| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <175573713856.21970.12879323697743523642.stgit@frogsfrogsfrogs>
Date: Wed, 20 Aug 2025 18:17:32 -0700
From: "Darrick J. Wong" <djwong@...nel.org>
To: tytso@....edu
Cc: John@...ves.net, bernd@...ernd.com, linux-fsdevel@...r.kernel.org,
linux-ext4@...r.kernel.org, miklos@...redi.hu, joannelkoong@...il.com,
neal@...pa.dev
Subject: [PATCH 07/19] fuse2fs: implement direct write support
From: Darrick J. Wong <djwong@...nel.org>
Wire up an iomap_begin method that can allocate into holes so that we
can do directio writes.
Signed-off-by: "Darrick J. Wong" <djwong@...nel.org>
---
misc/fuse2fs.c | 470 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-
misc/fuse4fs.c | 473 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 937 insertions(+), 6 deletions(-)
diff --git a/misc/fuse2fs.c b/misc/fuse2fs.c
index 4a9fda62f99bc2..e8e9056a661e71 100644
--- a/misc/fuse2fs.c
+++ b/misc/fuse2fs.c
@@ -5442,12 +5442,103 @@ static int fuse2fs_iomap_begin_read(struct fuse2fs *ff, ext2_ino_t ino,
opflags, read);
}
+static int fuse2fs_iomap_write_allocate(struct fuse2fs *ff, ext2_ino_t ino,
+ struct ext2_inode_large *inode, off_t pos,
+ uint64_t count, uint32_t opflags,
+ struct fuse_file_iomap *read, bool *dirty)
+{
+ ext2_filsys fs = ff->fs;
+ blk64_t startoff = FUSE2FS_B_TO_FSBT(ff, pos);
+ blk64_t stopoff = FUSE2FS_B_TO_FSB(ff, pos + count);
+ blk64_t old_iblocks;
+ errcode_t err;
+ int ret;
+
+ dbg_printf(ff, "%s: write_alloc ino=%u startoff 0x%llx blockcount 0x%llx\n",
+ __func__, ino, startoff, stopoff - startoff);
+
+ if (!fs_can_allocate(ff, stopoff - startoff))
+ return -ENOSPC;
+
+ old_iblocks = ext2fs_get_stat_i_blocks(fs, EXT2_INODE(inode));
+ err = ext2fs_fallocate(fs, EXT2_FALLOCATE_FORCE_UNINIT, ino,
+ EXT2_INODE(inode), ~0ULL, startoff,
+ stopoff - startoff);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ /*
+ * New allocations for file data blocks on indirect mapped files are
+ * zeroed through the IO manager so we have to flush it to disk.
+ */
+ if (!(inode->i_flags & EXT4_EXTENTS_FL) &&
+ old_iblocks != ext2fs_get_stat_i_blocks(fs, EXT2_INODE(inode))) {
+ err = io_channel_flush(fs->io);
+ if (err)
+ return translate_error(fs, ino, err);
+ }
+
+ /* pick up the newly allocated mapping */
+ ret = fuse2fs_iomap_begin_read(ff, ino, inode, pos, count, opflags,
+ read);
+ if (ret)
+ return ret;
+
+ read->flags |= FUSE_IOMAP_F_DIRTY;
+ *dirty = true;
+ return 0;
+}
+
+static off_t fuse2fs_max_file_size(const struct fuse2fs *ff,
+ const struct ext2_inode_large *inode)
+{
+ ext2_filsys fs = ff->fs;
+ blk64_t addr_per_block, max_map_block;
+
+ if (inode->i_flags & EXT4_EXTENTS_FL) {
+ max_map_block = (1ULL << 32) - 1;
+ } else {
+ addr_per_block = fs->blocksize >> 2;
+ max_map_block = addr_per_block;
+ max_map_block += addr_per_block * addr_per_block;
+ max_map_block += addr_per_block * addr_per_block * addr_per_block;
+ max_map_block += 12;
+ }
+
+ return FUSE2FS_FSB_TO_B(ff, max_map_block) + (fs->blocksize - 1);
+}
+
static int fuse2fs_iomap_begin_write(struct fuse2fs *ff, ext2_ino_t ino,
struct ext2_inode_large *inode, off_t pos,
uint64_t count, uint32_t opflags,
- struct fuse_file_iomap *read)
+ struct fuse_file_iomap *read,
+ bool *dirty)
{
- return -ENOSYS;
+ off_t max_size = fuse2fs_max_file_size(ff, inode);
+ int ret;
+
+ if (!(opflags & FUSE_IOMAP_OP_DIRECT))
+ return -ENOSYS;
+
+ if (pos >= max_size)
+ return -EFBIG;
+
+ if (pos >= max_size - count)
+ count = max_size - pos;
+
+ ret = fuse2fs_iomap_begin_read(ff, ino, inode, pos, count, opflags,
+ read);
+ if (ret)
+ return ret;
+
+ if (fuse_iomap_need_write_allocate(opflags, read)) {
+ ret = fuse2fs_iomap_write_allocate(ff, ino, inode, pos, count,
+ opflags, read, dirty);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
}
