1 files changed, 77 insertions, 69 deletions

diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 17584c524486..6a7dbd8451db 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -32,6 +32,7 @@
 #include <linux/kthread.h>
 #include <linux/crc32.h>
 #include <linux/pagevec.h>
+#include <linux/slab.h>
 #include "nilfs.h"
 #include "btnode.h"
 #include "page.h"
@@ -141,7 +142,7 @@ int nilfs_init_transaction_cache(void)
 }
 
 /**
- * nilfs_detroy_transaction_cache - destroy the cache for transaction info
+ * nilfs_destroy_transaction_cache - destroy the cache for transaction info
  *
  * nilfs_destroy_transaction_cache() frees the slab cache for the struct
  * nilfs_transaction_info.
@@ -201,7 +202,7 @@ static int nilfs_prepare_segment_lock(struct nilfs_transaction_info *ti)
  * This function allocates a nilfs_transaction_info struct to keep context
  * information on it.  It is initialized and hooked onto the current task in
  * the outermost call.  If a pre-allocated struct is given to @ti, it is used
- * instead; othewise a new struct is assigned from a slab.
+ * instead; otherwise a new struct is assigned from a slab.
  *
  * When @vacancy_check flag is set, this function will check the amount of
  * free space, and will wait for the GC to reclaim disk space if low capacity.
@@ -1510,6 +1511,12 @@ static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
                 if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE)
                         break;
 
+                nilfs_clear_logs(&sci->sc_segbufs);
+
+                err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
+                if (unlikely(err))
+                        return err;
+
                 if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
                         err = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
                                                         sci->sc_freesegs,
@@ -1517,12 +1524,6 @@ static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
                                                         NULL);
                         WARN_ON(err); /* do not happen */
                 }
-                nilfs_clear_logs(&sci->sc_segbufs);
-
-                err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
-                if (unlikely(err))
-                        return err;
-
                 nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
                 sci->sc_stage = prev_stage;
         }
@@ -1764,14 +1765,9 @@ static int nilfs_segctor_prepare_write(struct nilfs_sc_info *sci,
 static int nilfs_segctor_write(struct nilfs_sc_info *sci,
                                struct the_nilfs *nilfs)
 {
-        struct nilfs_segment_buffer *segbuf;
-        int ret = 0;
+        int ret;
 
-        list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
-                ret = nilfs_segbuf_write(segbuf, nilfs);
-                if (ret)
-                        break;
-        }
+        ret = nilfs_write_logs(&sci->sc_segbufs, nilfs);
         list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs);
         return ret;
 }
@@ -1902,8 +1898,7 @@ static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci,
 
         list_splice_tail_init(&sci->sc_write_logs, &logs);
         ret = nilfs_wait_on_logs(&logs);
-        if (ret)
-                nilfs_abort_logs(&logs, NULL, sci->sc_super_root, ret);
+        nilfs_abort_logs(&logs, NULL, sci->sc_super_root, ret ? : err);
 
         list_splice_tail_init(&sci->sc_segbufs, &logs);
         nilfs_cancel_segusage(&logs, nilfs->ns_sufile);
@@ -1937,8 +1932,7 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
 {
         struct nilfs_segment_buffer *segbuf;
         struct page *bd_page = NULL, *fs_page = NULL;
-        struct nilfs_sb_info *sbi = sci->sc_sbi;
-        struct the_nilfs *nilfs = sbi->s_nilfs;
+        struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
         int update_sr = (sci->sc_super_root != NULL);
 
         list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) {
@@ -2020,7 +2014,7 @@ static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
         if (update_sr) {
                 nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
                                        segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
-                sbi->s_super->s_dirt = 1;
+                set_nilfs_sb_dirty(nilfs);
 
                 clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
                 clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
@@ -2220,7 +2214,7 @@ static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
 }
 
 /**
- * nilfs_secgtor_start_timer - set timer of background write
+ * nilfs_segctor_start_timer - set timer of background write
  * @sci: nilfs_sc_info
  *
  * If the timer has already been set, it ignores the new request.
@@ -2425,43 +2419,43 @@ int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
         return err;
 }
 
-struct nilfs_segctor_req {
-        int mode;
-        __u32 seq_accepted;
-        int sc_err;  /* construction failure */
-        int sb_err;  /* super block writeback failure */
-};
-
 #define FLUSH_FILE_BIT  (0x1) /* data file only */
 #define FLUSH_DAT_BIT   (1 << NILFS_DAT_INO) /* DAT only */
 
