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-rw-r--r--fs/affs/file.c982
1 files changed, 982 insertions, 0 deletions
diff --git a/fs/affs/file.c b/fs/affs/file.c
new file mode 100644
index 000000000..659c579c4
--- /dev/null
+++ b/fs/affs/file.c
@@ -0,0 +1,982 @@
+/*
+ * linux/fs/affs/file.c
+ *
+ * (c) 1996 Hans-Joachim Widmaier - Rewritten
+ *
+ * (C) 1993 Ray Burr - Modified for Amiga FFS filesystem.
+ *
+ * (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem.
+ *
+ * (C) 1991 Linus Torvalds - minix filesystem
+ *
+ * affs regular file handling primitives
+ */
+
+#include <linux/uio.h>
+#include "affs.h"
+
+static struct buffer_head *affs_get_extblock_slow(struct inode *inode, u32 ext);
+
+static int
+affs_file_open(struct inode *inode, struct file *filp)
+{
+ pr_debug("open(%lu,%d)\n",
+ inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
+ atomic_inc(&AFFS_I(inode)->i_opencnt);
+ return 0;
+}
+
+static int
+affs_file_release(struct inode *inode, struct file *filp)
+{
+ pr_debug("release(%lu, %d)\n",
+ inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
+
+ if (atomic_dec_and_test(&AFFS_I(inode)->i_opencnt)) {
+ mutex_lock(&inode->i_mutex);
+ if (inode->i_size != AFFS_I(inode)->mmu_private)
+ affs_truncate(inode);
+ affs_free_prealloc(inode);
+ mutex_unlock(&inode->i_mutex);
+ }
+
+ return 0;
+}
+
+static int
+affs_grow_extcache(struct inode *inode, u32 lc_idx)
+{
+ struct super_block *sb = inode->i_sb;
+ struct buffer_head *bh;
+ u32 lc_max;
+ int i, j, key;
+
+ if (!AFFS_I(inode)->i_lc) {
+ char *ptr = (char *)get_zeroed_page(GFP_NOFS);
+ if (!ptr)
+ return -ENOMEM;
+ AFFS_I(inode)->i_lc = (u32 *)ptr;
+ AFFS_I(inode)->i_ac = (struct affs_ext_key *)(ptr + AFFS_CACHE_SIZE / 2);
+ }
+
+ lc_max = AFFS_LC_SIZE << AFFS_I(inode)->i_lc_shift;
+
+ if (AFFS_I(inode)->i_extcnt > lc_max) {
+ u32 lc_shift, lc_mask, tmp, off;
+
+ /* need to recalculate linear cache, start from old size */
+ lc_shift = AFFS_I(inode)->i_lc_shift;
+ tmp = (AFFS_I(inode)->i_extcnt / AFFS_LC_SIZE) >> lc_shift;
+ for (; tmp; tmp >>= 1)
+ lc_shift++;
+ lc_mask = (1 << lc_shift) - 1;
+
+ /* fix idx and old size to new shift */
+ lc_idx >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
+ AFFS_I(inode)->i_lc_size >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
+
+ /* first shrink old cache to make more space */
+ off = 1 << (lc_shift - AFFS_I(inode)->i_lc_shift);
+ for (i = 1, j = off; j < AFFS_LC_SIZE; i++, j += off)
+ AFFS_I(inode)->i_ac[i] = AFFS_I(inode)->i_ac[j];
+
+ AFFS_I(inode)->i_lc_shift = lc_shift;
+ AFFS_I(inode)->i_lc_mask = lc_mask;
+ }
+
+ /* fill cache to the needed index */
+ i = AFFS_I(inode)->i_lc_size;
+ AFFS_I(inode)->i_lc_size = lc_idx + 1;
+ for (; i <= lc_idx; i++) {
+ if (!i) {
+ AFFS_I(inode)->i_lc[0] = inode->i_ino;
+ continue;
+ }
+ key = AFFS_I(inode)->i_lc[i - 1];
+ j = AFFS_I(inode)->i_lc_mask + 1;
+ // unlock cache
+ for (; j > 0; j--) {
+ bh = affs_bread(sb, key);
+ if (!bh)
+ goto err;
+ key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
+ affs_brelse(bh);
+ }
+ // lock cache
+ AFFS_I(inode)->i_lc[i] = key;
+ }
+
+ return 0;
+
+err:
+ // lock cache