static int op_iomap_begin(const char *path, uint64_t nodeid, uint64_t attr_ino,
@@ -5459,6 +5550,7 @@ static int op_iomap_begin(const char *path, uint64_t nodeid, uint64_t attr_ino,
struct ext2_inode_large inode;
ext2_filsys fs;
errcode_t err;
+ bool dirty = false;
int ret = 0;
FUSE2FS_CHECK_CONTEXT(ff);
@@ -5484,7 +5576,7 @@ static int op_iomap_begin(const char *path, uint64_t nodeid, uint64_t attr_ino,
count, opflags, read);
else if (fuse_iomap_is_write(opflags))
ret = fuse2fs_iomap_begin_write(ff, attr_ino, &inode, pos,
- count, opflags, read);
+ count, opflags, read, &dirty);
else
ret = fuse2fs_iomap_begin_read(ff, attr_ino, &inode, pos,
count, opflags, read);
@@ -5506,6 +5598,14 @@ static int op_iomap_begin(const char *path, uint64_t nodeid, uint64_t attr_ino,
read->offset + read->length <= pos))
fuse2fs_dump_extents(ff, attr_ino, &inode, "BAD DATA");
+ if (dirty) {
+ err = fuse2fs_write_inode(fs, attr_ino, &inode);
+ if (err) {
+ ret = translate_error(fs, attr_ino, err);
+ goto out_unlock;
+ }
+ }
+
out_unlock:
fuse2fs_finish(ff, ret);
return ret;
@@ -5643,6 +5743,369 @@ static int op_iomap_config(uint64_t flags, off_t maxbytes,
if (ret)
goto out_unlock;
+out_unlock:
+ fuse2fs_finish(ff, ret);
+ return ret;
+}
+
+static inline bool fuse2fs_can_merge_mappings(const struct ext2fs_extent *left,
+ const struct ext2fs_extent *right)
+{
+ uint64_t max_len = (left->e_flags & EXT2_EXTENT_FLAGS_UNINIT) ?
+ EXT_UNINIT_MAX_LEN : EXT_INIT_MAX_LEN;
+
+ return left->e_lblk + left->e_len == right->e_lblk &&
+ left->e_pblk + left->e_len == right->e_pblk &&
+ (left->e_flags & EXT2_EXTENT_FLAGS_UNINIT) ==
+ (right->e_flags & EXT2_EXTENT_FLAGS_UNINIT) &&
+ (uint64_t)left->e_len + right->e_len <= max_len;
+}
+
+static int fuse2fs_try_merge_mappings(struct fuse2fs *ff, ext2_ino_t ino,
+ ext2_extent_handle_t handle,
+ blk64_t startoff)
+{
+ ext2_filsys fs = ff->fs;
+ struct ext2fs_extent left, right;
+ errcode_t err;
+
+ /* Look up the mappings before startoff */
+ err = fuse2fs_get_mapping_at(ff, handle, startoff - 1, &left);
+ if (err == EXT2_ET_EXTENT_NOT_FOUND)
+ return 0;
+ if (err)
+ return translate_error(fs, ino, err);
+
+ /* Look up the mapping at startoff */
+ err = fuse2fs_get_mapping_at(ff, handle, startoff, &right);
+ if (err == EXT2_ET_EXTENT_NOT_FOUND)
+ return 0;
+ if (err)
+ return translate_error(fs, ino, err);
+
+ /* Can we combine them? */
+ if (!fuse2fs_can_merge_mappings(&left, &right))
+ return 0;
+
+ /*
+ * Delete the mapping after startoff because libext2fs cannot handle
+ * overlapping mappings.
+ */
+ err = ext2fs_extent_delete(handle, 0);
+ DUMP_EXTENT(ff, "remover", startoff, err, &right);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ err = ext2fs_extent_fix_parents(handle);
+ DUMP_EXTENT(ff, "fixremover", startoff, err, &right);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ /* Move back and lengthen the mapping before startoff */
+ err = ext2fs_extent_goto(handle, left.e_lblk);
+ DUMP_EXTENT(ff, "movel", startoff - 1, err, &left);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ left.e_len += right.e_len;
+ err = ext2fs_extent_replace(handle, 0, &left);
+ DUMP_EXTENT(ff, "replacel", startoff - 1, err, &left);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ err = ext2fs_extent_fix_parents(handle);
+ DUMP_EXTENT(ff, "fixreplacel", startoff - 1, err, &left);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ return 0;
+}
+
+static int fuse2fs_convert_unwritten_mapping(struct fuse2fs *ff,
+ ext2_ino_t ino,
+ struct ext2_inode_large *inode,
+ ext2_extent_handle_t handle,
+ blk64_t *cursor, blk64_t stopoff)
+{
+ ext2_filsys fs = ff->fs;
+ struct ext2fs_extent extent;
+ blk64_t startoff = *cursor;
+ errcode_t err;
+
+ /*
+ * Find the mapping at startoff. Note that we can find holes because
+ * the mapping data can change due to racing writes.
