Garbage collection in storage devices based on flash memories
First Claim
1. A method for managing a storage device based on a flash memory, the method including the steps for:
- mapping a logical memory space of the storage device, including a plurality of logical blocks, on a physical memory space of the flash memory, including a plurality of physical blocks adapted to be erased individually, the physical blocks including a set of first physical blocks corresponding to the logical blocks and a set of second physical blocks for replacing each bad physical block being unusable,detecting each bad physical block, anddiscarding each bad physical block to prevent using the bad physical block for mapping the logical memory space.
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Accused Products
Abstract
A solution for managing a storage device based on a flash memory is proposed. A corresponding method starts with the step for mapping a logical memory space of the storage device (including a plurality of logical blocks) on a physical memory space of the flash memory (including a plurality of physical blocks, which are adapted to be erased individually). The physical blocks include a set of first physical blocks (corresponding to the logical blocks) and a set of second—or spare—physical blocks (for replacing each bad physical block that is unusable). The method continues by detecting each bad physical block. Each bad physical block is then discarded, so to prevent using the bad physical block for mapping the logical memory space.
501 Citations
21 Claims
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1. A method for managing a storage device based on a flash memory, the method including the steps for:
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mapping a logical memory space of the storage device, including a plurality of logical blocks, on a physical memory space of the flash memory, including a plurality of physical blocks adapted to be erased individually, the physical blocks including a set of first physical blocks corresponding to the logical blocks and a set of second physical blocks for replacing each bad physical block being unusable, detecting each bad physical block, and discarding each bad physical block to prevent using the bad physical block for mapping the logical memory space. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 19, 20, 21)
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17. A method for managing a storage device based on a flash memory, wherein the storage device emulates a logical memory space, including a plurality of logical blocks each one having a plurality of logical sectors adapted to be written repeatedly, being mapped on a physical memory space of the flash memory, including a plurality of physical blocks adapted to be erased individually each one having a plurality of physical sectors adapted to be programmed once, consecutive versions of the logical sectors of each logical block being stored in succession in the physical sectors of a root physical block and at least one child physical block when the root physical block is full, wherein the method includes the step for:
defining a mapping structure for mapping each logical sector on an associated physical sector of a corresponding physical block storing the last version of the logical sector, wherein for each written logical block having at least one logical sector being written the mapping structure includes a sector map having a field for each logical sector of the written logical block, the field storing an indication of the associated physical sector when the logical sector is written or a value equal to the indication of a predefined physical sector of the written logical block when the logical sector is not written, and a further field for storing an indication of the logical sector being written in the predefined physical sector.
Specification