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Merge pull request #511 from embeddedt/fix_lseek

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Skip flushing file if lfs_file_rawseek() doesn't change position
This commit is contained in:
Christopher Haster
2021-01-18 11:47:56 -06:00
committed by GitHub
parent cfe779fc08 47d6b2fcf3
commit 9449ef4be4
2 changed files with 66 additions and 15 deletions
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36
lfs.c
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@@ -3055,14 +3055,6 @@ relocate:
static lfs_soff_t lfs_file_rawseek(lfs_t *lfs, lfs_file_t *file,
lfs_soff_t off, int whence) {
#ifndef LFS_READONLY
// write out everything beforehand, may be noop if rdonly
int err = lfs_file_flush(lfs, file);
if (err) {
return err;
}
#endif
// find new pos
lfs_off_t npos = file->pos;
if (whence == LFS_SEEK_SET) {
@@ -3070,7 +3062,7 @@ static lfs_soff_t lfs_file_rawseek(lfs_t *lfs, lfs_file_t *file,
} else if (whence == LFS_SEEK_CUR) {
npos = file->pos + off;
} else if (whence == LFS_SEEK_END) {
npos = file->ctz.size + off;
npos = lfs_file_rawsize(lfs, file) + off;
}
if (npos > lfs->file_max) {
@@ -3078,6 +3070,19 @@ static lfs_soff_t lfs_file_rawseek(lfs_t *lfs, lfs_file_t *file,
return LFS_ERR_INVAL;
}
if (file->pos == npos) {
// noop - position has not changed
return npos;
}
#ifndef LFS_READONLY
// write out everything beforehand, may be noop if rdonly
int err = lfs_file_flush(lfs, file);
if (err) {
return err;
}
#endif
// update pos
file->pos = npos;
return npos;
@@ -3108,21 +3113,22 @@ static int lfs_file_rawtruncate(lfs_t *lfs, lfs_file_t *file, lfs_off_t size) {
return err;
}
// need to set pos/block/off consistently so seeking back to
// the old position does not get confused
file->pos = size;
file->ctz.head = file->block;
file->ctz.size = size;
file->flags |= LFS_F_DIRTY | LFS_F_READING;
} else if (size > oldsize) {
// flush+seek if not already at end
if (file->pos != oldsize) {
lfs_soff_t res = lfs_file_rawseek(lfs, file, 0, LFS_SEEK_END);
if (res < 0) {
return (int)res;
}
lfs_soff_t res = lfs_file_rawseek(lfs, file, 0, LFS_SEEK_END);
if (res < 0) {
return (int)res;
}
// fill with zeros
while (file->pos < size) {
lfs_ssize_t res = lfs_file_rawwrite(lfs, file, &(uint8_t){0}, 1);
res = lfs_file_rawwrite(lfs, file, &(uint8_t){0}, 1);
if (res < 0) {
return (int)res;
}