Commit 574c3fda authored by Linus Torvalds's avatar Linus Torvalds

Merge branch 'linux-next' of git://git.infradead.org/~dedekind/ubi-2.6

* 'linux-next' of git://git.infradead.org/~dedekind/ubi-2.6:
  UBI: fix checkpatch.pl warnings
  UBI: simplify PEB protection code
  UBI: prepare for protection tree improvements
  UBI: return -ENOMEM upon failing vmalloc
  UBI: document UBI ioctls
  UBI: handle write errors in WL worker
  UBI: fix error path
  UBI: some code re-structuring
  UBI: fix deadlock
  UBI: fix warnings when debugging is enabled
parents 56635f7e f2863c54
......@@ -97,6 +97,7 @@ Code Seq# Include File Comments
<http://linux01.gwdg.de/~alatham/ppdd.html>
'M' all linux/soundcard.h
'N' 00-1F drivers/usb/scanner.h
'O' 00-02 include/mtd/ubi-user.h UBI
'P' all linux/soundcard.h
'Q' all linux/soundcard.h
'R' 00-1F linux/random.h
......@@ -142,6 +143,9 @@ Code Seq# Include File Comments
'n' 00-7F linux/ncp_fs.h
'n' E0-FF video/matrox.h matroxfb
'o' 00-1F fs/ocfs2/ocfs2_fs.h OCFS2
'o' 00-03 include/mtd/ubi-user.h conflict! (OCFS2 and UBI overlaps)
'o' 40-41 include/mtd/ubi-user.h UBI
'o' 01-A1 include/linux/dvb/*.h DVB
'p' 00-0F linux/phantom.h conflict! (OpenHaptics needs this)
'p' 00-3F linux/mc146818rtc.h conflict!
'p' 40-7F linux/nvram.h
......
......@@ -815,6 +815,7 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
if (err)
goto out_free;
err = -ENOMEM;
ubi->peb_buf1 = vmalloc(ubi->peb_size);
if (!ubi->peb_buf1)
goto out_free;
......
......@@ -721,7 +721,8 @@ static int rename_volumes(struct ubi_device *ubi,
* It seems we need to remove volume with name @re->new_name,
* if it exists.
*/
desc = ubi_open_volume_nm(ubi->ubi_num, re->new_name, UBI_EXCLUSIVE);
desc = ubi_open_volume_nm(ubi->ubi_num, re->new_name,
UBI_EXCLUSIVE);
if (IS_ERR(desc)) {
err = PTR_ERR(desc);
if (err == -ENODEV)
......
......@@ -504,12 +504,9 @@ static int recover_peb(struct ubi_device *ubi, int pnum, int vol_id, int lnum,
if (!vid_hdr)
return -ENOMEM;
mutex_lock(&ubi->buf_mutex);
retry:
new_pnum = ubi_wl_get_peb(ubi, UBI_UNKNOWN);
if (new_pnum < 0) {
mutex_unlock(&ubi->buf_mutex);
ubi_free_vid_hdr(ubi, vid_hdr);
return new_pnum;
}
......@@ -529,20 +526,23 @@ retry:
goto write_error;
data_size = offset + len;
mutex_lock(&ubi->buf_mutex);
memset(ubi->peb_buf1 + offset, 0xFF, len);
/* Read everything before the area where the write failure happened */
if (offset > 0) {
err = ubi_io_read_data(ubi, ubi->peb_buf1, pnum, 0, offset);
if (err && err != UBI_IO_BITFLIPS)
goto out_put;
goto out_unlock;
}
memcpy(ubi->peb_buf1 + offset, buf, len);
err = ubi_io_write_data(ubi, ubi->peb_buf1, new_pnum, 0, data_size);
if (err)
if (err) {
mutex_unlock(&ubi->buf_mutex);
goto write_error;
}
mutex_unlock(&ubi->buf_mutex);
ubi_free_vid_hdr(ubi, vid_hdr);
......@@ -553,8 +553,9 @@ retry:
ubi_msg("data was successfully recovered");
return 0;
out_put:
out_unlock:
mutex_unlock(&ubi->buf_mutex);
out_put:
ubi_wl_put_peb(ubi, new_pnum, 1);
ubi_free_vid_hdr(ubi, vid_hdr);
return err;
......@@ -567,7 +568,6 @@ write_error:
ubi_warn("failed to write to PEB %d", new_pnum);
ubi_wl_put_peb(ubi, new_pnum, 1);
if (++tries > UBI_IO_RETRIES) {
mutex_unlock(&ubi->buf_mutex);
ubi_free_vid_hdr(ubi, vid_hdr);
return err;
}
......@@ -950,9 +950,13 @@ write_error:
* physical eraseblock @to. The @vid_hdr buffer may be changed by this
* function. Returns:
* o %0 in case of success;
* o %1 if the operation was canceled and should be tried later (e.g.,
* because a bit-flip was detected at the target PEB);
* o %2 if the volume is being deleted and this LEB should not be moved.
* o %1 if the operation was canceled because the volume is being deleted
* or because the PEB was put meanwhile;
* o %2 if the operation was canceled because there was a write error to the
* target PEB;
* o %-EAGAIN if the operation was canceled because a bit-flip was detected
* in the target PEB;
* o a negative error code in case of failure.
*/
int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
struct ubi_vid_hdr *vid_hdr)
......@@ -978,7 +982,7 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
/*
* Note, we may race with volume deletion, which means that the volume
* this logical eraseblock belongs to might be being deleted. Since the
* volume deletion unmaps all the volume's logical eraseblocks, it will
* volume deletion un-maps all the volume's logical eraseblocks, it will
* be locked in 'ubi_wl_put_peb()' and wait for the WL worker to finish.
