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Merge tag 'exfat-for-6.8-rc1' of git://git.kernel.org/pub/scm/linux/k…
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…ernel/git/linkinjeon/exfat

Pull exfat updates from Namjae Jeon:

 - Replace the internal table lookup algorithm with the hweight library
   and ffs of the bitops library.

 - Handle the two types of stream entry, valid data size (has been
   written) and data size separately. It improves compatibility with two
   differently sized files created on Windows.

* tag 'exfat-for-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat:
  exfat: do not zero the extended part
  exfat: change to get file size from DataLength
  exfat: using ffs instead of internal logic
  exfat: using hweight instead of internal logic
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@torvalds
torvalds committed Jan 13, 2024
2 parents f16ab99 + f55c096 commit 052d534
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87 changes: 35 additions & 52 deletions fs/exfat/balloc.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -5,42 +5,23 @@

#include <linux/blkdev.h>
#include <linux/slab.h>
#include <linux/bitmap.h>
#include <linux/buffer_head.h>

#include "exfat_raw.h"
#include "exfat_fs.h"

static const unsigned char free_bit[] = {
0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2,/* 0 ~ 19*/
0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5, 0, 1, 0, 2, 0, 1, 0, 3,/* 20 ~ 39*/
0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2,/* 40 ~ 59*/
0, 1, 0, 6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4,/* 60 ~ 79*/
0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5, 0, 1, 0, 2,/* 80 ~ 99*/
0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3,/*100 ~ 119*/
0, 1, 0, 2, 0, 1, 0, 7, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2,/*120 ~ 139*/
0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5,/*140 ~ 159*/
0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2,/*160 ~ 179*/
0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 6, 0, 1, 0, 2, 0, 1, 0, 3,/*180 ~ 199*/
0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2,/*200 ~ 219*/
0, 1, 0, 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4,/*220 ~ 239*/
0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0 /*240 ~ 254*/
};

static const unsigned char used_bit[] = {
0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, 1, 2, 2, 3,/* 0 ~ 19*/
2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 1, 2, 2, 3, 2, 3, 3, 4,/* 20 ~ 39*/
2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5,/* 40 ~ 59*/
4, 5, 5, 6, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5,/* 60 ~ 79*/
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 2, 3, 3, 4,/* 80 ~ 99*/
3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6,/*100 ~ 119*/
4, 5, 5, 6, 5, 6, 6, 7, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4,/*120 ~ 139*/
3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6,/*140 ~ 159*/
2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5,/*160 ~ 179*/
4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 2, 3, 3, 4, 3, 4, 4, 5,/*180 ~ 199*/
3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6,/*200 ~ 219*/
5, 6, 6, 7, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7,/*220 ~ 239*/
4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8 /*240 ~ 255*/
};
#if BITS_PER_LONG == 32
#define __le_long __le32
#define lel_to_cpu(A) le32_to_cpu(A)
#define cpu_to_lel(A) cpu_to_le32(A)
#elif BITS_PER_LONG == 64
#define __le_long __le64
#define lel_to_cpu(A) le64_to_cpu(A)
#define cpu_to_lel(A) cpu_to_le64(A)
#else
#error "BITS_PER_LONG not 32 or 64"
#endif

/*
* Allocation Bitmap Management Functions
Expand Down Expand Up @@ -200,32 +181,35 @@ unsigned int exfat_find_free_bitmap(struct super_block *sb, unsigned int clu)
{
unsigned int i, map_i, map_b, ent_idx;
unsigned int clu_base, clu_free;
unsigned char k, clu_mask;
unsigned long clu_bits, clu_mask;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
__le_long bitval;

