From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heiko Schocher Date: Wed, 21 Jan 2015 07:49:36 +0100 Subject: [U-Boot] [PATCH v3] Enable journal replay for UBIFS In-Reply-To: <20150120142229.GA49755@chhabea-vm-machine> References: <20150120142229.GA49755@chhabea-vm-machine> Message-ID: <54BF4C00.7010208@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hello Anton, Am 20.01.2015 15:22, schrieb Anton Habegger: > Hello Heiko > > Thank you fro the review. I added atomic_long_read in ubifs.h as > for other atomic operations. Hmm.. I see, there are other missing "atomic" defines for UBI also ... Ok, I tend to accept your patch, but the correct way would be to import "include/asm-generic/atomic-long.h" from linux and drop this definitions in ubifs.h ... Could you prepare such a second patch? > I hope (but I can't garantee) by this time the mail is well > formed. If not please tell me again. It looks good now! > During mount_ubifs the ubifs_replay_journal was disabled. This patch > enables it again and fix some unrecoverable UBIFS volumes. nitpick ... Sorry, this is not a valid commit message ... please look at http://www.denx.de/wiki/view/U-Boot/Patches how to write a commit message. Please add comments to your patch under a "---" line, and provide a patch history ... add also a hint from which linux version you picked up the new file fs/ubifs/gc.c Current version of the other MTD/UBI/UBIFS files is 1860e379875df: Linux 3.15 Could you use this as base for your patch? Thanks! > Signed-off-by: Anton Habegger > --- > fs/ubifs/Makefile | 2 +- > fs/ubifs/gc.c | 987 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ > fs/ubifs/replay.c | 4 - > fs/ubifs/super.c | 8 +- > fs/ubifs/tnc.c | 2 - > fs/ubifs/ubifs.h | 1 + > 6 files changed, 990 insertions(+), 14 deletions(-) > create mode 100644 fs/ubifs/gc.c Compiling current mainline with your patch drops the follwoing warning: CC fs/ubifs/tnc.o fs/ubifs/tnc.c: In function 'ubifs_tnc_close': fs/ubifs/tnc.c:2861:8: warning: variable 'n' set but not used [-Wunused-but-set-variable] Could you please fix this too? Thanks! Beside of this nitpicks, your patch looks good. bye, Heiko > diff --git a/fs/ubifs/Makefile b/fs/ubifs/Makefile > index 8c8c6ac..5efb349 100644 > --- a/fs/ubifs/Makefile > +++ b/fs/ubifs/Makefile > @@ -12,4 +12,4 @@ > obj-y := ubifs.o io.o super.o sb.o master.o lpt.o > obj-y += lpt_commit.o scan.o lprops.o > obj-y += tnc.o tnc_misc.o debug.o crc16.o budget.o > -obj-y += log.o orphan.o recovery.o replay.o > +obj-y += log.o orphan.o recovery.o replay.o gc.o > diff --git a/fs/ubifs/gc.c b/fs/ubifs/gc.c > new file mode 100644 > index 0000000..159ee67 > --- /dev/null > +++ b/fs/ubifs/gc.c > @@ -0,0 +1,987 @@ > +/* > + * This file is part of UBIFS. > + * > + * Copyright (C) 2006-2008 Nokia Corporation. > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms of the GNU General Public License version 2 as published by > + * the Free Software Foundation. > + * > + * This program is distributed in the hope that it will be useful, but WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for > + * more details. > + * > + * You should have received a copy of the GNU General Public License along with > + * this program; if not, write to the Free Software Foundation, Inc., 51 > + * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA > + * > + * Authors: Adrian Hunter > + * Artem Bityutskiy (???????? ?????) > + */ > + > +/* > + * This file implements garbage collection. The procedure for garbage collection > + * is different depending on whether a LEB as an index LEB (contains index > + * nodes) or not. For non-index LEBs, garbage collection finds a LEB which > + * contains a lot of dirty space (obsolete nodes), and copies the non-obsolete > + * nodes to the journal, at which point the garbage-collected LEB is free to be > + * reused. For index LEBs, garbage collection marks the non-obsolete index nodes > + * dirty in the TNC, and after the next commit, the garbage-collected LEB is > + * to be reused. Garbage collection will cause the number of dirty index nodes > + * to grow, however sufficient space is reserved for the index to ensure the > + * commit will never run out of space. > + * > + * Notes about dead watermark. At current UBIFS implementation we assume that > + * LEBs which have less than @c->dead_wm bytes of free + dirty space are full > + * and not worth garbage-collecting. The dead watermark is one min. I/O unit > + * size, or min. UBIFS node size, depending on what is greater. Indeed, UBIFS > + * Garbage Collector