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset];
+ if (S_ISDIR(inode->i_mode))
+ raw_entry->size = 0;
+ else
+ raw_entry->size = cpu_to_le32(inode->i_size);
+ raw_entry->attr = fat_make_attrs(inode);
+ fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart);
+ fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
+ &raw_entry->date, NULL);
+ if (sbi->options.isvfat) {
+ __le16 atime;
+ fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
+ &raw_entry->cdate, &raw_entry->ctime_cs);
+ fat_time_unix2fat(sbi, &inode->i_atime, &atime,
+ &raw_entry->adate, NULL);
+ }
+ spin_unlock(&sbi->inode_hash_lock);
+ mark_buffer_dirty(bh);
+ err = 0;
+ if (wait)
+ err = sync_dirty_buffer(bh);
+ brelse(bh);
+ return err;
+}
+
+static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+ int err;
+
+ if (inode->i_ino == MSDOS_FSINFO_INO) {
+ struct super_block *sb = inode->i_sb;
+
+ mutex_lock(&MSDOS_SB(sb)->s_lock);
+ err = fat_clusters_flush(sb);
+ mutex_unlock(&MSDOS_SB(sb)->s_lock);
+ } else
+ err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
+
+ return err;
+}
+
+int fat_sync_inode(struct inode *inode)
+{
+ return __fat_write_inode(inode, 1);
+}
+
+EXPORT_SYMBOL_GPL(fat_sync_inode);
+
+static int fat_show_options(struct seq_file *m, struct dentry *root);
+static const struct super_operations fat_sops = {
+ .alloc_inode = fat_alloc_inode,
+ .destroy_inode = fat_destroy_inode,
+ .write_inode = fat_write_inode,
+ .evict_inode = fat_evict_inode,
+ .put_super = fat_put_super,
+ .statfs = fat_statfs,
+ .remount_fs = fat_remount,
+
+ .show_options = fat_show_options,
+};
+
+static int fat_show_options(struct seq_file *m, struct dentry *root)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
+ struct fat_mount_options *opts = &sbi->options;
+ int isvfat = opts->isvfat;
+
+ if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
+ seq_printf(m, ",uid=%u",
+ from_kuid_munged(&init_user_ns, opts->fs_uid));
+ if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
+ seq_printf(m, ",gid=%u",
+ from_kgid_munged(&init_user_ns, opts->fs_gid));
+ seq_printf(m, ",fmask=%04o", opts->fs_fmask);
+ seq_printf(m, ",dmask=%04o", opts->fs_dmask);
+ if (opts->allow_utime)
+ seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
+ if (sbi->nls_disk)
+ /* strip "cp" prefix from displayed option */
+ seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]);
+ if (isvfat) {
+ if (sbi->nls_io)
+ seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
+
+ switch (opts->shortname) {
+ case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
+ seq_puts(m, ",shortname=win95");
+ break;
+ case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
+ seq_puts(m, ",shortname=winnt");
+ break;
+ case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
+ seq_puts(m, ",shortname=mixed");
+ break;
+ case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
+ seq_puts(m, ",shortname=lower");
+ break;
+ default:
+ seq_puts(m, ",shortname=unknown");
+ break;
+ }
+ }
+ if (opts->name_check != 'n')
+ seq_printf(m, ",check=%c", opts->name_check);
+ if (opts->usefree)
+ seq_puts(m, ",usefree");
+ if (opts->quiet)
+ seq_puts(m, ",quiet");
+ if (opts->showexec)
+ seq_puts(m, ",showexec");
+ if (opts->sys_immutable)
+ seq_puts(m, ",sys_immutable");
+ if (!isvfat) {
+ if (opts->dotsOK)
+ seq_puts(m, ",dotsOK=yes");
+ if (opts->nocase)
+ seq_puts(m, ",nocase");
+ } else {
+ if (opts->utf8)
+ seq_puts(m, ",utf8");
+ if (opts->unicode_xlate)
+ seq_puts(m, ",uni_xlate");
+ if (!opts->numtail)