+ return -EIO;
+}
+
+static struct buffer_head *
+affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext)
+{
+ struct super_block *sb = inode->i_sb;
+ struct buffer_head *new_bh;
+ u32 blocknr, tmp;
+
+ blocknr = affs_alloc_block(inode, bh->b_blocknr);
+ if (!blocknr)
+ return ERR_PTR(-ENOSPC);
+
+ new_bh = affs_getzeroblk(sb, blocknr);
+ if (!new_bh) {
+ affs_free_block(sb, blocknr);
+ return ERR_PTR(-EIO);
+ }
+
+ AFFS_HEAD(new_bh)->ptype = cpu_to_be32(T_LIST);
+ AFFS_HEAD(new_bh)->key = cpu_to_be32(blocknr);
+ AFFS_TAIL(sb, new_bh)->stype = cpu_to_be32(ST_FILE);
+ AFFS_TAIL(sb, new_bh)->parent = cpu_to_be32(inode->i_ino);
+ affs_fix_checksum(sb, new_bh);
+
+ mark_buffer_dirty_inode(new_bh, inode);
+
+ tmp = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
+ if (tmp)
+ affs_warning(sb, "alloc_ext", "previous extension set (%x)", tmp);
+ AFFS_TAIL(sb, bh)->extension = cpu_to_be32(blocknr);
+ affs_adjust_checksum(bh, blocknr - tmp);
+ mark_buffer_dirty_inode(bh, inode);
+
+ AFFS_I(inode)->i_extcnt++;
+ mark_inode_dirty(inode);
+
+ return new_bh;
+}
+
+static inline struct buffer_head *
+affs_get_extblock(struct inode *inode, u32 ext)
+{
+ /* inline the simplest case: same extended block as last time */
+ struct buffer_head *bh = AFFS_I(inode)->i_ext_bh;
+ if (ext == AFFS_I(inode)->i_ext_last)
+ get_bh(bh);
+ else
+ /* we have to do more (not inlined) */
+ bh = affs_get_extblock_slow(inode, ext);
+
+ return bh;
+}
+
+static struct buffer_head *
+affs_get_extblock_slow(struct inode *inode, u32 ext)
+{
+ struct super_block *sb = inode->i_sb;
+ struct buffer_head *bh;
+ u32 ext_key;
+ u32 lc_idx, lc_off, ac_idx;
+ u32 tmp, idx;
+
+ if (ext == AFFS_I(inode)->i_ext_last + 1) {
+ /* read the next extended block from the current one */
+ bh = AFFS_I(inode)->i_ext_bh;
+ ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
+ if (ext < AFFS_I(inode)->i_extcnt)
+ goto read_ext;
+ BUG_ON(ext > AFFS_I(inode)->i_extcnt);
+ bh = affs_alloc_extblock(inode, bh, ext);
+ if (IS_ERR(bh))
+ return bh;
+ goto store_ext;
+ }
+
+ if (ext == 0) {
+ /* we seek back to the file header block */
+ ext_key = inode->i_ino;
+ goto read_ext;
+ }
+
+ if (ext >= AFFS_I(inode)->i_extcnt) {
+ struct buffer_head *prev_bh;
+
+ /* allocate a new extended block */
+ BUG_ON(ext > AFFS_I(inode)->i_extcnt);
+
+ /* get previous extended block */
+ prev_bh = affs_get_extblock(inode, ext - 1);
+ if (IS_ERR(prev_bh))
+ return prev_bh;
+ bh = affs_alloc_extblock(inode, prev_bh, ext);
+ affs_brelse(prev_bh);
+ if (IS_ERR(bh))
+ return bh;
+ goto store_ext;
+ }
+
+again:
+ /* check if there is an extended cache and whether it's large enough */
+ lc_idx = ext >> AFFS_I(inode)->i_lc_shift;
+ lc_off = ext & AFFS_I(inode)->i_lc_mask;
+
+ if (lc_idx >= AFFS_I(inode)->i_lc_size) {
+ int err;
+
+ err = affs_grow_extcache(inode, lc_idx);
+ if (err)
+ return ERR_PTR(err);
+ goto again;
+ }
+
+ /* every n'th key we find in the linear cache */
+ if (!lc_off) {
+ ext_key = AFFS_I(inode)->i_lc[lc_idx];
+ goto read_ext;
+ }
+
+ /* maybe it's still in the associative cache */
+ ac_idx = (ext - lc_idx - 1) & AFFS_AC_MASK;
