Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Nathan Scott | 7b71876 | 2005-11-02 14:58:39 +1100 | [diff] [blame] | 2 | * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc. |
David Chinner | c7e8f26 | 2008-10-30 17:39:23 +1100 | [diff] [blame] | 3 | * Copyright (c) 2008 Dave Chinner |
Nathan Scott | 7b71876 | 2005-11-02 14:58:39 +1100 | [diff] [blame] | 4 | * All Rights Reserved. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 5 | * |
Nathan Scott | 7b71876 | 2005-11-02 14:58:39 +1100 | [diff] [blame] | 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License as |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | * published by the Free Software Foundation. |
| 9 | * |
Nathan Scott | 7b71876 | 2005-11-02 14:58:39 +1100 | [diff] [blame] | 10 | * This program is distributed in the hope that it would be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | * |
Nathan Scott | 7b71876 | 2005-11-02 14:58:39 +1100 | [diff] [blame] | 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write the Free Software Foundation, |
| 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | #include "xfs.h" |
Nathan Scott | a844f45 | 2005-11-02 14:38:42 +1100 | [diff] [blame] | 20 | #include "xfs_fs.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | #include "xfs_types.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | #include "xfs_log.h" |
Nathan Scott | a844f45 | 2005-11-02 14:38:42 +1100 | [diff] [blame] | 23 | #include "xfs_inum.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | #include "xfs_trans.h" |
| 25 | #include "xfs_sb.h" |
David Chinner | da353b0 | 2007-08-28 14:00:13 +1000 | [diff] [blame] | 26 | #include "xfs_ag.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | #include "xfs_mount.h" |
| 28 | #include "xfs_trans_priv.h" |
Christoph Hellwig | 9e4c109 | 2011-10-11 15:14:11 +0000 | [diff] [blame] | 29 | #include "xfs_trace.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | #include "xfs_error.h" |
| 31 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | #ifdef DEBUG |
Dave Chinner | cd4a3c5 | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 33 | /* |
| 34 | * Check that the list is sorted as it should be. |
| 35 | */ |
| 36 | STATIC void |
| 37 | xfs_ail_check( |
| 38 | struct xfs_ail *ailp, |
| 39 | xfs_log_item_t *lip) |
| 40 | { |
| 41 | xfs_log_item_t *prev_lip; |
| 42 | |
| 43 | if (list_empty(&ailp->xa_ail)) |
| 44 | return; |
| 45 | |
| 46 | /* |
| 47 | * Check the next and previous entries are valid. |
| 48 | */ |
| 49 | ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0); |
| 50 | prev_lip = list_entry(lip->li_ail.prev, xfs_log_item_t, li_ail); |
| 51 | if (&prev_lip->li_ail != &ailp->xa_ail) |
| 52 | ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0); |
| 53 | |
| 54 | prev_lip = list_entry(lip->li_ail.next, xfs_log_item_t, li_ail); |
| 55 | if (&prev_lip->li_ail != &ailp->xa_ail) |
| 56 | ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) >= 0); |
| 57 | |
| 58 | |
| 59 | #ifdef XFS_TRANS_DEBUG |
| 60 | /* |
| 61 | * Walk the list checking lsn ordering, and that every entry has the |
| 62 | * XFS_LI_IN_AIL flag set. This is really expensive, so only do it |
| 63 | * when specifically debugging the transaction subsystem. |
| 64 | */ |
| 65 | prev_lip = list_entry(&ailp->xa_ail, xfs_log_item_t, li_ail); |
| 66 | list_for_each_entry(lip, &ailp->xa_ail, li_ail) { |
| 67 | if (&prev_lip->li_ail != &ailp->xa_ail) |
| 68 | ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0); |
| 69 | ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0); |
| 70 | prev_lip = lip; |
| 71 | } |
| 72 | #endif /* XFS_TRANS_DEBUG */ |
| 73 | } |
| 74 | #else /* !DEBUG */ |
David Chinner | de08dbc | 2008-02-05 12:13:38 +1100 | [diff] [blame] | 75 | #define xfs_ail_check(a,l) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | #endif /* DEBUG */ |
| 77 | |
Dave Chinner | cd4a3c5 | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 78 | /* |
| 79 | * Return a pointer to the first item in the AIL. If the AIL is empty, then |
| 80 | * return NULL. |
| 81 | */ |
| 82 | static xfs_log_item_t * |
| 83 | xfs_ail_min( |
| 84 | struct xfs_ail *ailp) |
| 85 | { |
| 86 | if (list_empty(&ailp->xa_ail)) |
| 87 | return NULL; |
| 88 | |
| 89 | return list_first_entry(&ailp->xa_ail, xfs_log_item_t, li_ail); |
| 90 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | |
Dave Chinner | fd07484 | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 92 | /* |
| 93 | * Return a pointer to the last item in the AIL. If the AIL is empty, then |
| 94 | * return NULL. |
| 95 | */ |
| 96 | static xfs_log_item_t * |
| 97 | xfs_ail_max( |
| 98 | struct xfs_ail *ailp) |
| 99 | { |
| 100 | if (list_empty(&ailp->xa_ail)) |
| 101 | return NULL; |
| 102 | |
| 103 | return list_entry(ailp->xa_ail.prev, xfs_log_item_t, li_ail); |
| 104 | } |
| 105 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | /* |
Dave Chinner | cd4a3c5 | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 107 | * Return a pointer to the item which follows the given item in the AIL. If |
| 108 | * the given item is the last item in the list, then return NULL. |
| 109 | */ |
| 110 | static xfs_log_item_t * |
| 111 | xfs_ail_next( |
| 112 | struct xfs_ail *ailp, |
| 113 | xfs_log_item_t *lip) |
| 114 | { |
| 115 | if (lip->li_ail.next == &ailp->xa_ail) |
| 116 | return NULL; |
| 117 | |
| 118 | return list_first_entry(&lip->li_ail, xfs_log_item_t, li_ail); |
| 119 | } |
| 120 | |
| 121 | /* |
| 122 | * This is called by the log manager code to determine the LSN of the tail of |
| 123 | * the log. This is exactly the LSN of the first item in the AIL. If the AIL |
| 124 | * is empty, then this function returns 0. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | * |
Dave Chinner | cd4a3c5 | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 126 | * We need the AIL lock in order to get a coherent read of the lsn of the last |
| 127 | * item in the AIL. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | */ |
| 129 | xfs_lsn_t |
Dave Chinner | fd07484 | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 130 | xfs_ail_min_lsn( |
David Chinner | 5b00f14 | 2008-10-30 17:39:00 +1100 | [diff] [blame] | 131 | struct xfs_ail *ailp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | { |
Dave Chinner | cd4a3c5 | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 133 | xfs_lsn_t lsn = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | xfs_log_item_t *lip; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | |
David Chinner | c7e8f26 | 2008-10-30 17:39:23 +1100 | [diff] [blame] | 136 | spin_lock(&ailp->xa_lock); |
David Chinner | 5b00f14 | 2008-10-30 17:39:00 +1100 | [diff] [blame] | 137 | lip = xfs_ail_min(ailp); |
Dave Chinner | cd4a3c5 | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 138 | if (lip) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | lsn = lip->li_lsn; |
David Chinner | c7e8f26 | 2008-10-30 17:39:23 +1100 | [diff] [blame] | 140 | spin_unlock(&ailp->xa_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | |
| 142 | return lsn; |
| 143 | } |
| 144 | |
| 145 | /* |
Dave Chinner | fd07484 | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 146 | * Return the maximum lsn held in the AIL, or zero if the AIL is empty. |
| 147 | */ |
| 148 | static xfs_lsn_t |
| 149 | xfs_ail_max_lsn( |
| 150 | struct xfs_ail *ailp) |
| 151 | { |
| 152 | xfs_lsn_t lsn = 0; |
| 153 | xfs_log_item_t *lip; |
| 154 | |
| 155 | spin_lock(&ailp->xa_lock); |
| 156 | lip = xfs_ail_max(ailp); |
| 157 | if (lip) |
| 158 | lsn = lip->li_lsn; |
| 159 | spin_unlock(&ailp->xa_lock); |
| 160 | |
| 161 | return lsn; |
| 162 | } |
| 163 | |
| 164 | /* |
Dave Chinner | af3e402 | 2011-07-18 03:40:18 +0000 | [diff] [blame] | 165 | * The cursor keeps track of where our current traversal is up to by tracking |
| 166 | * the next item in the list for us. However, for this to be safe, removing an |
| 167 | * object from the AIL needs to invalidate any cursor that points to it. hence |
| 168 | * the traversal cursor needs to be linked to the struct xfs_ail so that |
| 169 | * deletion can search all the active cursors for invalidation. |
David Chinner | 27d8d5f | 2008-10-30 17:38:39 +1100 | [diff] [blame] | 170 | */ |
David Chinner | 5b00f14 | 2008-10-30 17:39:00 +1100 | [diff] [blame] | 171 | STATIC void |
David Chinner | 27d8d5f | 2008-10-30 17:38:39 +1100 | [diff] [blame] | 172 | xfs_trans_ail_cursor_init( |
| 173 | struct xfs_ail *ailp, |
| 174 | struct xfs_ail_cursor *cur) |
| 175 | { |
| 176 | cur->item = NULL; |
Dave Chinner | af3e402 | 2011-07-18 03:40:18 +0000 | [diff] [blame] | 177 | list_add_tail(&cur->list, &ailp->xa_cursors); |
David Chinner | 27d8d5f | 2008-10-30 17:38:39 +1100 | [diff] [blame] | 178 | } |
| 179 | |
| 180 | /* |
Dave Chinner | af3e402 | 2011-07-18 03:40:18 +0000 | [diff] [blame] | 181 | * Get the next item in the traversal and advance the cursor. If the cursor |
| 182 | * was invalidated (indicated by a lip of 1), restart the traversal. |
David Chinner | 27d8d5f | 2008-10-30 17:38:39 +1100 | [diff] [blame] | 183 | */ |
David Chinner | 5b00f14 | 2008-10-30 17:39:00 +1100 | [diff] [blame] | 184 | struct xfs_log_item * |
David Chinner | 27d8d5f | 2008-10-30 17:38:39 +1100 | [diff] [blame] | 185 | xfs_trans_ail_cursor_next( |
| 186 | struct xfs_ail *ailp, |
| 187 | struct xfs_ail_cursor *cur) |
| 188 | { |
| 189 | struct xfs_log_item *lip = cur->item; |
| 190 | |
| 191 | if ((__psint_t)lip & 1) |
| 192 | lip = xfs_ail_min(ailp); |
Dave Chinner | 16b5902 | 2011-07-18 03:40:17 +0000 | [diff] [blame] | 193 | if (lip) |
| 194 | cur->item = xfs_ail_next(ailp, lip); |
David Chinner | 27d8d5f | 2008-10-30 17:38:39 +1100 | [diff] [blame] | 195 | return lip; |
| 196 | } |
| 197 | |
| 198 | /* |
Dave Chinner | af3e402 | 2011-07-18 03:40:18 +0000 | [diff] [blame] | 199 | * When the traversal is complete, we need to remove the cursor from the list |
| 200 | * of traversing cursors. |
David Chinner | 27d8d5f | 2008-10-30 17:38:39 +1100 | [diff] [blame] | 201 | */ |
| 202 | void |
| 203 | xfs_trans_ail_cursor_done( |
| 204 | struct xfs_ail *ailp, |
Dave Chinner | af3e402 | 2011-07-18 03:40:18 +0000 | [diff] [blame] | 205 | struct xfs_ail_cursor *cur) |
David Chinner | 27d8d5f | 2008-10-30 17:38:39 +1100 | [diff] [blame] | 206 | { |
Dave Chinner | af3e402 | 2011-07-18 03:40:18 +0000 | [diff] [blame] | 207 | cur->item = NULL; |
| 208 | list_del_init(&cur->list); |
David Chinner | 27d8d5f | 2008-10-30 17:38:39 +1100 | [diff] [blame] | 209 | } |
| 210 | |
| 211 | /* |
Dave Chinner | af3e402 | 2011-07-18 03:40:18 +0000 | [diff] [blame] | 212 | * Invalidate any cursor that is pointing to this item. This is called when an |
| 213 | * item is removed from the AIL. Any cursor pointing to this object is now |
| 214 | * invalid and the traversal needs to be terminated so it doesn't reference a |
| 215 | * freed object. We set the low bit of the cursor item pointer so we can |
| 216 | * distinguish between an invalidation and the end of the list when getting the |
| 217 | * next item from the cursor. |
David Chinner | 5b00f14 | 2008-10-30 17:39:00 +1100 | [diff] [blame] | 218 | */ |
| 219 | STATIC void |
| 220 | xfs_trans_ail_cursor_clear( |
| 221 | struct xfs_ail *ailp, |
| 222 | struct xfs_log_item *lip) |
| 223 | { |
| 224 | struct xfs_ail_cursor *cur; |
| 225 | |
Dave Chinner | af3e402 | 2011-07-18 03:40:18 +0000 | [diff] [blame] | 226 | list_for_each_entry(cur, &ailp->xa_cursors, list) { |