+ seq_puts(m, ",nonumtail");
+ if (opts->rodir)
+ seq_puts(m, ",rodir");
+ }
+ if (opts->flush)
+ seq_puts(m, ",flush");
+ if (opts->tz_set) {
+ if (opts->time_offset)
+ seq_printf(m, ",time_offset=%d", opts->time_offset);
+ else
+ seq_puts(m, ",tz=UTC");
+ }
+ if (opts->errors == FAT_ERRORS_CONT)
+ seq_puts(m, ",errors=continue");
+ else if (opts->errors == FAT_ERRORS_PANIC)
+ seq_puts(m, ",errors=panic");
+ else
+ seq_puts(m, ",errors=remount-ro");
+ if (opts->nfs == FAT_NFS_NOSTALE_RO)
+ seq_puts(m, ",nfs=nostale_ro");
+ else if (opts->nfs)
+ seq_puts(m, ",nfs=stale_rw");
+ if (opts->discard)
+ seq_puts(m, ",discard");
+ if (opts->dos1xfloppy)
+ seq_puts(m, ",dos1xfloppy");
+
+ return 0;
+}
+
+enum {
+ Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
+ Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
+ Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
+ Opt_immutable, Opt_dots, Opt_nodots,
+ Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
+ Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
+ Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
+ Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
+ Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset,
+ Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy,
+};
+
+static const match_table_t fat_tokens = {
+ {Opt_check_r, "check=relaxed"},
+ {Opt_check_s, "check=strict"},
+ {Opt_check_n, "check=normal"},
+ {Opt_check_r, "check=r"},
+ {Opt_check_s, "check=s"},
+ {Opt_check_n, "check=n"},
+ {Opt_uid, "uid=%u"},
+ {Opt_gid, "gid=%u"},
+ {Opt_umask, "umask=%o"},
+ {Opt_dmask, "dmask=%o"},
+ {Opt_fmask, "fmask=%o"},
+ {Opt_allow_utime, "allow_utime=%o"},
+ {Opt_codepage, "codepage=%u"},
+ {Opt_usefree, "usefree"},
+ {Opt_nocase, "nocase"},
+ {Opt_quiet, "quiet"},
+ {Opt_showexec, "showexec"},
+ {Opt_debug, "debug"},
+ {Opt_immutable, "sys_immutable"},
+ {Opt_flush, "flush"},
+ {Opt_tz_utc, "tz=UTC"},
+ {Opt_time_offset, "time_offset=%d"},
+ {Opt_err_cont, "errors=continue"},
+ {Opt_err_panic, "errors=panic"},
+ {Opt_err_ro, "errors=remount-ro"},
+ {Opt_discard, "discard"},
+ {Opt_nfs_stale_rw, "nfs"},
+ {Opt_nfs_stale_rw, "nfs=stale_rw"},
+ {Opt_nfs_nostale_ro, "nfs=nostale_ro"},
+ {Opt_dos1xfloppy, "dos1xfloppy"},
+ {Opt_obsolete, "conv=binary"},
+ {Opt_obsolete, "conv=text"},
+ {Opt_obsolete, "conv=auto"},
+ {Opt_obsolete, "conv=b"},
+ {Opt_obsolete, "conv=t"},
+ {Opt_obsolete, "conv=a"},
+ {Opt_obsolete, "fat=%u"},
+ {Opt_obsolete, "blocksize=%u"},
+ {Opt_obsolete, "cvf_format=%20s"},
+ {Opt_obsolete, "cvf_options=%100s"},
+ {Opt_obsolete, "posix"},
+ {Opt_err, NULL},
+};
+static const match_table_t msdos_tokens = {
+ {Opt_nodots, "nodots"},
+ {Opt_nodots, "dotsOK=no"},
+ {Opt_dots, "dots"},
+ {Opt_dots, "dotsOK=yes"},
+ {Opt_err, NULL}
+};
+static const match_table_t vfat_tokens = {
+ {Opt_charset, "iocharset=%s"},
+ {Opt_shortname_lower, "shortname=lower"},
+ {Opt_shortname_win95, "shortname=win95"},
+ {Opt_shortname_winnt, "shortname=winnt"},
+ {Opt_shortname_mixed, "shortname=mixed"},
+ {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
+ {Opt_utf8_no, "utf8=no"},
+ {Opt_utf8_no, "utf8=false"},
+ {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
+ {Opt_utf8_yes, "utf8=yes"},
+ {Opt_utf8_yes, "utf8=true"},
+ {Opt_utf8_yes, "utf8"},
+ {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
+ {Opt_uni_xl_no, "uni_xlate=no"},
+ {Opt_uni_xl_no, "uni_xlate=false"},
+ {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
+ {Opt_uni_xl_yes, "uni_xlate=yes"},