+ if (AFFS_I(inode)->i_ac[ac_idx].ext == ext) {
+ ext_key = AFFS_I(inode)->i_ac[ac_idx].key;
+ goto read_ext;
+ }
+
+ /* try to find one of the previous extended blocks */
+ tmp = ext;
+ idx = ac_idx;
+ while (--tmp, --lc_off > 0) {
+ idx = (idx - 1) & AFFS_AC_MASK;
+ if (AFFS_I(inode)->i_ac[idx].ext == tmp) {
+ ext_key = AFFS_I(inode)->i_ac[idx].key;
+ goto find_ext;
+ }
+ }
+
+ /* fall back to the linear cache */
+ ext_key = AFFS_I(inode)->i_lc[lc_idx];
+find_ext:
+ /* read all extended blocks until we find the one we need */
+ //unlock cache
+ do {
+ bh = affs_bread(sb, ext_key);
+ if (!bh)
+ goto err_bread;
+ ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
+ affs_brelse(bh);
+ tmp++;
+ } while (tmp < ext);
+ //lock cache
+
+ /* store it in the associative cache */
+ // recalculate ac_idx?
+ AFFS_I(inode)->i_ac[ac_idx].ext = ext;
+ AFFS_I(inode)->i_ac[ac_idx].key = ext_key;
+
+read_ext:
+ /* finally read the right extended block */
+ //unlock cache
+ bh = affs_bread(sb, ext_key);
+ if (!bh)
+ goto err_bread;
+ //lock cache
+
+store_ext:
+ /* release old cached extended block and store the new one */
+ affs_brelse(AFFS_I(inode)->i_ext_bh);
+ AFFS_I(inode)->i_ext_last = ext;
+ AFFS_I(inode)->i_ext_bh = bh;
+ get_bh(bh);
+
+ return bh;
+
+err_bread:
+ affs_brelse(bh);
+ return ERR_PTR(-EIO);
+}
+
+static int
+affs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_result, int create)
+{
+ struct super_block *sb = inode->i_sb;
+ struct buffer_head *ext_bh;
+ u32 ext;
+
+ pr_debug("%s(%lu, %llu)\n", __func__, inode->i_ino,
+ (unsigned long long)block);
+
+ BUG_ON(block > (sector_t)0x7fffffffUL);
+
+ if (block >= AFFS_I(inode)->i_blkcnt) {
+ if (block > AFFS_I(inode)->i_blkcnt || !create)
+ goto err_big;
+ } else
+ create = 0;
+
+ //lock cache
+ affs_lock_ext(inode);
+
+ ext = (u32)block / AFFS_SB(sb)->s_hashsize;
+ block -= ext * AFFS_SB(sb)->s_hashsize;
+ ext_bh = affs_get_extblock(inode, ext);
+ if (IS_ERR(ext_bh))
+ goto err_ext;
+ map_bh(bh_result, sb, (sector_t)be32_to_cpu(AFFS_BLOCK(sb, ext_bh, block)));
+
+ if (create) {
+ u32 blocknr = affs_alloc_block(inode, ext_bh->b_blocknr);
+ if (!blocknr)
+ goto err_alloc;
+ set_buffer_new(bh_result);
+ AFFS_I(inode)->mmu_private += AFFS_SB(sb)->s_data_blksize;
+ AFFS_I(inode)->i_blkcnt++;
+
+ /* store new block */
+ if (bh_result->b_blocknr)
+ affs_warning(sb, "get_block",
+ "block already set (%llx)",
+ (unsigned long long)bh_result->b_blocknr);
+ AFFS_BLOCK(sb, ext_bh, block) = cpu_to_be32(blocknr);
+ AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(block + 1);
+ affs_adjust_checksum(ext_bh, blocknr - bh_result->b_blocknr + 1);
+ bh_result->b_blocknr = blocknr;
+
+ if (!block) {
+ /* insert first block into header block */
+ u32 tmp = be32_to_cpu(AFFS_HEAD(ext_bh)->first_data);
+ if (tmp)
+ affs_warning(sb, "get_block", "first block already set (%d)", tmp);
+ AFFS_HEAD(ext_bh)->first_data = cpu_to_be32(blocknr);
+ affs_adjust_checksum(ext_bh, blocknr - tmp);
+ }
+ }
+
+ affs_brelse(ext_bh);
+ //unlock cache
+ affs_unlock_ext(inode);
+ return 0;
+
+err_big:
+ affs_error(inode->i_sb, "get_block", "strange block request %llu",