*/
vol = ubi->volumes[idx];
......@@ -986,7 +990,7 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
/* No need to do further work, cancel */
dbg_eba("volume %d is being removed, cancel", vol_id);
spin_unlock(&ubi->volumes_lock);
return 2;
return 1;
}
spin_unlock(&ubi->volumes_lock);
......@@ -1023,7 +1027,7 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
/*
* OK, now the LEB is locked and we can safely start moving it. Since
* this function utilizes thie @ubi->peb1_buf buffer which is shared
* this function utilizes the @ubi->peb1_buf buffer which is shared
* with some other functions, so lock the buffer by taking the
* @ubi->buf_mutex.
*/
......@@ -1068,8 +1072,11 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
err = ubi_io_write_vid_hdr(ubi, to, vid_hdr);
if (err)
if (err) {
if (err == -EIO)
err = 2;
goto out_unlock_buf;
}
cond_resched();
......@@ -1079,14 +1086,17 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
if (err != UBI_IO_BITFLIPS)
ubi_warn("cannot read VID header back from PEB %d", to);
else
err = 1;
err = -EAGAIN;
goto out_unlock_buf;
}
if (data_size > 0) {
err = ubi_io_write_data(ubi, ubi->peb_buf1, to, 0, aldata_size);
if (err)
if (err) {
if (err == -EIO)
err = 2;
goto out_unlock_buf;
}
cond_resched();
......@@ -1101,15 +1111,16 @@ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
ubi_warn("cannot read data back from PEB %d",
to);
else
err = 1;
err = -EAGAIN;
goto out_unlock_buf;
}
cond_resched();
if (memcmp(ubi->peb_buf1, ubi->peb_buf2, aldata_size)) {
ubi_warn("read data back from PEB %d - it is different",
to);
ubi_warn("read data back from PEB %d and it is "
"different", to);
err = -EINVAL;
goto out_unlock_buf;
}
}
......
......@@ -637,8 +637,6 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
dbg_io("read EC header from PEB %d", pnum);
ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
if (UBI_IO_DEBUG)
verbose = 1;
err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
if (err) {
......@@ -685,6 +683,9 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
if (verbose)
ubi_warn("no EC header found at PEB %d, "
"only 0xFF bytes", pnum);
else if (UBI_IO_DEBUG)
dbg_msg("no EC header found at PEB %d, "
"only 0xFF bytes", pnum);
return UBI_IO_PEB_EMPTY;
}
......@@ -696,7 +697,9 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
ubi_warn("bad magic number at PEB %d: %08x instead of "
"%08x", pnum, magic, UBI_EC_HDR_MAGIC);
ubi_dbg_dump_ec_hdr(ec_hdr);
}
} else if (UBI_IO_DEBUG)
dbg_msg("bad magic number at PEB %d: %08x instead of "
"%08x", pnum, magic, UBI_EC_HDR_MAGIC);
return UBI_IO_BAD_EC_HDR;
}
......@@ -708,7 +711,9 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
ubi_warn("bad EC header CRC at PEB %d, calculated "
"%#08x, read %#08x", pnum, crc, hdr_crc);
ubi_dbg_dump_ec_hdr(ec_hdr);
}
} else if (UBI_IO_DEBUG)
dbg_msg("bad EC header CRC at PEB %d, calculated "
"%#08x, read %#08x", pnum, crc, hdr_crc);
return UBI_IO_BAD_EC_HDR;
}
......@@ -912,8 +917,6 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
dbg_io("read VID header from PEB %d", pnum);
ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
if (UBI_IO_DEBUG)
verbose = 1;
p = (char *)vid_hdr - ubi->vid_hdr_shift;
err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
......@@ -960,6 +963,9 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
if (verbose)
ubi_warn("no VID header found at PEB %d, "
"only 0xFF bytes", pnum);
else if (UBI_IO_DEBUG)
dbg_msg("no VID header found at PEB %d, "
"only 0xFF bytes", pnum);
return UBI_IO_PEB_FREE;
}
......@@ -971,7 +977,9 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
ubi_warn("bad magic number at PEB %d: %08x instead of "
"%08x", pnum, magic, UBI_VID_HDR_MAGIC);
ubi_dbg_dump_vid_hdr(vid_hdr);
}
} else if (UBI_IO_DEBUG)
dbg_msg("bad magic number at PEB %d: %08x instead of "
"%08x", pnum, magic, UBI_VID_HDR_MAGIC);
return UBI_IO_BAD_VID_HDR;
}
......@@ -983,7 +991,9 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
ubi_warn("bad CRC at PEB %d, calculated %#08x, "
"read %#08x", pnum, crc, hdr_crc);
ubi_dbg_dump_vid_hdr(vid_hdr);
}
} else if (UBI_IO_DEBUG)
dbg_msg("bad CRC at PEB %d, calculated %#08x, "
"read %#08x", pnum, crc, hdr_crc);
return UBI_IO_BAD_VID_HDR;
}
......@@ -1024,7 +1034,7 @@ int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
err = paranoid_check_peb_ec_hdr(ubi, pnum);
if (err)
return err > 0 ? -EINVAL: err;
return err > 0 ? -EINVAL : err;
vid_hdr->magic = cpu_to_be32(UBI_VID_HDR_MAGIC);
vid_hdr->version = UBI_VERSION;
......
......@@ -73,6 +73,13 @@
*/
#define UBI_IO_RETRIES 3
/*
* Length of the protection queue. The length is effectively equivalent to the
* number of (global) erase cycles PEBs are protected from the wear-leveling
* worker.
*/
#define UBI_PROT_QUEUE_LEN 10
/*
* Error codes returned by the I/O sub-system.
*
......@@ -95,7 +102,8 @@ enum {
/**
* struct ubi_wl_entry - wear-leveling entry.
* @rb: link in the corresponding RB-tree
* @u.rb: link in the corresponding (free/used) RB-tree
* @u.list: link in the protection queue
* @ec: erase counter
* @pnum: physical eraseblock number
*
......@@ -104,7 +112,10 @@ enum {
* RB-trees. See WL sub-system for details.
