/* * Copyright (c) 2006-2007 Silicon Graphics, Inc. * All Rights Reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation. * * This program is distributed in the hope that it would be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include "xfs.h" #include "xfs_bmap_btree.h" #include "xfs_inum.h" #include "xfs_dir2.h" #include "xfs_dir2_sf.h" #include "xfs_attr_sf.h" #include "xfs_dinode.h" #include "xfs_inode.h" #include "xfs_ag.h" #include "xfs_log.h" #include "xfs_trans.h" #include "xfs_sb.h" #include "xfs_mount.h" #include "xfs_bmap.h" #include "xfs_alloc.h" #include "xfs_utils.h" #include "xfs_mru_cache.h" #include "xfs_filestream.h" #include "xfs_trace.h" #ifdef XFS_FILESTREAMS_TRACE ktrace_t *xfs_filestreams_trace_buf; STATIC void xfs_filestreams_trace( xfs_mount_t *mp, /* mount point */ int type, /* type of trace */ const char *func, /* source function */ int line, /* source line number */ __psunsigned_t arg0, __psunsigned_t arg1, __psunsigned_t arg2, __psunsigned_t arg3, __psunsigned_t arg4, __psunsigned_t arg5) { ktrace_enter(xfs_filestreams_trace_buf, (void *)(__psint_t)(type | (line << 16)), (void *)func, (void *)(__psunsigned_t)current_pid(), (void *)mp, (void *)(__psunsigned_t)arg0, (void *)(__psunsigned_t)arg1, (void *)(__psunsigned_t)arg2, (void *)(__psunsigned_t)arg3, (void *)(__psunsigned_t)arg4, (void *)(__psunsigned_t)arg5, NULL, NULL, NULL, NULL, NULL, NULL); } #define TRACE0(mp,t) TRACE6(mp,t,0,0,0,0,0,0) #define TRACE1(mp,t,a0) TRACE6(mp,t,a0,0,0,0,0,0) #define TRACE2(mp,t,a0,a1) TRACE6(mp,t,a0,a1,0,0,0,0) #define TRACE3(mp,t,a0,a1,a2) TRACE6(mp,t,a0,a1,a2,0,0,0) #define TRACE4(mp,t,a0,a1,a2,a3) TRACE6(mp,t,a0,a1,a2,a3,0,0) #define TRACE5(mp,t,a0,a1,a2,a3,a4) TRACE6(mp,t,a0,a1,a2,a3,a4,0) #define TRACE6(mp,t,a0,a1,a2,a3,a4,a5) \ xfs_filestreams_trace(mp, t, __func__, __LINE__, \ (__psunsigned_t)a0, (__psunsigned_t)a1, \ (__psunsigned_t)a2, (__psunsigned_t)a3, \ (__psunsigned_t)a4, (__psunsigned_t)a5) #define TRACE_AG_SCAN(mp, ag, ag2) \ TRACE2(mp, XFS_FSTRM_KTRACE_AGSCAN, ag, ag2); #define TRACE_AG_PICK1(mp, max_ag, maxfree) \ TRACE2(mp, XFS_FSTRM_KTRACE_AGPICK1, max_ag, maxfree); #define TRACE_AG_PICK2(mp, ag, ag2, cnt, free, scan, flag) \ TRACE6(mp, XFS_FSTRM_KTRACE_AGPICK2, ag, ag2, \ cnt, free, scan, flag) #define TRACE_UPDATE(mp, ip, ag, cnt, ag2, cnt2) \ TRACE5(mp, XFS_FSTRM_KTRACE_UPDATE, ip, ag, cnt, ag2, cnt2) #define TRACE_FREE(mp, ip, pip, ag, cnt) \ TRACE4(mp, XFS_FSTRM_KTRACE_FREE, ip, pip, ag, cnt) #define TRACE_LOOKUP(mp, ip, pip, ag, cnt) \ TRACE4(mp, XFS_FSTRM_KTRACE_ITEM_LOOKUP, ip, pip, ag, cnt) #define TRACE_ASSOCIATE(mp, ip, pip, ag, cnt) \ TRACE4(mp, XFS_FSTRM_KTRACE_ASSOCIATE, ip, pip, ag, cnt) #define TRACE_MOVEAG(mp, ip, pip, oag, ocnt, nag, ncnt) \ TRACE6(mp, XFS_FSTRM_KTRACE_MOVEAG, ip, pip, oag, ocnt, nag, ncnt) #define TRACE_ORPHAN(mp, ip, ag) \ TRACE2(mp, XFS_FSTRM_KTRACE_ORPHAN, ip, ag); #else #define TRACE_AG_SCAN(mp, ag, ag2) #define TRACE_AG_PICK1(mp, max_ag, maxfree) #define TRACE_AG_PICK2(mp, ag, ag2, cnt, free, scan, flag) #define TRACE_UPDATE(mp, ip, ag, cnt, ag2, cnt2) #define