tcp: skip zero-length iovecs in tcp_writev2#39
Open
anican wants to merge 1 commit intoshenango:devfrom
Open
Conversation
This commit fixes a bug with tcp_writev2. Applications, such as memcached, can pass iovecs with zero length into tcp_writev2. Then, the main writev loop passes these entries to tcp_tx_send(). If an early entry is zero-length, tcp_tx_send() returns 0 and tcp_writev2() breaks early instead of continuing to later non-empty iovecs. This can cause applications to get stuck retrying sendmsg's that never make progress. Skip iovecs with iov_len == 0 before calling tcp_tx_send(). This avoids premature termination of the main writev loop
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
This commit fixes a bug with tcp_writev2.
Applications, such as memcached, can pass iovecs with zero length into tcp_writev2. Then, the main writev loop passes these entries to tcp_tx_send(). If an early entry is zero-length, tcp_tx_send() returns 0 and tcp_writev2() breaks early instead of continuing to later non-empty iovecs.
This can cause applications to get stuck retrying sendmsg's that never make progress.
Skip iovecs with iov_len == 0 before calling tcp_tx_send(). This avoids premature termination of the main writev loop