Searched hist:d41efb52 (Results 1 – 2 of 2) sorted by relevance
/openbmc/linux/include/linux/ |
H A D | dcache.h | d41efb52 Mon Nov 04 21:30:52 CST 2019 Al Viro <viro@zeniv.linux.org.uk> fs/namei.c: pull positivity check into follow_managed()
There are 4 callers; two proceed to check if result is positive and fail with ENOENT if it isn't; one (in handle_lookup_down()) is guaranteed to yield positive and one (in lookup_fast()) is _preceded_ by positivity check.
However, follow_managed() on a negative dentry is a (fairly cheap) no-op on anything other than autofs. And negative autofs dentries are never hashed, so lookup_fast() is not going to run into one of those. Moreover, successful follow_managed() on a _positive_ dentry never yields a negative one (and we significantly rely upon that in callers of lookup_fast()).
In other words, we can easily transpose the positivity check and the call of follow_managed() in lookup_fast(). And that allows to fold the positivity check *into* follow_managed(), simplifying life for the code downstream of its calls.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> d41efb52 Mon Nov 04 21:30:52 CST 2019 Al Viro <viro@zeniv.linux.org.uk> fs/namei.c: pull positivity check into follow_managed() There are 4 callers; two proceed to check if result is positive and fail with ENOENT if it isn't; one (in handle_lookup_down()) is guaranteed to yield positive and one (in lookup_fast()) is _preceded_ by positivity check. However, follow_managed() on a negative dentry is a (fairly cheap) no-op on anything other than autofs. And negative autofs dentries are never hashed, so lookup_fast() is not going to run into one of those. Moreover, successful follow_managed() on a _positive_ dentry never yields a negative one (and we significantly rely upon that in callers of lookup_fast()). In other words, we can easily transpose the positivity check and the call of follow_managed() in lookup_fast(). And that allows to fold the positivity check *into* follow_managed(), simplifying life for the code downstream of its calls. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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/openbmc/linux/fs/ |
H A D | namei.c | d41efb52 Mon Nov 04 21:30:52 CST 2019 Al Viro <viro@zeniv.linux.org.uk> fs/namei.c: pull positivity check into follow_managed()
There are 4 callers; two proceed to check if result is positive and fail with ENOENT if it isn't; one (in handle_lookup_down()) is guaranteed to yield positive and one (in lookup_fast()) is _preceded_ by positivity check.
However, follow_managed() on a negative dentry is a (fairly cheap) no-op on anything other than autofs. And negative autofs dentries are never hashed, so lookup_fast() is not going to run into one of those. Moreover, successful follow_managed() on a _positive_ dentry never yields a negative one (and we significantly rely upon that in callers of lookup_fast()).
In other words, we can easily transpose the positivity check and the call of follow_managed() in lookup_fast(). And that allows to fold the positivity check *into* follow_managed(), simplifying life for the code downstream of its calls.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> d41efb52 Mon Nov 04 21:30:52 CST 2019 Al Viro <viro@zeniv.linux.org.uk> fs/namei.c: pull positivity check into follow_managed() There are 4 callers; two proceed to check if result is positive and fail with ENOENT if it isn't; one (in handle_lookup_down()) is guaranteed to yield positive and one (in lookup_fast()) is _preceded_ by positivity check. However, follow_managed() on a negative dentry is a (fairly cheap) no-op on anything other than autofs. And negative autofs dentries are never hashed, so lookup_fast() is not going to run into one of those. Moreover, successful follow_managed() on a _positive_ dentry never yields a negative one (and we significantly rely upon that in callers of lookup_fast()). In other words, we can easily transpose the positivity check and the call of follow_managed() in lookup_fast(). And that allows to fold the positivity check *into* follow_managed(), simplifying life for the code downstream of its calls. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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