David Chinner | 5b00f14 | 2008-10-30 17:39:00 +1100 | [diff] [blame] | 227 | if (cur->item == lip) |
| 228 | cur->item = (struct xfs_log_item *) |
| 229 | ((__psint_t)cur->item | 1); |
| 230 | } |
| 231 | } |
| 232 | |
| 233 | /* |
Dave Chinner | 16b5902 | 2011-07-18 03:40:17 +0000 | [diff] [blame] | 234 | * Find the first item in the AIL with the given @lsn by searching in ascending |
| 235 | * LSN order and initialise the cursor to point to the next item for a |
| 236 | * ascending traversal. Pass a @lsn of zero to initialise the cursor to the |
| 237 | * first item in the AIL. Returns NULL if the list is empty. |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 238 | */ |
David Chinner | 5b00f14 | 2008-10-30 17:39:00 +1100 | [diff] [blame] | 239 | xfs_log_item_t * |
| 240 | xfs_trans_ail_cursor_first( |
David Chinner | 27d8d5f | 2008-10-30 17:38:39 +1100 | [diff] [blame] | 241 | struct xfs_ail *ailp, |
| 242 | struct xfs_ail_cursor *cur, |
| 243 | xfs_lsn_t lsn) |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 244 | { |
David Chinner | 27d8d5f | 2008-10-30 17:38:39 +1100 | [diff] [blame] | 245 | xfs_log_item_t *lip; |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 246 | |
David Chinner | 5b00f14 | 2008-10-30 17:39:00 +1100 | [diff] [blame] | 247 | xfs_trans_ail_cursor_init(ailp, cur); |
Dave Chinner | 16b5902 | 2011-07-18 03:40:17 +0000 | [diff] [blame] | 248 | |
| 249 | if (lsn == 0) { |
| 250 | lip = xfs_ail_min(ailp); |
David Chinner | 5b00f14 | 2008-10-30 17:39:00 +1100 | [diff] [blame] | 251 | goto out; |
Dave Chinner | 16b5902 | 2011-07-18 03:40:17 +0000 | [diff] [blame] | 252 | } |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 253 | |
David Chinner | 27d8d5f | 2008-10-30 17:38:39 +1100 | [diff] [blame] | 254 | list_for_each_entry(lip, &ailp->xa_ail, li_ail) { |
David Chinner | 5b00f14 | 2008-10-30 17:39:00 +1100 | [diff] [blame] | 255 | if (XFS_LSN_CMP(lip->li_lsn, lsn) >= 0) |
David Chinner | 7ee49ac | 2008-10-30 18:26:51 +1100 | [diff] [blame] | 256 | goto out; |
Josef 'Jeff' Sipek | 535f6b3 | 2008-03-27 17:58:27 +1100 | [diff] [blame] | 257 | } |
Dave Chinner | 16b5902 | 2011-07-18 03:40:17 +0000 | [diff] [blame] | 258 | return NULL; |
| 259 | |
David Chinner | 5b00f14 | 2008-10-30 17:39:00 +1100 | [diff] [blame] | 260 | out: |
Dave Chinner | 16b5902 | 2011-07-18 03:40:17 +0000 | [diff] [blame] | 261 | if (lip) |
| 262 | cur->item = xfs_ail_next(ailp, lip); |
David Chinner | 5b00f14 | 2008-10-30 17:39:00 +1100 | [diff] [blame] | 263 | return lip; |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 264 | } |
| 265 | |
Dave Chinner | 1d8c95a | 2011-07-18 03:40:16 +0000 | [diff] [blame] | 266 | static struct xfs_log_item * |
| 267 | __xfs_trans_ail_cursor_last( |
| 268 | struct xfs_ail *ailp, |
| 269 | xfs_lsn_t lsn) |
| 270 | { |
| 271 | xfs_log_item_t *lip; |
| 272 | |
| 273 | list_for_each_entry_reverse(lip, &ailp->xa_ail, li_ail) { |
| 274 | if (XFS_LSN_CMP(lip->li_lsn, lsn) <= 0) |
| 275 | return lip; |
| 276 | } |
| 277 | return NULL; |
| 278 | } |
| 279 | |
| 280 | /* |
Dave Chinner | 16b5902 | 2011-07-18 03:40:17 +0000 | [diff] [blame] | 281 | * Find the last item in the AIL with the given @lsn by searching in descending |
| 282 | * LSN order and initialise the cursor to point to that item. If there is no |
| 283 | * item with the value of @lsn, then it sets the cursor to the last item with an |
| 284 | * LSN lower than @lsn. Returns NULL if the list is empty. |
Dave Chinner | 1d8c95a | 2011-07-18 03:40:16 +0000 | [diff] [blame] | 285 | */ |
| 286 | struct xfs_log_item * |
| 287 | xfs_trans_ail_cursor_last( |
| 288 | struct xfs_ail *ailp, |
| 289 | struct xfs_ail_cursor *cur, |
| 290 | xfs_lsn_t lsn) |
| 291 | { |
| 292 | xfs_trans_ail_cursor_init(ailp, cur); |
| 293 | cur->item = __xfs_trans_ail_cursor_last(ailp, lsn); |
| 294 | return cur->item; |
| 295 | } |
| 296 | |
| 297 | /* |
Dave Chinner | 16b5902 | 2011-07-18 03:40:17 +0000 | [diff] [blame] | 298 | * Splice the log item list into the AIL at the given LSN. We splice to the |
Dave Chinner | 1d8c95a | 2011-07-18 03:40:16 +0000 | [diff] [blame] | 299 | * tail of the given LSN to maintain insert order for push traversals. The |
| 300 | * cursor is optional, allowing repeated updates to the same LSN to avoid |
Alex Elder | e44f411 | 2011-07-22 16:04:41 +0000 | [diff] [blame] | 301 | * repeated traversals. This should not be called with an empty list. |
Dave Chinner | cd4a3c5 | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 302 | */ |
| 303 | static void |
| 304 | xfs_ail_splice( |
Dave Chinner | 1d8c95a | 2011-07-18 03:40:16 +0000 | [diff] [blame] | 305 | struct xfs_ail *ailp, |
| 306 | struct xfs_ail_cursor *cur, |
| 307 | struct list_head *list, |
| 308 | xfs_lsn_t lsn) |
Dave Chinner | cd4a3c5 | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 309 | { |
Alex Elder | e44f411 | 2011-07-22 16:04:41 +0000 | [diff] [blame] | 310 | struct xfs_log_item *lip; |
| 311 | |
| 312 | ASSERT(!list_empty(list)); |
Dave Chinner | cd4a3c5 | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 313 | |
Dave Chinner | 1d8c95a | 2011-07-18 03:40:16 +0000 | [diff] [blame] | 314 | /* |
Alex Elder | e44f411 | 2011-07-22 16:04:41 +0000 | [diff] [blame] | 315 | * Use the cursor to determine the insertion point if one is |
| 316 | * provided. If not, or if the one we got is not valid, |
| 317 | * find the place in the AIL where the items belong. |
Dave Chinner | 1d8c95a | 2011-07-18 03:40:16 +0000 | [diff] [blame] | 318 | */ |
Alex Elder | e44f411 | 2011-07-22 16:04:41 +0000 | [diff] [blame] | 319 | lip = cur ? cur->item : NULL; |
| 320 | if (!lip || (__psint_t) lip & 1) |
Dave Chinner | 1d8c95a | 2011-07-18 03:40:16 +0000 | [diff] [blame] | 321 | lip = __xfs_trans_ail_cursor_last(ailp, lsn); |
