Routing I/O requests to improve read/write concurrency

A method comprising:

• receiving a plurality of requests targeting a single file stored in an extent-based file system;
• identifying a plurality of extent maps that correspond to the single file;
• determining which extent map of the plurality of extent maps to use for routing each of the plurality of requests;
• routing a given request of the plurality of requests to a first extent map, responsive to determining a size of the given request is greater than a first threshold;
• routing the given request to a second extent map different from the first extent map responsive to determining a size of the given request is less than the first threshold;
• accessing the first extent map as an initial map used to identify first physical storage locations storing actual data corresponding to the first extent;
• and
• accessing the second extent map, simultaneous with the access of the first extent map, as an initial map used to identify second physical storage locations storing actual data corresponding to the second extent.

A non-transitory computer readable storage medium storing program instructions, wherein the program instructions are executable by a processor to:

• receive a plurality of requests targeting a single file stored in an extent-based file system;
• identify a plurality of extent maps that correspond to the single file;
• determine which extent map of the plurality of extent maps to use for routing each of the plurality of requests, based on one or more characteristics of each of the plurality of requests;
• route a given request of the plurality of requests to a first extent map, responsive to determining a size of the given request is greater than a first threshold;
• route the given request to a second extent map different from the first extent map responsive to determining a size of the given request is less than the first threshold;
• access the first extent map as an initial map used to identify first physical storage locations storing actual data corresponding to the first extent;
• and
• access the second extent map, simultaneous with the access of the first extent map, as an initial map used to identify second physical storage locations storing actual data corresponding to the second extent.