+ */
+ err = fuse2fs_get_mapping_at(ff, handle, startoff, &extent);
+ if (err == EXT2_ET_EXTENT_NOT_FOUND) {
+ /*
+ * If we didn't find any mappings at all then the file is
+ * completely sparse. There's nothing to convert.
+ */
+ *cursor = stopoff;
+ return 0;
+ }
+ if (err)
+ return translate_error(fs, ino, err);
+
+ /*
+ * The mapping is completely to the left of the range that we want.
+ * Let's see what's in the next extent, if there is one.
+ */
+ if (startoff >= extent.e_lblk + extent.e_len) {
+ /*
+ * Mapping ends to the left of the current position. Try to
+ * find the next mapping. If there is no next mapping, then
+ * we're done.
+ */
+ err = fuse2fs_get_next_mapping(ff, handle, startoff, &extent);
+ if (err == EXT2_ET_EXTENT_NOT_FOUND) {
+ *cursor = stopoff;
+ return 0;
+ }
+ if (err)
+ return translate_error(fs, ino, err);
+ }
+
+ /*
+ * The mapping is completely to the right of the range that we want,
+ * so we're done.
+ */
+ if (extent.e_lblk >= stopoff) {
+ *cursor = stopoff;
+ return 0;
+ }
+
+ /*
+ * At this point, we have a mapping that overlaps (startoff, stopoff].
+ * If the mapping is already written, move on to the next one.
+ */
+ if (!(extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT))
+ goto next;
+
+ if (startoff > extent.e_lblk) {
+ struct ext2fs_extent newex = extent;
+
+ /*
+ * Unwritten mapping starts before startoff. Shorten
+ * the previous mapping...
+ */
+ newex.e_len = startoff - extent.e_lblk;
+ err = ext2fs_extent_replace(handle, 0, &newex);
+ DUMP_EXTENT(ff, "shortenp", startoff, err, &newex);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ err = ext2fs_extent_fix_parents(handle);
+ DUMP_EXTENT(ff, "fixshortenp", startoff, err, &newex);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ /* ...and create new written mapping at startoff. */
+ extent.e_len -= newex.e_len;
+ extent.e_lblk += newex.e_len;
+ extent.e_pblk += newex.e_len;
+ extent.e_flags = newex.e_flags & ~EXT2_EXTENT_FLAGS_UNINIT;
+
+ err = ext2fs_extent_insert(handle,
+ EXT2_EXTENT_INSERT_AFTER,
+ &extent);
+ DUMP_EXTENT(ff, "insertx", startoff, err, &extent);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ err = ext2fs_extent_fix_parents(handle);
+ DUMP_EXTENT(ff, "fixinsertx", startoff, err, &extent);
+ if (err)
+ return translate_error(fs, ino, err);
+ }
+
+ if (extent.e_lblk + extent.e_len > stopoff) {
+ struct ext2fs_extent newex = extent;
+
+ /*
+ * Unwritten mapping ends after stopoff. Shorten the current
+ * mapping...
+ */
+ extent.e_len = stopoff - extent.e_lblk;
+ extent.e_flags &= ~EXT2_EXTENT_FLAGS_UNINIT;
+
+ err = ext2fs_extent_replace(handle, 0, &extent);
+ DUMP_EXTENT(ff, "shortenn", startoff, err, &extent);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ err = ext2fs_extent_fix_parents(handle);
+ DUMP_EXTENT(ff, "fixshortenn", startoff, err, &extent);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ /* ..and create a new unwritten mapping at stopoff. */
+ newex.e_pblk += extent.e_len;
+ newex.e_lblk += extent.e_len;
+ newex.e_len -= extent.e_len;
+ newex.e_flags |= EXT2_EXTENT_FLAGS_UNINIT;
+
+ err = ext2fs_extent_insert(handle,
+ EXT2_EXTENT_INSERT_AFTER,
+ &newex);
+ DUMP_EXTENT(ff, "insertn", startoff, err, &newex);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ err = ext2fs_extent_fix_parents(handle);
+ DUMP_EXTENT(ff, "fixinsertn", startoff, err, &newex);
+ if (err)
+ return translate_error(fs, ino, err);
+ }
+
+ /* Still unwritten? Update the state. */
+ if (extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT) {
+ extent.e_flags &= ~EXT2_EXTENT_FLAGS_UNINIT;