| 322 | |
Alex Elder | e44f411 | 2011-07-22 16:04:41 +0000 | [diff] [blame] | 323 | /* |
| 324 | * If a cursor is provided, we know we're processing the AIL |
| 325 | * in lsn order, and future items to be spliced in will |
| 326 | * follow the last one being inserted now. Update the |
| 327 | * cursor to point to that last item, now while we have a |
| 328 | * reliable pointer to it. |
| 329 | */ |
| 330 | if (cur) |
| 331 | cur->item = list_entry(list->prev, struct xfs_log_item, li_ail); |
Dave Chinner | cd4a3c5 | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 332 | |
Dave Chinner | 1d8c95a | 2011-07-18 03:40:16 +0000 | [diff] [blame] | 333 | /* |
Alex Elder | e44f411 | 2011-07-22 16:04:41 +0000 | [diff] [blame] | 334 | * Finally perform the splice. Unless the AIL was empty, |
| 335 | * lip points to the item in the AIL _after_ which the new |
| 336 | * items should go. If lip is null the AIL was empty, so |
| 337 | * the new items go at the head of the AIL. |
Dave Chinner | 1d8c95a | 2011-07-18 03:40:16 +0000 | [diff] [blame] | 338 | */ |
Alex Elder | e44f411 | 2011-07-22 16:04:41 +0000 | [diff] [blame] | 339 | if (lip) |
| 340 | list_splice(list, &lip->li_ail); |
| 341 | else |
| 342 | list_splice(list, &ailp->xa_ail); |
Dave Chinner | cd4a3c5 | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 343 | } |
| 344 | |
| 345 | /* |
| 346 | * Delete the given item from the AIL. Return a pointer to the item. |
| 347 | */ |
| 348 | static void |
| 349 | xfs_ail_delete( |
| 350 | struct xfs_ail *ailp, |
| 351 | xfs_log_item_t *lip) |
| 352 | { |
| 353 | xfs_ail_check(ailp, lip); |
| 354 | list_del(&lip->li_ail); |
| 355 | xfs_trans_ail_cursor_clear(ailp, lip); |
| 356 | } |
| 357 | |
Christoph Hellwig | 0030807 | 2011-10-11 11:14:10 -0400 | [diff] [blame] | 358 | static long |
| 359 | xfsaild_push( |
| 360 | struct xfs_ail *ailp) |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 361 | { |
Dave Chinner | 9e7004e | 2011-05-06 02:54:05 +0000 | [diff] [blame] | 362 | xfs_mount_t *mp = ailp->xa_mount; |
Dave Chinner | af3e402 | 2011-07-18 03:40:18 +0000 | [diff] [blame] | 363 | struct xfs_ail_cursor cur; |
Dave Chinner | 9e7004e | 2011-05-06 02:54:05 +0000 | [diff] [blame] | 364 | xfs_log_item_t *lip; |
| 365 | xfs_lsn_t lsn; |
Dave Chinner | fe0da76 | 2011-05-06 02:54:07 +0000 | [diff] [blame] | 366 | xfs_lsn_t target; |
Dave Chinner | 9e7004e | 2011-05-06 02:54:05 +0000 | [diff] [blame] | 367 | long tout = 10; |
Dave Chinner | 9e7004e | 2011-05-06 02:54:05 +0000 | [diff] [blame] | 368 | int stuck = 0; |
| 369 | int count = 0; |
| 370 | int push_xfsbufd = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 371 | |
Dave Chinner | 670ce93 | 2011-09-30 04:45:03 +0000 | [diff] [blame] | 372 | /* |
| 373 | * If last time we ran we encountered pinned items, force the log first |
| 374 | * and wait for it before pushing again. |
| 375 | */ |
David Chinner | c7e8f26 | 2008-10-30 17:39:23 +1100 | [diff] [blame] | 376 | spin_lock(&ailp->xa_lock); |
Dave Chinner | 670ce93 | 2011-09-30 04:45:03 +0000 | [diff] [blame] | 377 | if (ailp->xa_last_pushed_lsn == 0 && ailp->xa_log_flush && |
| 378 | !list_empty(&ailp->xa_ail)) { |
| 379 | ailp->xa_log_flush = 0; |
| 380 | spin_unlock(&ailp->xa_lock); |
| 381 | XFS_STATS_INC(xs_push_ail_flush); |
| 382 | xfs_log_force(mp, XFS_LOG_SYNC); |
| 383 | spin_lock(&ailp->xa_lock); |
| 384 | } |
| 385 | |
Dave Chinner | fe0da76 | 2011-05-06 02:54:07 +0000 | [diff] [blame] | 386 | target = ailp->xa_target; |
Dave Chinner | af3e402 | 2011-07-18 03:40:18 +0000 | [diff] [blame] | 387 | lip = xfs_trans_ail_cursor_first(ailp, &cur, ailp->xa_last_pushed_lsn); |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 388 | if (!lip || XFS_FORCED_SHUTDOWN(mp)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 389 | /* |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 390 | * AIL is empty or our push has reached the end. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | */ |
Dave Chinner | af3e402 | 2011-07-18 03:40:18 +0000 | [diff] [blame] | 392 | xfs_trans_ail_cursor_done(ailp, &cur); |
David Chinner | c7e8f26 | 2008-10-30 17:39:23 +1100 | [diff] [blame] | 393 | spin_unlock(&ailp->xa_lock); |
Dave Chinner | 9e7004e | 2011-05-06 02:54:05 +0000 | [diff] [blame] | 394 | goto out_done; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 395 | } |
| 396 | |
| 397 | XFS_STATS_INC(xs_push_ail); |
| 398 | |
| 399 | /* |
| 400 | * While the item we are looking at is below the given threshold |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 401 | * try to flush it out. We'd like not to stop until we've at least |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 402 | * tried to push on everything in the AIL with an LSN less than |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 403 | * the given threshold. |
| 404 | * |
| 405 | * However, we will stop after a certain number of pushes and wait |
| 406 | * for a reduced timeout to fire before pushing further. This |
| 407 | * prevents use from spinning when we can't do anything or there is |
| 408 | * lots of contention on the AIL lists. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | */ |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 410 | lsn = lip->li_lsn; |
Dave Chinner | 50e8668 | 2011-05-06 02:54:06 +0000 | [diff] [blame] | 411 | while ((XFS_LSN_CMP(lip->li_lsn, target) <= 0)) { |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 412 | int lock_result; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | /* |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 414 | * If we can lock the item without sleeping, unlock the AIL |
| 415 | * lock and flush the item. Then re-grab the AIL lock so we |
| 416 | * can look for the next item on the AIL. List changes are |