+ (unsigned long long)block);
+ return -EIO;
+err_ext:
+ // unlock cache
+ affs_unlock_ext(inode);
+ return PTR_ERR(ext_bh);
+err_alloc:
+ brelse(ext_bh);
+ clear_buffer_mapped(bh_result);
+ bh_result->b_bdev = NULL;
+ // unlock cache
+ affs_unlock_ext(inode);
+ return -ENOSPC;
+}
+
+static int affs_writepage(struct page *page, struct writeback_control *wbc)
+{
+ return block_write_full_page(page, affs_get_block, wbc);
+}
+
+static int affs_readpage(struct file *file, struct page *page)
+{
+ return block_read_full_page(page, affs_get_block);
+}
+
+static void affs_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);
+ affs_truncate(inode);
+ }
+}
+
+static ssize_t
+affs_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 (iov_iter_rw(iter) == WRITE) {
+ loff_t size = offset + count;
+
+ if (AFFS_I(inode)->mmu_private < size)
+ return 0;
+ }
+
+ ret = blockdev_direct_IO(iocb, inode, iter, offset, affs_get_block);
+ if (ret < 0 && iov_iter_rw(iter) == WRITE)
+ affs_write_failed(mapping, offset + count);
+ return ret;
+}
+
+static int affs_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ int ret;
+
+ *pagep = NULL;
+ ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+ affs_get_block,
+ &AFFS_I(mapping->host)->mmu_private);
+ if (unlikely(ret))
+ affs_write_failed(mapping, pos + len);
+
+ return ret;
+}
+
+static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
+{
+ return generic_block_bmap(mapping,block,affs_get_block);
+}
+
+const struct address_space_operations affs_aops = {
+ .readpage = affs_readpage,
+ .writepage = affs_writepage,
+ .write_begin = affs_write_begin,
+ .write_end = generic_write_end,
+ .direct_IO = affs_direct_IO,
+ .bmap = _affs_bmap
+};
+
+static inline struct buffer_head *
+affs_bread_ino(struct inode *inode, int block, int create)
+{
+ struct buffer_head *bh, tmp_bh;
+ int err;
+
+ tmp_bh.b_state = 0;
+ err = affs_get_block(inode, block, &tmp_bh, create);
+ if (!err) {
+ bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr);
+ if (bh) {
+ bh->b_state |= tmp_bh.b_state;
+ return bh;
+ }
+ err = -EIO;
+ }
+ return ERR_PTR(err);
+}
+
+static inline struct buffer_head *
+affs_getzeroblk_ino(struct inode *inode, int block)
+{
+ struct buffer_head *bh, tmp_bh;
+ int err;
+
+ tmp_bh.b_state = 0;
+ err = affs_get_block(inode, block, &tmp_bh, 1);
+ if (!err) {
+ bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr);
+ if (bh) {
+ bh->b_state |= tmp_bh.b_state;
+ return bh;
+ }
+ err = -EIO;
+ }
+ return ERR_PTR(err);
+}
+
+static inline struct buffer_head *
+affs_getemptyblk_ino(struct inode *inode, int block)
+{
+ struct buffer_head *bh, tmp_bh;
+ int err;
+
+ tmp_bh.b_state = 0;
+ err = affs_get_block(inode, block, &tmp_bh, 1);
+ if (!err) {
+ bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr);
+ if (bh) {
+ bh->b_state |= tmp_bh.b_state;
+ return bh;
+ }
+ err = -EIO;
+ }
+ return ERR_PTR(err);
+}
+
+static int
+affs_do_readpage_ofs(struct page *page, unsigned to)
+{
+ struct inode *inode = page->mapping->host;
+ struct super_block *sb = inode->i_sb;
+ struct buffer_head *bh;
+ char *data;
+ unsigned pos = 0;
+ u32 bidx, boff, bsize;
+ u32 tmp;