has to synchronize the GC head's write buffer before > + * returning, so this is about wasting one min. I/O unit. However, UBIFS GC can > + * actually reclaim even very small pieces of dirty space by garbage collecting > + * enough dirty LEBs, but we do not bother doing this at this implementation. > + * > + * Notes about dark watermark. The results of GC work depends on how big are > + * the UBIFS nodes GC deals with. Large nodes make GC waste more space. Indeed, > + * if GC move data from LEB A to LEB B and nodes in LEB A are large, GC would > + * have to waste large pieces of free space at the end of LEB B, because nodes > + * from LEB A would not fit. And the worst situation is when all nodes are of > + * maximum size. So dark watermark is the amount of free + dirty space in LEB > + * which are guaranteed to be reclaimable. If LEB has less space, the GC might > + * be unable to reclaim it. So, LEBs with free + dirty greater than dark > + * watermark are "good" LEBs from GC's point of few. The other LEBs are not so > + * good, and GC takes extra care when moving them. > + */ > +#ifndef __UBOOT__ > +#include > +#include > +#include > +#endif > +#include "ubifs.h" > + > +#ifndef __UBOOT__ > +/* > + * GC may need to move more than one LEB to make progress. The below constants > + * define "soft" and "hard" limits on the number of LEBs the garbage collector > + * may move. > + */ > +#define SOFT_LEBS_LIMIT 4 > +#define HARD_LEBS_LIMIT 32 > + > +/** > + * switch_gc_head - switch the garbage collection journal head. > + * @c: UBIFS file-system description object > + * @buf: buffer to write > + * @len: length of the buffer to write > + * @lnum: LEB number written is returned here > + * @offs: offset written is returned here > + * > + * This function switch the GC head to the next LEB which is reserved in > + * @c->gc_lnum. Returns %0 in case of success, %-EAGAIN if commit is required, > + * and other negative error code in case of failures. > + */ > +static int switch_gc_head(struct ubifs_info *c) > +{ > + int err, gc_lnum = c->gc_lnum; > + struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf; > + > + ubifs_assert(gc_lnum != -1); > + dbg_gc("switch GC head from LEB %d:%d to LEB %d (waste %d bytes)", > + wbuf->lnum, wbuf->offs + wbuf->used, gc_lnum, > + c->leb_size - wbuf->offs - wbuf->used); > + > + err = ubifs_wbuf_sync_nolock(wbuf); > + if (err) > + return err; > + > + /* > + * The GC write-buffer was synchronized, we may safely unmap > + * 'c->gc_lnum'. > + */ > + err = ubifs_leb_unmap(c, gc_lnum); > + if (err) > + return err; > + > + err = ubifs_wbuf_sync_nolock(wbuf); > + if (err) > + return err; > + > + err = ubifs_add_bud_to_log(c, GCHD, gc_lnum, 0); > + if (err) > + return err; > + > + c->gc_lnum = -1; > + err = ubifs_wbuf_seek_nolock(wbuf, gc_lnum, 0); > + return err; > +} > + > +/** > + * data_nodes_cmp - compare 2 data nodes. > + * @priv: UBIFS file-system description object > + * @a: first data node > + * @a: second data node > + * > + * This function compares data nodes @a and @b. Returns %1 if @a has greater > + * inode or block number, and %-1 otherwise. > + */ > +static int data_nodes_cmp(void *priv, struct list_head *a, struct list_head *b) > +{ > + ino_t inuma, inumb; > + struct ubifs_info *c = priv; > + struct ubifs_scan_node *sa, *sb; > + > + cond_resched(); > + if (a == b) > + return 0; > + > + sa = list_entry(a, struct ubifs_scan_node, list); > + sb = list_entry(b, struct ubifs_scan_node, list); > + > + ubifs_assert(key_type(c, &sa->key) == UBIFS_DATA_KEY); > + ubifs_assert(key_type(c, &sb->key) == UBIFS_DATA_KEY); > + ubifs_assert(sa->type == UBIFS_DATA_NODE); > + ubifs_assert(sb->type == UBIFS_DATA_NODE); > + > + inuma = key_inum(c, &sa->key); > + inumb = key_inum(c, &sb->key); > + > + if (inuma == inumb) { > + unsigned int blka = key_block(c, &sa->key); > + unsigned int blkb = key_block(c, &sb->key); > + > + if (blka <= blkb) > + return -1; > + } else if (inuma <= inumb) > + return -1; > + > + return 1; > +} > + > +/* > + * nondata_nodes_cmp - compare 2 non-data nodes. > + * @priv: UBIFS file-system description object > + * @a: first node > + * @a: second node > + * > + * This function compares nodes @a and @b. It makes sure that inode nodes go > + * first and sorted by length in descending order. Directory entry nodes go > + * after inode nodes and are sorted in ascending hash valuer order. > + */ > +static int nondata_nodes_cmp(void *priv, struct list_head *a, > + struct list_head *b) > +{ > + ino_t inuma, inumb; > + struct ubifs_info *c = priv; > + struct ubifs_scan_node *sa, *sb; > + > + cond_resched(); > + if (a == b) > + return 0; > + > + sa = list_entry(a, struct ubifs_scan_node, list); > + sb = list_entry(b, struct ubifs_scan_node, list); > + > + ubifs_assert(key_type(c, &sa->key) != UBIFS_DATA_KEY && > + key_type(c, &sb->key) != UBIFS_DATA_KEY); > + ubifs_assert(sa->type != UBIFS_DATA_NODE && > + sb->type != UBIFS_DATA_NODE); > + > + /* Inodes go before directory entries */ > + if (sa->type == UBIFS_INO_NODE) { > + if (sb->type == UBIFS_INO_NODE) > + return sb->len - sa->len; > + return -1; > + } > + if (sb->type == UBIFS_INO_NODE) > + return 1; > + > + ubifs_assert(key_type(c, &sa->key) == UBIFS_DENT_KEY || > + key_type(c, &sa->key) == UBIFS_XENT_KEY); > + ubifs_assert(key_type(c, &sb->key) == UBIFS_DENT_KEY || > + key_type(c, &sb->key) == UBIFS_XENT_KEY); > + ubifs_assert(sa->type == UBIFS_DENT_NODE || > + sa->type == UBIFS_XENT_NODE); > + ubifs_assert(sb->type == UBIFS_DENT_NODE || > + sb->type == UBIFS_XENT_NODE); > + > + inuma = key_inum(c, &sa->key); > + inumb = key_inum(c, &sb->key); > + > + if (inuma == inumb) { > + uint32_t hasha = key_hash(c, &sa->key); > + uint32_t hashb = key_hash(c, &sb->key); > + > + if (hasha <= hashb) > + return -1; > + } else if (inuma <= inumb) > + return -1; > + > + return 1; > +} > + > +/** > + * sort_nodes - sort nodes for GC. > + * @c: UBIFS file-system description object > + * @sleb: describes nodes to sort and contains the result on exit > + * @nondata: contains non-data nodes on exit > + * @min: minimum node size is returned here > + * > + * This function sorts the list of inodes to garbage collect. First of all, it > + * kills obsolete nodes and separates data and non-data nodes to the > + * @sleb->nodes and @nondata lists correspondingly. > + * > + * Data nodes are then sorted in block number order - this is important for > + * bulk-read; data nodes with lower inode number go before data nodes with > + * higher inode number, and data nodes with lower block number go before data > + * nodes with higher block number; > + * > + * Non-data nodes are sorted as follows. > + * o First go inode nodes - they are sorted in descending length order. > + * o Then go directory entry nodes - they are sorted in hash order, which > + * should supposedly optimize 'readdir()'. Direntry nodes with lower parent > + * inode number go before direntry nodes with higher parent inode number, > + * and direntry nodes with lower name hash values go before direntry nodes > + * with higher name hash values. > + * > + * This function returns zero in case of success and a negative error code in > + * case of failure. > + */ > +static int sort_nodes(struct ubifs_info *c, struct ubifs_scan_leb *sleb, > + struct list_head *nondata, int *min) > +{ > + int err; > + struct ubifs_scan_node *snod, *tmp; > + > + *min = INT_MAX; > + > + /* Separate data nodes and non-data nodes */ > + list_for_each_entry_safe(snod, tmp, &sleb->nodes, list) { > + ubifs_assert(snod->type == UBIFS_INO_NODE || > + snod->type == UBIFS_DATA_NODE || > + snod->type == UBIFS_DENT_NODE || > + snod->type == UBIFS_XENT_NODE || > + snod->type == UBIFS_TRUN_NODE); > + > + if (snod->type != UBIFS_INO_NODE && > + snod->type != UBIFS_DATA_NODE && > + snod->type != UBIFS_DENT_NODE && > + snod->type != UBIFS_XENT_NODE) { > + /* Probably truncation node, zap it */ > + list_del(&snod->list); > + kfree(snod); > + continue; > + } > + > + ubifs_assert(key_type(c, &snod->key) == UBIFS_DATA_KEY || > + key_type(c, &snod->key) == UBIFS_INO_KEY || > + key_type(c, &snod->key) == UBIFS_DENT_KEY || > + key_type(c, &snod->key) == UBIFS_XENT_KEY); > + > + err = ubifs_tnc_has_node(c, &snod->key, 0, sleb->lnum, > + snod->offs, 0); > + if (err < 0) > + return err; > + > + if (!err) { > + /* The node is obsolete, remove it from the list */ > + list_del(&snod->list); > + kfree(snod); > + continue; > + } > + > + if (snod->len < *min) > + *min = snod->len; > + > + if (key_type(c, &snod->key) != UBIFS_DATA_KEY) > + list_move_tail(&snod->list, nondata); > + } > + > + /* Sort data and non-data nodes */ > + list_sort(c, &sleb->nodes, &data_nodes_cmp); > + list_sort(c, nondata, &nondata_nodes_cmp); > + > + err = dbg_check_data_nodes_order(c, &sleb->nodes); > + if (err) > + return err; > + err = dbg_check_nondata_nodes_order(c, nondata); > + if (err) > + return err; > + return 0; > +} > + > +/** > + * move_node - move a node. > + * @c: UBIFS file-system description object > + * @sleb: describes the LEB to move nodes from > + * @snod: the mode to move > + * @wbuf: write-buffer to move node to > + * > + * This function moves node @snod to @wbuf, changes TNC correspondingly, and > + * destroys @snod. Returns zero in case of success and a negative error code in > + * case of failure. > + */ > +static int move_node(struct ubifs_info *c, struct ubifs_scan_leb *sleb, > + struct ubifs_scan_node *snod, struct ubifs_wbuf *wbuf) > +{ > + int err, new_lnum = wbuf->lnum, new_offs = wbuf->offs + wbuf->used; > + > + cond_resched(); > + err = ubifs_wbuf_write_nolock(wbuf, snod->node, snod->len); > + if (err) > + return err; > + > + err = ubifs_tnc_replace(c, &snod->key, sleb->lnum, > + snod->offs, new_lnum, new_offs, > + snod->len); > + list_del(&snod->list); > + kfree(snod); > + return err; > +} > + > +/** > + * move_nodes - move nodes. > + * @c: UBIFS file-system description object > + * @sleb: describes the LEB to move nodes from > + * > + * This function moves valid nodes from data LEB described by @sleb to the GC > + * journal head. This function returns zero in case of success, %-EAGAIN if > + * commit is required, and other negative error codes in case of other > + * failures. > + */ > +static int move_nodes(struct ubifs_info *c, struct ubifs_scan_leb *sleb) > +{ > + int err, min; > + LIST_HEAD(nondata); > + struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf; > + > + if (wbuf->lnum == -1) { > + /* > + * The GC journal head is not set, because it is the first GC > + * invocation since mount. > + */ > + err = switch_gc_head(c); > + if (err) > + return err; > + } > + > + err = sort_nodes(c, sleb, &nondata, &min); > + if (err) > + goto out; > + > + /* Write nodes to their new location. Use the first-fit strategy */ > + while (1) { > + int avail; > + struct ubifs_scan_node *snod, *tmp; > + > + /* Move data nodes */ > + list_for_each_entry_safe(snod, tmp, &sleb->nodes, list) { > + avail = c->leb_size - wbuf->offs - wbuf->used; > + if (snod->len > avail) > + /* > + * Do not skip data nodes in order to optimize > + * bulk-read. > + */ > + break; > + > + err = move_node(c, sleb, snod, wbuf); > + if (err) > + goto out; > + } > + > + /* Move non-data nodes */ > + list_for_each_entry_safe(snod, tmp, &nondata, list) { > + avail = c->leb_size - wbuf->offs - wbuf->used; > + if (avail < min) > + break; > + > + if (snod->len > avail) { > + /* > + * Keep going only if this is an inode with > + * some data. Otherwise stop and switch the GC > + * head. IOW, we assume that data-less inode > + * nodes and direntry nodes are roughly of the > + * same size. > + */ > + if (key_type(c, &snod->key) == UBIFS_DENT_KEY || > + snod->len == UBIFS_INO_NODE_SZ) > + break; > + continue; > + } > + > + err = move_node(c, sleb, snod, wbuf); > + if (err) > + goto out; > + } > + > + if (list_empty(&sleb->nodes) && list_empty(&nondata)) > + break; > + > + /* > + * Waste the rest of the space in the LEB and switch to the > + * next LEB. > + */ > + err = switch_gc_head(c); > + if (err) > + goto out; > + } > + > + return 0; > + > +out: > + list_splice_tail(&nondata, &sleb->nodes); > + return err; > +} > + > +/** > + * gc_sync_wbufs - sync write-buffers for GC. > + * @c: UBIFS file-system description object > + * > + * We must guarantee that obsoleting nodes are on flash. Unfortunately they may > + * be in a write-buffer instead. That is, a node could be written to a > + * write-buffer, obsoleting another node in a LEB that is GC'd. If that LEB is > + * erased before the write-buffer is sync'd and then there is an unclean > + * unmount, then an existing node is lost. To avoid this, we sync all > + * write-buffers. > + * > + * This function returns %0 on success or a negative error code on failure. > + */ > +static int gc_sync_wbufs(struct ubifs_info *c) > +{ > + int err, i; > + > + for (i = 0; i < c->jhead_cnt; i++) { > + if (i == GCHD) > + continue; > + err = ubifs_wbuf_sync(&c->jheads[i].wbuf); > + if (err) > + return err; > + } > + return 0; > +} > + > +/** > + * ubifs_garbage_collect_leb - garbage-collect a logical eraseblock. > + * @c: UBIFS file-system description object > + * @lp: describes the LEB to garbage collect > + * > + * This function garbage-collects an LEB and returns one of the @LEB_FREED, > + * @LEB_RETAINED, etc positive codes in case of success, %-EAGAIN if commit is > + * required, and other negative error codes in case of failures. > + */ > +int ubifs_garbage_collect_leb(struct ubifs_info *c, struct ubifs_lprops *lp) > +{ > + struct ubifs_scan_leb *sleb; > + struct ubifs_scan_node *snod; > + struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf; > + int err = 0, lnum = lp->lnum; > + > + ubifs_assert(c->gc_lnum != -1 || wbuf->offs + wbuf->used == 0 || > + c->need_recovery); > + ubifs_assert(c->gc_lnum != lnum); > + ubifs_assert(wbuf->lnum != lnum); > + > + if (lp->free + lp->dirty == c->leb_size) { > + /* Special case - a free LEB */ > + dbg_gc("LEB %d is free, return it", lp->lnum); > + ubifs_assert(!