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Add the ext2_clean_inode_content function to clear the content of an inode. Use it to implement the O_TRUNC.

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This commit is contained in:
Enrico Fraccaroli (Galfurian)
2024-02-29 16:44:11 -05:00
parent d213be2bcf
commit e4e740c1c5
1 changed files with 38 additions and 6 deletions
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mentos/src/fs/ext2.c
+38 -6
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@@ -4,10 +4,10 @@
/// See LICENSE.md for details.
// Setup the logging for this file (do this before any other include).
#include "sys/kernel_levels.h" // Include kernel log levels.
#define __DEBUG_HEADER__ "[EXT2 ]" ///< Change header.
#include "sys/kernel_levels.h" // Include kernel log levels.
#define __DEBUG_HEADER__ "[EXT2 ]" ///< Change header.
#define __DEBUG_LEVEL__ LOGLEVEL_INFO ///< Set log level.
#include "io/debug.h" // Include debugging functions.
#include "io/debug.h" // Include debugging functions.
#include "assert.h"
#include "fcntl.h"
@@ -1717,6 +1717,30 @@ static inline int ext2_directory_is_empty(ext2_filesystem_t *fs, uint8_t *cache,
return 1;
}
static int ext2_clean_inode_content(ext2_filesystem_t *fs, ext2_inode_t *inode, uint32_t inode_index)
{
// Check the type of operation.
if ((inode->mode & EXT2_S_IFREG) != EXT2_S_IFREG) {
pr_alert("Trying to clean the content of a non-regular file.\n");
return 1;
}
// Allocate the cache.
uint8_t *cache = kmem_cache_alloc(fs->ext2_buffer_cache, GFP_KERNEL);
// Get the cache size.
size_t cache_size = fs->ext2_buffer_cache->size;
// Clean the cache.
memset(cache, 0, cache_size);
for (ssize_t offset = 0, to_write; offset < inode->size;) {
// We do not want to extend the size of the inode.
to_write = max(min(offset + cache_size, inode->size), 0);
// Override the content.
offset += ext2_write_inode_data(fs, inode, inode_index, offset, to_write, (char *)cache);
}
// Free the cache.
kmem_cache_free(cache);
return 0;
}
// ============================================================================
// Directory Entry Management Functions
// ============================================================================
@@ -2256,7 +2280,7 @@ static int ext2_create_inode(
/// @return file descriptor number, -1 otherwise and errno is set to indicate the error.
/// @details
/// It is equivalent to: open(path, O_WRONLY|O_CREAT|O_TRUNC, mode)
static vfs_file_t *ext2_creat(const char *path, mode_t permission)
static vfs_file_t *ext2_creat(const char *path, mode_t mode)
{
// Get the name of the directory.
char parent_path[PATH_MAX];
@@ -2308,8 +2332,7 @@ static vfs_file_t *ext2_creat(const char *path, mode_t permission)
return file;
}
// Set the inode mode.
uint32_t mode = EXT2_S_IFREG;
mode |= 0xFFF & permission;
mode = EXT2_S_IFREG | (0xFFF & mode);
// Get the group index of the parent.
uint32_t group_index = ext2_get_group_index_from_inode(fs, parent->ino);
// Create and initialize the new inode.
@@ -2323,6 +2346,10 @@ static vfs_file_t *ext2_creat(const char *path, mode_t permission)
pr_err("Failed to write the newly created inode.\n");
goto close_parent_return_null;
}
// Clean the content of the newly created file.
ext2_clean_inode_content(fs, &inode, inode_index);
// Initialize the file.
if (ext2_allocate_direntry(fs, parent->ino, inode_index, file_name, ext2_file_type_regular_file) == -1) {
pr_err("Failed to allocate a new direntry for the inode.\n");
@@ -2416,6 +2443,11 @@ static vfs_file_t *ext2_open(const char *path, int flags, mode_t mode)
return NULL;
}
// Check if the file is a regular file, and the user wants to write and truncate.
if (bitmask_exact(inode.mode, EXT2_S_IFREG) && (bitmask_exact(flags, O_RDWR | O_TRUNC) || bitmask_exact(flags, O_RDONLY | O_TRUNC))) {
ext2_clean_inode_content(fs, &inode, direntry.inode);
}
vfs_file_t *file = ext2_find_vfs_file_with_inode(fs, direntry.inode);
if (file == NULL) {
// Allocate the memory for the file.