+
+ err = ext2fs_extent_replace(handle, 0, &extent);
+ DUMP_EXTENT(ff, "replacex", startoff, err, &extent);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ err = ext2fs_extent_fix_parents(handle);
+ DUMP_EXTENT(ff, "fixreplacex", startoff, err, &extent);
+ if (err)
+ return translate_error(fs, ino, err);
+ }
+
+next:
+ /* Try to merge with the previous extent */
+ if (startoff > 0) {
+ err = fuse2fs_try_merge_mappings(ff, ino, handle, startoff);
+ if (err)
+ return translate_error(fs, ino, err);
+ }
+
+ *cursor = extent.e_lblk + extent.e_len;
+ return 0;
+}
+
+static int fuse2fs_convert_unwritten_mappings(struct fuse2fs *ff,
+ ext2_ino_t ino,
+ struct ext2_inode_large *inode,
+ off_t pos, size_t written)
+{
+ ext2_extent_handle_t handle;
+ ext2_filsys fs = ff->fs;
+ blk64_t startoff = FUSE2FS_B_TO_FSBT(ff, pos);
+ const blk64_t stopoff = FUSE2FS_B_TO_FSB(ff, pos + written);
+ errcode_t err;
+ int ret;
+
+ err = ext2fs_extent_open2(fs, ino, EXT2_INODE(inode), &handle);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ /* Walk every mapping in the range, converting them. */
+ while (startoff < stopoff) {
+ blk64_t old_startoff = startoff;
+
+ ret = fuse2fs_convert_unwritten_mapping(ff, ino, inode, handle,
+ &startoff, stopoff);
+ if (ret)
+ goto out_handle;
+ if (startoff <= old_startoff) {
+ /* Do not go backwards. */
+ ret = translate_error(fs, ino, EXT2_ET_INODE_CORRUPTED);
+ goto out_handle;
+ }
+ }
+
+ /* Try to merge the right edge */
+ ret = fuse2fs_try_merge_mappings(ff, ino, handle, stopoff);
+out_handle:
+ ext2fs_extent_free(handle);
+ return ret;
+}
+
+static int op_iomap_ioend(const char *path, uint64_t nodeid, uint64_t attr_ino,
+ off_t pos, size_t written, uint32_t ioendflags,
+ int error, uint64_t new_addr)
+{
+ struct fuse2fs *ff = fuse2fs_get();
+ struct ext2_inode_large inode;
+ ext2_filsys fs;
+ errcode_t err;
+ bool dirty = false;
+ int ret = 0;
+
+ FUSE2FS_CHECK_CONTEXT(ff);
+
+ dbg_printf(ff,
+ "%s: path=%s nodeid=%llu attr_ino=%llu pos=0x%llx written=0x%zx ioendflags=0x%x error=%d new_addr=%llu\n",
+ __func__, path,
+ (unsigned long long)nodeid,
+ (unsigned long long)attr_ino,
+ (unsigned long long)pos,
+ written,
+ ioendflags,
+ error,
+ (unsigned long long)new_addr);
+
+ fs = fuse2fs_start(ff);
+ if (error) {
+ ret = error;
+ goto out_unlock;
+ }
+
+ /* should never see these ioend types */
+ if (ioendflags & FUSE_IOMAP_IOEND_SHARED) {
+ ret = translate_error(fs, attr_ino,
+ EXT2_ET_FILESYSTEM_CORRUPTED);
+ goto out_unlock;
+ }
+
+ err = fuse2fs_read_inode(fs, attr_ino, &inode);
+ if (err) {
+ ret = translate_error(fs, attr_ino, err);
+ goto out_unlock;
+ }
+
+ if (ioendflags & FUSE_IOMAP_IOEND_UNWRITTEN) {
+ /* unwritten extents are only supported on extents files */
+ if (!(inode.i_flags & EXT4_EXTENTS_FL)) {
+ ret = translate_error(fs, attr_ino,
+ EXT2_ET_FILESYSTEM_CORRUPTED);
+ goto out_unlock;
+ }
+
+ ret = fuse2fs_convert_unwritten_mappings(ff, attr_ino, &inode,
+ pos, written);
+ if (ret)
+ goto out_unlock;
+
+ dirty = true;
+ }
+
+ if (ioendflags & FUSE_IOMAP_IOEND_APPEND) {
+ ext2_off64_t isize = EXT2_I_SIZE(&inode);
+
+ if (pos + written > isize) {
+ err = ext2fs_inode_size_set(fs, EXT2_INODE(&inode),
+ pos + written);
+ if (err) {
+ ret = translate_error(fs, attr_ino, err);
+ goto out_unlock;
+ }
+
+ dirty = true;
+ }
+ }
+
+ if (dirty) {
+ err = fuse2fs_write_inode(fs, attr_ino, &inode);
+ if (err) {
+ ret = translate_error(fs, attr_ino, err);
+ goto out_unlock;
+ }
+ }
+
out_unlock:
fuse2fs_finish(ff, ret);
return ret;
@@ -5713,6 +6176,7 @@ static struct fuse_operations fs_ops = {