+ {Opt_uni_xl_yes, "uni_xlate=true"},
+ {Opt_uni_xl_yes, "uni_xlate"},
+ {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
+ {Opt_nonumtail_no, "nonumtail=no"},
+ {Opt_nonumtail_no, "nonumtail=false"},
+ {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
+ {Opt_nonumtail_yes, "nonumtail=yes"},
+ {Opt_nonumtail_yes, "nonumtail=true"},
+ {Opt_nonumtail_yes, "nonumtail"},
+ {Opt_rodir, "rodir"},
+ {Opt_err, NULL}
+};
+
+static int parse_options(struct super_block *sb, char *options, int is_vfat,
+ int silent, int *debug, struct fat_mount_options *opts)
+{
+ char *p;
+ substring_t args[MAX_OPT_ARGS];
+ int option;
+ char *iocharset;
+
+ opts->isvfat = is_vfat;
+
+ opts->fs_uid = current_uid();
+ opts->fs_gid = current_gid();
+ opts->fs_fmask = opts->fs_dmask = current_umask();
+ opts->allow_utime = -1;
+ opts->codepage = fat_default_codepage;
+ fat_reset_iocharset(opts);
+ if (is_vfat) {
+ opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
+ opts->rodir = 0;
+ } else {
+ opts->shortname = 0;
+ opts->rodir = 1;
+ }
+ opts->name_check = 'n';
+ opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
+ opts->unicode_xlate = 0;
+ opts->numtail = 1;
+ opts->usefree = opts->nocase = 0;
+ opts->tz_set = 0;
+ opts->nfs = 0;
+ opts->errors = FAT_ERRORS_RO;
+ *debug = 0;
+
+ opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat;
+
+ if (!options)
+ goto out;
+
+ while ((p = strsep(&options, ",")) != NULL) {
+ int token;
+ if (!*p)
+ continue;
+
+ token = match_token(p, fat_tokens, args);
+ if (token == Opt_err) {
+ if (is_vfat)
+ token = match_token(p, vfat_tokens, args);
+ else
+ token = match_token(p, msdos_tokens, args);
+ }
+ switch (token) {
+ case Opt_check_s:
+ opts->name_check = 's';
+ break;
+ case Opt_check_r:
+ opts->name_check = 'r';
+ break;
+ case Opt_check_n:
+ opts->name_check = 'n';
+ break;
+ case Opt_usefree:
+ opts->usefree = 1;
+ break;
+ case Opt_nocase:
+ if (!is_vfat)
+ opts->nocase = 1;
+ else {
+ /* for backward compatibility */
+ opts->shortname = VFAT_SFN_DISPLAY_WIN95
+ | VFAT_SFN_CREATE_WIN95;
+ }
+ break;
+ case Opt_quiet:
+ opts->quiet = 1;
+ break;
+ case Opt_showexec:
+ opts->showexec = 1;
+ break;
+ case Opt_debug:
+ *debug = 1;
+ break;
+ case Opt_immutable:
+ opts->sys_immutable = 1;
+ break;
+ case Opt_uid:
+ if (match_int(&args[0], &option))
+ return -EINVAL;
+ opts->fs_uid = make_kuid(current_user_ns(), option);
+ if (!uid_valid(opts->fs_uid))
+ return -EINVAL;
+ break;
+ case Opt_gid:
+ if (match_int(&args[0], &option))
+ return -EINVAL;
+ opts->fs_gid = make_kgid(current_user_ns(), option);
+ if (!gid_valid(opts->fs_gid))
+ return -EINVAL;
+ break;
+ case Opt_umask:
+ if (match_octal(&args[0], &option))
+ return -EINVAL;
+ opts->fs_fmask = opts->fs_dmask = option;
+ break;
+ case Opt_dmask:
+ if (match_octal(&args[0], &option))
+ return -EINVAL;
+ opts->fs_dmask = option;
+ break;
+ case Opt_fmask:
+ if (match_octal(&args[0], &option))
+ return -EINVAL;
+ opts->fs_fmask = option;
+ break;
+ case Opt_allow_utime:
+ if (match_octal(&args[0], &option))
+ return -EINVAL;
+ opts->allow_utime = option & (S_IWGRP | S_IWOTH);
+ break;
+ case Opt_codepage:
+ if (match_int(&args[0], &option))
+ return -EINVAL;
+ opts->codepage = option;
+ break;
+ case Opt_flush:
+ opts->flush = 1;
+ break;
+ case Opt_time_offset:
+ if (match_int(&args[0], &option))
+ return -EINVAL;
+ /*
+ * GMT+-12 zones may have DST corrections so at least
+ * 13 hours difference is needed. Make the limit 24
+ * just in case someone invents something unusual.
