#include <unistd.h>
#endif
-#if EXT2_FLAT_INCLUDES
#include "ext2_fs.h"
-#else
-#include <linux/ext2_fs.h>
-#endif
-
#include "ext2fs.h"
struct ext2_file {
ext2_ino_t ino;
struct ext2_inode inode;
int flags;
- ext2_off_t pos;
+ __u64 pos;
blk_t blockno;
blk_t physblock;
char *buf;
};
+#define BMAP_BUFFER (file->buf + fs->blocksize)
+
errcode_t ext2fs_file_open(ext2_filsys fs, ext2_ino_t ino,
int flags, ext2_file_t *ret)
{
if (retval)
goto fail;
- retval = ext2fs_get_mem(fs->blocksize * 2, (void **) &file->buf);
+ retval = ext2fs_get_mem(fs->blocksize * 3, (void **) &file->buf);
if (retval)
goto fail;
* This function flushes the dirty block buffer out to disk if
* necessary.
*/
-static errcode_t ext2fs_file_flush(ext2_file_t file)
+errcode_t ext2fs_file_flush(ext2_file_t file)
{
errcode_t retval;
+ ext2_filsys fs;
EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE);
+ fs = file->fs;
if (!(file->flags & EXT2_FILE_BUF_VALID) ||
!(file->flags & EXT2_FILE_BUF_DIRTY))
* Allocate it.
*/
if (!file->physblock) {
- retval = ext2fs_bmap(file->fs, file->ino, &file->inode,
- file->buf, BMAP_ALLOC,
+ retval = ext2fs_bmap(fs, file->ino, &file->inode,
+ BMAP_BUFFER, BMAP_ALLOC,
file->blockno, &file->physblock);
if (retval)
return retval;
}
- retval = io_channel_write_blk(file->fs->io, file->physblock,
+ retval = io_channel_write_blk(fs->io, file->physblock,
1, file->buf);
if (retval)
return retval;
return retval;
}
+/*
+ * This function synchronizes the file's block buffer and the current
+ * file position, possibly invalidating block buffer if necessary
+ */
+static errcode_t sync_buffer_position(ext2_file_t file)
+{
+ blk_t b;
+ errcode_t retval;
+
+ b = file->pos / file->fs->blocksize;
+ if (b != file->blockno) {
+ retval = ext2fs_file_flush(file);
+ if (retval)
+ return retval;
+ file->flags &= ~EXT2_FILE_BUF_VALID;
+ }
+ file->blockno = b;
+ return 0;
+}
+
+/*
+ * This function loads the file's block buffer with valid data from
+ * the disk as necessary.
+ *
+ * If dontfill is true, then skip initializing the buffer since we're
+ * going to be replacing its entire contents anyway. If set, then the
+ * function basically only sets file->physblock and EXT2_FILE_BUF_VALID
+ */
+#define DONTFILL 1
+static errcode_t load_buffer(ext2_file_t file, int dontfill)
+{
+ ext2_filsys fs = file->fs;
+ errcode_t retval;
+
+ if (!(file->flags & EXT2_FILE_BUF_VALID)) {
+ retval = ext2fs_bmap(fs, file->ino, &file->inode,
+ BMAP_BUFFER, 0, file->blockno,
+ &file->physblock);
+ if (retval)
+ return retval;
+ if (!dontfill) {
+ if (file->physblock) {
+ retval = io_channel_read_blk(fs->io,
+ file->physblock,
+ 1, file->buf);
+ if (retval)
+ return retval;
+ } else
+ memset(file->buf, 0, fs->blocksize);
+ }
+ file->flags |= EXT2_FILE_BUF_VALID;
+ }
+ return 0;
+}
+
+
errcode_t ext2fs_file_close(ext2_file_t file)
{
errcode_t retval;
unsigned int wanted, unsigned int *got)
{
ext2_filsys fs;
- errcode_t retval;
- blk_t b, pb;
- unsigned int start, left, c, count = 0;
+ errcode_t retval = 0;
+ unsigned int start, c, count = 0;
+ __u64 left;
char *ptr = (char *) buf;
EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE);
fs = file->fs;
-again:
- if (file->pos >= file->inode.i_size)
- goto done;
-
- b = file->pos / fs->blocksize;
- if (b != file->blockno) {
- retval = ext2fs_file_flush(file);
+ while ((file->pos < EXT2_I_SIZE(&file->inode)) && (wanted > 0)) {
+ retval = sync_buffer_position(file);
if (retval)
goto fail;
- file->flags &= ~EXT2_FILE_BUF_VALID;
- }
- file->blockno = b;
- if (!(file->flags & EXT2_FILE_BUF_VALID)) {
- retval = ext2fs_bmap(fs, file->ino, &file->inode,
- file->buf, 0, b, &pb);
+ retval = load_buffer(file, 0);
if (retval)
goto fail;
- if (pb) {
- file->physblock = pb;
- retval = io_channel_read_blk(fs->io, pb, 1, file->buf);
- if (retval)
- goto fail;
- } else {
- file->physblock = 0;
- memset(file->buf, 0, fs->blocksize);
- }
-
- file->flags |= EXT2_FILE_BUF_VALID;
+
+ start = file->pos % fs->blocksize;
+ c = fs->blocksize - start;
+ if (c > wanted)
+ c = wanted;
+ left = EXT2_I_SIZE(&file->inode) - file->pos ;