.iomap_begin = op_iomap_begin,
.iomap_end = op_iomap_end,
.iomap_config = op_iomap_config,
+ .iomap_ioend = op_iomap_ioend,
#endif /* HAVE_FUSE_IOMAP */
};
diff --git a/misc/fuse4fs.c b/misc/fuse4fs.c
index 0ac5de90498dac..ff50182b929974 100644
--- a/misc/fuse4fs.c
+++ b/misc/fuse4fs.c
@@ -5850,12 +5850,106 @@ static int fuse4fs_iomap_begin_read(struct fuse4fs *ff, ext2_ino_t ino,
opflags, read);
}
+static int fuse4fs_iomap_write_allocate(struct fuse4fs *ff, ext2_ino_t ino,
+ struct ext2_inode_large *inode,
+ off_t pos, uint64_t count,
+ uint32_t opflags,
+ struct fuse_file_iomap *read,
+ bool *dirty)
+{
+ ext2_filsys fs = ff->fs;
+ blk64_t startoff = FUSE4FS_B_TO_FSBT(ff, pos);
+ blk64_t stopoff = FUSE4FS_B_TO_FSB(ff, pos + count);
+ blk64_t old_iblocks;
+ errcode_t err;
+ int ret;
+
+ dbg_printf(ff,
+ "%s: ino=%d startoff 0x%llx blockcount 0x%llx\n",
+ __func__, ino, startoff, stopoff - startoff);
+
+ if (!fuse4fs_can_allocate(ff, stopoff - startoff))
+ return -ENOSPC;
+
+ old_iblocks = ext2fs_get_stat_i_blocks(fs, EXT2_INODE(inode));
+ err = ext2fs_fallocate(fs, EXT2_FALLOCATE_FORCE_UNINIT, ino,
+ EXT2_INODE(inode), ~0ULL, startoff,
+ stopoff - startoff);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ /*
+ * New allocations for file data blocks on indirect mapped files are
+ * zeroed through the IO manager so we have to flush it to disk.
+ */
+ if (!(inode->i_flags & EXT4_EXTENTS_FL) &&
+ old_iblocks != ext2fs_get_stat_i_blocks(fs, EXT2_INODE(inode))) {
+ err = io_channel_flush(fs->io);
+ if (err)
+ return translate_error(fs, ino, err);
+ }
+
+ /* pick up the newly allocated mapping */
+ ret = fuse4fs_iomap_begin_read(ff, ino, inode, pos, count, opflags,
+ read);
+ if (ret)
+ return ret;
+
+ read->flags |= FUSE_IOMAP_F_DIRTY;
+ *dirty = true;
+ return 0;
+}
+
+static off_t fuse4fs_max_file_size(const struct fuse4fs *ff,
+ const struct ext2_inode_large *inode)
+{
+ ext2_filsys fs = ff->fs;
+ blk64_t addr_per_block, max_map_block;
+
+ if (inode->i_flags & EXT4_EXTENTS_FL) {
+ max_map_block = (1ULL << 32) - 1;
+ } else {
+ addr_per_block = fs->blocksize >> 2;
+ max_map_block = addr_per_block;
+ max_map_block += addr_per_block * addr_per_block;
+ max_map_block += addr_per_block * addr_per_block * addr_per_block;
+ max_map_block += 12;
+ }
+
+ return FUSE4FS_FSB_TO_B(ff, max_map_block) + (fs->blocksize - 1);
+}
+
static int fuse4fs_iomap_begin_write(struct fuse4fs *ff, ext2_ino_t ino,
struct ext2_inode_large *inode, off_t pos,
uint64_t count, uint32_t opflags,
- struct fuse_file_iomap *read)
+ struct fuse_file_iomap *read,
+ bool *dirty)
{
- return -ENOSYS;
+ off_t max_size = fuse4fs_max_file_size(ff, inode);
+ int ret;
+
+ if (!(opflags & FUSE_IOMAP_OP_DIRECT))
+ return -ENOSYS;
+
+ if (pos >= max_size)
+ return -EFBIG;
+
+ if (pos >= max_size - count)
+ count = max_size - pos;
+
+ ret = fuse4fs_iomap_begin_read(ff, ino, inode, pos, count, opflags,
+ read);
+ if (ret)
+ return ret;
+
+ if (fuse_iomap_need_write_allocate(opflags, read)) {
+ ret = fuse4fs_iomap_write_allocate(ff, ino, inode, pos, count,
+ opflags, read, dirty);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
}
static void op_iomap_begin(fuse_req_t req, fuse_ino_t fino, uint64_t dontcare,
@@ -5867,6 +5961,7 @@ static void op_iomap_begin(fuse_req_t req, fuse_ino_t fino, uint64_t dontcare,
ext2_filsys fs;
ext2_ino_t ino;
errcode_t err;
+ bool dirty = false;
int ret = 0;
FUSE4FS_CHECK_CONTEXT(req);
@@ -5890,7 +5985,7 @@ static void op_iomap_begin(fuse_req_t req, fuse_ino_t fino, uint64_t dontcare,
opflags, &read);