(lp->flags & LPROPS_INDEX)); > + > + if (lp->free != c->leb_size) { > + /* > + * Write buffers must be sync'd before unmapping > + * freeable LEBs, because one of them may contain data > + * which obsoletes something in 'lp->pnum'. > + */ > + err = gc_sync_wbufs(c); > + if (err) > + return err; > + err = ubifs_change_one_lp(c, lp->lnum, c->leb_size, > + 0, 0, 0, 0); > + if (err) > + return err; > + } > + err = ubifs_leb_unmap(c, lp->lnum); > + if (err) > + return err; > + > + if (c->gc_lnum == -1) { > + c->gc_lnum = lnum; > + return LEB_RETAINED; > + } > + > + return LEB_FREED; > + } > + > + /* > + * We scan the entire LEB even though we only really need to scan up to > + * (c->leb_size - lp->free). > + */ > + sleb = ubifs_scan(c, lnum, 0, c->sbuf, 0); > + if (IS_ERR(sleb)) > + return PTR_ERR(sleb); > + > + ubifs_assert(!list_empty(&sleb->nodes)); > + snod = list_entry(sleb->nodes.next, struct ubifs_scan_node, list); > + > + if (snod->type == UBIFS_IDX_NODE) { > + struct ubifs_gced_idx_leb *idx_gc; > + > + dbg_gc("indexing LEB %d (free %d, dirty %d)", > + lnum, lp->free, lp->dirty); > + list_for_each_entry(snod, &sleb->nodes, list) { > + struct ubifs_idx_node *idx = snod->node; > + int level = le16_to_cpu(idx->level); > + > + ubifs_assert(snod->type == UBIFS_IDX_NODE); > + key_read(c, ubifs_idx_key(c, idx), &snod->key); > + err = ubifs_dirty_idx_node(c, &snod->key, level, lnum, > + snod->offs); > + if (err) > + goto out; > + } > + > + idx_gc = kmalloc(sizeof(struct ubifs_gced_idx_leb), GFP_NOFS); > + if (!idx_gc) { > + err = -ENOMEM; > + goto out; > + } > + > + idx_gc->lnum = lnum; > + idx_gc->unmap = 0; > + list_add(&idx_gc->list, &c->idx_gc); > + > + /* > + * Don't release the LEB until after the next commit, because > + * it may contain data which is needed for recovery. So > + * although we freed this LEB, it will become usable only after > + * the commit. > + */ > + err = ubifs_change_one_lp(c, lnum, c->leb_size, 0, 0, > + LPROPS_INDEX, 1); > + if (err) > + goto out; > + err = LEB_FREED_IDX; > + } else { > + dbg_gc("data LEB %d (free %d, dirty %d)", > + lnum, lp->free, lp->dirty); > + > + err = move_nodes(c, sleb); > + if (err) > + goto out_inc_seq; > + > + err = gc_sync_wbufs(c); > + if (err) > + goto out_inc_seq; > + > + err = ubifs_change_one_lp(c, lnum, c->leb_size, 0, 0, 0, 0); > + if (err) > + goto out_inc_seq; > + > + /* Allow for races with TNC */ > + c->gced_lnum = lnum; > + smp_wmb(); > + c->gc_seq += 1; > + smp_wmb(); > + > + if (c->gc_lnum == -1) { > + c->gc_lnum = lnum; > + err = LEB_RETAINED; > + } else { > + err = ubifs_wbuf_sync_nolock(wbuf); > + if (err) > + goto out; > + > + err = ubifs_leb_unmap(c, lnum); > + if (err) > + goto out; > + > + err = LEB_FREED; > + } > + } > + > +out: > + ubifs_scan_destroy(sleb); > + return err; > + > +out_inc_seq: > + /* We may have moved at least some nodes so allow for races with TNC */ > + c->gced_lnum = lnum; > + smp_wmb(); > + c->gc_seq += 1; > + smp_wmb(); > + goto out; > +} > + > +/** > + * ubifs_garbage_collect - UBIFS garbage collector. > + * @c: UBIFS file-system description object > + * @anyway: do GC even if there are free LEBs > + * > + * This function does out-of-place garbage collection. The return codes are: > + * o positive LEB number if the LEB has been freed and may be used; > + * o %-EAGAIN if the caller has to run commit; > + * o %-ENOSPC if GC failed to make any progress; > + * o other negative error codes in case of other errors. > + * > + * Garbage collector writes data to the journal when GC'ing data LEBs, and just > + * marking indexing nodes dirty when GC'ing indexing LEBs. Thus, at some point > + * commit may be required. But commit cannot be run from inside GC, because the > + * caller might be holding the commit lock, so %-EAGAIN is returned instead; > + * And this error code means that the caller has to run commit, and re-run GC > + * if there is still no free space. > + * > + * There are many reasons why this function may return %-EAGAIN: > + * o the log is full and there is no space to write an LEB reference for > + * @c->gc_lnum; > + * o the journal is too large and exceeds size limitations; > + * o GC moved indexing LEBs, but they can be used