WARN_ON(clu < EXFAT_FIRST_CLUSTER);
ent_idx = CLUSTER_TO_BITMAP_ENT(clu);
clu_base = BITMAP_ENT_TO_CLUSTER(ent_idx & ~(BITS_PER_BYTE_MASK));
ent_idx = ALIGN_DOWN(CLUSTER_TO_BITMAP_ENT(clu), BITS_PER_LONG);
clu_base = BITMAP_ENT_TO_CLUSTER(ent_idx);
clu_mask = IGNORED_BITS_REMAINED(clu, clu_base);

map_i = BITMAP_OFFSET_SECTOR_INDEX(sb, ent_idx);
map_b = BITMAP_OFFSET_BYTE_IN_SECTOR(sb, ent_idx);

for (i = EXFAT_FIRST_CLUSTER; i < sbi->num_clusters;
i += BITS_PER_BYTE) {
k = *(sbi->vol_amap[map_i]->b_data + map_b);
i += BITS_PER_LONG) {
bitval = *(__le_long *)(sbi->vol_amap[map_i]->b_data + map_b);
if (clu_mask > 0) {
k |= clu_mask;
bitval |= cpu_to_lel(clu_mask);
clu_mask = 0;
}
if (k < 0xFF) {
clu_free = clu_base + free_bit[k];
if (lel_to_cpu(bitval) != ULONG_MAX) {
clu_bits = lel_to_cpu(bitval);
clu_free = clu_base + ffz(clu_bits);
if (clu_free < sbi->num_clusters)
return clu_free;
}
clu_base += BITS_PER_BYTE;
clu_base += BITS_PER_LONG;
map_b += sizeof(long);

if (++map_b >= sb->s_blocksize ||
if (map_b >= sb->s_blocksize ||
clu_base >= sbi->num_clusters) {
if (++map_i >= sbi->map_sectors) {
clu_base = EXFAT_FIRST_CLUSTER;
Expand All @@ -244,25 +228,24 @@ int exfat_count_used_clusters(struct super_block *sb, unsigned int *ret_count)
unsigned int count = 0;
unsigned int i, map_i = 0, map_b = 0;
unsigned int total_clus = EXFAT_DATA_CLUSTER_COUNT(sbi);
unsigned int last_mask = total_clus & BITS_PER_BYTE_MASK;
unsigned char clu_bits;
const unsigned char last_bit_mask[] = {0, 0b00000001, 0b00000011,
0b00000111, 0b00001111, 0b00011111, 0b00111111, 0b01111111};
unsigned int last_mask = total_clus & (BITS_PER_LONG - 1);
unsigned long *bitmap, clu_bits;

total_clus &= ~last_mask;
for (i = 0; i < total_clus; i += BITS_PER_BYTE) {
clu_bits = *(sbi->vol_amap[map_i]->b_data + map_b);
count += used_bit[clu_bits];
if (++map_b >= (unsigned int)sb->s_blocksize) {
for (i = 0; i < total_clus; i += BITS_PER_LONG) {
bitmap = (void *)(sbi->vol_amap[map_i]->b_data + map_b);
count += hweight_long(*bitmap);
map_b += sizeof(long);
if (map_b >= (unsigned int)sb->s_blocksize) {
map_i++;
map_b = 0;
}
}

if (last_mask) {
clu_bits = *(sbi->vol_amap[map_i]->b_data + map_b);
clu_bits &= last_bit_mask[last_mask];
count += used_bit[clu_bits];
bitmap = (void *)(sbi->vol_amap[map_i]->b_data + map_b);
clu_bits = lel_to_cpu(*(__le_long *)bitmap);
count += hweight_long(clu_bits & BITMAP_LAST_WORD_MASK(last_mask));
}

*ret_count = count;
Expand Down
5 changes: 3 additions & 2 deletions fs/exfat/exfat_fs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -135,8 +135,7 @@ enum {
#define BITMAP_OFFSET_BIT_IN_SECTOR(sb, ent) (ent & BITS_PER_SECTOR_MASK(sb))
#define BITMAP_OFFSET_BYTE_IN_SECTOR(sb, ent) \
((ent / BITS_PER_BYTE) & ((sb)->s_blocksize - 1))
#define BITS_PER_BYTE_MASK 0x7
#define IGNORED_BITS_REMAINED(clu, clu_base) ((1 << ((clu) - (clu_base))) - 1)
#define IGNORED_BITS_REMAINED(clu, clu_base) ((1UL << ((clu) - (clu_base))) - 1)