+ */
+ if (option < -24 * 60 || option > 24 * 60)
+ return -EINVAL;
+ opts->tz_set = 1;
+ opts->time_offset = option;
+ break;
+ case Opt_tz_utc:
+ opts->tz_set = 1;
+ opts->time_offset = 0;
+ break;
+ case Opt_err_cont:
+ opts->errors = FAT_ERRORS_CONT;
+ break;
+ case Opt_err_panic:
+ opts->errors = FAT_ERRORS_PANIC;
+ break;
+ case Opt_err_ro:
+ opts->errors = FAT_ERRORS_RO;
+ break;
+ case Opt_nfs_stale_rw:
+ opts->nfs = FAT_NFS_STALE_RW;
+ break;
+ case Opt_nfs_nostale_ro:
+ opts->nfs = FAT_NFS_NOSTALE_RO;
+ break;
+ case Opt_dos1xfloppy:
+ opts->dos1xfloppy = 1;
+ break;
+
+ /* msdos specific */
+ case Opt_dots:
+ opts->dotsOK = 1;
+ break;
+ case Opt_nodots:
+ opts->dotsOK = 0;
+ break;
+
+ /* vfat specific */
+ case Opt_charset:
+ fat_reset_iocharset(opts);
+ iocharset = match_strdup(&args[0]);
+ if (!iocharset)
+ return -ENOMEM;
+ opts->iocharset = iocharset;
+ break;
+ case Opt_shortname_lower:
+ opts->shortname = VFAT_SFN_DISPLAY_LOWER
+ | VFAT_SFN_CREATE_WIN95;
+ break;
+ case Opt_shortname_win95:
+ opts->shortname = VFAT_SFN_DISPLAY_WIN95
+ | VFAT_SFN_CREATE_WIN95;
+ break;
+ case Opt_shortname_winnt:
+ opts->shortname = VFAT_SFN_DISPLAY_WINNT
+ | VFAT_SFN_CREATE_WINNT;
+ break;
+ case Opt_shortname_mixed:
+ opts->shortname = VFAT_SFN_DISPLAY_WINNT
+ | VFAT_SFN_CREATE_WIN95;
+ break;
+ case Opt_utf8_no: /* 0 or no or false */
+ opts->utf8 = 0;
+ break;
+ case Opt_utf8_yes: /* empty or 1 or yes or true */
+ opts->utf8 = 1;
+ break;
+ case Opt_uni_xl_no: /* 0 or no or false */
+ opts->unicode_xlate = 0;
+ break;
+ case Opt_uni_xl_yes: /* empty or 1 or yes or true */
+ opts->unicode_xlate = 1;
+ break;
+ case Opt_nonumtail_no: /* 0 or no or false */
+ opts->numtail = 1; /* negated option */
+ break;
+ case Opt_nonumtail_yes: /* empty or 1 or yes or true */
+ opts->numtail = 0; /* negated option */
+ break;
+ case Opt_rodir:
+ opts->rodir = 1;
+ break;
+ case Opt_discard:
+ opts->discard = 1;
+ break;
+
+ /* obsolete mount options */
+ case Opt_obsolete:
+ fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, "
+ "not supported now", p);
+ break;
+ /* unknown option */
+ default:
+ if (!silent) {
+ fat_msg(sb, KERN_ERR,
+ "Unrecognized mount option \"%s\" "
+ "or missing value", p);
+ }
+ return -EINVAL;
+ }
+ }
+
+out:
+ /* UTF-8 doesn't provide FAT semantics */
+ if (!strcmp(opts->iocharset, "utf8")) {
+ fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
+ " for FAT filesystems, filesystem will be "
+ "case sensitive!");
+ }
+
+ /* If user doesn't specify allow_utime, it's initialized from dmask. */
+ if (opts->allow_utime == (unsigned short)-1)
+ opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
+ if (opts->unicode_xlate)
+ opts->utf8 = 0;
+ if (opts->nfs == FAT_NFS_NOSTALE_RO) {
+ sb->s_flags |= SB_RDONLY;
+ sb->s_export_op = &fat_export_ops_nostale;
+ }
+
+ return 0;
+}
+
+static void fat_dummy_inode_init(struct inode *inode)
+{
+ /* Initialize this dummy inode to work as no-op. */
+ MSDOS_I(inode)->mmu_private = 0;
+ MSDOS_I(inode)->i_start = 0;
+ MSDOS_I(inode)->i_logstart = 0;
+ MSDOS_I(inode)->i_attrs = 0;
+ MSDOS_I(inode)->i_pos = 0;
+}
+
+static int fat_read_root(struct inode *inode)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
+ int error;
+
+ MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO;
+ inode->i_uid = sbi->options.fs_uid;
+ inode->i_gid = sbi->options.fs_gid;
+ inode_inc_iversion(inode);
+ inode->i_generation = 0;
+ inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
+ inode->i_op = sbi->dir_ops;
+ inode->i_fop = &fat_dir_operations;
+ if (sbi->fat_bits == 32) {
+ MSDOS_I(inode)->i_start = sbi->root_cluster;
+ error = fat_calc_dir_size(inode);
+ if (error < 0)
+ return error;
+ } else {
+ MSDOS_I(inode)->i_start = 0;
+ inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
+ }
+ inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