*/
struct ubi_wl_entry {
union {
struct rb_node rb;
struct list_head list;
} u;
int ec;
int pnum;
};
......@@ -288,7 +299,7 @@ struct ubi_wl_entry;
* @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
*
* @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
* of UBI ititializetion
* of UBI initialization
* @vtbl_slots: how many slots are available in the volume table
* @vtbl_size: size of the volume table in bytes
* @vtbl: in-RAM volume table copy
......@@ -306,18 +317,17 @@ struct ubi_wl_entry;
* @used: RB-tree of used physical eraseblocks
* @free: RB-tree of free physical eraseblocks
* @scrub: RB-tree of physical eraseblocks which need scrubbing
* @prot: protection trees
* @prot.pnum: protection tree indexed by physical eraseblock numbers
* @prot.aec: protection tree indexed by absolute erase counter value
* @wl_lock: protects the @used, @free, @prot, @lookuptbl, @abs_ec, @move_from,
* @move_to, @move_to_put @erase_pending, @wl_scheduled, and @works
* @pq: protection queue (contain physical eraseblocks which are temporarily
* protected from the wear-leveling worker)
* @pq_head: protection queue head
* @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
* @move_to, @move_to_put @erase_pending, @wl_scheduled and @works
* fields
* @move_mutex: serializes eraseblock moves
* @work_sem: sycnhronizes the WL worker with use tasks
* @work_sem: synchronizes the WL worker with use tasks
* @wl_scheduled: non-zero if the wear-leveling was scheduled
* @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
* physical eraseblock
* @abs_ec: absolute erase counter
* @move_from: physical eraseblock from where the data is being moved
* @move_to: physical eraseblock where the data is being moved to
* @move_to_put: if the "to" PEB was put
......@@ -351,11 +361,11 @@ struct ubi_wl_entry;
*
* @peb_buf1: a buffer of PEB size used for different purposes
* @peb_buf2: another buffer of PEB size used for different purposes
* @buf_mutex: proptects @peb_buf1 and @peb_buf2
* @buf_mutex: protects @peb_buf1 and @peb_buf2
* @ckvol_mutex: serializes static volume checking when opening
* @mult_mutex: serializes operations on multiple volumes, like re-nameing
* @mult_mutex: serializes operations on multiple volumes, like re-naming
* @dbg_peb_buf: buffer of PEB size used for debugging
* @dbg_buf_mutex: proptects @dbg_peb_buf
* @dbg_buf_mutex: protects @dbg_peb_buf
*/
struct ubi_device {
struct cdev cdev;
......@@ -392,16 +402,13 @@ struct ubi_device {
struct rb_root used;
struct rb_root free;
struct rb_root scrub;
struct {
struct rb_root pnum;
struct rb_root aec;
} prot;
struct list_head pq[UBI_PROT_QUEUE_LEN];
int pq_head;
spinlock_t wl_lock;
struct mutex move_mutex;
struct rw_semaphore work_sem;
int wl_scheduled;
struct ubi_wl_entry **lookuptbl;
unsigned long long abs_ec;
struct ubi_wl_entry *move_from;
struct ubi_wl_entry *move_to;
int move_to_put;
......
......@@ -22,7 +22,7 @@
* UBI wear-leveling sub-system.
*
* This sub-system is responsible for wear-leveling. It works in terms of
* physical* eraseblocks and erase counters and knows nothing about logical
* physical eraseblocks and erase counters and knows nothing about logical
* eraseblocks, volumes, etc. From this sub-system's perspective all physical
* eraseblocks are of two types - used and free. Used physical eraseblocks are
* those that were "get" by the 'ubi_wl_get_peb()' function, and free physical
......@@ -55,8 +55,39 @@
*
* As it was said, for the UBI sub-system all physical eraseblocks are either
* "free" or "used". Free eraseblock are kept in the @wl->free RB-tree, while
* used eraseblocks are kept in a set of different RB-trees: @wl->used,
* @wl->prot.pnum, @wl->prot.aec, and @wl->scrub.
* used eraseblocks are kept in @wl->used or @wl->scrub RB-trees, or
* (temporarily) in the @wl->pq queue.
*
* When the WL sub-system returns a physical eraseblock, the physical
* eraseblock is protected from being moved for some "time". For this reason,
* the physical eraseblock is not directly moved from the @wl->free tree to the
* @wl->used tree. There is a protection queue in between where this
* physical eraseblock is temporarily stored (@wl->pq).
*
* All this protection stuff is needed because:
* o we don't want to move physical eraseblocks just after we have given them
* to the user; instead, we first want to let users fill them up with data;
*
* o there is a chance that the user will put the physical eraseblock very
* soon, so it makes sense not to move it for some time, but wait; this is
* especially important in case of "short term" physical eraseblocks.
*
* Physical eraseblocks stay protected only for limited time. But the "time" is
* measured in erase cycles in this case. This is implemented with help of the
* protection queue. Eraseblocks are put to the tail of this queue when they
* are returned by the 'ubi_wl_get_peb()', and eraseblocks are removed from the
* head of the queue on each erase operation (for any eraseblock). So the
* length of the queue defines how may (global) erase cycles PEBs are protected.
*
* To put it differently, each physical eraseblock has 2 main states: free and
* used. The former state corresponds to the @wl->free tree. The latter state
* is split up on several sub-states:
* o the WL movement is allowed (@wl->used tree);
* o the WL movement is temporarily prohibited (@wl->pq queue);
* o scrubbing is needed (@wl->scrub tree).
*
* Depending on the sub-state, wear-leveling entries of the used physical
* eraseblocks may be kept in one of those structures.
*
* Note, in this implementation, we keep a small in-RAM object for each physical
* eraseblock. This is surely not a scalable solution. But it appears to be good
......@@ -70,9 +101,6 @@
* target PEB, we pick a PEB with the highest EC if our PEB is "old" and we
* pick target PEB with an average EC if our PEB is not very "old". This is a
* room for future re-works of the WL sub-system.