-static void nilfs_segctor_accept(struct nilfs_sc_info *sci,
-                                 struct nilfs_segctor_req *req)
+/**
+ * nilfs_segctor_accept - record accepted sequence count of log-write requests
+ * @sci: segment constructor object
+ */
+static void nilfs_segctor_accept(struct nilfs_sc_info *sci)
 {
-        req->sc_err = req->sb_err = 0;
         spin_lock(&sci->sc_state_lock);
-        req->seq_accepted = sci->sc_seq_request;
+        sci->sc_seq_accepted = sci->sc_seq_request;
         spin_unlock(&sci->sc_state_lock);
 
         if (sci->sc_timer)
                 del_timer_sync(sci->sc_timer);
 }
 
-static void nilfs_segctor_notify(struct nilfs_sc_info *sci,
-                                 struct nilfs_segctor_req *req)
+/**
+ * nilfs_segctor_notify - notify the result of request to caller threads
+ * @sci: segment constructor object
+ * @mode: mode of log forming
+ * @err: error code to be notified
+ */
+static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err)
 {
         /* Clear requests (even when the construction failed) */
         spin_lock(&sci->sc_state_lock);
 
-        if (req->mode == SC_LSEG_SR) {
+        if (mode == SC_LSEG_SR) {
                 sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
-                sci->sc_seq_done = req->seq_accepted;
-                nilfs_segctor_wakeup(sci, req->sc_err ? : req->sb_err);
+                sci->sc_seq_done = sci->sc_seq_accepted;
+                nilfs_segctor_wakeup(sci, err);
                 sci->sc_flush_request = 0;
         } else {
-                if (req->mode == SC_FLUSH_FILE)
+                if (mode == SC_FLUSH_FILE)
                         sci->sc_flush_request &= ~FLUSH_FILE_BIT;
-                else if (req->mode == SC_FLUSH_DAT)
+                else if (mode == SC_FLUSH_DAT)
                         sci->sc_flush_request &= ~FLUSH_DAT_BIT;
 
                 /* re-enable timer if checkpoint creation was not done */
@@ -2472,30 +2466,37 @@ static void nilfs_segctor_notify(struct nilfs_sc_info *sci,
         spin_unlock(&sci->sc_state_lock);
 }
 
-static int nilfs_segctor_construct(struct nilfs_sc_info *sci,
-                                   struct nilfs_segctor_req *req)
+/**
+ * nilfs_segctor_construct - form logs and write them to disk
+ * @sci: segment constructor object
+ * @mode: mode of log forming
+ */
+static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode)
 {
         struct nilfs_sb_info *sbi = sci->sc_sbi;
         struct the_nilfs *nilfs = sbi->s_nilfs;
         int err = 0;
 
+        nilfs_segctor_accept(sci);
+
         if (nilfs_discontinued(nilfs))
-                req->mode = SC_LSEG_SR;
-        if (!nilfs_segctor_confirm(sci)) {
-                err = nilfs_segctor_do_construct(sci, req->mode);
-                req->sc_err = err;
-        }
+                mode = SC_LSEG_SR;
+        if (!nilfs_segctor_confirm(sci))
+                err = nilfs_segctor_do_construct(sci, mode);
+
         if (likely(!err)) {
-                if (req->mode != SC_FLUSH_DAT)
+                if (mode != SC_FLUSH_DAT)
                         atomic_set(&nilfs->ns_ndirtyblks, 0);
                 if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
                     nilfs_discontinued(nilfs)) {
                         down_write(&nilfs->ns_sem);
-                        req->sb_err = nilfs_commit_super(sbi,
-                                        nilfs_altsb_need_update(nilfs));
+                        err = nilfs_commit_super(
+                                sbi, nilfs_altsb_need_update(nilfs));
                         up_write(&nilfs->ns_sem);
                 }
         }
+
+        nilfs_segctor_notify(sci, mode, err);
         return err;
 }
 