else if (fuse_iomap_is_write(opflags))
ret = fuse4fs_iomap_begin_write(ff, ino, &inode, pos, count,
- opflags, &read);
+ opflags, &read, &dirty);
else
ret = fuse4fs_iomap_begin_read(ff, ino, &inode, pos, count,
opflags, &read);
@@ -5912,6 +6007,14 @@ static void op_iomap_begin(fuse_req_t req, fuse_ino_t fino, uint64_t dontcare,
read.offset + read.length <= pos))
fuse4fs_dump_extents(ff, ino, &inode, "BAD DATA");
+ if (dirty) {
+ err = fuse4fs_write_inode(fs, ino, &inode);
+ if (err) {
+ ret = translate_error(fs, ino, err);
+ goto out_unlock;
+ }
+ }
+
out_unlock:
fuse4fs_finish(ff, ret);
if (ret)
@@ -6059,6 +6162,369 @@ static void op_iomap_config(fuse_req_t req, uint64_t flags, uint64_t maxbytes)
else
fuse_reply_iomap_config(req, &cfg);
}
+
+static inline bool fuse4fs_can_merge_mappings(const struct ext2fs_extent *left,
+ const struct ext2fs_extent *right)
+{
+ uint64_t max_len = (left->e_flags & EXT2_EXTENT_FLAGS_UNINIT) ?
+ EXT_UNINIT_MAX_LEN : EXT_INIT_MAX_LEN;
+
+ return left->e_lblk + left->e_len == right->e_lblk &&
+ left->e_pblk + left->e_len == right->e_pblk &&
+ (left->e_flags & EXT2_EXTENT_FLAGS_UNINIT) ==
+ (right->e_flags & EXT2_EXTENT_FLAGS_UNINIT) &&
+ (uint64_t)left->e_len + right->e_len <= max_len;
+}
+
+static int fuse4fs_try_merge_mappings(struct fuse4fs *ff, ext2_ino_t ino,
+ ext2_extent_handle_t handle,
+ blk64_t startoff)
+{
+ ext2_filsys fs = ff->fs;
+ struct ext2fs_extent left, right;
+ errcode_t err;
+
+ /* Look up the mappings before startoff */
+ err = fuse4fs_get_mapping_at(ff, handle, startoff - 1, &left);
+ if (err == EXT2_ET_EXTENT_NOT_FOUND)
+ return 0;
+ if (err)
+ return translate_error(fs, ino, err);
+
+ /* Look up the mapping at startoff */
+ err = fuse4fs_get_mapping_at(ff, handle, startoff, &right);
+ if (err == EXT2_ET_EXTENT_NOT_FOUND)
+ return 0;
+ if (err)
+ return translate_error(fs, ino, err);
+
+ /* Can we combine them? */
+ if (!fuse4fs_can_merge_mappings(&left, &right))
+ return 0;
+
+ /*
+ * Delete the mapping after startoff because libext2fs cannot handle
+ * overlapping mappings.
+ */
+ err = ext2fs_extent_delete(handle, 0);
+ DUMP_EXTENT(ff, "remover", startoff, err, &right);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ err = ext2fs_extent_fix_parents(handle);
+ DUMP_EXTENT(ff, "fixremover", startoff, err, &right);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ /* Move back and lengthen the mapping before startoff */
+ err = ext2fs_extent_goto(handle, left.e_lblk);
+ DUMP_EXTENT(ff, "movel", startoff - 1, err, &left);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ left.e_len += right.e_len;
+ err = ext2fs_extent_replace(handle, 0, &left);
+ DUMP_EXTENT(ff, "replacel", startoff - 1, err, &left);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ err = ext2fs_extent_fix_parents(handle);
+ DUMP_EXTENT(ff, "fixreplacel", startoff - 1, err, &left);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ return 0;
+}
+
+static int fuse4fs_convert_unwritten_mapping(struct fuse4fs *ff,
+ ext2_ino_t ino,
+ struct ext2_inode_large *inode,
+ ext2_extent_handle_t handle,
+ blk64_t *cursor, blk64_t stopoff)
+{
+ ext2_filsys fs = ff->fs;
+ struct ext2fs_extent extent;
+ blk64_t startoff = *cursor;
+ errcode_t err;
+
+ /*
+ * Find the mapping at startoff. Note that we can find holes because
+ * the mapping data can change due to racing writes.
+ */
+ err = fuse4fs_get_mapping_at(ff, handle, startoff, &extent);
+ if (err == EXT2_ET_EXTENT_NOT_FOUND) {
+ /*
+ * If we didn't find any mappings at all then the file is
+ * completely sparse. There's nothing to convert.