+
+ pr_debug("%s(%lu, %ld, 0, %d)\n", __func__, inode->i_ino,
+ page->index, to);
+ BUG_ON(to > PAGE_CACHE_SIZE);
+ kmap(page);
+ data = page_address(page);
+ bsize = AFFS_SB(sb)->s_data_blksize;
+ tmp = page->index << PAGE_CACHE_SHIFT;
+ bidx = tmp / bsize;
+ boff = tmp % bsize;
+
+ while (pos < to) {
+ bh = affs_bread_ino(inode, bidx, 0);
+ if (IS_ERR(bh))
+ return PTR_ERR(bh);
+ tmp = min(bsize - boff, to - pos);
+ BUG_ON(pos + tmp > to || tmp > bsize);
+ memcpy(data + pos, AFFS_DATA(bh) + boff, tmp);
+ affs_brelse(bh);
+ bidx++;
+ pos += tmp;
+ boff = 0;
+ }
+ flush_dcache_page(page);
+ kunmap(page);
+ return 0;
+}
+
+static int
+affs_extent_file_ofs(struct inode *inode, u32 newsize)
+{
+ struct super_block *sb = inode->i_sb;
+ struct buffer_head *bh, *prev_bh;
+ u32 bidx, boff;
+ u32 size, bsize;
+ u32 tmp;
+
+ pr_debug("%s(%lu, %d)\n", __func__, inode->i_ino, newsize);
+ bsize = AFFS_SB(sb)->s_data_blksize;
+ bh = NULL;
+ size = AFFS_I(inode)->mmu_private;
+ bidx = size / bsize;
+ boff = size % bsize;
+ if (boff) {
+ bh = affs_bread_ino(inode, bidx, 0);
+ if (IS_ERR(bh))
+ return PTR_ERR(bh);
+ tmp = min(bsize - boff, newsize - size);
+ BUG_ON(boff + tmp > bsize || tmp > bsize);
+ memset(AFFS_DATA(bh) + boff, 0, tmp);
+ be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
+ affs_fix_checksum(sb, bh);
+ mark_buffer_dirty_inode(bh, inode);
+ size += tmp;
+ bidx++;
+ } else if (bidx) {
+ bh = affs_bread_ino(inode, bidx - 1, 0);
+ if (IS_ERR(bh))
+ return PTR_ERR(bh);
+ }
+
+ while (size < newsize) {
+ prev_bh = bh;
+ bh = affs_getzeroblk_ino(inode, bidx);
+ if (IS_ERR(bh))
+ goto out;
+ tmp = min(bsize, newsize - size);
+ BUG_ON(tmp > bsize);
+ AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
+ AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
+ AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
+ AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
+ affs_fix_checksum(sb, bh);
+ bh->b_state &= ~(1UL << BH_New);
+ mark_buffer_dirty_inode(bh, inode);
+ if (prev_bh) {
+ u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
+
+ if (tmp_next)
+ affs_warning(sb, "extent_file_ofs",
+ "next block already set for %d (%d)",
+ bidx, tmp_next);
+ AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
+ affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
+ mark_buffer_dirty_inode(prev_bh, inode);
+ affs_brelse(prev_bh);
+ }
+ size += bsize;
+ bidx++;
+ }
+ affs_brelse(bh);
+ inode->i_size = AFFS_I(inode)->mmu_private = newsize;
+ return 0;
+
+out:
+ inode->i_size = AFFS_I(inode)->mmu_private = newsize;
+ return PTR_ERR(bh);
+}
+
+static int
+affs_readpage_ofs(struct file *file, struct page *page)
+{
+ struct inode *inode = page->mapping->host;
+ u32 to;
+ int err;
+
+ pr_debug("%s(%lu, %ld)\n", __func__, inode->i_ino, page->index);
+ to = PAGE_CACHE_SIZE;
+ if (((page->index + 1) << PAGE_CACHE_SHIFT) > inode->i_size) {
+ to = inode->i_size & ~PAGE_CACHE_MASK;
+ memset(page_address(page) + to, 0, PAGE_CACHE_SIZE - to);
+ }
+
+ err = affs_do_readpage_ofs(page, to);
+ if (!err)
+ SetPageUptodate(page);
+ unlock_page(page);
+ return err;
+}
+