only after the commit; > + * o the shrinker fails to find clean znodes to free and requests the commit; > + * o etc. > + * > + * Note, if the file-system is close to be full, this function may return > + * %-EAGAIN infinitely, so the caller has to limit amount of re-invocations of > + * the function. E.g., this happens if the limits on the journal size are too > + * tough and GC writes too much to the journal before an LEB is freed. This > + * might also mean that the journal is too large, and the TNC becomes to big, > + * so that the shrinker is constantly called, finds not clean znodes to free, > + * and requests commit. Well, this may also happen if the journal is all right, > + * but another kernel process consumes too much memory. Anyway, infinite > + * %-EAGAIN may happen, but in some extreme/misconfiguration cases. > + */ > +int ubifs_garbage_collect(struct ubifs_info *c, int anyway) > +{ > + int i, err, ret, min_space = c->dead_wm; > + struct ubifs_lprops lp; > + struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf; > + > + ubifs_assert_cmt_locked(c); > + ubifs_assert(!c->ro_media && !c->ro_mount); > + > + if (ubifs_gc_should_commit(c)) > + return -EAGAIN; > + > + mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); > + > + if (c->ro_error) { > + ret = -EROFS; > + goto out_unlock; > + } > + > + /* We expect the write-buffer to be empty on entry */ > + ubifs_assert(!wbuf->used); > + > + for (i = 0; ; i++) { > + int space_before, space_after; > + > + cond_resched(); > + > + /* Give the commit an opportunity to run */ > + if (ubifs_gc_should_commit(c)) { > + ret = -EAGAIN; > + break; > + } > + > + if (i > SOFT_LEBS_LIMIT && !list_empty(&c->idx_gc)) { > + /* > + * We've done enough iterations. Indexing LEBs were > + * moved and will be available after the commit. > + */ > + dbg_gc("soft limit, some index LEBs GC'ed, -EAGAIN"); > + ubifs_commit_required(c); > + ret = -EAGAIN; > + break; > + } > + > + if (i > HARD_LEBS_LIMIT) { > + /* > + * We've moved too many LEBs and have not made > + * progress, give up. > + */ > + dbg_gc("hard limit, -ENOSPC"); > + ret = -ENOSPC; > + break; > + } > + > + /* > + * Empty and freeable LEBs can turn up while we waited for > + * the wbuf lock, or while we have been running GC. In that > + * case, we should just return one of those instead of > + * continuing to GC dirty LEBs. Hence we request > + * 'ubifs_find_dirty_leb()' to return an empty LEB if it can. > + */ > + ret = ubifs_find_dirty_leb(c, &lp, min_space, anyway ? 0 : 1); > + if (ret) { > + if (ret == -ENOSPC) > + dbg_gc("no more dirty LEBs"); > + break; > + } > + > + dbg_gc("found LEB %d: free %d, dirty %d, sum %d (min. space %d)", > + lp.lnum, lp.free, lp.dirty, lp.free + lp.dirty, > + min_space); > + > + space_before = c->leb_size - wbuf->offs - wbuf->used; > + if (wbuf->lnum == -1) > + space_before = 0; > + > + ret = ubifs_garbage_collect_leb(c, &lp); > + if (ret < 0) { > + if (ret == -EAGAIN) { > + /* > + * This is not error, so we have to return the > + * LEB to lprops. But if 'ubifs_return_leb()' > + * fails, its failure code is propagated to the > + * caller instead of the original '-EAGAIN'. > + */ > + err = ubifs_return_leb(c, lp.lnum); > + if (err) > + ret = err; > + break; > + } > + goto out; > + } > + > + if (ret == LEB_FREED) { > + /* An LEB has been freed and is ready for use */ > + dbg_gc("LEB %d freed, return", lp.lnum); > + ret = lp.lnum; > + break; > + } > + > + if (ret == LEB_FREED_IDX) { > + /* > + * This was an indexing LEB and it cannot be > + * immediately used. And instead of requesting the > + * commit straight away, we try to garbage collect some > + * more. > + */ > + dbg_gc("indexing LEB %d freed, continue", lp.lnum); > + continue; > + } > + > + ubifs_assert(ret == LEB_RETAINED); > + space_after = c->leb_size - wbuf->offs - wbuf->used; > + dbg_gc("LEB %d retained, freed %d bytes", lp.lnum, > + space_after - space_before); > + > + if (space_after > space_before) { > + /* GC makes progress, keep working */ > + min_space >>= 1; > + if (min_space < c->dead_wm) > + min_space = c->dead_wm; > + continue; > + } > + > + dbg_gc("did not make progress"); > + > + /* > + * GC moved an LEB bud have not done any progress. This means > + * that the previous GC head LEB contained too few free space > + * and the LEB which was GC'ed contained only large nodes which > + * did not fit that space. > + * > + * We can do 2 things: > + * 1. pick another LEB in a hope it'll contain a small node > + * which will fit the space we have at the end of current GC > + * head