*
* Note: the stuff with protection trees looks too complex and is difficult to
* understand. Should be fixed.
*/
#include <linux/slab.h>
......@@ -84,14 +112,6 @@
/* Number of physical eraseblocks reserved for wear-leveling purposes */
#define WL_RESERVED_PEBS 1
/*
* How many erase cycles are short term, unknown, and long term physical
* eraseblocks protected.
*/
#define ST_PROTECTION 16
#define U_PROTECTION 10
#define LT_PROTECTION 4
/*
* Maximum difference between two erase counters. If this threshold is
* exceeded, the WL sub-system starts moving data from used physical
......@@ -119,65 +139,10 @@
*/
#define WL_MAX_FAILURES 32
/**
* struct ubi_wl_prot_entry - PEB protection entry.
* @rb_pnum: link in the @wl->prot.pnum RB-tree
* @rb_aec: link in the @wl->prot.aec RB-tree
* @abs_ec: the absolute erase counter value when the protection ends
* @e: the wear-leveling entry of the physical eraseblock under protection
*
* When the WL sub-system returns a physical eraseblock, the physical
* eraseblock is protected from being moved for some "time". For this reason,
* the physical eraseblock is not directly moved from the @wl->free tree to the
* @wl->used tree. There is one more tree in between where this physical
* eraseblock is temporarily stored (@wl->prot).
*
* All this protection stuff is needed because:
* o we don't want to move physical eraseblocks just after we have given them
* to the user; instead, we first want to let users fill them up with data;
*
* o there is a chance that the user will put the physical eraseblock very
* soon, so it makes sense not to move it for some time, but wait; this is
* especially important in case of "short term" physical eraseblocks.
*
* Physical eraseblocks stay protected only for limited time. But the "time" is
* measured in erase cycles in this case. This is implemented with help of the
* absolute erase counter (@wl->abs_ec). When it reaches certain value, the
* physical eraseblocks are moved from the protection trees (@wl->prot.*) to
* the @wl->used tree.
*
* Protected physical eraseblocks are searched by physical eraseblock number
* (when they are put) and by the absolute erase counter (to check if it is
* time to move them to the @wl->used tree). So there are actually 2 RB-trees
* storing the protected physical eraseblocks: @wl->prot.pnum and
* @wl->prot.aec. They are referred to as the "protection" trees. The
* first one is indexed by the physical eraseblock number. The second one is
* indexed by the absolute erase counter. Both trees store
* &struct ubi_wl_prot_entry objects.
*
* Each physical eraseblock has 2 main states: free and used. The former state
* corresponds to the @wl->free tree. The latter state is split up on several
* sub-states:
* o the WL movement is allowed (@wl->used tree);
* o the WL movement is temporarily prohibited (@wl->prot.pnum and
* @wl->prot.aec trees);
* o scrubbing is needed (@wl->scrub tree).
*
* Depending on the sub-state, wear-leveling entries of the used physical
* eraseblocks may be kept in one of those trees.
*/
struct ubi_wl_prot_entry {
struct rb_node rb_pnum;
struct rb_node rb_aec;
unsigned long long abs_ec;
struct ubi_wl_entry *e;
};
/**
* struct ubi_work - UBI work description data structure.
* @list: a link in the list of pending works
* @func: worker function
* @priv: private data of the worker function
* @e: physical eraseblock to erase
* @torture: if the physical eraseblock has to be tortured
*
......@@ -198,9 +163,11 @@ struct ubi_work {
static int paranoid_check_ec(struct ubi_device *ubi, int pnum, int ec);
static int paranoid_check_in_wl_tree(struct ubi_wl_entry *e,
struct rb_root *root);
static int paranoid_check_in_pq(struct ubi_device *ubi, struct ubi_wl_entry *e);
#else
#define paranoid_check_ec(ubi, pnum, ec) 0
#define paranoid_check_in_wl_tree(e, root)
#define paranoid_check_in_pq(ubi, e) 0
#endif
/**
......@@ -220,7 +187,7 @@ static void wl_tree_add(struct ubi_wl_entry *e, struct rb_root *root)
struct ubi_wl_entry *e1;
parent = *p;
e1 = rb_entry(parent, struct ubi_wl_entry, rb);
e1 = rb_entry(parent, struct ubi_wl_entry, u.rb);
if (e->ec < e1->ec)
p = &(*p)->rb_left;
......@@ -235,8 +202,8 @@ static void wl_tree_add(struct ubi_wl_entry *e, struct rb_root *root)
}
}
rb_link_node(&e->rb, parent, p);
rb_insert_color(&e->rb, root);
rb_link_node(&e->u.rb, parent, p);
rb_insert_color(&e->u.rb, root);
}
/**
......@@ -331,7 +298,7 @@ static int in_wl_tree(struct ubi_wl_entry *e, struct rb_root *root)
while (p) {
struct ubi_wl_entry *e1;
e1 = rb_entry(p, struct ubi_wl_entry, rb);
e1 = rb_entry(p, struct ubi_wl_entry, u.rb);
if (e->pnum == e1->pnum) {
ubi_assert(e == e1);
......@@ -355,50 +322,24 @@ static int in_wl_tree(struct ubi_wl_entry *e, struct rb_root *root)
}
/**
* prot_tree_add - add physical eraseblock to protection trees.
* prot_queue_add - add physical eraseblock to the protection queue.
* @ubi: UBI device description object
* @e: the physical eraseblock to add
* @pe: protection entry object to use
* @abs_ec: absolute erase counter value when this physical eraseblock has
* to be removed from the protection trees.
*
* @wl->lock has to be locked.
* This function adds @e to the tail of the protection queue @ubi->pq, where
* @e will stay for %UBI_PROT_QUEUE_LEN erase operations and will be
* temporarily protected from the wear-leveling worker. Note, @wl->lock has to
* be locked.