+static int affs_write_begin_ofs(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ struct inode *inode = mapping->host;
+ struct page *page;
+ pgoff_t index;
+ int err = 0;
+
+ pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos,
+ pos + len);
+ if (pos > AFFS_I(inode)->mmu_private) {
+ /* XXX: this probably leaves a too-big i_size in case of
+ * failure. Should really be updating i_size at write_end time
+ */
+ err = affs_extent_file_ofs(inode, pos);
+ if (err)
+ return err;
+ }
+
+ index = pos >> PAGE_CACHE_SHIFT;
+ page = grab_cache_page_write_begin(mapping, index, flags);
+ if (!page)
+ return -ENOMEM;
+ *pagep = page;
+
+ if (PageUptodate(page))
+ return 0;
+
+ /* XXX: inefficient but safe in the face of short writes */
+ err = affs_do_readpage_ofs(page, PAGE_CACHE_SIZE);
+ if (err) {
+ unlock_page(page);
+ page_cache_release(page);
+ }
+ return err;
+}
+
+static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
+{
+ struct inode *inode = mapping->host;
+ struct super_block *sb = inode->i_sb;
+ struct buffer_head *bh, *prev_bh;
+ char *data;
+ u32 bidx, boff, bsize;
+ unsigned from, to;
+ u32 tmp;
+ int written;
+
+ from = pos & (PAGE_CACHE_SIZE - 1);
+ to = pos + len;
+ /*
+ * XXX: not sure if this can handle short copies (len < copied), but
+ * we don't have to, because the page should always be uptodate here,
+ * due to write_begin.
+ */
+
+ pr_debug("%s(%lu, %llu, %llu)\n", __func__, inode->i_ino, pos,
+ pos + len);
+ bsize = AFFS_SB(sb)->s_data_blksize;
+ data = page_address(page);
+
+ bh = NULL;
+ written = 0;
+ tmp = (page->index << PAGE_CACHE_SHIFT) + from;
+ bidx = tmp / bsize;
+ boff = tmp % bsize;
+ if (boff) {
+ bh = affs_bread_ino(inode, bidx, 0);
+ if (IS_ERR(bh)) {
+ written = PTR_ERR(bh);
+ goto err_first_bh;
+ }
+ tmp = min(bsize - boff, to - from);
+ BUG_ON(boff + tmp > bsize || tmp > bsize);
+ memcpy(AFFS_DATA(bh) + boff, data + from, tmp);
+ be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
+ affs_fix_checksum(sb, bh);
+ mark_buffer_dirty_inode(bh, inode);
+ written += tmp;
+ from += tmp;
+ bidx++;
+ } else if (bidx) {
+ bh = affs_bread_ino(inode, bidx - 1, 0);
+ if (IS_ERR(bh)) {
+ written = PTR_ERR(bh);
+ goto err_first_bh;
+ }
+ }
+ while (from + bsize <= to) {
+ prev_bh = bh;
+ bh = affs_getemptyblk_ino(inode, bidx);
+ if (IS_ERR(bh))
+ goto err_bh;
+ memcpy(AFFS_DATA(bh), data + from, bsize);
+ if (buffer_new(bh)) {
+ AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
+ AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
+ AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
+ AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize);
+ AFFS_DATA_HEAD(bh)->next = 0;
+ bh->b_state &= ~(1UL << BH_New);
+ if (prev_bh) {
+ u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
+
+ if (tmp_next)
+ affs_warning(sb, "commit_write_ofs",
+ "next block already set for %d (%d)",
+ bidx, tmp_next);
+ AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
+ affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
+ mark_buffer_dirty_inode(prev_bh, inode);
+ }
+ }
+ affs_brelse(prev_bh);
+ affs_fix_checksum(sb, bh);
+ mark_buffer_dirty_inode(bh, inode);