LEB, but there is no guarantee, so we try this out > + * unless we have already been working for too long; > + * 2. request an LEB with more dirty space, which will force > + * 'ubifs_find_dirty_leb()' to start scanning the lprops > + * table, instead of just picking one from the heap > + * (previously it already picked the dirtiest LEB). > + */ > + if (i < SOFT_LEBS_LIMIT) { > + dbg_gc("try again"); > + continue; > + } > + > + min_space <<= 1; > + if (min_space > c->dark_wm) > + min_space = c->dark_wm; > + dbg_gc("set min. space to %d", min_space); > + } > + > + if (ret == -ENOSPC && !list_empty(&c->idx_gc)) { > + dbg_gc("no space, some index LEBs GC'ed, -EAGAIN"); > + ubifs_commit_required(c); > + ret = -EAGAIN; > + } > + > + err = ubifs_wbuf_sync_nolock(wbuf); > + if (!err) > + err = ubifs_leb_unmap(c, c->gc_lnum); > + if (err) { > + ret = err; > + goto out; > + } > +out_unlock: > + mutex_unlock(&wbuf->io_mutex); > + return ret; > + > +out: > + ubifs_assert(ret < 0); > + ubifs_assert(ret != -ENOSPC && ret != -EAGAIN); > + ubifs_wbuf_sync_nolock(wbuf); > + ubifs_ro_mode(c, ret); > + mutex_unlock(&wbuf->io_mutex); > + ubifs_return_leb(c, lp.lnum); > + return ret; > +} > + > +/** > + * ubifs_gc_start_commit - garbage collection at start of commit. > + * @c: UBIFS file-system description object > + * > + * If a LEB has only dirty and free space, then we may safely unmap it and make > + * it free. Note, we cannot do this with indexing LEBs because dirty space may > + * correspond index nodes that are required for recovery. In that case, the > + * LEB cannot be unmapped until after the next commit. > + * > + * This function returns %0 upon success and a negative error code upon failure. > + */ > +int ubifs_gc_start_commit(struct ubifs_info *c) > +{ > + struct ubifs_gced_idx_leb *idx_gc; > + const struct ubifs_lprops *lp; > + int err = 0, flags; > + > + ubifs_get_lprops(c); > + > + /* > + * Unmap (non-index) freeable LEBs. Note that recovery requires that all > + * wbufs are sync'd before this, which is done in 'do_commit()'. > + */ > + while (1) { > + lp = ubifs_fast_find_freeable(c); > + if (IS_ERR(lp)) { > + err = PTR_ERR(lp); > + goto out; > + } > + if (!lp) > + break; > + ubifs_assert(!(lp->flags & LPROPS_TAKEN)); > + ubifs_assert(!(lp->flags & LPROPS_INDEX)); > + err = ubifs_leb_unmap(c, lp->lnum); > + if (err) > + goto out; > + lp = ubifs_change_lp(c, lp, c->leb_size, 0, lp->flags, 0); > + if (IS_ERR(lp)) { > + err = PTR_ERR(lp); > + goto out; > + } > + ubifs_assert(!(lp->flags & LPROPS_TAKEN)); > + ubifs_assert(!(lp->flags & LPROPS_INDEX)); > + } > + > + /* Mark GC'd index LEBs OK to unmap after this commit finishes */ > + list_for_each_entry(idx_gc, &c->idx_gc, list) > + idx_gc->unmap = 1; > + > + /* Record index freeable LEBs for unmapping after commit */ > + while (1) { > + lp = ubifs_fast_find_frdi_idx(c); > + if (IS_ERR(lp)) { > + err = PTR_ERR(lp); > + goto out; > + } > + if (!lp) > + break; > + idx_gc = kmalloc(sizeof(struct ubifs_gced_idx_leb), GFP_NOFS); > + if (!idx_gc) { > + err = -ENOMEM; > + goto out; > + } > + ubifs_assert(!(lp->flags & LPROPS_TAKEN)); > + ubifs_assert(lp->flags & LPROPS_INDEX); > + /* Don't release the LEB until after the next commit */ > + flags = (lp->flags | LPROPS_TAKEN) ^ LPROPS_INDEX; > + lp = ubifs_change_lp(c, lp, c->leb_size, 0, flags, 1); > + if (IS_ERR(lp)) { > + err = PTR_ERR(lp); > + kfree(idx_gc); > + goto out; > + } > + ubifs_assert(lp->flags & LPROPS_TAKEN); > + ubifs_assert(!(lp->flags & LPROPS_INDEX)); > + idx_gc->lnum = lp->lnum; > + idx_gc->unmap = 1; > + list_add(&idx_gc->list, &c->idx_gc); > + } > +out: > + ubifs_release_lprops(c); > + return err; > +} > + > +/** > + * ubifs_gc_end_commit - garbage collection at end of commit. > + * @c: UBIFS file-system description object > + * > + * This function completes out-of-place garbage collection of index LEBs. > + */ > +int ubifs_gc_end_commit(struct ubifs_info *c) > +{ > + struct ubifs_gced_idx_leb *idx_gc, *tmp; > + struct ubifs_wbuf *wbuf; > + int err = 0; > + > + wbuf = &c->jheads[GCHD].wbuf; > + mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); > + list_for_each_entry_safe(idx_gc, tmp, &c->idx_gc, list) > + if (idx_gc->unmap) { > + dbg_gc("LEB %d", idx_gc->lnum); > + err = ubifs_leb_unmap(c, idx_gc->lnum); > + if (err) > + goto out; > + err = ubifs_change_one_lp(c, idx_gc->lnum, LPROPS_NC, > + LPROPS_NC, 0, LPROPS_TAKEN, -1); > + if (err) > + goto out; > + list_del(&idx_gc->list); > + kfree(idx_gc); > + } > +out: > + mutex_unlock(&wbuf->io_mutex); > + return