*/
static void prot_tree_add(struct ubi_device *ubi, struct ubi_wl_entry *e,
struct ubi_wl_prot_entry *pe, int abs_ec)
static void prot_queue_add(struct ubi_device *ubi, struct ubi_wl_entry *e)
{
struct rb_node **p, *parent = NULL;
struct ubi_wl_prot_entry *pe1;
pe->e = e;
pe->abs_ec = ubi->abs_ec + abs_ec;
p = &ubi->prot.pnum.rb_node;
while (*p) {
parent = *p;
pe1 = rb_entry(parent, struct ubi_wl_prot_entry, rb_pnum);
int pq_tail = ubi->pq_head - 1;
if (e->pnum < pe1->e->pnum)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
rb_link_node(&pe->rb_pnum, parent, p);
rb_insert_color(&pe->rb_pnum, &ubi->prot.pnum);
p = &ubi->prot.aec.rb_node;
parent = NULL;
while (*p) {
parent = *p;
pe1 = rb_entry(parent, struct ubi_wl_prot_entry, rb_aec);
if (pe->abs_ec < pe1->abs_ec)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
rb_link_node(&pe->rb_aec, parent, p);
rb_insert_color(&pe->rb_aec, &ubi->prot.aec);
if (pq_tail < 0)
pq_tail = UBI_PROT_QUEUE_LEN - 1;
ubi_assert(pq_tail >= 0 && pq_tail < UBI_PROT_QUEUE_LEN);
list_add_tail(&e->u.list, &ubi->pq[pq_tail]);
dbg_wl("added PEB %d EC %d to the protection queue", e->pnum, e->ec);
}
/**
......@@ -414,14 +355,14 @@ static struct ubi_wl_entry *find_wl_entry(struct rb_root *root, int max)
struct rb_node *p;
struct ubi_wl_entry *e;
e = rb_entry(rb_first(root), struct ubi_wl_entry, rb);
e = rb_entry(rb_first(root), struct ubi_wl_entry, u.rb);
max += e->ec;
p = root->rb_node;
while (p) {
struct ubi_wl_entry *e1;
e1 = rb_entry(p, struct ubi_wl_entry, rb);
e1 = rb_entry(p, struct ubi_wl_entry, u.rb);
if (e1->ec >= max)
p = p->rb_left;
else {
......@@ -443,17 +384,12 @@ static struct ubi_wl_entry *find_wl_entry(struct rb_root *root, int max)
*/
int ubi_wl_get_peb(struct ubi_device *ubi, int dtype)
{
int err, protect, medium_ec;
int err, medium_ec;
struct ubi_wl_entry *e, *first, *last;
struct ubi_wl_prot_entry *pe;
ubi_assert(dtype == UBI_LONGTERM || dtype == UBI_SHORTTERM ||
dtype == UBI_UNKNOWN);
pe = kmalloc(sizeof(struct ubi_wl_prot_entry), GFP_NOFS);
if (!pe)
return -ENOMEM;
retry:
spin_lock(&ubi->wl_lock);
if (!ubi->free.rb_node) {
......@@ -461,16 +397,13 @@ retry:
ubi_assert(list_empty(&ubi->works));
ubi_err("no free eraseblocks");
spin_unlock(&ubi->wl_lock);
kfree(pe);
return -ENOSPC;
}
spin_unlock(&ubi->wl_lock);
err = produce_free_peb(ubi);
if (err < 0) {
kfree(pe);
if (err < 0)
return err;
}
goto retry;
}
......@@ -483,7 +416,6 @@ retry:
* %WL_FREE_MAX_DIFF.
*/
e = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF);
protect = LT_PROTECTION;
break;
case UBI_UNKNOWN:
/*
......@@ -492,81 +424,63 @@ retry:
* eraseblock with erase counter greater or equivalent than the
* lowest erase counter plus %WL_FREE_MAX_DIFF.
*/
first = rb_entry(rb_first(&ubi->free), struct ubi_wl_entry, rb);
last = rb_entry(rb_last(&ubi->free), struct ubi_wl_entry, rb);
first = rb_entry(rb_first(&ubi->free), struct ubi_wl_entry,
u.rb);
last = rb_entry(rb_last(&ubi->free), struct ubi_wl_entry, u.rb);
if (last->ec - first->ec < WL_FREE_MAX_DIFF)
e = rb_entry(ubi->free.rb_node,
struct ubi_wl_entry, rb);
struct ubi_wl_entry, u.rb);
else {
medium_ec = (first->ec + WL_FREE_MAX_DIFF)/2;
e = find_wl_entry(&ubi->free, medium_ec);
}
protect = U_PROTECTION;
break;
case UBI_SHORTTERM:
/*
* For short term data we pick a physical eraseblock with the
* lowest erase counter as we expect it will be erased soon.
*/
e = rb_entry(rb_first(&ubi->free), struct ubi_wl_entry, rb);
protect = ST_PROTECTION;
e = rb_entry(rb_first(&ubi->free), struct ubi_wl_entry, u.rb);
break;
default:
protect = 0;
e = NULL;
BUG();
}
paranoid_check_in_wl_tree(e, &ubi->free);
/*
* Move the physical eraseblock to the protection trees where it will
* Move the physical eraseblock to the protection queue where it will
* be protected from being moved for some time.
*/
paranoid_check_in_wl_tree(e, &ubi->free);
rb_erase(&e->rb, &ubi->free);
prot_tree_add(ubi, e, pe, protect);
dbg_wl("PEB %d EC %d, protection %d", e->pnum, e->ec, protect);
rb_erase(&e->u.rb, &ubi->free);
dbg_wl("PEB %d EC %d", e->pnum, e->ec);
prot_queue_add(ubi, e);
spin_unlock(&ubi->wl_lock);
return e->pnum;
}
/**
* prot_tree_del - remove a physical eraseblock from the protection trees
* prot_queue_del - remove a physical eraseblock from the protection queue.