+ */
+ *cursor = stopoff;
+ return 0;
+ }
+ if (err)
+ return translate_error(fs, ino, err);
+
+ /*
+ * The mapping is completely to the left of the range that we want.
+ * Let's see what's in the next extent, if there is one.
+ */
+ if (startoff >= extent.e_lblk + extent.e_len) {
+ /*
+ * Mapping ends to the left of the current position. Try to
+ * find the next mapping. If there is no next mapping, then
+ * we're done.
+ */
+ err = fuse4fs_get_next_mapping(ff, handle, startoff, &extent);
+ if (err == EXT2_ET_EXTENT_NOT_FOUND) {
+ *cursor = stopoff;
+ return 0;
+ }
+ if (err)
+ return translate_error(fs, ino, err);
+ }
+
+ /*
+ * The mapping is completely to the right of the range that we want,
+ * so we're done.
+ */
+ if (extent.e_lblk >= stopoff) {
+ *cursor = stopoff;
+ return 0;
+ }
+
+ /*
+ * At this point, we have a mapping that overlaps (startoff, stopoff].
+ * If the mapping is already written, move on to the next one.
+ */
+ if (!(extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT))
+ goto next;
+
+ if (startoff > extent.e_lblk) {
+ struct ext2fs_extent newex = extent;
+
+ /*
+ * Unwritten mapping starts before startoff. Shorten
+ * the previous mapping...
+ */
+ newex.e_len = startoff - extent.e_lblk;
+ err = ext2fs_extent_replace(handle, 0, &newex);
+ DUMP_EXTENT(ff, "shortenp", startoff, err, &newex);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ err = ext2fs_extent_fix_parents(handle);
+ DUMP_EXTENT(ff, "fixshortenp", startoff, err, &newex);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ /* ...and create new written mapping at startoff. */
+ extent.e_len -= newex.e_len;
+ extent.e_lblk += newex.e_len;
+ extent.e_pblk += newex.e_len;
+ extent.e_flags = newex.e_flags & ~EXT2_EXTENT_FLAGS_UNINIT;
+
+ err = ext2fs_extent_insert(handle,
+ EXT2_EXTENT_INSERT_AFTER,
+ &extent);
+ DUMP_EXTENT(ff, "insertx", startoff, err, &extent);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ err = ext2fs_extent_fix_parents(handle);
+ DUMP_EXTENT(ff, "fixinsertx", startoff, err, &extent);
+ if (err)
+ return translate_error(fs, ino, err);
+ }
+
+ if (extent.e_lblk + extent.e_len > stopoff) {
+ struct ext2fs_extent newex = extent;
+
+ /*
+ * Unwritten mapping ends after stopoff. Shorten the current
+ * mapping...
+ */
+ extent.e_len = stopoff - extent.e_lblk;
+ extent.e_flags &= ~EXT2_EXTENT_FLAGS_UNINIT;
+
+ err = ext2fs_extent_replace(handle, 0, &extent);
+ DUMP_EXTENT(ff, "shortenn", startoff, err, &extent);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ err = ext2fs_extent_fix_parents(handle);
+ DUMP_EXTENT(ff, "fixshortenn", startoff, err, &extent);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ /* ..and create a new unwritten mapping at stopoff. */
+ newex.e_pblk += extent.e_len;
+ newex.e_lblk += extent.e_len;
+ newex.e_len -= extent.e_len;
+ newex.e_flags |= EXT2_EXTENT_FLAGS_UNINIT;
+
+ err = ext2fs_extent_insert(handle,
+ EXT2_EXTENT_INSERT_AFTER,
+ &newex);
+ DUMP_EXTENT(ff, "insertn", startoff, err, &newex);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ err = ext2fs_extent_fix_parents(handle);
+ DUMP_EXTENT(ff, "fixinsertn", startoff, err, &newex);
+ if (err)
+ return translate_error(fs, ino, err);
+ }
+
+ /* Still unwritten? Update the state. */
+ if (extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT) {
+ extent.e_flags &= ~EXT2_EXTENT_FLAGS_UNINIT;
+
+ err = ext2fs_extent_replace(handle, 0, &extent);
+ DUMP_EXTENT(ff, "replacex", startoff, err, &extent);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ err = ext2fs_extent_fix_parents(handle);
+ DUMP_EXTENT(ff, "fixreplacex", startoff, err, &extent);
+ if (err)
+ return translate_error(fs, ino, err);
+ }
+
+next:
+ /* Try to merge with the previous extent */
+ if (startoff > 0) {
+ err = fuse4fs_try_merge_mappings(ff, ino, handle, startoff);
+ if (err)
+ return translate_error(fs, ino, err);
+ }
+
+ *cursor = extent.e_lblk + extent.e_len;
+ return 0;
+}
+
+static int fuse4fs_convert_unwritten_mappings(struct fuse4fs *ff,
+ ext2_ino_t ino,
+ struct ext2_inode_large *inode,
+ off_t pos, size_t written)
+{
+ ext2_extent_handle_t handle;
+ ext2_filsys fs = ff->fs;
+ blk64_t startoff = FUSE4FS_B_TO_FSBT(ff, pos);
+ const blk64_t stopoff = FUSE4FS_B_TO_FSB(ff, pos + written);
+ errcode_t err;
+ int ret;
+
+ err = ext2fs_extent_open2(fs, ino, EXT2_INODE(inode), &handle);
+ if (err)
+ return translate_error(fs, ino, err);
+
+ /* Walk every mapping in the range, converting them. */
+ while (startoff < stopoff) {
+ blk64_t old_startoff = startoff;
+
+ ret = fuse4fs_convert_unwritten_mapping(ff, ino, inode, handle,
+ &startoff, stopoff);
+ if (ret)
+ goto out_handle;
+ if (startoff <= old_startoff) {
+ /* Do not go backwards. */
+ ret = translate_error(fs, ino, EXT2_ET_INODE_CORRUPTED);
+ goto out_handle;
+ }
+ }
+
+ /* Try to merge the right edge */
+ ret = fuse4fs_try_merge_mappings(ff, ino, handle, stopoff);
+out_handle:
+ ext2fs_extent_free(handle);
+ return ret;
+}
+
+static void op_iomap_ioend(fuse_req_t req, fuse_ino_t fino, uint64_t dontcare,
+ off_t pos, size_t written, uint32_t ioendflags,
+ int error, uint64_t new_addr)
+{
+ struct fuse4fs *ff = fuse4fs_get(req);
+ struct ext2_inode_large inode;
+ ext2_filsys fs;
+ ext2_ino_t ino;
+ errcode_t err;
+ bool dirty = false;
+ int ret = 0;
+
+ FUSE4FS_CHECK_CONTEXT(req);
+ FUSE4FS_CONVERT_FINO(req, &ino, fino);
+
+ dbg_printf(ff,
+ "%s: ino=%d pos=0x%llx written=0x%zx ioendflags=0x%x error=%d new_addr=0x%llx\n",
+ __func__, ino,
+ (unsigned long long)pos,
+ written,
+ ioendflags,
+ error,
+ (unsigned long long)new_addr);
+
+ if (error) {
+ fuse_reply_err(req, -error);
+ return;
+ }
+
+ fs = fuse4fs_start(ff);
+
+ /* should never see these ioend types */
+ if (ioendflags & FUSE_IOMAP_IOEND_SHARED) {
+ ret = translate_error(fs, ino, EXT2_ET_FILESYSTEM_CORRUPTED);
+ goto out_unlock;
+ }
+
+ err = fuse4fs_read_inode(fs, ino, &inode);
+ if (err) {
+ ret = translate_error(fs, ino, err);
+ goto out_unlock;
+ }
+
+ if (ioendflags & FUSE_IOMAP_IOEND_UNWRITTEN) {
+ /* unwritten extents are only supported on extents files */
+ if (!(inode.i_flags & EXT4_EXTENTS_FL)) {
+ ret = translate_error(fs, ino,
+ EXT2_ET_FILESYSTEM_CORRUPTED);
+ goto out_unlock;
+ }
+
+ ret = fuse4fs_convert_unwritten_mappings(ff, ino, &inode,
+ pos, written);
+ if (ret)
+ goto out_unlock;
+
+ dirty = true;
+ }
+
+ if (ioendflags & FUSE_IOMAP_IOEND_APPEND) {
+ ext2_off64_t isize = EXT2_I_SIZE(&inode);
+
+ if (pos + written > isize) {
+ err = ext2fs_inode_size_set(fs, EXT2_INODE(&inode),
+ pos + written);
+ if (err) {
+ ret = translate_error(fs, ino, err);
+ goto out_unlock;
+ }
+
+ dirty = true;
+ }
+ }
+
+ if (dirty) {
+ err = fuse4fs_write_inode(fs, ino, &inode);
+ if (err) {
+ ret = translate_error(fs, ino, err);
+ goto out_unlock;
+ }
+ }
+
+out_unlock:
+ fuse4fs_finish(ff, ret);
+ fuse_reply_err(req, -ret);
+}
#endif /* HAVE_FUSE_IOMAP */
static struct fuse_lowlevel_ops fs_ops = {
@@ -6108,6 +6574,7 @@ static struct fuse_lowlevel_ops fs_ops = {
.iomap_begin = op_iomap_begin,
.iomap_end = op_iomap_end,
.iomap_config = op_iomap_config,
+ .iomap_ioend = op_iomap_ioend,
#endif /* HAVE_FUSE_IOMAP */
};
Powered by blists - more mailing lists