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Message-ID: <875xzhxizb.fsf@mailhost.krisman.be> Date: Thu, 25 Jan 2024 17:20:56 -0300 From: Gabriel Krisman Bertazi <krisman@...e.de> To: Eric Biggers <ebiggers@...nel.org> Cc: viro@...iv.linux.org.uk, jaegeuk@...nel.org, tytso@....edu, linux-ext4@...r.kernel.org, linux-f2fs-devel@...ts.sourceforge.net, linux-fsdevel@...r.kernel.org, amir73il@...il.com Subject: Re: [PATCH v3 04/10] fscrypt: Drop d_revalidate once the key is added Eric Biggers <ebiggers@...nel.org> writes: > On Fri, Jan 19, 2024 at 03:47:36PM -0300, Gabriel Krisman Bertazi wrote: >> /* >> * When d_splice_alias() moves a directory's no-key alias to its plaintext alias >> * as a result of the encryption key being added, DCACHE_NOKEY_NAME must be >> * cleared. Note that we don't have to support arbitrary moves of this flag >> * because fscrypt doesn't allow no-key names to be the source or target of a >> * rename(). >> */ >> static inline void fscrypt_handle_d_move(struct dentry *dentry) >> { >> dentry->d_flags &= ~DCACHE_NOKEY_NAME; >> + >> + /* >> + * Save the d_revalidate call cost during VFS operations. We >> + * can do it because, when the key is available, the dentry >> + * can't go stale and the key won't go away without eviction. >> + */ >> + if (dentry->d_op && dentry->d_op->d_revalidate == fscrypt_d_revalidate) >> + dentry->d_flags &= ~DCACHE_OP_REVALIDATE; >> } > > Is there any way to optimize this further for the case where fscrypt is not > being used? This is called unconditionally from d_move(). I've generally been > trying to avoid things like this where the fscrypt support slows things down for > everyone even when they're not using the feature. The problem would be figuring out whether the filesystem has fscrypt enabled. I think we can rely on sb->s_cop always being set: if (sb->s_cop) fscrypt_handle_d_move(dentry); What do you think? -- Gabriel Krisman Bertazi
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