+ & ~((loff_t)sbi->cluster_size - 1)) >> 9;
+ MSDOS_I(inode)->i_logstart = 0;
+ MSDOS_I(inode)->mmu_private = inode->i_size;
+
+ fat_save_attrs(inode, ATTR_DIR);
+ inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
+ inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
+ set_nlink(inode, fat_subdirs(inode)+2);
+
+ return 0;
+}
+
+static unsigned long calc_fat_clusters(struct super_block *sb)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+
+ /* Divide first to avoid overflow */
+ if (sbi->fat_bits != 12) {
+ unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits;
+ return ent_per_sec * sbi->fat_length;
+ }
+
+ return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
+}
+
+static bool fat_bpb_is_zero(struct fat_boot_sector *b)
+{
+ if (get_unaligned_le16(&b->sector_size))
+ return false;
+ if (b->sec_per_clus)
+ return false;
+ if (b->reserved)
+ return false;
+ if (b->fats)
+ return false;
+ if (get_unaligned_le16(&b->dir_entries))
+ return false;
+ if (get_unaligned_le16(&b->sectors))
+ return false;
+ if (b->media)
+ return false;
+ if (b->fat_length)
+ return false;
+ if (b->secs_track)
+ return false;
+ if (b->heads)
+ return false;
+ return true;
+}
+
+static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b,
+ int silent, struct fat_bios_param_block *bpb)
+{
+ int error = -EINVAL;
+
+ /* Read in BPB ... */
+ memset(bpb, 0, sizeof(*bpb));
+ bpb->fat_sector_size = get_unaligned_le16(&b->sector_size);
+ bpb->fat_sec_per_clus = b->sec_per_clus;
+ bpb->fat_reserved = le16_to_cpu(b->reserved);
+ bpb->fat_fats = b->fats;
+ bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries);
+ bpb->fat_sectors = get_unaligned_le16(&b->sectors);
+ bpb->fat_fat_length = le16_to_cpu(b->fat_length);
+ bpb->fat_total_sect = le32_to_cpu(b->total_sect);
+
+ bpb->fat16_state = b->fat16.state;
+ bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id);
+
+ bpb->fat32_length = le32_to_cpu(b->fat32.length);
+ bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster);
+ bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector);
+ bpb->fat32_state = b->fat32.state;
+ bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id);
+
+ /* Validate this looks like a FAT filesystem BPB */
+ if (!bpb->fat_reserved) {
+ if (!silent)
+ fat_msg(sb, KERN_ERR,
+ "bogus number of reserved sectors");
+ goto out;
+ }
+ if (!bpb->fat_fats) {
+ if (!silent)
+ fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
+ goto out;
+ }
+
+ /*
+ * Earlier we checked here that b->secs_track and b->head are nonzero,
+ * but it turns out valid FAT filesystems can have zero there.
+ */
+
+ if (!fat_valid_media(b->media)) {
+ if (!silent)
+ fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
+ (unsigned)b->media);
+ goto out;
+ }
+
+ if (!is_power_of_2(bpb->fat_sector_size)
+ || (bpb->fat_sector_size < 512)
+ || (bpb->fat_sector_size > 4096)) {
+ if (!silent)
+ fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
+ (unsigned)bpb->fat_sector_size);
+ goto out;
+ }
+
+ if (!is_power_of_2(bpb->fat_sec_per_clus)) {
+ if (!silent)
+ fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
+ (unsigned)bpb->fat_sec_per_clus);
+ goto out;
+ }
+
+ error = 0;
+
+out:
+ return error;
+}
+
+static int fat_read_static_bpb(struct super_block *sb,
+ struct fat_boot_sector *b, int silent,
+ struct fat_bios_param_block *bpb)
+{
+ static const char *notdos1x = "This doesn't look like a DOS 1.x volume";
+
+ struct fat_floppy_defaults *fdefaults = NULL;
+ int error = -EINVAL;
+ sector_t bd_sects;
+ unsigned i;
+
+ bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE;
+
+ /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */
+ if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) {
+ if (!silent)
+ fat_msg(sb, KERN_ERR,
+ "%s; no bootstrapping code", notdos1x);
+ goto out;
+ }
+
+ /*
+ * If any value in this region is non-zero, it isn't archaic
+ * DOS.