* @ubi: UBI device description object
* @pnum: the physical eraseblock to remove
*
* This function returns PEB @pnum from the protection trees and returns zero
* in case of success and %-ENODEV if the PEB was not found in the protection
* trees.
* This function deletes PEB @pnum from the protection queue and returns zero
* in case of success and %-ENODEV if the PEB was not found.
*/
static int prot_tree_del(struct ubi_device *ubi, int pnum)
static int prot_queue_del(struct ubi_device *ubi, int pnum)
{
struct rb_node *p;
struct ubi_wl_prot_entry *pe = NULL;
p = ubi->prot.pnum.rb_node;
while (p) {
pe = rb_entry(p, struct ubi_wl_prot_entry, rb_pnum);
if (pnum == pe->e->pnum)
goto found;
struct ubi_wl_entry *e;
if (pnum < pe->e->pnum)
p = p->rb_left;
else
p = p->rb_right;
}
e = ubi->lookuptbl[pnum];
if (!e)
return -ENODEV;
if (paranoid_check_in_pq(ubi, e))
return -ENODEV;
found:
ubi_assert(pe->e->pnum == pnum);
rb_erase(&pe->rb_aec, &ubi->prot.aec);
rb_erase(&pe->rb_pnum, &ubi->prot.pnum);
kfree(pe);
list_del(&e->u.list);
dbg_wl("deleted PEB %d from the protection queue", e->pnum);
return 0;
}
......@@ -632,47 +546,47 @@ out_free:
}
/**
* check_protection_over - check if it is time to stop protecting some PEBs.
* serve_prot_queue - check if it is time to stop protecting PEBs.
* @ubi: UBI device description object
*
* This function is called after each erase operation, when the absolute erase
* counter is incremented, to check if some physical eraseblock have not to be
* protected any longer. These physical eraseblocks are moved from the
* protection trees to the used tree.
* This function is called after each erase operation and removes PEBs from the
* tail of the protection queue. These PEBs have been protected for long enough
* and should be moved to the used tree.
*/
static void check_protection_over(struct ubi_device *ubi)
static void serve_prot_queue(struct ubi_device *ubi)
{
struct ubi_wl_prot_entry *pe;
struct ubi_wl_entry *e, *tmp;
int count;
/*
* There may be several protected physical eraseblock to remove,
* process them all.
*/
while (1) {
repeat:
count = 0;
spin_lock(&ubi->wl_lock);
if (!ubi->prot.aec.rb_node) {
spin_unlock(&ubi->wl_lock);
break;
}
pe = rb_entry(rb_first(&ubi->prot.aec),
struct ubi_wl_prot_entry, rb_aec);
list_for_each_entry_safe(e, tmp, &ubi->pq[ubi->pq_head], u.list) {
dbg_wl("PEB %d EC %d protection over, move to used tree",
e->pnum, e->ec);
if (pe->abs_ec > ubi->abs_ec) {
list_del(&e->u.list);
wl_tree_add(e, &ubi->used);
if (count++ > 32) {
/*
* Let's be nice and avoid holding the spinlock for
* too long.
*/
spin_unlock(&ubi->wl_lock);
break;
cond_resched();
goto repeat;
}
}
dbg_wl("PEB %d protection over, abs_ec %llu, PEB abs_ec %llu",
pe->e->pnum, ubi->abs_ec, pe->abs_ec);
rb_erase(&pe->rb_aec, &ubi->prot.aec);
rb_erase(&pe->rb_pnum, &ubi->prot.pnum);
wl_tree_add(pe->e, &ubi->used);
ubi->pq_head += 1;
if (ubi->pq_head == UBI_PROT_QUEUE_LEN)
ubi->pq_head = 0;
ubi_assert(ubi->pq_head >= 0 && ubi->pq_head < UBI_PROT_QUEUE_LEN);
spin_unlock(&ubi->wl_lock);
kfree(pe);
cond_resched();
}
}
/**
......@@ -680,8 +594,8 @@ static void check_protection_over(struct ubi_device *ubi)
* @ubi: UBI device description object
* @wrk: the work to schedule
*
* This function enqueues a work defined by @wrk to the tail of the pending
* works list.
* This function adds a work defined by @wrk to the tail of the pending works
* list.
*/
static void schedule_ubi_work(struct ubi_device *ubi, struct ubi_work *wrk)
{
......@@ -739,13 +653,11 @@ static int schedule_erase(struct ubi_device *ubi, struct ubi_wl_entry *e,
static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
int cancel)
{
int err, put = 0, scrubbing = 0, protect = 0;
struct ubi_wl_prot_entry *uninitialized_var(pe);
int err, scrubbing = 0, torture = 0;
struct ubi_wl_entry *e1, *e2;
struct ubi_vid_hdr *vid_hdr;
kfree(wrk);
if (cancel)
return 0;
......@@ -781,7 +693,7 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
* highly worn-out free physical eraseblock. If the erase
* counters differ much enough, start wear-leveling.
*/
e1 = rb_entry(rb_first(&ubi->used), struct ubi_wl_entry, rb);
e1 = rb_entry(rb_first(&ubi->used), struct ubi_wl_entry, u.rb);
e2 = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF);
if (!(e2->ec - e1->ec >= UBI_WL_THRESHOLD)) {
......@@ -790,21 +702,21 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
goto out_cancel;
}
paranoid_check_in_wl_tree(e1, &ubi->used);
rb_erase(&e1->rb, &ubi->used);
rb_erase(&e1->u.rb, &ubi->used);
dbg_wl("move PEB %d EC %d to PEB %d EC %d",
e1->pnum, e1->ec, e2->pnum, e2->ec);
} else {
/* Perform scrubbing */
scrubbing = 1;
e1 = rb_entry(rb_first(&ubi->scrub), struct ubi_wl_entry, rb);
e1 = rb_entry(rb_first(&ubi->scrub), struct ubi_wl_entry, u.rb);
e2 = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF);
paranoid_check_in_wl_tree(e1, &ubi->scrub);
rb_erase(&e1->rb, &ubi->scrub);
rb_erase(&e1->u.rb, &ubi->scrub);
dbg_wl("scrub PEB %d to PEB %d", e1->pnum, e2->pnum);
}
paranoid_check_in_wl_tree(e2, &ubi->free);
rb_erase(&e2->rb, &ubi->free);
rb_erase(&e2->u.rb, &ubi->free);
ubi->move_from = e1;
ubi->move_to = e2;
spin_unlock(&ubi->wl_lock);
......@@ -844,46 +756,67 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
err = ubi_eba_copy_leb(ubi, e1->pnum, e2->pnum, vid_hdr);
if (err) {
if (err == -EAGAIN)
goto out_not_moved;
if (err < 0)
goto out_error;
if (err == 1)
if (err == 2) {
/* Target PEB write error, torture it */
torture = 1;
goto out_not_moved;
}
/*
* For some reason the LEB was not moved - it might be because
* the volume is being deleted. We should prevent this PEB from
* being selected for wear-levelling movement for some "time",
* so put it to the protection tree.
* The LEB has not been moved because the volume is being
* deleted or the PEB has been put meanwhile. We should prevent
* this PEB from being selected for wear-leveling movement
* again, so put it to the protection queue.
*/
dbg_wl("cancelled moving PEB %d", e1->pnum);
pe = kmalloc(sizeof(struct ubi_wl_prot_entry), GFP_NOFS);
if (!pe) {
err = -ENOMEM;
goto out_error;
}
dbg_wl("canceled moving PEB %d", e1->pnum);
ubi_assert(err == 1);
ubi_free_vid_hdr(ubi, vid_hdr);
vid_hdr = NULL;
protect = 1;
spin_lock(&ubi->wl_lock);
prot_queue_add(ubi, e1);
ubi_assert(!ubi->move_to_put);
ubi->move_from = ubi->move_to = NULL;
ubi->wl_scheduled = 0;
spin_unlock(&ubi->wl_lock);
e1 = NULL;
err = schedule_erase(ubi, e2, 0);
if (err)
goto out_error;
mutex_unlock(&ubi->move_mutex);
return 0;
}
/* The PEB has been successfully moved */
ubi_free_vid_hdr(ubi, vid_hdr);
if (scrubbing && !protect)
vid_hdr = NULL;
if (scrubbing)
ubi_msg("scrubbed PEB %d, data moved to PEB %d",
e1->pnum, e2->pnum);
spin_lock(&ubi->wl_lock);
if (protect)
prot_tree_add(ubi, e1, pe, protect);
if (!ubi->move_to_put)
if (!ubi->move_to_put) {
wl_tree_add(e2, &ubi->used);
else
put = 1;
e2 = NULL;
}
ubi->move_from = ubi->move_to = NULL;
ubi->move_to_put = ubi->wl_scheduled = 0;
spin_unlock(&ubi->wl_lock);
if (put) {
err = schedule_erase(ubi, e1, 0);
if (err) {
e1 = NULL;
goto out_error;
}
if (e2) {
/*
* Well, the target PEB was put meanwhile, schedule it for
* erasure.
......@@ -894,13 +827,6 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
goto out_error;
}
if (!protect) {
err = schedule_erase(ubi, e1, 0);
if (err)
goto out_error;
}
dbg_wl("done");
mutex_unlock(&ubi->move_mutex);
return 0;
......@@ -908,20 +834,24 @@ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
/*
* For some reasons the LEB was not moved, might be an error, might be
* something else. @e1 was not changed, so return it back. @e2 might
* be changed, schedule it for erasure.
* have been changed, schedule it for erasure.
*/
out_not_moved:
dbg_wl("canceled moving PEB %d", e1->pnum);
ubi_free_vid_hdr(ubi, vid_hdr);
vid_hdr = NULL;
spin_lock(&ubi->wl_lock);
if (scrubbing)
wl_tree_add(e1, &ubi->scrub);
else
wl_tree_add(e1, &ubi->used);
ubi_assert(!ubi->move_to_put);
ubi->move_from = ubi->move_to = NULL;
ubi->move_to_put = ubi->wl_scheduled = 0;
ubi->wl_scheduled = 0;
spin_unlock(&ubi->wl_lock);
err = schedule_erase(ubi, e2, 0);
e1 = NULL;
err = schedule_erase(ubi, e2, torture);
if (err)
goto out_error;
......@@ -938,7 +868,9 @@ out_error:
ubi->move_to_put = ubi->wl_scheduled = 0;
spin_unlock(&ubi->wl_lock);
if (e1)
kmem_cache_free(ubi_wl_entry_slab, e1);
if (e2)
kmem_cache_free(ubi_wl_entry_slab, e2);
ubi_ro_mode(ubi);
......@@ -988,7 +920,7 @@ static int ensure_wear_leveling(struct ubi_device *ubi)
* erase counter of free physical eraseblocks is greater then
* %UBI_WL_THRESHOLD.
*/
e1 = rb_entry(rb_first(&ubi->used), struct ubi_wl_entry, rb);
e1 = rb_entry(rb_first(&ubi->used), struct ubi_wl_entry, u.rb);
e2 = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF);
if (!(e2->ec - e1->ec >= UBI_WL_THRESHOLD))
......@@ -1050,7 +982,6 @@ static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
kfree(wl_wrk);
spin_lock(&ubi->wl_lock);
ubi->abs_ec += 1;
wl_tree_add(e, &ubi->free);
spin_unlock(&ubi->wl_lock);
......@@ -1058,7 +989,7 @@ static int erase_worker(struct ubi_device *ubi, struct ubi_work *wl_wrk,
* One more erase operation has happened, take care about
* protected physical eraseblocks.