@@ -2526,7 +2527,6 @@ int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
         struct nilfs_sc_info *sci = NILFS_SC(sbi);
         struct the_nilfs *nilfs = sbi->s_nilfs;
         struct nilfs_transaction_info ti;
-        struct nilfs_segctor_req req = { .mode = SC_LSEG_SR };
         int err;
 
         if (unlikely(!sci))
@@ -2547,10 +2547,8 @@ int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
         list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes);
 
         for (;;) {
-                nilfs_segctor_accept(sci, &req);
-                err = nilfs_segctor_construct(sci, &req);
+                err = nilfs_segctor_construct(sci, SC_LSEG_SR);
                 nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
-                nilfs_segctor_notify(sci, &req);
 
                 if (likely(!err))
                         break;
@@ -2560,6 +2558,16 @@ int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
                 set_current_state(TASK_INTERRUPTIBLE);
                 schedule_timeout(sci->sc_interval);
         }
+        if (nilfs_test_opt(sbi, DISCARD)) {
+                int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs,
+                                                 sci->sc_nfreesegs);
+                if (ret) {
+                        printk(KERN_WARNING
+                               "NILFS warning: error %d on discard request, "
+                               "turning discards off for the device\n", ret);
+                        nilfs_clear_opt(sbi, DISCARD);
+                }
+        }
 
  out_unlock:
         sci->sc_freesegs = NULL;
@@ -2573,13 +2581,9 @@ static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
 {
         struct nilfs_sb_info *sbi = sci->sc_sbi;
         struct nilfs_transaction_info ti;
-        struct nilfs_segctor_req req = { .mode = mode };
 
         nilfs_transaction_lock(sbi, &ti, 0);
-
-        nilfs_segctor_accept(sci, &req);
-        nilfs_segctor_construct(sci, &req);
-        nilfs_segctor_notify(sci, &req);
+        nilfs_segctor_construct(sci, mode);
 
         /*
          * Unclosed segment should be retried.  We do this using sc_timer.
@@ -2635,6 +2639,7 @@ static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
 static int nilfs_segctor_thread(void *arg)
 {
         struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
+        struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
         struct timer_list timer;
         int timeout = 0;
 
@@ -2680,7 +2685,6 @@ static int nilfs_segctor_thread(void *arg)
         } else {
                 DEFINE_WAIT(wait);
                 int should_sleep = 1;
-                struct the_nilfs *nilfs;
 
                 prepare_to_wait(&sci->sc_wait_daemon, &wait,
                                 TASK_INTERRUPTIBLE);
@@ -2701,8 +2705,8 @@ static int nilfs_segctor_thread(void *arg)
                 finish_wait(&sci->sc_wait_daemon, &wait);
                 timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
                            time_after_eq(jiffies, sci->sc_timer->expires));
-                nilfs = sci->sc_sbi->s_nilfs;
-                if (sci->sc_super->s_dirt && nilfs_sb_need_update(nilfs))
+
+                if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs))
                         set_nilfs_discontinued(nilfs);
         }
         goto loop;
@@ -2797,12 +2801,9 @@ static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
         do {
                 struct nilfs_sb_info *sbi = sci->sc_sbi;
                 struct nilfs_transaction_info ti;
-                struct nilfs_segctor_req req = { .mode = SC_LSEG_SR };
 
                 nilfs_transaction_lock(sbi, &ti, 0);
-                nilfs_segctor_accept(sci, &req);
-                ret = nilfs_segctor_construct(sci, &req);
-                nilfs_segctor_notify(sci, &req);
+                ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
                 nilfs_transaction_unlock(sbi);
 
         } while (ret && retrycount-- > 0);
@@ -2829,7 +2830,7 @@ static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
                 || sci->sc_seq_request != sci->sc_seq_done);
         spin_unlock(&sci->sc_state_lock);
 
-        if (flag || nilfs_segctor_confirm(sci))
+        if (flag || !nilfs_segctor_confirm(sci))
                 nilfs_segctor_write_out(sci);
 
         WARN_ON(!list_empty(&sci->sc_copied_buffers));
@@ -2853,7 +2854,7 @@ static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
  * @sbi: nilfs_sb_info
  *
  * nilfs_attach_segment_constructor() allocates a struct nilfs_sc_info,
- * initilizes it, and starts the segment constructor.
+ * initializes it, and starts the segment constructor.
  *
  * Return Value: On success, 0 is returned. On error, one of the following
  * negative error code is returned.
@@ -2865,8 +2866,15 @@ int nilfs_attach_segment_constructor(struct nilfs_sb_info *sbi)
         struct the_nilfs *nilfs = sbi->s_nilfs;
         int err;
 
-        /* Each field of nilfs_segctor is cleared through the initialization
-           of super-block info */
+        if (NILFS_SC(sbi)) {
+                /*
+                 * This happens if the filesystem was remounted
+                 * read/write after nilfs_error degenerated it into a
+                 * read-only mount.
+                 */
+                nilfs_detach_segment_constructor(sbi);
+        }
+
         sbi->s_sc_info = nilfs_segctor_new(sbi);
         if (!sbi->s_sc_info)
                 return -ENOMEM;