err; > +} > +#endif > +/** > + * ubifs_destroy_idx_gc - destroy idx_gc list. > + * @c: UBIFS file-system description object > + * > + * This function destroys the @c->idx_gc list. It is called when unmounting > + * so locks are not needed. Returns zero in case of success and a negative > + * error code in case of failure. > + */ > +void ubifs_destroy_idx_gc(struct ubifs_info *c) > +{ > + while (!list_empty(&c->idx_gc)) { > + struct ubifs_gced_idx_leb *idx_gc; > + > + idx_gc = list_entry(c->idx_gc.next, struct ubifs_gced_idx_leb, > + list); > + c->idx_gc_cnt -= 1; > + list_del(&idx_gc->list); > + kfree(idx_gc); > + } > +} > +#ifndef __UBOOT__ > +/** > + * ubifs_get_idx_gc_leb - get a LEB from GC'd index LEB list. > + * @c: UBIFS file-system description object > + * > + * Called during start commit so locks are not needed. > + */ > +int ubifs_get_idx_gc_leb(struct ubifs_info *c) > +{ > + struct ubifs_gced_idx_leb *idx_gc; > + int lnum; > + > + if (list_empty(&c->idx_gc)) > + return -ENOSPC; > + idx_gc = list_entry(c->idx_gc.next, struct ubifs_gced_idx_leb, list); > + lnum = idx_gc->lnum; > + /* c->idx_gc_cnt is updated by the caller when lprops are updated */ > + list_del(&idx_gc->list); > + kfree(idx_gc); > + return lnum; > +} > +#endif > diff --git a/fs/ubifs/replay.c b/fs/ubifs/replay.c > index 7268b37..1064cb2 100644 > --- a/fs/ubifs/replay.c > +++ b/fs/ubifs/replay.c > @@ -78,7 +78,6 @@ struct bud_entry { > int dirty; > }; > > -#ifndef __UBOOT__ > /** > * set_bud_lprops - set free and dirty space used by a bud. > * @c: UBIFS file-system description object > @@ -432,7 +431,6 @@ static int insert_dent(struct ubifs_info *c, int lnum, int offs, int len, > list_add_tail(&r->list, &c->replay_list); > return 0; > } > -#endif > > /** > * ubifs_validate_entry - validate directory or extended attribute entry node. > @@ -466,7 +464,6 @@ int ubifs_validate_entry(struct ubifs_info *c, > return 0; > } > > -#ifndef __UBOOT__ > /** > * is_last_bud - check if the bud is the last in the journal head. > * @c: UBIFS file-system description object > @@ -1063,4 +1060,3 @@ out: > c->replaying = 0; > return err; > } > -#endif > diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c > index 01d449a..10f8fff 100644 > --- a/fs/ubifs/super.c > +++ b/fs/ubifs/super.c > @@ -1049,7 +1049,6 @@ static void free_orphans(struct ubifs_info *c) > c->orph_buf = NULL; > } > > -#ifndef __UBOOT__ > /** > * free_buds - free per-bud objects. > * @c: UBIFS file-system description object > @@ -1061,7 +1060,6 @@ static void free_buds(struct ubifs_info *c) > rbtree_postorder_for_each_entry_safe(bud, n, &c->buds, rb) > kfree(bud); > } > -#endif > > /** > * check_volume_empty - check if the UBI volume is empty. > @@ -1242,6 +1240,7 @@ static int ubifs_parse_options(struct ubifs_info *c, char *options, > > return 0; > } > +#endif > > /** > * destroy_journal - destroy journal data structures. > @@ -1272,7 +1271,6 @@ static void destroy_journal(struct ubifs_info *c) > ubifs_tnc_close(c); > free_buds(c); > } > -#endif > > /** > * bu_init - initialize bulk-read information. > @@ -1502,11 +1500,9 @@ static int mount_ubifs(struct ubifs_info *c) > if (err) > goto out_lpt; > > -#ifndef __UBOOT__ > err = ubifs_replay_journal(c); > if (err) > goto out_journal; > -#endif > > /* Calculate 'min_idx_lebs' after journal replay */ > c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c); > @@ -1678,10 +1674,8 @@ out_infos: > spin_unlock(&ubifs_infos_lock); > out_orphans: > free_orphans(c); > -#ifndef __UBOOT__ > out_journal: > destroy_journal(c); > -#endif > out_lpt: > ubifs_lpt_free(c, 0); > out_master: > diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c > index 95cae54..e20cedd 100644 > --- a/fs/ubifs/tnc.c > +++ b/fs/ubifs/tnc.c > @@ -2827,7 +2827,6 @@ out_unlock: > return ERR_PTR(err); > } > > -#ifndef __UBOOT__ > /** > * tnc_destroy_cnext - destroy left-over obsolete znodes from a failed commit. > * @c: UBIFS file-system description object > @@ -2869,7 +2868,6 @@ void ubifs_tnc_close(struct ubifs_info *c) > kfree(c->ilebs); > destroy_old_idx(c); > } > -#endif > > /** > * left_znode - get the znode to the left. > diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h > index c120261..1be0864 100644 > --- a/fs/ubifs/ubifs.h > +++ b/fs/ubifs/ubifs.h > @@ -70,6 +70,7 @@ void iput(struct inode *inode); > #define atomic_long_inc(a) > #define atomic_long_dec(a) > #define atomic_long_sub(a, b) > +#define atomic_long_read(a) *(a) > > typedef unsigned long atomic_long_t; > > -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany