Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
cachefiles: change cachefiles_bury_object to use start_renaming_dentry()
Rather then using lock_rename() and lookup_one() etc we can use
the new start_renaming_dentry(). This is part of centralising dir
locking and lookup so that locking rules can be changed.
Some error check are removed as not necessary. Checks for rep being a
non-dir or IS_DEADDIR and the check that ->graveyard is still a
directory only provide slightly more informative errors and have been
dropped.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: NeilBrown <neil@brown.name>
Link: https://patch.msgid.link/20260224222542.3458677-11-neilb@ownmail.net
Signed-off-by: Christian Brauner <brauner@kernel.org>
authored by
NeilBrown
and committed by
Christian Brauner
deef0499
2c3a9eb1
+34
-63
+34
-63
fs/cachefiles/namei.c
+34
-63
fs/cachefiles/namei.c
···
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struct dentry *rep,
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enum fscache_why_object_killed why)
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{
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-
struct dentry *grave, *trap;
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+
struct dentry *grave;
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+
struct renamedata rd = {};
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struct path path, path_to_graveyard;
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char nbuffer[8 + 8 + 1];
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int ret;
···
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(uint32_t) ktime_get_real_seconds(),
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(uint32_t) atomic_inc_return(&cache->gravecounter));
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-
/* do the multiway lock magic */
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trap = lock_rename(cache->graveyard, dir);
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if (IS_ERR(trap))
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return PTR_ERR(trap);
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-
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-
/* do some checks before getting the grave dentry */
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if (rep->d_parent != dir || IS_DEADDIR(d_inode(rep))) {
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/* the entry was probably culled when we dropped the parent dir
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* lock */
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unlock_rename(cache->graveyard, dir);
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_leave(" = 0 [culled?]");
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return 0;
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}
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-
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if (!d_can_lookup(cache->graveyard)) {
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unlock_rename(cache->graveyard, dir);
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cachefiles_io_error(cache, "Graveyard no longer a directory");
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return -EIO;
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}
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-
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if (trap == rep) {
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unlock_rename(cache->graveyard, dir);
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cachefiles_io_error(cache, "May not make directory loop");
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return -EIO;
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}
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-
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if (d_mountpoint(rep)) {
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unlock_rename(cache->graveyard, dir);
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cachefiles_io_error(cache, "Mountpoint in cache");
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return -EIO;
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}
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-
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grave = lookup_one(&nop_mnt_idmap, &QSTR(nbuffer), cache->graveyard);
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if (IS_ERR(grave)) {
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unlock_rename(cache->graveyard, dir);
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trace_cachefiles_vfs_error(object, d_inode(cache->graveyard),
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PTR_ERR(grave),
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cachefiles_trace_lookup_error);
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-
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if (PTR_ERR(grave) == -ENOMEM) {
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+
rd.mnt_idmap = &nop_mnt_idmap;
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+
rd.old_parent = dir;
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rd.new_parent = cache->graveyard;
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rd.flags = 0;
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ret = start_renaming_dentry(&rd, 0, rep, &QSTR(nbuffer));
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if (ret) {
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/* Some errors aren't fatal */
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if (ret == -EXDEV)
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/* double-lock failed */
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return ret;
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if (d_unhashed(rep) || rep->d_parent != dir || IS_DEADDIR(d_inode(rep))) {
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/* the entry was probably culled when we dropped the parent dir
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* lock */
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_leave(" = 0 [culled?]");
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return 0;
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}
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if (ret == -EINVAL || ret == -ENOTEMPTY) {
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cachefiles_io_error(cache, "May not make directory loop");
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return -EIO;
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+
}
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if (ret == -ENOMEM) {
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_leave(" = -ENOMEM");
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return -ENOMEM;
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}
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-
cachefiles_io_error(cache, "Lookup error %ld", PTR_ERR(grave));
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cachefiles_io_error(cache, "Lookup error %d", ret);
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return -EIO;
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}
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+
if (d_mountpoint(rep)) {
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end_renaming(&rd);
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cachefiles_io_error(cache, "Mountpoint in cache");
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+
return -EIO;
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+
}
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+
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grave = rd.new_dentry;
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if (d_is_positive(grave)) {
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unlock_rename(cache->graveyard, dir);
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dput(grave);
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end_renaming(&rd);
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grave = NULL;
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cond_resched();
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goto try_again;
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}
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if (d_mountpoint(grave)) {
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unlock_rename(cache->graveyard, dir);
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dput(grave);
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+
end_renaming(&rd);
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cachefiles_io_error(cache, "Mountpoint in graveyard");
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-
return -EIO;
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-
}
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-
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/* target should not be an ancestor of source */
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if (trap == grave) {
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unlock_rename(cache->graveyard, dir);
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dput(grave);
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cachefiles_io_error(cache, "May not make directory loop");
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return -EIO;
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}
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···
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if (ret < 0) {
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cachefiles_io_error(cache, "Rename security error %d", ret);
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} else {
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struct renamedata rd = {
365
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.mnt_idmap = &nop_mnt_idmap,
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-
.old_parent = dir,
367
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.old_dentry = rep,
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.new_parent = cache->graveyard,
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.new_dentry = grave,
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-
};
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trace_cachefiles_rename(object, d_inode(rep)->i_ino, why);
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ret = cachefiles_inject_read_error();
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if (ret == 0)
···
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}
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404
__cachefiles_unmark_inode_in_use(object, d_inode(rep));
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-
unlock_rename(cache->graveyard, dir);
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-
dput(grave);
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+
end_renaming(&rd);
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_leave(" = 0");
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return 0;
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}