+ if (c > left)
+ c = left;
+
+ memcpy(ptr, file->buf+start, c);
+ file->pos += c;
+ ptr += c;
+ count += c;
+ wanted -= c;
}
- start = file->pos % fs->blocksize;
- c = fs->blocksize - start;
- if (c > wanted)
- c = wanted;
- left = file->inode.i_size - file->pos ;
- if (c > left)
- c = left;
- memcpy(ptr, file->buf+start, c);
- file->pos += c;
- ptr += c;
- count += c;
- wanted -= c;
-
- if (wanted > 0)
- goto again;
-
-done:
+fail:
if (got)
*got = count;
- return 0;
-
-fail:
- if (count)
- goto done;
return retval;
}
-errcode_t ext2fs_file_write(ext2_file_t file, void *buf,
+errcode_t ext2fs_file_write(ext2_file_t file, const void *buf,
unsigned int nbytes, unsigned int *written)
{
ext2_filsys fs;
- errcode_t retval;
- blk_t b, pb;
- unsigned int start, c, count = 0;
- char *ptr = (char *) buf;
+ errcode_t retval = 0;
+ unsigned int start, c, count = 0;
+ const char *ptr = (const char *) buf;
EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE);
fs = file->fs;
if (!(file->flags & EXT2_FILE_WRITE))
return EXT2_ET_FILE_RO;
-again:
- b = file->pos / fs->blocksize;
- if (b != file->blockno) {
- retval = ext2fs_file_flush(file);
+ while (nbytes > 0) {
+ retval = sync_buffer_position(file);
if (retval)
goto fail;
- file->flags &= ~EXT2_FILE_BUF_VALID;
- }
- file->blockno = b;
- if (!(file->flags & EXT2_FILE_BUF_VALID)) {
- retval = ext2fs_bmap(fs, file->ino, &file->inode,
- file->buf, BMAP_ALLOC, b, &pb);
- if (retval)
- goto fail;
- file->physblock = pb;
- retval = io_channel_read_blk(fs->io, pb, 1, file->buf);
+ start = file->pos % fs->blocksize;
+ c = fs->blocksize - start;
+ if (c > nbytes)
+ c = nbytes;
+
+ /*
+ * We only need to do a read-modify-update cycle if
+ * we're doing a partial write.
+ */
+ retval = load_buffer(file, (c == fs->blocksize));
if (retval)
goto fail;
- file->flags |= EXT2_FILE_BUF_VALID;
+
+ file->flags |= EXT2_FILE_BUF_DIRTY;
+ memcpy(file->buf+start, ptr, c);
+ file->pos += c;
+ ptr += c;
+ count += c;
+ nbytes -= c;
}
- start = file->pos % fs->blocksize;
- c = fs->blocksize - start;
- if (c > nbytes)
- c = nbytes;
- file->flags |= EXT2_FILE_BUF_DIRTY;
- memcpy(file->buf+start, ptr, c);
- file->pos += c;
- ptr += c;
- count += c;
- nbytes -= c;
-
- if (nbytes > 0)
- goto again;
-
-done:
+fail:
if (written)
*written = count;
- return 0;
-
-fail:
- if (count)
- goto done;
return retval;
}
-
-errcode_t ext2fs_file_lseek(ext2_file_t file, ext2_off_t offset,
- int whence, ext2_off_t *ret_pos)
+errcode_t ext2fs_file_llseek(ext2_file_t file, __u64 offset,
+ int whence, __u64 *ret_pos)
{
EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE);
else if (whence == EXT2_SEEK_CUR)
file->pos += offset;
else if (whence == EXT2_SEEK_END)
- file->pos = file->inode.i_size + offset;
+ file->pos = EXT2_I_SIZE(&file->inode) + offset;
else
return EXT2_ET_INVALID_ARGUMENT;
return 0;
}
+errcode_t ext2fs_file_lseek(ext2_file_t file, ext2_off_t offset,
+ int whence, ext2_off_t *ret_pos)
+{
+ __u64 loffset, ret_loffset;
+ errcode_t retval;
+
+ loffset = offset;
+ retval = ext2fs_file_llseek(file, loffset, whence, &ret_loffset);
+ if (ret_pos)
+ *ret_pos = (ext2_off_t) ret_loffset;
+ return retval;
+}
+
+
/*
* This function returns the size of the file, according to the inode
*/
-ext2_off_t ext2fs_file_get_size(ext2_file_t file)
+errcode_t ext2fs_file_get_lsize(ext2_file_t file, __u64 *ret_size)
{
if (file->magic != EXT2_ET_MAGIC_EXT2_FILE)
+ return EXT2_ET_MAGIC_EXT2_FILE;
+ *ret_size = EXT2_I_SIZE(&file->inode);
+ return 0;
+}
+
+/*
+ * This function returns the size of the file, according to the inode
+ */
+ext2_off_t ext2fs_file_get_size(ext2_file_t file)
+{
+ __u64 size;
+
+ if (ext2fs_file_get_lsize(file, &size))
+ return 0;
+ if ((size >> 32) != 0)
return 0;
- return file->inode.i_size;
+ return size;
}
/*
EXT2_CHECK_MAGIC(file, EXT2_ET_MAGIC_EXT2_FILE);
file->inode.i_size = size;
+ file->inode.i_size_high = 0;
retval = ext2fs_write_inode(file->fs, file->ino, &file->inode);
if (retval)
return retval;
git://git.whamcloud.com / tools / e2fsprogs.git / blobdiff