| 417 | * handled by the AIL lookup functions internally |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 418 | * |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 419 | * If we can't lock the item, either its holder will flush it |
| 420 | * or it is already being flushed or it is being relogged. In |
| 421 | * any of these case it is being taken care of and we can just |
| 422 | * skip to the next item in the list. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | */ |
| 424 | lock_result = IOP_TRYLOCK(lip); |
David Chinner | c7e8f26 | 2008-10-30 17:39:23 +1100 | [diff] [blame] | 425 | spin_unlock(&ailp->xa_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 426 | switch (lock_result) { |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 427 | case XFS_ITEM_SUCCESS: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 428 | XFS_STATS_INC(xs_push_ail_success); |
Christoph Hellwig | 9e4c109 | 2011-10-11 15:14:11 +0000 | [diff] [blame] | 429 | trace_xfs_ail_push(lip); |
| 430 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 431 | IOP_PUSH(lip); |
Dave Chinner | 0bf6a5b | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 432 | ailp->xa_last_pushed_lsn = lsn; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 433 | break; |
| 434 | |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 435 | case XFS_ITEM_PUSHBUF: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 436 | XFS_STATS_INC(xs_push_ail_pushbuf); |
Christoph Hellwig | 9e4c109 | 2011-10-11 15:14:11 +0000 | [diff] [blame] | 437 | trace_xfs_ail_pushbuf(lip); |
Christoph Hellwig | 17b3847 | 2011-10-11 15:14:09 +0000 | [diff] [blame] | 438 | |
| 439 | if (!IOP_PUSHBUF(lip)) { |
Christoph Hellwig | 9e4c109 | 2011-10-11 15:14:11 +0000 | [diff] [blame] | 440 | trace_xfs_ail_pushbuf_pinned(lip); |
Christoph Hellwig | 17b3847 | 2011-10-11 15:14:09 +0000 | [diff] [blame] | 441 | stuck++; |
Alex Elder | 2900b33 | 2011-10-18 20:00:14 +0000 | [diff] [blame] | 442 | ailp->xa_log_flush++; |
Christoph Hellwig | 17b3847 | 2011-10-11 15:14:09 +0000 | [diff] [blame] | 443 | } else { |
| 444 | ailp->xa_last_pushed_lsn = lsn; |
| 445 | } |
Dave Chinner | d808f61 | 2010-02-02 10:13:42 +1100 | [diff] [blame] | 446 | push_xfsbufd = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 447 | break; |
| 448 | |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 449 | case XFS_ITEM_PINNED: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | XFS_STATS_INC(xs_push_ail_pinned); |
Christoph Hellwig | 9e4c109 | 2011-10-11 15:14:11 +0000 | [diff] [blame] | 451 | trace_xfs_ail_pinned(lip); |
| 452 | |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 453 | stuck++; |
Dave Chinner | 670ce93 | 2011-09-30 04:45:03 +0000 | [diff] [blame] | 454 | ailp->xa_log_flush++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 455 | break; |
| 456 | |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 457 | case XFS_ITEM_LOCKED: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | XFS_STATS_INC(xs_push_ail_locked); |
Christoph Hellwig | 9e4c109 | 2011-10-11 15:14:11 +0000 | [diff] [blame] | 459 | trace_xfs_ail_locked(lip); |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 460 | stuck++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 461 | break; |
| 462 | |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 463 | default: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 464 | ASSERT(0); |
| 465 | break; |
| 466 | } |
| 467 | |
David Chinner | c7e8f26 | 2008-10-30 17:39:23 +1100 | [diff] [blame] | 468 | spin_lock(&ailp->xa_lock); |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 469 | /* should we bother continuing? */ |
| 470 | if (XFS_FORCED_SHUTDOWN(mp)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 471 | break; |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 472 | ASSERT(mp->m_log); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 474 | count++; |
| 475 | |
| 476 | /* |
| 477 | * Are there too many items we can't do anything with? |
| 478 | * If we we are skipping too many items because we can't flush |
| 479 | * them or they are already being flushed, we back off and |
| 480 | * given them time to complete whatever operation is being |
| 481 | * done. i.e. remove pressure from the AIL while we can't make |
| 482 | * progress so traversals don't slow down further inserts and |
| 483 | * removals to/from the AIL. |
| 484 | * |
| 485 | * The value of 100 is an arbitrary magic number based on |
| 486 | * observation. |
| 487 | */ |
| 488 | if (stuck > 100) |
| 489 | break; |
| 490 | |
Dave Chinner | af3e402 | 2011-07-18 03:40:18 +0000 | [diff] [blame] | 491 | lip = xfs_trans_ail_cursor_next(ailp, &cur); |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 492 | if (lip == NULL) |
| 493 | break; |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 494 | lsn = lip->li_lsn; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 495 | } |
Dave Chinner | af3e402 | 2011-07-18 03:40:18 +0000 | [diff] [blame] | 496 | xfs_trans_ail_cursor_done(ailp, &cur); |
David Chinner | c7e8f26 | 2008-10-30 17:39:23 +1100 | [diff] [blame] | 497 | spin_unlock(&ailp->xa_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | |
Dave Chinner | d808f61 | 2010-02-02 10:13:42 +1100 | [diff] [blame] | 499 | if (push_xfsbufd) { |
| 500 | /* we've got delayed write buffers to flush */ |
| 501 | wake_up_process(mp->m_ddev_targp->bt_task); |
| 502 | } |
| 503 | |
Dave Chinner | 0bf6a5b | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 504 | /* assume we have more work to do in a short while */ |
Dave Chinner | 9e7004e | 2011-05-06 02:54:05 +0000 | [diff] [blame] | 505 | out_done: |
David Chinner | 92d9cd1 | 2008-03-06 13:45:10 +1100 | [diff] [blame] | 506 | if (!count) { |