+ */
+ if (!fat_bpb_is_zero(b)) {
+ if (!silent)
+ fat_msg(sb, KERN_ERR,
+ "%s; DOS 2.x BPB is non-zero", notdos1x);
+ goto out;
+ }
+
+ for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) {
+ if (floppy_defaults[i].nr_sectors == bd_sects) {
+ fdefaults = &floppy_defaults[i];
+ break;
+ }
+ }
+
+ if (fdefaults == NULL) {
+ if (!silent)
+ fat_msg(sb, KERN_WARNING,
+ "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)",
+ (u64)bd_sects);
+ goto out;
+ }
+
+ if (!silent)
+ fat_msg(sb, KERN_INFO,
+ "This looks like a DOS 1.x volume; assuming default BPB values");
+
+ memset(bpb, 0, sizeof(*bpb));
+ bpb->fat_sector_size = SECTOR_SIZE;
+ bpb->fat_sec_per_clus = fdefaults->sec_per_clus;
+ bpb->fat_reserved = 1;
+ bpb->fat_fats = 2;
+ bpb->fat_dir_entries = fdefaults->dir_entries;
+ bpb->fat_sectors = fdefaults->nr_sectors;
+ bpb->fat_fat_length = fdefaults->fat_length;
+
+ error = 0;
+
+out:
+ return error;
+}
+
+/*
+ * Read the super block of an MS-DOS FS.
+ */
+int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
+ void (*setup)(struct super_block *))
+{
+ struct inode *root_inode = NULL, *fat_inode = NULL;
+ struct inode *fsinfo_inode = NULL;
+ struct buffer_head *bh;
+ struct fat_bios_param_block bpb;
+ struct msdos_sb_info *sbi;
+ u16 logical_sector_size;
+ u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
+ int debug;
+ long error;
+ char buf[50];
+
+ /*
+ * GFP_KERNEL is ok here, because while we do hold the
+ * superblock lock, memory pressure can't call back into
+ * the filesystem, since we're only just about to mount
+ * it and have no inodes etc active!
+ */
+ sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
+ if (!sbi)
+ return -ENOMEM;
+ sb->s_fs_info = sbi;
+
+ sb->s_flags |= SB_NODIRATIME;
+ sb->s_magic = MSDOS_SUPER_MAGIC;
+ sb->s_op = &fat_sops;
+ sb->s_export_op = &fat_export_ops;
+ mutex_init(&sbi->nfs_build_inode_lock);
+ ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
+ DEFAULT_RATELIMIT_BURST);
+
+ error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options);
+ if (error)
+ goto out_fail;
+
+ setup(sb); /* flavour-specific stuff that needs options */
+
+ error = -EIO;
+ sb_min_blocksize(sb, 512);
+ bh = sb_bread(sb, 0);
+ if (bh == NULL) {
+ fat_msg(sb, KERN_ERR, "unable to read boot sector");
+ goto out_fail;
+ }
+
+ error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent,
+ &bpb);
+ if (error == -EINVAL && sbi->options.dos1xfloppy)
+ error = fat_read_static_bpb(sb,
+ (struct fat_boot_sector *)bh->b_data, silent, &bpb);
+ brelse(bh);
+
+ if (error == -EINVAL)
+ goto out_invalid;
+ else if (error)
+ goto out_fail;
+
+ logical_sector_size = bpb.fat_sector_size;
+ sbi->sec_per_clus = bpb.fat_sec_per_clus;
+
+ error = -EIO;
+ if (logical_sector_size < sb->s_blocksize) {
+ fat_msg(sb, KERN_ERR, "logical sector size too small for device"
+ " (logical sector size = %u)", logical_sector_size);
+ goto out_fail;
+ }
+
+ if (logical_sector_size > sb->s_blocksize) {
+ struct buffer_head *bh_resize;
+
+ if (!sb_set_blocksize(sb, logical_sector_size)) {
+ fat_msg(sb, KERN_ERR, "unable to set blocksize %u",
+ logical_sector_size);
+ goto out_fail;
+ }
+
+ /* Verify that the larger boot sector is fully readable */
+ bh_resize = sb_bread(sb, 0);
+ if (bh_resize == NULL) {
+ fat_msg(sb, KERN_ERR, "unable to read boot sector"
+ " (logical sector size = %lu)",
+ sb->s_blocksize);
+ goto out_fail;
+ }
+ brelse(bh_resize);
+ }
+
+ mutex_init(&sbi->s_lock);
+ sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
+ sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
+ sbi->fats = bpb.fat_fats;