+ written += bsize;
+ from += bsize;
+ bidx++;
+ }
+ if (from < to) {
+ prev_bh = bh;
+ bh = affs_bread_ino(inode, bidx, 1);
+ if (IS_ERR(bh))
+ goto err_bh;
+ tmp = min(bsize, to - from);
+ BUG_ON(tmp > bsize);
+ memcpy(AFFS_DATA(bh), data + from, tmp);
+ if (buffer_new(bh)) {
+ AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
+ AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
+ AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
+ AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
+ AFFS_DATA_HEAD(bh)->next = 0;
+ bh->b_state &= ~(1UL << BH_New);
+ if (prev_bh) {
+ u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
+
+ if (tmp_next)
+ affs_warning(sb, "commit_write_ofs",
+ "next block already set for %d (%d)",
+ bidx, tmp_next);
+ AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
+ affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
+ mark_buffer_dirty_inode(prev_bh, inode);
+ }
+ } else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp)
+ AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
+ affs_brelse(prev_bh);
+ affs_fix_checksum(sb, bh);
+ mark_buffer_dirty_inode(bh, inode);
+ written += tmp;
+ from += tmp;
+ bidx++;
+ }
+ SetPageUptodate(page);
+
+done:
+ affs_brelse(bh);
+ tmp = (page->index << PAGE_CACHE_SHIFT) + from;
+ if (tmp > inode->i_size)
+ inode->i_size = AFFS_I(inode)->mmu_private = tmp;
+
+err_first_bh:
+ unlock_page(page);
+ page_cache_release(page);
+
+ return written;
+
+err_bh:
+ bh = prev_bh;
+ if (!written)
+ written = PTR_ERR(bh);
+ goto done;
+}
+
+const struct address_space_operations affs_aops_ofs = {
+ .readpage = affs_readpage_ofs,
+ //.writepage = affs_writepage_ofs,
+ .write_begin = affs_write_begin_ofs,
+ .write_end = affs_write_end_ofs
+};
+
+/* Free any preallocated blocks. */
+
+void
+affs_free_prealloc(struct inode *inode)
+{
+ struct super_block *sb = inode->i_sb;
+
+ pr_debug("free_prealloc(ino=%lu)\n", inode->i_ino);
+
+ while (AFFS_I(inode)->i_pa_cnt) {
+ AFFS_I(inode)->i_pa_cnt--;
+ affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc);
+ }
+}
+
+/* Truncate (or enlarge) a file to the requested size. */
+
+void
+affs_truncate(struct inode *inode)
+{
+ struct super_block *sb = inode->i_sb;
+ u32 ext, ext_key;
+ u32 last_blk, blkcnt, blk;
+ u32 size;
+ struct buffer_head *ext_bh;
+ int i;
+
+ pr_debug("truncate(inode=%lu, oldsize=%llu, newsize=%llu)\n",
+ inode->i_ino, AFFS_I(inode)->mmu_private, inode->i_size);
+
+ last_blk = 0;
+ ext = 0;
+ if (inode->i_size) {
+ last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize;
+ ext = last_blk / AFFS_SB(sb)->s_hashsize;
+ }
+
+ if (inode->i_size > AFFS_I(inode)->mmu_private) {
+ struct address_space *mapping = inode->i_mapping;
+ struct page *page;
+ void *fsdata;
+ loff_t isize = inode->i_size;
+ int res;
+
+ res = mapping->a_ops->write_begin(NULL, mapping, isize, 0, 0, &page, &fsdata);
+ if (!res)
+ res = mapping->a_ops->write_end(NULL, mapping, isize, 0, 0, page, fsdata);
+ else
+ inode->i_size = AFFS_I(inode)->mmu_private;
+ mark_inode_dirty(inode);
+ return;
+ } else if (inode->i_size == AFFS_I(inode)->mmu_private)
+ return;
+
+ // lock cache