| 507 | /* We're past our target or empty, so idle */ |
Dave Chinner | 0bf6a5b | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 508 | ailp->xa_last_pushed_lsn = 0; |
Dave Chinner | 670ce93 | 2011-09-30 04:45:03 +0000 | [diff] [blame] | 509 | ailp->xa_log_flush = 0; |
Dave Chinner | 0bf6a5b | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 510 | |
Dave Chinner | 0bf6a5b | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 511 | tout = 50; |
David Chinner | 92d9cd1 | 2008-03-06 13:45:10 +1100 | [diff] [blame] | 512 | } else if (XFS_LSN_CMP(lsn, target) >= 0) { |
| 513 | /* |
| 514 | * We reached the target so wait a bit longer for I/O to |
| 515 | * complete and remove pushed items from the AIL before we |
| 516 | * start the next scan from the start of the AIL. |
| 517 | */ |
Dave Chinner | 453eac8 | 2010-01-11 11:49:58 +0000 | [diff] [blame] | 518 | tout = 50; |
Dave Chinner | 0bf6a5b | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 519 | ailp->xa_last_pushed_lsn = 0; |
David Chinner | 27d8d5f | 2008-10-30 17:38:39 +1100 | [diff] [blame] | 520 | } else if ((stuck * 100) / count > 90) { |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 521 | /* |
| 522 | * Either there is a lot of contention on the AIL or we |
| 523 | * are stuck due to operations in progress. "Stuck" in this |
| 524 | * case is defined as >90% of the items we tried to push |
| 525 | * were stuck. |
| 526 | * |
| 527 | * Backoff a bit more to allow some I/O to complete before |
Dave Chinner | 670ce93 | 2011-09-30 04:45:03 +0000 | [diff] [blame] | 528 | * restarting from the start of the AIL. This prevents us |
| 529 | * from spinning on the same items, and if they are pinned will |
| 530 | * all the restart to issue a log force to unpin the stuck |
| 531 | * items. |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 532 | */ |
Dave Chinner | 453eac8 | 2010-01-11 11:49:58 +0000 | [diff] [blame] | 533 | tout = 20; |
Dave Chinner | 670ce93 | 2011-09-30 04:45:03 +0000 | [diff] [blame] | 534 | ailp->xa_last_pushed_lsn = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 535 | } |
Dave Chinner | 0bf6a5b | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 536 | |
Christoph Hellwig | 0030807 | 2011-10-11 11:14:10 -0400 | [diff] [blame] | 537 | return tout; |
| 538 | } |
| 539 | |
| 540 | static int |
| 541 | xfsaild( |
| 542 | void *data) |
| 543 | { |
| 544 | struct xfs_ail *ailp = data; |
| 545 | long tout = 0; /* milliseconds */ |
| 546 | |
| 547 | while (!kthread_should_stop()) { |
| 548 | if (tout && tout <= 20) |
| 549 | __set_current_state(TASK_KILLABLE); |
| 550 | else |
| 551 | __set_current_state(TASK_INTERRUPTIBLE); |
| 552 | schedule_timeout(tout ? |
| 553 | msecs_to_jiffies(tout) : MAX_SCHEDULE_TIMEOUT); |
| 554 | |
| 555 | try_to_freeze(); |
| 556 | |
| 557 | tout = xfsaild_push(ailp); |
| 558 | } |
| 559 | |
| 560 | return 0; |
Dave Chinner | 453eac8 | 2010-01-11 11:49:58 +0000 | [diff] [blame] | 561 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 562 | |
Dave Chinner | 0bf6a5b | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 563 | /* |
| 564 | * This routine is called to move the tail of the AIL forward. It does this by |
| 565 | * trying to flush items in the AIL whose lsns are below the given |
| 566 | * threshold_lsn. |
| 567 | * |
| 568 | * The push is run asynchronously in a workqueue, which means the caller needs |
| 569 | * to handle waiting on the async flush for space to become available. |
| 570 | * We don't want to interrupt any push that is in progress, hence we only queue |
| 571 | * work if we set the pushing bit approriately. |
| 572 | * |
| 573 | * We do this unlocked - we only need to know whether there is anything in the |
| 574 | * AIL at the time we are called. We don't need to access the contents of |
| 575 | * any of the objects, so the lock is not needed. |
| 576 | */ |
| 577 | void |
Dave Chinner | fd07484 | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 578 | xfs_ail_push( |
Dave Chinner | 0bf6a5b | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 579 | struct xfs_ail *ailp, |
| 580 | xfs_lsn_t threshold_lsn) |
| 581 | { |
| 582 | xfs_log_item_t *lip; |
| 583 | |
| 584 | lip = xfs_ail_min(ailp); |
| 585 | if (!lip || XFS_FORCED_SHUTDOWN(ailp->xa_mount) || |
| 586 | XFS_LSN_CMP(threshold_lsn, ailp->xa_target) <= 0) |
| 587 | return; |
| 588 | |
| 589 | /* |
| 590 | * Ensure that the new target is noticed in push code before it clears |
| 591 | * the XFS_AIL_PUSHING_BIT. |
| 592 | */ |
| 593 | smp_wmb(); |
Dave Chinner | fe0da76 | 2011-05-06 02:54:07 +0000 | [diff] [blame] | 594 | xfs_trans_ail_copy_lsn(ailp, &ailp->xa_target, &threshold_lsn); |
Christoph Hellwig | 0030807 | 2011-10-11 11:14:10 -0400 | [diff] [blame] | 595 | smp_wmb(); |
| 596 | |
| 597 | wake_up_process(ailp->xa_task); |
Dave Chinner | 0bf6a5b | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 598 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 599 | |
| 600 | /* |
Dave Chinner | fd07484 | 2011-04-08 12:45:07 +1000 | [diff] [blame] | 601 | * Push out all items in the AIL immediately |
| 602 | */ |
| 603 | void |
| 604 | xfs_ail_push_all( |
| 605 | struct xfs_ail *ailp) |
| 606 | { |
| 607 | xfs_lsn_t threshold_lsn = xfs_ail_max_lsn(ailp); |
| 608 | |
| 609 | if (threshold_lsn) |
| 610 | xfs_ail_push(ailp, threshold_lsn); |
| 611 | } |
| 612 | |
| 613 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 614 | * This is to be called when an item is unlocked that may have |
| 615 | * been in the AIL. It will wake up the first member of the AIL |
| 616 | * wait list if this item's unlocking might allow it to progress. |
| 617 | * If the item is in the AIL, then we need to get the AIL lock |