+ sbi->fat_bits = 0; /* Don't know yet */
+ sbi->fat_start = bpb.fat_reserved;
+ sbi->fat_length = bpb.fat_fat_length;
+ sbi->root_cluster = 0;
+ sbi->free_clusters = -1; /* Don't know yet */
+ sbi->free_clus_valid = 0;
+ sbi->prev_free = FAT_START_ENT;
+ sb->s_maxbytes = 0xffffffff;
+
+ if (!sbi->fat_length && bpb.fat32_length) {
+ struct fat_boot_fsinfo *fsinfo;
+ struct buffer_head *fsinfo_bh;
+
+ /* Must be FAT32 */
+ sbi->fat_bits = 32;
+ sbi->fat_length = bpb.fat32_length;
+ sbi->root_cluster = bpb.fat32_root_cluster;
+
+ /* MC - if info_sector is 0, don't multiply by 0 */
+ sbi->fsinfo_sector = bpb.fat32_info_sector;
+ if (sbi->fsinfo_sector == 0)
+ sbi->fsinfo_sector = 1;
+
+ fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
+ if (fsinfo_bh == NULL) {
+ fat_msg(sb, KERN_ERR, "bread failed, FSINFO block"
+ " (sector = %lu)", sbi->fsinfo_sector);
+ goto out_fail;
+ }
+
+ fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
+ if (!IS_FSINFO(fsinfo)) {
+ fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
+ "0x%08x, 0x%08x (sector = %lu)",
+ le32_to_cpu(fsinfo->signature1),
+ le32_to_cpu(fsinfo->signature2),
+ sbi->fsinfo_sector);
+ } else {
+ if (sbi->options.usefree)
+ sbi->free_clus_valid = 1;
+ sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
+ sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
+ }
+
+ brelse(fsinfo_bh);
+ }
+
+ /* interpret volume ID as a little endian 32 bit integer */
+ if (sbi->fat_bits == 32)
+ sbi->vol_id = bpb.fat32_vol_id;
+ else /* fat 16 or 12 */
+ sbi->vol_id = bpb.fat16_vol_id;
+
+ sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
+ sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
+
+ sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
+ sbi->dir_entries = bpb.fat_dir_entries;
+ if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
+ if (!silent)
+ fat_msg(sb, KERN_ERR, "bogus number of directory entries"
+ " (%u)", sbi->dir_entries);
+ goto out_invalid;
+ }
+
+ rootdir_sectors = sbi->dir_entries
+ * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
+ sbi->data_start = sbi->dir_start + rootdir_sectors;
+ total_sectors = bpb.fat_sectors;
+ if (total_sectors == 0)
+ total_sectors = bpb.fat_total_sect;
+
+ total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
+
+ if (sbi->fat_bits != 32)
+ sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
+
+ /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */
+ if (sbi->fat_bits == 32)
+ sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY;
+ else /* fat 16 or 12 */
+ sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY;
+
+ /* check that FAT table does not overflow */
+ fat_clusters = calc_fat_clusters(sb);
+ total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
+ if (total_clusters > MAX_FAT(sb)) {
+ if (!silent)
+ fat_msg(sb, KERN_ERR, "count of clusters too big (%u)",
+ total_clusters);
+ goto out_invalid;
+ }
+
+ sbi->max_cluster = total_clusters + FAT_START_ENT;
+ /* check the free_clusters, it's not necessarily correct */
+ if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
+ sbi->free_clusters = -1;
+ /* check the prev_free, it's not necessarily correct */
+ sbi->prev_free %= sbi->max_cluster;
+ if (sbi->prev_free < FAT_START_ENT)
+ sbi->prev_free = FAT_START_ENT;
+
+ /* set up enough so that it can read an inode */
+ fat_hash_init(sb);
+ dir_hash_init(sb);
+ fat_ent_access_init(sb);
+
+ /*
+ * The low byte of FAT's first entry must have same value with
+ * media-field. But in real world, too many devices is
+ * writing wrong value. So, removed that validity check.
+ *
+ * if (FAT_FIRST_ENT(sb, media) != first)
+ */
+
+ error = -EINVAL;
+ sprintf(buf, "cp%d", sbi->options.codepage);
+ sbi->nls_disk = load_nls(buf);
+ if (!sbi->nls_disk) {
+ fat_msg(sb, KERN_ERR, "codepage %s not found", buf);
+ goto out_fail;
+ }
+
+ /* FIXME: utf8 is using iocharset for upper/lower conversion */
+ if (sbi->options.isvfat) {
+ sbi->nls_io = load_nls(sbi->options.iocharset);
+ if (!sbi->nls_io) {
+ fat_msg(sb, KERN_ERR, "IO charset %s not found",
+ sbi->options.iocharset);
+ goto out_fail;
+ }
+ }
+
+ error = -ENOMEM;
+ fat_inode = new_inode(sb);
+ if (!fat_inode)
+ goto out_fail;
+ fat_dummy_inode_init(fat_inode);
+ sbi->fat_inode = fat_inode;
+
+ fsinfo_inode = new_inode(sb);
+ if (!fsinfo_inode)
+ goto out_fail;
+ fat_dummy_inode_init(fsinfo_inode);
+ fsinfo_inode->i_ino = MSDOS_FSINFO_INO;
+ sbi->fsinfo_inode = fsinfo_inode;
+ insert_inode_hash(fsinfo_inode);
+
+ root_inode = new_inode(sb);
+ if (!root_inode)
+ goto out_fail;
+ root_inode->i_ino = MSDOS_ROOT_INO;
+ inode_set_iversion(root_inode, 1);
+ error = fat_read_root(root_inode);
+ if (error < 0) {
+ iput(root_inode);
+ goto out_fail;
+ }
+ error = -ENOMEM;
+ insert_inode_hash(root_inode);
+ fat_attach(root_inode, 0);
+ sb->s_root = d_make_root(root_inode);
+ if (!sb->s_root) {
+ fat_msg(sb, KERN_ERR, "get root inode failed");
+ goto out_fail;
+ }
+
+ if (sbi->options.discard) {
+ struct request_queue *q = bdev_get_queue(sb->s_bdev);
+ if (!blk_queue_discard(q))
+ fat_msg(sb, KERN_WARNING,
+ "mounting with \"discard\" option, but "
+ "the device does not support discard");
+ }
+
+ fat_set_state(sb, 1, 0);
+ return 0;
+
+out_invalid:
+ error = -EINVAL;
+ if (!silent)
+ fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");
+
+out_fail:
+ if (fsinfo_inode)
+ iput(fsinfo_inode);
+ if (fat_inode)
+ iput(fat_inode);
+ unload_nls(sbi->nls_io);
+ unload_nls(sbi->nls_disk);
+ fat_reset_iocharset(&sbi->options);
+ sb->s_fs_info = NULL;
+ kfree(sbi);
+ return error;
+}
+
+EXPORT_SYMBOL_GPL(fat_fill_super);
+
+/*
+ * helper function for fat_flush_inodes. This writes both the inode
+ * and the file data blocks, waiting for in flight data blocks before
+ * the start of the call. It does not wait for any io started
+ * during the call
+ */
+static int writeback_inode(struct inode *inode)
+{
+
+ int ret;
+
+ /* if we used wait=1, sync_inode_metadata waits for the io for the
+ * inode to finish. So wait=0 is sent down to sync_inode_metadata
+ * and filemap_fdatawrite is used for the data blocks
+ */
+ ret = sync_inode_metadata(inode, 0);
+ if (!ret)
+ ret = filemap_fdatawrite(inode->i_mapping);
+ return ret;
+}
+
+/*
+ * write data and metadata corresponding to i1 and i2. The io is
+ * started but we do not wait for any of it to finish.
+ *
+ * filemap_flush is used for the block device, so if there is a dirty
+ * page for a block already in flight, we will not wait and start the
+ * io over again
+ */
+int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
+{
+ int ret = 0;
+ if (!MSDOS_SB(sb)->options.flush)
+ return 0;
+ if (i1)
+ ret = writeback_inode(i1);
+ if (!ret && i2)
+ ret = writeback_inode(i2);
+ if (!ret) {
+ struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
+ ret = filemap_flush(mapping);
+ }
+ return ret;
+}
+EXPORT_SYMBOL_GPL(fat_flush_inodes);
+
+static int __init init_fat_fs(void)
+{
+ int err;
+
+ err = fat_cache_init();
+ if (err)
+ return err;
+
+ err = fat_init_inodecache();
+ if (err)
+ goto failed;
+
+ return 0;
+
+failed:
+ fat_cache_destroy();
+ return err;
+}
+
+static void __exit exit_fat_fs(void)
+{
+ fat_cache_destroy();
+ fat_destroy_inodecache();
+}
+
+module_init(init_fat_fs)
+module_exit(exit_fat_fs)
+
+MODULE_LICENSE("GPL");