Ensure superblock always fits SIMPLEFS_BLOCK_SIZE #49
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jserv
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May 7, 2024
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Read https://cbea.ms/git-commit/ carefully and rework the git commit message.
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In the commit message, instead of stating that "This commit ensures...," you should explain the issues or limitations present in the current implementation, such as poor cache locality. Additionally, if the proposed changes aim to enhance performance and/or improve the memory layout, utilize the term "improve" in the git commit message to accurately reflect the intended improvements. |
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jserv
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jserv
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jserv
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jserv
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Consider the following changes: --- a/mkfs.c
+++ b/mkfs.c
@@ -17,6 +17,8 @@ struct superblock {
};
};
+_Static_assert(sizeof(struct superblock) == SIMPLEFS_BLOCK_SIZE);
+
/**
* DIV_ROUND_UP - round up a division
* @n: dividend
@@ -239,7 +241,6 @@ static int write_data_blocks(int fd, struct superblock *sb)
int main(int argc, char **argv)
{
- _Static_assert(sizeof(struct superblock) == SIMPLEFS_BLOCK_SIZE);
if (argc != 2) {
fprintf(stderr, "Usage: %s disk\n", argv[0]);
return EXIT_FAILURE;In git commit message, you should explain why union does matter. |
In current implementation, the struct superblock used padding via subtraction to match the SIMPLEFS_BLOCK_SIZE, which could lead to the need for recalculating the padding when the data structure changed. This commit introduces a union that allocates the largest size among its members to set the struct superblock size, ensuring that it is at least SIMPLEFS_BLOCK_SIZE. Additionally, it utilizes the _Static_assert keyword to verify whether the size matches SIMPLEFS_BLOCK_SIZE.
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Thank @HotMercury for contributing! |
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This commit ensures that the padding size always matches the block size defined by SIMPLEFS_BLOCK_SIZE.