Skip to content

Read and write syscalls may read less bytes than requested #27

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Read and write syscalls may read less bytes than requested #27

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
47 changes: 31 additions & 16 deletions lfs_fuse_bd.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -71,17 +71,24 @@ int lfs_fuse_bd_read(const struct lfs_config *cfg, lfs_block_t block,
assert(block < cfg->block_count);

// go to block
off_t err = lseek(fd, (off_t)block*cfg->block_size + (off_t)off, SEEK_SET);
off_t offrq = (off_t)block*cfg->block_size + (off_t)off;
off_t err = lseek(fd,offrq, SEEK_SET);
if (err < 0) {
return -errno;
} else if( err != offrq ) {
return LFS_ERR_IO;
}

// read block
ssize_t res = read(fd, buffer, (size_t)size);
if (res < 0) {
return -errno;
}

char* rdb = buffer;
do {
// read block
ssize_t res = read(fd, rdb, (size_t)size);
if (res <= 0) {
return (res==0)?(LFS_ERR_IO):(-errno);
} else {
rdb += res;
size -= res;
}
} while( size > 0 );
return 0;
}

Expand All @@ -93,16 +100,25 @@ int lfs_fuse_bd_prog(const struct lfs_config *cfg, lfs_block_t block,
assert(block < cfg->block_count);

// go to block
off_t err = lseek(fd, (off_t)block*cfg->block_size + (off_t)off, SEEK_SET);
off_t offrq = (off_t)block*cfg->block_size + (off_t)off;
off_t err = lseek(fd,offrq, SEEK_SET);
if (err < 0) {
return -errno;
} else if(err != offrq )
{
return LFS_ERR_IO;
}

// write block
ssize_t res = write(fd, buffer, (size_t)size);
if (res < 0) {
return -errno;
}
const char* wrb = buffer;
do {
// write block
ssize_t res = write(fd, wrb, (size_t)size);
if (res <= 0) {
return (res==0)?(LFS_ERR_IO):(-errno);
} else {
wrb += res;
size -= res;
}
} while(0);
Copy link
Member

@geky geky Dec 18, 2020

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I may be missing something, but why does this do/while loop have 0 as a condition?


return 0;
}
Expand All @@ -119,7 +135,6 @@ int lfs_fuse_bd_sync(const struct lfs_config *cfg) {
if (err) {
return -errno;
}

return 0;
}