+ ext_bh = affs_get_extblock(inode, ext);
+ if (IS_ERR(ext_bh)) {
+ affs_warning(sb, "truncate",
+ "unexpected read error for ext block %u (%ld)",
+ ext, PTR_ERR(ext_bh));
+ return;
+ }
+ if (AFFS_I(inode)->i_lc) {
+ /* clear linear cache */
+ i = (ext + 1) >> AFFS_I(inode)->i_lc_shift;
+ if (AFFS_I(inode)->i_lc_size > i) {
+ AFFS_I(inode)->i_lc_size = i;
+ for (; i < AFFS_LC_SIZE; i++)
+ AFFS_I(inode)->i_lc[i] = 0;
+ }
+ /* clear associative cache */
+ for (i = 0; i < AFFS_AC_SIZE; i++)
+ if (AFFS_I(inode)->i_ac[i].ext >= ext)
+ AFFS_I(inode)->i_ac[i].ext = 0;
+ }
+ ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
+
+ blkcnt = AFFS_I(inode)->i_blkcnt;
+ i = 0;
+ blk = last_blk;
+ if (inode->i_size) {
+ i = last_blk % AFFS_SB(sb)->s_hashsize + 1;
+ blk++;
+ } else
+ AFFS_HEAD(ext_bh)->first_data = 0;
+ AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(i);
+ size = AFFS_SB(sb)->s_hashsize;
+ if (size > blkcnt - blk + i)
+ size = blkcnt - blk + i;
+ for (; i < size; i++, blk++) {
+ affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
+ AFFS_BLOCK(sb, ext_bh, i) = 0;
+ }
+ AFFS_TAIL(sb, ext_bh)->extension = 0;
+ affs_fix_checksum(sb, ext_bh);
+ mark_buffer_dirty_inode(ext_bh, inode);
+ affs_brelse(ext_bh);
+
+ if (inode->i_size) {
+ AFFS_I(inode)->i_blkcnt = last_blk + 1;
+ AFFS_I(inode)->i_extcnt = ext + 1;
+ if (affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS)) {
+ struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0);
+ u32 tmp;
+ if (IS_ERR(bh)) {
+ affs_warning(sb, "truncate",
+ "unexpected read error for last block %u (%ld)",
+ ext, PTR_ERR(bh));
+ return;
+ }
+ tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next);
+ AFFS_DATA_HEAD(bh)->next = 0;
+ affs_adjust_checksum(bh, -tmp);
+ affs_brelse(bh);
+ }
+ } else {
+ AFFS_I(inode)->i_blkcnt = 0;
+ AFFS_I(inode)->i_extcnt = 1;
+ }
+ AFFS_I(inode)->mmu_private = inode->i_size;
+ // unlock cache
+
+ while (ext_key) {
+ ext_bh = affs_bread(sb, ext_key);
+ size = AFFS_SB(sb)->s_hashsize;
+ if (size > blkcnt - blk)
+ size = blkcnt - blk;
+ for (i = 0; i < size; i++, blk++)
+ affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
+ affs_free_block(sb, ext_key);
+ ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
+ affs_brelse(ext_bh);
+ }
+ affs_free_prealloc(inode);
+}
+
+int affs_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
+{
+ struct inode *inode = filp->f_mapping->host;
+ int ret, err;
+
+ err = filemap_write_and_wait_range(inode->i_mapping, start, end);
+ if (err)
+ return err;
+
+ mutex_lock(&inode->i_mutex);
+ ret = write_inode_now(inode, 0);
+ err = sync_blockdev(inode->i_sb->s_bdev);
+ if (!ret)
+ ret = err;
+ mutex_unlock(&inode->i_mutex);
+ return ret;
+}
+const struct file_operations affs_file_operations = {
+ .llseek = generic_file_llseek,
+ .read_iter = generic_file_read_iter,
+ .write_iter = generic_file_write_iter,
+ .mmap = generic_file_mmap,
+ .open = affs_file_open,
+ .release = affs_file_release,
+ .fsync = affs_file_fsync,
+ .splice_read = generic_file_splice_read,
+};
+
+const struct inode_operations affs_file_inode_operations = {
+ .setattr = affs_notify_change,
+};