#define ES_ENTRY_NUM(name_len) (ES_IDX_LAST_FILENAME(name_len) + 1)
/* 19 entries = 1 file entry + 1 stream entry + 17 filename entries */
Expand Down Expand Up @@ -208,6 +207,7 @@ struct exfat_dir_entry {
unsigned char flags;
unsigned short attr;
loff_t size;
loff_t valid_size;
unsigned int num_subdirs;
struct timespec64 atime;
struct timespec64 mtime;
Expand Down Expand Up @@ -317,6 +317,7 @@ struct exfat_inode_info {
loff_t i_size_aligned;
/* on-disk position of directory entry or 0 */
loff_t i_pos;
loff_t valid_size;
/* hash by i_location */
struct hlist_node i_hash_fat;
/* protect bmap against truncate */
Expand Down
193 changes: 172 additions & 21 deletions fs/exfat/file.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -11,37 +11,76 @@
#include <linux/fsnotify.h>
#include <linux/security.h>
#include <linux/msdos_fs.h>
#include <linux/writeback.h>

#include "exfat_raw.h"
#include "exfat_fs.h"

static int exfat_cont_expand(struct inode *inode, loff_t size)
{
struct address_space *mapping = inode->i_mapping;
loff_t start = i_size_read(inode), count = size - i_size_read(inode);
int err, err2;
int ret;
unsigned int num_clusters, new_num_clusters, last_clu;
struct exfat_inode_info *ei = EXFAT_I(inode);
struct super_block *sb = inode->i_sb;
struct exfat_sb_info *sbi = EXFAT_SB(sb);
struct exfat_chain clu;

err = generic_cont_expand_simple(inode, size);
if (err)
return err;
ret = inode_newsize_ok(inode, size);
if (ret)
return ret;

num_clusters = EXFAT_B_TO_CLU_ROUND_UP(ei->i_size_ondisk, sbi);
new_num_clusters = EXFAT_B_TO_CLU_ROUND_UP(size, sbi);

if (new_num_clusters == num_clusters)
goto out;

exfat_chain_set(&clu, ei->start_clu, num_clusters, ei->flags);
ret = exfat_find_last_cluster(sb, &clu, &last_clu);
if (ret)
return ret;

clu.dir = (last_clu == EXFAT_EOF_CLUSTER) ?
EXFAT_EOF_CLUSTER : last_clu + 1;
clu.size = 0;
clu.flags = ei->flags;

ret = exfat_alloc_cluster(inode, new_num_clusters - num_clusters,
&clu, IS_DIRSYNC(inode));
if (ret)
return ret;

/* Append new clusters to chain */
if (clu.flags != ei->flags) {
exfat_chain_cont_cluster(sb, ei->start_clu, num_clusters);
ei->flags = ALLOC_FAT_CHAIN;
}
if (clu.flags == ALLOC_FAT_CHAIN)
if (exfat_ent_set(sb, last_clu, clu.dir))
goto free_clu;

if (num_clusters == 0)
ei->start_clu = clu.dir;

out:
inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
mark_inode_dirty(inode);
/* Expanded range not zeroed, do not update valid_size */
i_size_write(inode, size);

if (!IS_SYNC(inode))
return 0;
ei->i_size_aligned = round_up(size, sb->s_blocksize);
ei->i_size_ondisk = ei->i_size_aligned;
inode->i_blocks = round_up(size, sbi->cluster_size) >> 9;

err = filemap_fdatawrite_range(mapping, start, start + count - 1);
err2 = sync_mapping_buffers(mapping);
if (!err)
err = err2;
err2 = write_inode_now(inode, 1);
if (!err)
err = err2;
if (err)
return err;
if (IS_DIRSYNC(inode))
return write_inode_now(inode, 1);

mark_inode_dirty(inode);

return filemap_fdatawait_range(mapping, start, start + count - 1);
return 0;

free_clu:
exfat_free_cluster(inode, &clu);
return -EIO;
}

static bool exfat_allow_set_time(struct exfat_sb_info *sbi, struct inode *inode)
Expand Down Expand Up @@ -146,6 +185,9 @@ int __exfat_truncate(struct inode *inode)
ei->start_clu = EXFAT_EOF_CLUSTER;
}

if (i_size_read(inode) < ei->valid_size)
ei->valid_size = i_size_read(inode);

if (ei->type == TYPE_FILE)
ei->attr |= EXFAT_ATTR_ARCHIVE;

