Caching techniques using a two-level read cache

A system comprising:

• one or more processors;
• and
• a memory comprising code stored thereon that, when executed, performs a method comprising:
• receiving a read I/O operation that reads first content stored at a target logical address;
• determining, using the target logical address as a first key to index into a first cache, whether the first cache includes a first cache entry caching first metadata used to access a first physical storage location including the first content stored at the target logical address;
• responsive to determining the first cache includes the first cache entry, determining, using the first metadata as a second key to index into a second cache, whether the second cache includes a second cache entry caching the first content stored at the target logical address;
• and
• responsive to determining the second cache includes the second entry, returning the first content from the second entry of the second cache in response to the read I/O operation.

A non-transitory computer readable medium comprising code stored thereon that, when executed, performs a method comprising:

• receiving a read I/O operation that reads first content stored at a target logical address;
• determining, using the target logical address as a first key to index into a first cache, whether the first cache includes a first cache entry caching first metadata used to access a first physical storage location including the first content stored at the target logical address;
• responsive to determining the first cache includes the first cache entry, determining, using the first metadata as a second key to index into a second cache, whether the second cache includes a second cache entry caching the first content stored at the target logical address;
• and
• responsive to determining the second cache includes the second entry, returning the first content from the second entry of the second cache in response to the read I/O operation.