UBIFS: split ubifs_rcvry_gc_commit
Split the 'ubifs_rcvry_gc_commit()' function and introduce a 'grab_empty_leb()' heler. This cleans 'ubifs_rcvry_gc_commit()' a little and makes it a bit less of spagetti. Also, add a commentary which explains why it is crucial to first search for an empty LEB and then run commit. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This commit is contained in:
Родитель
ec06814265
Коммит
447442139c
|
@ -1069,6 +1069,53 @@ int ubifs_clean_lebs(const struct ubifs_info *c, void *sbuf)
|
||||||
return 0;
|
return 0;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* grab_empty_leb - grab an empty LEB to use as GC LEB and run commit.
|
||||||
|
* @c: UBIFS file-system description object
|
||||||
|
*
|
||||||
|
* This is a helper function for 'ubifs_rcvry_gc_commit()' which grabs an empty
|
||||||
|
* LEB to be used as GC LEB (@c->gc_lnum), and then runs the commit. Returns
|
||||||
|
* zero in case of success and a negative error code in case of failure.
|
||||||
|
*/
|
||||||
|
static int grab_empty_leb(struct ubifs_info *c)
|
||||||
|
{
|
||||||
|
int lnum, err;
|
||||||
|
|
||||||
|
/*
|
||||||
|
* Note, it is very important to first search for an empty LEB and then
|
||||||
|
* run the commit, not vice-versa. The reason is that there might be
|
||||||
|
* only one empty LEB at the moment, the one which has been the
|
||||||
|
* @c->gc_lnum just before the power cut happened. During the regular
|
||||||
|
* UBIFS operation (not now) @c->gc_lnum is marked as "taken", so no
|
||||||
|
* one but GC can grab it. But at this moment this single empty LEB is
|
||||||
|
* not marked as taken, so if we run commit - what happens? Right, the
|
||||||
|
* commit will grab it and write the index there. Remember that the
|
||||||
|
* index always expands as long as there is free space, and it only
|
||||||
|
* starts consolidating when we run out of space.
|
||||||
|
*
|
||||||
|
* IOW, if we run commit now, we might not be able to find a free LEB
|
||||||
|
* after this.
|
||||||
|
*/
|
||||||
|
lnum = ubifs_find_free_leb_for_idx(c);
|
||||||
|
if (lnum < 0) {
|
||||||
|
dbg_err("could not find an empty LEB");
|
||||||
|
dbg_dump_lprops(c);
|
||||||
|
dbg_dump_budg(c, &c->bi);
|
||||||
|
return lnum;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Reset the index flag */
|
||||||
|
err = ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
|
||||||
|
LPROPS_INDEX, 0);
|
||||||
|
if (err)
|
||||||
|
return err;
|
||||||
|
|
||||||
|
c->gc_lnum = lnum;
|
||||||
|
dbg_rcvry("found empty LEB %d, run commit", lnum);
|
||||||
|
|
||||||
|
return ubifs_run_commit(c);
|
||||||
|
}
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* ubifs_rcvry_gc_commit - recover the GC LEB number and run the commit.
|
* ubifs_rcvry_gc_commit - recover the GC LEB number and run the commit.
|
||||||
* @c: UBIFS file-system description object
|
* @c: UBIFS file-system description object
|
||||||
|
@ -1096,7 +1143,7 @@ int ubifs_rcvry_gc_commit(struct ubifs_info *c)
|
||||||
c->gc_lnum = -1;
|
c->gc_lnum = -1;
|
||||||
if (wbuf->lnum == -1) {
|
if (wbuf->lnum == -1) {
|
||||||
dbg_rcvry("no GC head LEB");
|
dbg_rcvry("no GC head LEB");
|
||||||
goto find_free;
|
return grab_empty_leb(c);
|
||||||
}
|
}
|
||||||
/*
|
/*
|
||||||
* See whether the used space in the dirtiest LEB fits in the GC head
|
* See whether the used space in the dirtiest LEB fits in the GC head
|
||||||
|
@ -1104,7 +1151,7 @@ int ubifs_rcvry_gc_commit(struct ubifs_info *c)
|
||||||
*/
|
*/
|
||||||
if (wbuf->offs == c->leb_size) {
|
if (wbuf->offs == c->leb_size) {
|
||||||
dbg_rcvry("no room in GC head LEB");
|
dbg_rcvry("no room in GC head LEB");
|
||||||
goto find_free;
|
return grab_empty_leb(c);
|
||||||
}
|
}
|
||||||
err = ubifs_find_dirty_leb(c, &lp, wbuf->offs, 2);
|
err = ubifs_find_dirty_leb(c, &lp, wbuf->offs, 2);
|
||||||
if (err) {
|
if (err) {
|
||||||
|
@ -1121,7 +1168,7 @@ int ubifs_rcvry_gc_commit(struct ubifs_info *c)
|
||||||
*/
|
*/
|
||||||
if (err == -ENOSPC) {
|
if (err == -ENOSPC) {
|
||||||
dbg_rcvry("could not find a dirty LEB");
|
dbg_rcvry("could not find a dirty LEB");
|
||||||
goto find_free;
|
return grab_empty_leb(c);
|
||||||
}
|
}
|
||||||
return err;
|
return err;
|
||||||
}
|
}
|
||||||
|
@ -1167,30 +1214,6 @@ int ubifs_rcvry_gc_commit(struct ubifs_info *c)
|
||||||
return err;
|
return err;
|
||||||
dbg_rcvry("allocated LEB %d for GC", lnum);
|
dbg_rcvry("allocated LEB %d for GC", lnum);
|
||||||
return 0;
|
return 0;
|
||||||
|
|
||||||
find_free:
|
|
||||||
/*
|
|
||||||
* There is no GC head LEB or the free space in the GC head LEB is too
|
|
||||||
* small, or there are not dirty LEBs. Allocate gc_lnum by calling
|
|
||||||
* 'ubifs_find_free_leb_for_idx()' so GC is not run.
|
|
||||||
*/
|
|
||||||
lnum = ubifs_find_free_leb_for_idx(c);
|
|
||||||
if (lnum < 0) {
|
|
||||||
dbg_err("could not find an empty LEB");
|
|
||||||
dbg_dump_lprops(c);
|
|
||||||
dbg_dump_budg(c, &c->bi);
|
|
||||||
return lnum;
|
|
||||||
}
|
|
||||||
/* And reset the index flag */
|
|
||||||
err = ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
|
|
||||||
LPROPS_INDEX, 0);
|
|
||||||
if (err)
|
|
||||||
return err;
|
|
||||||
c->gc_lnum = lnum;
|
|
||||||
dbg_rcvry("allocated LEB %d for GC", lnum);
|
|
||||||
/* Run the commit */
|
|
||||||
dbg_rcvry("committing");
|
|
||||||
return ubifs_run_commit(c);
|
|
||||||
}
|
}
|
||||||
|
|
||||||
/**
|
/**
|
||||||
|
|
Загрузка…
Ссылка в новой задаче