| 618 | * while doing our checking so we don't race with someone going |
| 619 | * to sleep waiting for this event in xfs_trans_push_ail(). |
| 620 | */ |
| 621 | void |
| 622 | xfs_trans_unlocked_item( |
David Chinner | 783a2f6 | 2008-10-30 17:39:58 +1100 | [diff] [blame] | 623 | struct xfs_ail *ailp, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 624 | xfs_log_item_t *lip) |
| 625 | { |
| 626 | xfs_log_item_t *min_lip; |
| 627 | |
| 628 | /* |
| 629 | * If we're forcibly shutting down, we may have |
| 630 | * unlocked log items arbitrarily. The last thing |
| 631 | * we want to do is to move the tail of the log |
| 632 | * over some potentially valid data. |
| 633 | */ |
| 634 | if (!(lip->li_flags & XFS_LI_IN_AIL) || |
David Chinner | 783a2f6 | 2008-10-30 17:39:58 +1100 | [diff] [blame] | 635 | XFS_FORCED_SHUTDOWN(ailp->xa_mount)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 636 | return; |
| 637 | } |
| 638 | |
| 639 | /* |
| 640 | * This is the one case where we can call into xfs_ail_min() |
| 641 | * without holding the AIL lock because we only care about the |
| 642 | * case where we are at the tail of the AIL. If the object isn't |
| 643 | * at the tail, it doesn't matter what result we get back. This |
| 644 | * is slightly racy because since we were just unlocked, we could |
| 645 | * go to sleep between the call to xfs_ail_min and the call to |
| 646 | * xfs_log_move_tail, have someone else lock us, commit to us disk, |
| 647 | * move us out of the tail of the AIL, and then we wake up. However, |
| 648 | * the call to xfs_log_move_tail() doesn't do anything if there's |
| 649 | * not enough free space to wake people up so we're safe calling it. |
| 650 | */ |
David Chinner | 783a2f6 | 2008-10-30 17:39:58 +1100 | [diff] [blame] | 651 | min_lip = xfs_ail_min(ailp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 652 | |
| 653 | if (min_lip == lip) |
David Chinner | 783a2f6 | 2008-10-30 17:39:58 +1100 | [diff] [blame] | 654 | xfs_log_move_tail(ailp->xa_mount, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 655 | } /* xfs_trans_unlocked_item */ |
| 656 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 657 | /* |
Dave Chinner | 0e57f6a | 2010-12-20 12:02:19 +1100 | [diff] [blame] | 658 | * xfs_trans_ail_update - bulk AIL insertion operation. |
| 659 | * |
| 660 | * @xfs_trans_ail_update takes an array of log items that all need to be |
| 661 | * positioned at the same LSN in the AIL. If an item is not in the AIL, it will |
| 662 | * be added. Otherwise, it will be repositioned by removing it and re-adding |
| 663 | * it to the AIL. If we move the first item in the AIL, update the log tail to |
| 664 | * match the new minimum LSN in the AIL. |
| 665 | * |
| 666 | * This function takes the AIL lock once to execute the update operations on |
| 667 | * all the items in the array, and as such should not be called with the AIL |
| 668 | * lock held. As a result, once we have the AIL lock, we need to check each log |
| 669 | * item LSN to confirm it needs to be moved forward in the AIL. |
| 670 | * |
| 671 | * To optimise the insert operation, we delete all the items from the AIL in |
| 672 | * the first pass, moving them into a temporary list, then splice the temporary |
| 673 | * list into the correct position in the AIL. This avoids needing to do an |
| 674 | * insert operation on every item. |
| 675 | * |
| 676 | * This function must be called with the AIL lock held. The lock is dropped |
| 677 | * before returning. |
| 678 | */ |
| 679 | void |
| 680 | xfs_trans_ail_update_bulk( |
| 681 | struct xfs_ail *ailp, |
Dave Chinner | 1d8c95a | 2011-07-18 03:40:16 +0000 | [diff] [blame] | 682 | struct xfs_ail_cursor *cur, |
Dave Chinner | 0e57f6a | 2010-12-20 12:02:19 +1100 | [diff] [blame] | 683 | struct xfs_log_item **log_items, |
| 684 | int nr_items, |
| 685 | xfs_lsn_t lsn) __releases(ailp->xa_lock) |
| 686 | { |
| 687 | xfs_log_item_t *mlip; |
| 688 | xfs_lsn_t tail_lsn; |
| 689 | int mlip_changed = 0; |
| 690 | int i; |
| 691 | LIST_HEAD(tmp); |
| 692 | |
Alex Elder | e44f411 | 2011-07-22 16:04:41 +0000 | [diff] [blame] | 693 | ASSERT(nr_items > 0); /* Not required, but true. */ |
Dave Chinner | 0e57f6a | 2010-12-20 12:02:19 +1100 | [diff] [blame] | 694 | mlip = xfs_ail_min(ailp); |
| 695 | |
| 696 | for (i = 0; i < nr_items; i++) { |
| 697 | struct xfs_log_item *lip = log_items[i]; |
| 698 | if (lip->li_flags & XFS_LI_IN_AIL) { |
| 699 | /* check if we really need to move the item */ |
| 700 | if (XFS_LSN_CMP(lsn, lip->li_lsn) <= 0) |
| 701 | continue; |
| 702 | |
| 703 | xfs_ail_delete(ailp, lip); |
| 704 | if (mlip == lip) |
| 705 | mlip_changed = 1; |
| 706 | } else { |
| 707 | lip->li_flags |= XFS_LI_IN_AIL; |
| 708 | } |
| 709 | lip->li_lsn = lsn; |
| 710 | list_add(&lip->li_ail, &tmp); |
| 711 | } |
| 712 | |
Alex Elder | e44f411 | 2011-07-22 16:04:41 +0000 | [diff] [blame] | 713 | if (!list_empty(&tmp)) |
| 714 | xfs_ail_splice(ailp, cur, &tmp, lsn); |
Dave Chinner | 0e57f6a | 2010-12-20 12:02:19 +1100 | [diff] [blame] | 715 | |
| 716 | if (!mlip_changed) { |
| 717 | spin_unlock(&ailp->xa_lock); |
| 718 | return; |
| 719 | } |
| 720 | |
| 721 | /* |
| 722 | * It is not safe to access mlip after the AIL lock is dropped, so we |
| 723 | * must get a copy of li_lsn before we do so. This is especially |
| 724 | * important on 32-bit platforms where accessing and updating 64-bit |
| 725 | * values like li_lsn is not atomic. |
| 726 | */ |
| 727 | mlip = xfs_ail_min(ailp); |
| 728 | tail_lsn = mlip->li_lsn; |
| 729 | spin_unlock(&ailp->xa_lock); |
| 730 | xfs_log_move_tail(ailp->xa_mount, tail_lsn); |
| 731 | } |
| 732 | |
| 733 | /* |
Dave Chinner | 3013683 | 2010-12-20 12:03:17 +1100 | [diff] [blame] | 734 | * xfs_trans_ail_delete_bulk - remove multiple log items from the AIL |
