Lines Matching refs:data
20 to realize savings from the compression. In these cases, the data may be stored uncompressed on
31 The backing storage device must be sized for the worst case scenario, where no data can be
33 compressed block device. Since this algorithm ensures atomicity by never overwriting data
34 in place, some additional backing storage is required to temporarily store data for writes in
42 A compressed block device compresses and decompresses data in units of chunks, where a chunk is a
115 * Compress the incoming 16KB of data into this allocated buffer
116 * Assume this data compresses to 6KB. This requires 2 4KB backing IO units.
120 * Write the 6KB of data to backing IO units 0 and 1.
123 store the 16KB of data.
149 source data.
150 * Copy the incoming 4KB data to offset 8KB of this 16KB buffer. Zero the rest of the 16KB buffer.
152 * Compress the 16KB source data buffer into the 16KB destination buffer
153 * Assume this data compresses to 3KB. This requires 1 4KB backing IO unit.
155 * Write the 3KB of data to block 2.
182 * Since no data has been written to this chunk, return all 0's to satisfy the read I/O.
190 2 into it. This will be called the compressed data buffer. Note that 16KB is allocated
191 instead of 4KB so that we can reuse this buffer to hold the compressed data that will
193 * Allocate a 16KB buffer for the uncompressed data for this chunk. Decompress the data from
194 the compressed data buffer into this buffer.
195 * Copy the incoming 4KB of data to offset 4KB of the uncompressed data buffer.
196 * Compress the 16KB uncompressed data buffer into the compressed data buffer.
197 * Assume this data compresses to 5KB. This requires 2 4KB backing IO units.
199 * Write the 5KB of data to blocks 3 and 4.
202 by the logical map. If there was a power fail at this point, the previous data for this chunk
246 detected via the uncompressed data equaling all zeroes. When this occurs, the chunk map entry
276 operation 1 writes some data to chunk A, and while this is in progress, operation 2 also writes
277 some data to chunk A. In this case, operation 2 should not start until operation 1 has