Expand Down Expand Up @@ -474,15 +516,124 @@ int exfat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
return blkdev_issue_flush(inode->i_sb->s_bdev);
}

static int exfat_file_zeroed_range(struct file *file, loff_t start, loff_t end)
{
int err;
struct inode *inode = file_inode(file);
struct address_space *mapping = inode->i_mapping;
const struct address_space_operations *ops = mapping->a_ops;

while (start < end) {
u32 zerofrom, len;
struct page *page = NULL;

zerofrom = start & (PAGE_SIZE - 1);
len = PAGE_SIZE - zerofrom;
if (start + len > end)
len = end - start;

err = ops->write_begin(file, mapping, start, len, &page, NULL);
if (err)
goto out;

zero_user_segment(page, zerofrom, zerofrom + len);

err = ops->write_end(file, mapping, start, len, len, page, NULL);
if (err < 0)
goto out;
start += len;

balance_dirty_pages_ratelimited(mapping);
cond_resched();
}

out:
return err;
}

static ssize_t exfat_file_write_iter(struct kiocb *iocb, struct iov_iter *iter)
{
ssize_t ret;
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
struct exfat_inode_info *ei = EXFAT_I(inode);
loff_t pos = iocb->ki_pos;
loff_t valid_size;

inode_lock(inode);

valid_size = ei->valid_size;

ret = generic_write_checks(iocb, iter);
if (ret < 0)
goto unlock;

if (pos > valid_size) {
ret = exfat_file_zeroed_range(file, valid_size, pos);
if (ret < 0 && ret != -ENOSPC) {
exfat_err(inode->i_sb,
"write: fail to zero from %llu to %llu(%zd)",
valid_size, pos, ret);
}
if (ret < 0)
goto unlock;
}

ret = __generic_file_write_iter(iocb, iter);
if (ret < 0)
goto unlock;

inode_unlock(inode);

if (pos > valid_size)
pos = valid_size;

if (iocb_is_dsync(iocb) && iocb->ki_pos > pos) {
ssize_t err = vfs_fsync_range(file, pos, iocb->ki_pos - 1,
iocb->ki_flags & IOCB_SYNC);
if (err < 0)
return err;
}

return ret;

unlock:
inode_unlock(inode);

return ret;
}

static int exfat_file_mmap(struct file *file, struct vm_area_struct *vma)
{
int ret;
struct inode *inode = file_inode(file);
struct exfat_inode_info *ei = EXFAT_I(inode);
loff_t start = ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
loff_t end = min_t(loff_t, i_size_read(inode),
start + vma->vm_end - vma->vm_start);

if ((vma->vm_flags & VM_WRITE) && ei->valid_size < end) {
ret = exfat_file_zeroed_range(file, ei->valid_size, end);
if (ret < 0) {
exfat_err(inode->i_sb,
"mmap: fail to zero from %llu to %llu(%d)",
start, end, ret);
return ret;
}
}

return generic_file_mmap(file, vma);
}

const struct file_operations exfat_file_operations = {
.llseek = generic_file_llseek,
.read_iter = generic_file_read_iter,
.write_iter = generic_file_write_iter,
.write_iter = exfat_file_write_iter,
.unlocked_ioctl = exfat_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = exfat_compat_ioctl,
#endif
.mmap = generic_file_mmap,
.mmap = exfat_file_mmap,
.fsync = exfat_file_fsync,
.splice_read = filemap_splice_read,
.splice_write = iter_file_splice_write,
Expand Down
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