*/
check_protection_over(ubi);
serve_prot_queue(ubi);
/* And take care about wear-leveling */
err = ensure_wear_leveling(ubi);
......@@ -1190,12 +1121,12 @@ retry:
} else {
if (in_wl_tree(e, &ubi->used)) {
paranoid_check_in_wl_tree(e, &ubi->used);
rb_erase(&e->rb, &ubi->used);
rb_erase(&e->u.rb, &ubi->used);
} else if (in_wl_tree(e, &ubi->scrub)) {
paranoid_check_in_wl_tree(e, &ubi->scrub);
rb_erase(&e->rb, &ubi->scrub);
rb_erase(&e->u.rb, &ubi->scrub);
} else {
err = prot_tree_del(ubi, e->pnum);
err = prot_queue_del(ubi, e->pnum);
if (err) {
ubi_err("PEB %d not found", pnum);
ubi_ro_mode(ubi);
......@@ -1255,11 +1186,11 @@ retry:
if (in_wl_tree(e, &ubi->used)) {
paranoid_check_in_wl_tree(e, &ubi->used);
rb_erase(&e->rb, &ubi->used);
rb_erase(&e->u.rb, &ubi->used);
} else {
int err;
err = prot_tree_del(ubi, e->pnum);
err = prot_queue_del(ubi, e->pnum);
if (err) {
ubi_err("PEB %d not found", pnum);
ubi_ro_mode(ubi);
......@@ -1290,7 +1221,7 @@ int ubi_wl_flush(struct ubi_device *ubi)
int err;
/*
* Erase while the pending works queue is not empty, but not more then
* Erase while the pending works queue is not empty, but not more than
* the number of currently pending works.
*/
dbg_wl("flush (%d pending works)", ubi->works_count);
......@@ -1308,7 +1239,7 @@ int ubi_wl_flush(struct ubi_device *ubi)
up_write(&ubi->work_sem);
/*
* And in case last was the WL worker and it cancelled the LEB
* And in case last was the WL worker and it canceled the LEB
* movement, flush again.
*/
while (ubi->works_count) {
......@@ -1337,11 +1268,11 @@ static void tree_destroy(struct rb_root *root)
else if (rb->rb_right)
rb = rb->rb_right;
else {
e = rb_entry(rb, struct ubi_wl_entry, rb);
e = rb_entry(rb, struct ubi_wl_entry, u.rb);
rb = rb_parent(rb);
if (rb) {
if (rb->rb_left == &e->rb)
if (rb->rb_left == &e->u.rb)
rb->rb_left = NULL;
else
rb->rb_right = NULL;
......@@ -1436,15 +1367,13 @@ static void cancel_pending(struct ubi_device *ubi)
*/
int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
{
int err;
int err, i;
struct rb_node *rb1, *rb2;
struct ubi_scan_volume *sv;
struct ubi_scan_leb *seb, *tmp;
struct ubi_wl_entry *e;
ubi->used = ubi->free = ubi->scrub = RB_ROOT;
ubi->prot.pnum = ubi->prot.aec = RB_ROOT;
spin_lock_init(&ubi->wl_lock);
mutex_init(&ubi->move_mutex);
init_rwsem(&ubi->work_sem);
......@@ -1458,6 +1387,10 @@ int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
if (!ubi->lookuptbl)
return err;
for (i = 0; i < UBI_PROT_QUEUE_LEN; i++)
INIT_LIST_HEAD(&ubi->pq[i]);
ubi->pq_head = 0;
list_for_each_entry_safe(seb, tmp, &si->erase, u.list) {
cond_resched();
......@@ -1552,33 +1485,18 @@ out_free:
}
/**
* protection_trees_destroy - destroy the protection RB-trees.
* protection_queue_destroy - destroy the protection queue.
* @ubi: UBI device description object
*/
static void protection_trees_destroy(struct ubi_device *ubi)
static void protection_queue_destroy(struct ubi_device *ubi)
{
struct rb_node *rb;
struct ubi_wl_prot_entry *pe;
rb = ubi->prot.aec.rb_node;
while (rb) {
if (rb->rb_left)
rb = rb->rb_left;
else if (rb->rb_right)
rb = rb->rb_right;
else {
pe = rb_entry(rb, struct ubi_wl_prot_entry, rb_aec);
int i;
struct ubi_wl_entry *e, *tmp;
rb = rb_parent(rb);
if (rb) {
if (rb->rb_left == &pe->rb_aec)
rb->rb_left = NULL;
else
rb->rb_right = NULL;
}
kmem_cache_free(ubi_wl_entry_slab, pe->e);
kfree(pe);
for (i = 0; i < UBI_PROT_QUEUE_LEN; ++i) {
list_for_each_entry_safe(e, tmp, &ubi->pq[i], u.list) {
list_del(&e->u.list);
kmem_cache_free(ubi_wl_entry_slab, e);
}
}
}
......@@ -1591,7 +1509,7 @@ void ubi_wl_close(struct ubi_device *ubi)
{
dbg_wl("close the WL sub-system");
cancel_pending(ubi);
protection_trees_destroy(ubi);
protection_queue_destroy(ubi);
tree_destroy(&ubi->used);
tree_destroy(&ubi->free);
tree_destroy(&ubi->scrub);
......@@ -1661,4 +1579,27 @@ static int paranoid_check_in_wl_tree(struct ubi_wl_entry *e,
return 1;
}
/**
* paranoid_check_in_pq - check if wear-leveling entry is in the protection
* queue.
* @ubi: UBI device description object
* @e: the wear-leveling entry to check
*
* This function returns zero if @e is in @ubi->pq and %1 if it is not.
*/
static int paranoid_check_in_pq(struct ubi_device *ubi, struct ubi_wl_entry *e)
{
struct ubi_wl_entry *p;
int i;
for (i = 0; i < UBI_PROT_QUEUE_LEN; ++i)
list_for_each_entry(p, &ubi->pq[i], u.list)
if (p == e)
return 0;
ubi_err("paranoid check failed for PEB %d, EC %d, Protect queue",
e->pnum, e->ec);
ubi_dbg_dump_stack();
return 1;
}
#endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment