*/
#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/time.h>
-#include <linux/slab.h>
-#include <linux/seq_file.h>
#include <linux/pagemap.h>
#include <linux/mpage.h>
-#include <linux/buffer_head.h>
-#include <linux/mount.h>
-#include <linux/aio.h>
#include <linux/vfs.h>
+#include <linux/seq_file.h>
#include <linux/parser.h>
#include <linux/uio.h>
-#include <linux/writeback.h>
-#include <linux/log2.h>
-#include <linux/hash.h>
#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
#include <asm/unaligned.h>
#include "fat.h"
#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,
+},
+};
static int fat_add_cluster(struct inode *inode)
{
struct inode *inode = mapping->host;
if (to > inode->i_size) {
- truncate_pagecache(inode, to, inode->i_size);
+ truncate_pagecache(inode, inode->i_size);
fat_truncate_blocks(inode, inode->i_size);
}
}
return err;
}
-static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
- const struct iovec *iov,
- loff_t offset, unsigned long nr_segs)
+static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
+ loff_t offset)
{
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);
ssize_t ret;
- if (rw == WRITE) {
+ 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.
*
* Return 0, and fallback to normal buffered write.
*/
- loff_t size = offset + iov_length(iov, nr_segs);
+ 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(rw, iocb, inode, iov, offset, nr_segs,
- fat_get_block);
- if (ret < 0 && (rw & WRITE))
- fat_write_failed(mapping, offset + iov_length(iov, nr_segs));
+ ret = blockdev_direct_IO(iocb, inode, iter, offset, fat_get_block);
+ if (ret < 0 && iov_iter_rw(iter) == WRITE)
+ fat_write_failed(mapping, offset + count);
return ret;
}
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,
static int is_exec(unsigned char *extension)
{
- unsigned char *exe_extensions = "EXECOMBAT", *walk;
+ unsigned char exe_extensions[] = "EXECOMBAT", *walk;
for (walk = exe_extensions; *walk; walk += 3)
if (!strncmp(extension, walk, 3))
static void fat_evict_inode(struct inode *inode)
{
- truncate_inode_pages(&inode->i_data, 0);
+ truncate_inode_pages_final(&inode->i_data);
if (!inode->i_nlink) {
inode->i_size = 0;
fat_truncate_blocks(inode, 0);
{
struct buffer_head *bh;
struct fat_boot_sector *b;
- struct msdos_sb_info *sbi = sb->s_fs_info;
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
/* do not change any thing if mounted read only */
if ((sb->s_flags & MS_RDONLY) && !force)
brelse(bh);
}
+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);
+ if (sbi->options.iocharset != fat_default_iocharset)
+ kfree(sbi->options.iocharset);
+ kfree(sbi);
+}
+
static void fat_put_super(struct super_block *sb)
{
struct msdos_sb_info *sbi = MSDOS_SB(sb);
iput(sbi->fsinfo_inode);
iput(sbi->fat_inode);
- unload_nls(sbi->nls_disk);
- unload_nls(sbi->nls_io);
-
- if (sbi->options.iocharset != fat_default_iocharset)
- kfree(sbi->options.iocharset);
-
- sb->s_fs_info = NULL;
- kfree(sbi);
+ call_rcu(&sbi->rcu, delayed_free);
}
static struct kmem_cache *fat_inode_cachep;
seq_puts(m, ",nfs=stale_rw");
if (opts->discard)
seq_puts(m, ",discard");
+ if (opts->dos1xfloppy)
+ seq_puts(m, ",dos1xfloppy");
return 0;
}
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_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy,
};
static const match_table_t fat_tokens = {
{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"},
case Opt_nfs_nostale_ro:
opts->nfs = FAT_NFS_NOSTALE_RO;
break;
+ case Opt_dos1xfloppy:
+ opts->dos1xfloppy = 1;
+ break;
/* msdos specific */
case Opt_dots:
static int fat_read_root(struct inode *inode)
{
- struct super_block *sb = inode->i_sb;
- struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
int error;
MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO;
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.
*/
struct inode *root_inode = NULL, *fat_inode = NULL;
struct inode *fsinfo_inode = NULL;
struct buffer_head *bh;
- struct fat_boot_sector *b;
- struct fat_boot_bsx *bsx;
+ 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;
- unsigned int media;
long error;
char buf[50];
goto out_fail;
}
- b = (struct fat_boot_sector *) bh->b_data;
- if (!b->reserved) {
- if (!silent)
- fat_msg(sb, KERN_ERR, "bogus number of reserved sectors");
- brelse(bh);
- goto out_invalid;
- }
- if (!b->fats) {
- if (!silent)
- fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
- brelse(bh);
- goto out_invalid;
- }
-
- /*
- * Earlier we checked here that b->secs_track and b->head are nonzero,
- * but it turns out valid FAT filesystems can have zero there.
- */
+ 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);
- media = b->media;
- if (!fat_valid_media(media)) {
- if (!silent)
- fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
- media);
- brelse(bh);
- goto out_invalid;
- }
- logical_sector_size = get_unaligned_le16(&b->sector_size);
- if (!is_power_of_2(logical_sector_size)
- || (logical_sector_size < 512)
- || (logical_sector_size > 4096)) {
- if (!silent)
- fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
- logical_sector_size);
- brelse(bh);
- goto out_invalid;
- }
- sbi->sec_per_clus = b->sec_per_clus;
- if (!is_power_of_2(sbi->sec_per_clus)) {
- if (!silent)
- fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
- sbi->sec_per_clus);
- 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);
- brelse(bh);
goto out_fail;
}
+
if (logical_sector_size > sb->s_blocksize) {
- brelse(bh);
+ 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;
}
- bh = sb_bread(sb, 0);
- if (bh == NULL) {
+
+ /* 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;
}
- b = (struct fat_boot_sector *) bh->b_data;
+ 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 = b->fats;
+ sbi->fats = bpb.fat_fats;
sbi->fat_bits = 0; /* Don't know yet */
- sbi->fat_start = le16_to_cpu(b->reserved);
- sbi->fat_length = le16_to_cpu(b->fat_length);
+ 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 && b->fat32.length) {
+ 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 = le32_to_cpu(b->fat32.length);
- sbi->root_cluster = le32_to_cpu(b->fat32.root_cluster);
+ 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 = le16_to_cpu(b->fat32.info_sector);
+ sbi->fsinfo_sector = bpb.fat32_info_sector;
if (sbi->fsinfo_sector == 0)
sbi->fsinfo_sector = 1;
if (fsinfo_bh == NULL) {
fat_msg(sb, KERN_ERR, "bread failed, FSINFO block"
" (sector = %lu)", sbi->fsinfo_sector);
- brelse(bh);
goto out_fail;
}
- bsx = (struct fat_boot_bsx *)(bh->b_data + FAT32_BSX_OFFSET);
-
fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
if (!IS_FSINFO(fsinfo)) {
fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
}
brelse(fsinfo_bh);
- } else {
- bsx = (struct fat_boot_bsx *)(bh->b_data + FAT16_BSX_OFFSET);
}
/* interpret volume ID as a little endian 32 bit integer */
- sbi->vol_id = (((u32)bsx->vol_id[0]) | ((u32)bsx->vol_id[1] << 8) |
- ((u32)bsx->vol_id[2] << 16) | ((u32)bsx->vol_id[3] << 24));
+ 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 = get_unaligned_le16(&b->dir_entries);
+ sbi->dir_entries = bpb.fat_dir_entries;
if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
if (!silent)
fat_msg(sb, KERN_ERR, "bogus directory-entries per block"
" (%u)", sbi->dir_entries);
- brelse(bh);
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 = get_unaligned_le16(&b->sectors);
+ total_sectors = bpb.fat_sectors;
if (total_sectors == 0)
- total_sectors = le32_to_cpu(b->total_sect);
+ total_sectors = bpb.fat_total_sect;
total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
/* some OSes set FAT_STATE_DIRTY and clean it on unmount. */
if (sbi->fat_bits == 32)
- sbi->dirty = b->fat32.state & FAT_STATE_DIRTY;
+ sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY;
else /* fat 16 or 12 */
- sbi->dirty = b->fat16.state & FAT_STATE_DIRTY;
+ sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY;
/* check that FAT table does not overflow */
fat_clusters = calc_fat_clusters(sb);
if (!silent)
fat_msg(sb, KERN_ERR, "count of clusters too big (%u)",
total_clusters);
- brelse(bh);
goto out_invalid;
}
if (sbi->prev_free < FAT_START_ENT)
sbi->prev_free = FAT_START_ENT;
- brelse(bh);
-
/* set up enough so that it can read an inode */
fat_hash_init(sb);
dir_hash_init(sb);
projects / firefly-linux-kernel-4.4.55.git / blobdiff