mirror of
https://review.haiku-os.org/haiku
synced 2025-01-20 21:41:28 +01:00
e1b7c1c7ac
After this patch, "UnitTester BSymLink" passes. BSymLink::ReadLink() in BeOS would always return the length of the link unless an error occurred. Before this patch, Haiku instead seemed to emulate posix readlink() behavior, returning the number of bytes copied into the output buffer. BeOS also did not guarantee that the string written into the output buffer is NULL terminated if the output buffer cannot contain the entire link contents, but the Haiku implementation does since it is is a basic safety issue. This patch fixes this and updates the Haiku API docs to describe the behavior explicitly. Fixing this required changing behavior in bfs_read_link, which required changes in many more places. docs/user/storage/SymLink.dox: src/kits/storage/SymLink.cpp: * Don't return B_BUFFER_OVERFLOW if the provided buffer is not large enough to hold the link contents. * Update documentation to clearly describe behavior. src/add-ons/kernel/file_systems/bfs/kernel_interface.cpp: * Change bfs_read_link() to always return the link length. This is called by common_read_link in the VFS, which is called by _kern_read_link(). src/add-ons/kernel/file_systems/btrfs/kernel_interface.cpp: src/add-ons/kernel/file_systems/exfat/kernel_interface.cpp: src/add-ons/kernel/file_systems/ext2/kernel_interface.cpp: src/add-ons/kernel/file_systems/iso9660/kernel_interface.cpp: src/add-ons/kernel/file_systems/netfs/client/netfs.cpp: src/add-ons/kernel/file_systems/nfs/nfs_add_on.c: src/add-ons/kernel/file_systems/ramfs/kernel_interface.cpp: src/add-ons/kernel/file_systems/reiserfs/Iterators.cpp: src/add-ons/kernel/file_systems/reiserfs/Iterators.h: src/add-ons/kernel/file_systems/reiserfs/Volume.cpp: src/add-ons/kernel/file_systems/reiserfs/Volume.h: * Update the implementation of read_link for these filesystems. Some of them were incorrect, and some had just copied the posix behavior of bfs from before this patch. * Use user_memcpy in ext2_read_link() * Use user_memcpy in nfs fs_read_link() * Use user_memcpy in reiserfs StreamReader::_ReadIndirectItem and StreamReader::_ReadDirectItem * Remove unused method Volume::ReadObject in reiserfs. src/add-ons/kernel/file_systems/packagefs/nodes/UnpackingLeafNode.cpp: src/add-ons/kernel/file_systems/packagefs/package_links/PackageLinkSymlink.cpp: * Update UnpackingLeafNode::ReadSymlink and PackageSymLink::ReadSymLink() to set the bufferSize out parameter to the symlink length. Both of these are called by packagefs_read_symlink. * Use user_memcpy src/add-ons/kernel/file_systems/netfs/client/netfs.cpp: * netfs seems mostly unimplemented. Added a FIXME note for future implementers so that they know to implement the correct behavior. src/system/libroot/posix/unistd/link.c: * readlinkat() was just wrapping _kern_read_link() because before this patch it had expected posix behavior. But now it does not, so we need to return the number of bytes written to the output buffer. src/build/libroot/fs.cpp: * Update _kern_read_link() in the compatibility code to emulate the Haiku behavior on the host system. This is done by using an intermediate buffer that is guaranteed to fit the link contents and returning its length. The intermediate buffer is copied into the output buffer until there is no more room. src/tests/kits/storage/SymLinkTest.cpp: * This patch also resolves some test failures similar to those resolved in ee8cf35f0 which fixed tests for BNode. The tests were failing because Haiku's error checking is just better. BeOS allowed constructing a BSymLink with BSymLink(BDirectory*, const char*) with the entry name of "". The same is true of the equivilant SetTo() method. The BSymLink object will appear valid until you attempt to use it by, for example, calling the ReadLink method, which will return B_BAD_VALUE. Haiku does a more appropriate thing and returns B_ENTRY_NOT_FOUND, for this constructor and the equivilant SetTo(BDirectory*, const char*) method. This patch fixes these test assertions to match Haiku behavior. docs/develop/file_systems/overview.txt: * Add notes for future filesystem driver implementers to call this mistake when implementing fs_vnode_ops::read_symlink. docs/user/drivers/fs_interface.dox: * Fix documentation for fs_vnode_ops::read_symlink Change-Id: I8bcb8b2a0c9333059c84ace15844c32d4efeed9d Reviewed-on: https://review.haiku-os.org/c/haiku/+/2502 Reviewed-by: waddlesplash <waddlesplash@gmail.com> Reviewed-by: Axel Dörfler <axeld@pinc-software.de>