| 735 | * |
| 736 | * @xfs_trans_ail_delete_bulk takes an array of log items that all need to |
| 737 | * removed from the AIL. The caller is already holding the AIL lock, and done |
| 738 | * all the checks necessary to ensure the items passed in via @log_items are |
| 739 | * ready for deletion. This includes checking that the items are in the AIL. |
| 740 | * |
| 741 | * For each log item to be removed, unlink it from the AIL, clear the IN_AIL |
| 742 | * flag from the item and reset the item's lsn to 0. If we remove the first |
| 743 | * item in the AIL, update the log tail to match the new minimum LSN in the |
| 744 | * AIL. |
| 745 | * |
| 746 | * This function will not drop the AIL lock until all items are removed from |
| 747 | * the AIL to minimise the amount of lock traffic on the AIL. This does not |
| 748 | * greatly increase the AIL hold time, but does significantly reduce the amount |
| 749 | * of traffic on the lock, especially during IO completion. |
| 750 | * |
| 751 | * This function must be called with the AIL lock held. The lock is dropped |
| 752 | * before returning. |
| 753 | */ |
| 754 | void |
| 755 | xfs_trans_ail_delete_bulk( |
| 756 | struct xfs_ail *ailp, |
| 757 | struct xfs_log_item **log_items, |
| 758 | int nr_items) __releases(ailp->xa_lock) |
| 759 | { |
| 760 | xfs_log_item_t *mlip; |
| 761 | xfs_lsn_t tail_lsn; |
| 762 | int mlip_changed = 0; |
| 763 | int i; |
| 764 | |
| 765 | mlip = xfs_ail_min(ailp); |
| 766 | |
| 767 | for (i = 0; i < nr_items; i++) { |
| 768 | struct xfs_log_item *lip = log_items[i]; |
| 769 | if (!(lip->li_flags & XFS_LI_IN_AIL)) { |
| 770 | struct xfs_mount *mp = ailp->xa_mount; |
| 771 | |
| 772 | spin_unlock(&ailp->xa_lock); |
| 773 | if (!XFS_FORCED_SHUTDOWN(mp)) { |
Dave Chinner | 6a19d93 | 2011-03-07 10:02:35 +1100 | [diff] [blame] | 774 | xfs_alert_tag(mp, XFS_PTAG_AILDELETE, |
Dave Chinner | 3013683 | 2010-12-20 12:03:17 +1100 | [diff] [blame] | 775 | "%s: attempting to delete a log item that is not in the AIL", |
| 776 | __func__); |
| 777 | xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE); |
| 778 | } |
| 779 | return; |
| 780 | } |
| 781 | |
| 782 | xfs_ail_delete(ailp, lip); |
| 783 | lip->li_flags &= ~XFS_LI_IN_AIL; |
| 784 | lip->li_lsn = 0; |
| 785 | if (mlip == lip) |
| 786 | mlip_changed = 1; |
| 787 | } |
| 788 | |
| 789 | if (!mlip_changed) { |
| 790 | spin_unlock(&ailp->xa_lock); |
| 791 | return; |
| 792 | } |
| 793 | |
| 794 | /* |
| 795 | * It is not safe to access mlip after the AIL lock is dropped, so we |
| 796 | * must get a copy of li_lsn before we do so. This is especially |
| 797 | * important on 32-bit platforms where accessing and updating 64-bit |
| 798 | * values like li_lsn is not atomic. It is possible we've emptied the |
| 799 | * AIL here, so if that is the case, pass an LSN of 0 to the tail move. |
| 800 | */ |
| 801 | mlip = xfs_ail_min(ailp); |
| 802 | tail_lsn = mlip ? mlip->li_lsn : 0; |
| 803 | spin_unlock(&ailp->xa_lock); |
| 804 | xfs_log_move_tail(ailp->xa_mount, tail_lsn); |
| 805 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 806 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 807 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 808 | * The active item list (AIL) is a doubly linked list of log |
| 809 | * items sorted by ascending lsn. The base of the list is |
| 810 | * a forw/back pointer pair embedded in the xfs mount structure. |
| 811 | * The base is initialized with both pointers pointing to the |
| 812 | * base. This case always needs to be distinguished, because |
| 813 | * the base has no lsn to look at. We almost always insert |
| 814 | * at the end of the list, so on inserts we search from the |
| 815 | * end of the list to find where the new item belongs. |
| 816 | */ |
| 817 | |
| 818 | /* |
| 819 | * Initialize the doubly linked list to point only to itself. |
| 820 | */ |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 821 | int |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 822 | xfs_trans_ail_init( |
| 823 | xfs_mount_t *mp) |
| 824 | { |
David Chinner | 82fa901 | 2008-10-30 17:38:26 +1100 | [diff] [blame] | 825 | struct xfs_ail *ailp; |
| 826 | |
| 827 | ailp = kmem_zalloc(sizeof(struct xfs_ail), KM_MAYFAIL); |
| 828 | if (!ailp) |
| 829 | return ENOMEM; |
| 830 | |
| 831 | ailp->xa_mount = mp; |
| 832 | INIT_LIST_HEAD(&ailp->xa_ail); |
Dave Chinner | af3e402 | 2011-07-18 03:40:18 +0000 | [diff] [blame] | 833 | INIT_LIST_HEAD(&ailp->xa_cursors); |
David Chinner | c7e8f26 | 2008-10-30 17:39:23 +1100 | [diff] [blame] | 834 | spin_lock_init(&ailp->xa_lock); |
Christoph Hellwig | 0030807 | 2011-10-11 11:14:10 -0400 | [diff] [blame] | 835 | |
| 836 | ailp->xa_task = kthread_run(xfsaild, ailp, "xfsaild/%s", |
| 837 | ailp->xa_mount->m_fsname); |
| 838 | if (IS_ERR(ailp->xa_task)) |
| 839 | goto out_free_ailp; |
| 840 | |
David Chinner | 27d8d5f | 2008-10-30 17:38:39 +1100 | [diff] [blame] | 841 | mp->m_ail = ailp; |
| 842 | return 0; |
Christoph Hellwig | 0030807 | 2011-10-11 11:14:10 -0400 | [diff] [blame] | 843 | |
| 844 | out_free_ailp: |
| 845 | kmem_free(ailp); |
| 846 | return ENOMEM; |
David Chinner | 249a8c1 | 2008-02-05 12:13:32 +1100 | [diff] [blame] | 847 | } |
| 848 | |
| 849 | void |
| 850 | xfs_trans_ail_destroy( |
| 851 | xfs_mount_t *mp) |
| 852 | { |
David Chinner | 82fa901 | 2008-10-30 17:38:26 +1100 | [diff] [blame] | 853 | struct xfs_ail *ailp = mp->m_ail; |
| 854 | |
Christoph Hellwig | 0030807 | 2011-10-11 11:14:10 -0400 | [diff] [blame] | 855 | kthread_stop(ailp->xa_task); |
David Chinner | 82fa901 | 2008-10-30 17:38:26 +1100 | [diff] [blame] | 856 | kmem_free(ailp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 857 | } |