kernel/linux.git/fs/ext2/namei.c, branch v7.1

ext2: avoid drop_nlink() during unlink of zero-nlink inode in ext2_unlink()

2026-02-27T11:17:52+00:00

ext2_unlink() calls inode_dec_link_count() unconditionally, which invokes drop_nlink(). If the inode was loaded from a corrupted disk image with i_links_count == 0, drop_nlink() triggers WARN_ON(inode->i_nlink == 0) Follow the ext4 pattern from __ext4_unlink(): check i_nlink before decrementing. If already zero, skip the decrement. Signed-off-by: Ziyi Guo Link: https://patch.msgid.link/20260211022052.973114-1-n7l8m4@u.northwestern.edu Signed-off-by: Jan Kara

ext2: remove stale TODO about kmap

2026-02-27T11:12:32+00:00

The TODO comment in the file header asking to get rid of kmap() is outdated. The code has already been converted to use the folio API (specifically kmap_local_folio). Remove the stale comment to reflect the current state of the code. Signed-off-by: Milos Nikic Link: https://patch.msgid.link/20260207002908.176933-1-nikic.milos@gmail.com Signed-off-by: Jan Kara

Change inode_operations.mkdir to return struct dentry *

2025-02-27T19:00:17+00:00

Some filesystems, such as NFS, cifs, ceph, and fuse, do not have complete control of sequencing on the actual filesystem (e.g. on a different server) and may find that the inode created for a mkdir request already exists in the icache and dcache by the time the mkdir request returns. For example, if the filesystem is mounted twice the directory could be visible on the other mount before it is on the original mount, and a pair of name_to_handle_at(), open_by_handle_at() calls could instantiate the directory inode with an IS_ROOT() dentry before the first mkdir returns. This means that the dentry passed to ->mkdir() may not be the one that is associated with the inode after the ->mkdir() completes. Some callers need to interact with the inode after the ->mkdir completes and they currently need to perform a lookup in the (rare) case that the dentry is no longer hashed. This lookup-after-mkdir requires that the directory remains locked to avoid races. Planned future patches to lock the dentry rather than the directory will mean that this lookup cannot be performed atomically with the mkdir. To remove this barrier, this patch changes ->mkdir to return the resulting dentry if it is different from the one passed in. Possible returns are: NULL - the directory was created and no other dentry was used ERR_PTR() - an error occurred non-NULL - this other dentry was spliced in This patch only changes file-systems to return "ERR_PTR(err)" instead of "err" or equivalent transformations. Subsequent patches will make further changes to some file-systems to return a correct dentry. Not all filesystems reliably result in a positive hashed dentry: - NFS, cifs, hostfs will sometimes need to perform a lookup of the name to get inode information. Races could result in this returning something different. Note that this lookup is non-atomic which is what we are trying to avoid. Placing the lookup in filesystem code means it only happens when the filesystem has no other option. - kernfs and tracefs leave the dentry negative and the ->revalidate operation ensures that lookup will be called to correctly populate the dentry. This could be fixed but I don't think it is important to any of the users of vfs_mkdir() which look at the dentry. The recommendation to use d_drop();d_splice_alias() is ugly but fits with current practice. A planned future patch will change this. Reviewed-by: Jeff Layton Reviewed-by: Jan Kara Signed-off-by: NeilBrown Link: https://lore.kernel.org/r/20250227013949.536172-2-neilb@suse.de Signed-off-by: Christian Brauner

ext2: Avoid reading renamed directory if parent does not change

2023-11-25T07:53:20+00:00

The VFS will not be locking moved directory if its parent does not change. Change ext2 rename code to avoid reading renamed directory if its parent does not change. Although it is currently harmless it is a bad practice to read directory contents without inode->i_rwsem. Signed-off-by: Jan Kara Signed-off-by: Al Viro

ext2: Convert ext2_unlink() and ext2_rename() to use folios

2023-10-25T18:31:29+00:00

This involves changing ext2_find_entry(), ext2_dotdot(), ext2_inode_by_name(), ext2_set_link() and ext2_delete_entry() to take a folio. These were also the last users of ext2_get_page() and ext2_put_page(), so remove those at the same time. Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Jan Kara Message-Id: <20230921200746.3303942-8-willy@infradead.org>

ext2: convert to ctime accessor functions

2023-07-13T08:28:07+00:00

In later patches, we're going to change how the inode's ctime field is used. Switch to using accessor functions instead of raw accesses of inode->i_ctime. Signed-off-by: Jeff Layton Reviewed-by: Jan Kara Message-Id: <20230705190309.579783-39-jlayton@kernel.org> Signed-off-by: Christian Brauner

ext2_find_entry()/ext2_dotdot(): callers don't need page_addr anymore

2023-05-29T09:03:31+00:00

... and that's how it should've been done in the first place Signed-off-by: Al Viro Reviewed-by: Fabio M. De Francesco Tested-by: Fabio M. De Francesco Signed-off-by: Jan Kara

ext2_{set_link,delete_entry}(): don't bother with page_addr

2023-05-29T09:03:28+00:00

ext2_set_link() simply doesn't use it anymore and ext2_delete_entry() can easily obtain it from the directory entry pointer... Signed-off-by: Al Viro Reviewed-by: Fabio M. De Francesco Tested-by: Fabio M. De Francesco Signed-off-by: Jan Kara

ext2_put_page(): accept any pointer within the page

2023-05-29T09:03:25+00:00

eliminates the need to keep the pointer to the first byte within the page if we are guaranteed to have pointers to some byte in the same page at hand. Don't backport without commit 88d7b12068b9 ("highmem: round down the address passed to kunmap_flush_on_unmap()"). Signed-off-by: Al Viro Reviewed-by: Fabio M. De Francesco Tested-by: Fabio M. De Francesco Signed-off-by: Jan Kara

ext2_rename(): set_link and delete_entry may fail

2023-05-29T09:03:06+00:00

Signed-off-by: Al Viro Reviewed-by: Fabio M. De Francesco Tested-by: Fabio M. De Francesco Signed-off-by: Jan Kara