TRACE_FREE(mp, ip, pip, ag, cnt) #define TRACE_LOOKUP(mp, ip, pip, ag, cnt) #define TRACE_ASSOCIATE(mp, ip, pip, ag, cnt) #define TRACE_MOVEAG(mp, ip, pip, oag, ocnt, nag, ncnt) #define TRACE_ORPHAN(mp, ip, ag) #endif static kmem_zone_t *item_zone; /* * Structure for associating a file or a directory with an allocation group. * The parent directory pointer is only needed for files, but since there will * generally be vastly more files than directories in the cache, using the same * data structure simplifies the code with very little memory overhead. */ typedef struct fstrm_item { xfs_agnumber_t ag; /* AG currently in use for the file/directory. */ xfs_inode_t *ip; /* inode self-pointer. */ xfs_inode_t *pip; /* Parent directory inode pointer. */ } fstrm_item_t; /* * Scan the AGs starting at startag looking for an AG that isn't in use and has * at least minlen blocks free. */ static int _xfs_filestream_pick_ag( xfs_mount_t *mp, xfs_agnumber_t startag, xfs_agnumber_t *agp, int flags, xfs_extlen_t minlen) { int streams, max_streams; int err, trylock, nscan; xfs_extlen_t longest, free, minfree, maxfree = 0; xfs_agnumber_t ag, max_ag = NULLAGNUMBER; struct xfs_perag *pag; /* 2% of an AG's blocks must be free for it to be chosen. */ minfree = mp->m_sb.sb_agblocks / 50; ag = startag; *agp = NULLAGNUMBER; /* For the first pass, don't sleep trying to init the per-AG. */ trylock = XFS_ALLOC_FLAG_TRYLOCK; for (nscan = 0; 1; nscan++) { pag = xfs_perag_get(mp, ag); TRACE_AG_SCAN(mp, ag, atomic_read(&pag->pagf_fstrms)); if (!pag->pagf_init) { err = xfs_alloc_pagf_init(mp, NULL, ag, trylock); if (err && !trylock) { xfs_perag_put(pag); return err; } } /* Might fail sometimes during the 1st pass with trylock set. */ if (!pag->pagf_init) goto next_ag; /* Keep track of the AG with the most free blocks. */ if (pag->pagf_freeblks > maxfree) { maxfree = pag->pagf_freeblks; max_streams = atomic_read(&pag->pagf_fstrms); max_ag = ag; } /* * The AG reference count does two things: it enforces mutual * exclusion when examining the suitability of an AG in this * loop, and it guards against two filestreams being established * in the same AG as each other. */ if (xfs_filestream_get_ag(mp, ag) > 1) { xfs_filestream_put_ag(mp, ag); goto next_ag; } longest = xfs_alloc_longest_free_extent(mp, pag); if (((minlen && longest >= minlen) || (!minlen && pag->pagf_freeblks >= minfree)) && (!pag->pagf_metadata || !(flags & XFS_PICK_USERDATA) || (flags & XFS_PICK_LOWSPACE))) { /* Break out, retaining the reference on the AG. */ free = pag->pagf_freeblks; streams = atomic_read(&pag->pagf_fstrms); xfs_perag_put(pag); *agp = ag; break; } /* Drop the reference on this AG, it's not usable. */ xfs_filestream_put_ag(mp, ag); next_ag: xfs_perag_put(pag); /* Move to the next AG, wrapping to AG 0 if necessary. */ if (++ag >= mp->m_sb.sb_agcount) ag = 0; /* If a full pass of the AGs hasn't been done yet, continue. */ if (ag != startag) continue; /* Allow sleeping in xfs_alloc_pagf_init() on the 2nd pass. */ if (trylock != 0) { trylock = 0; continue; } /* Finally, if lowspace wasn't set, set it for the 3rd pass. */ if (!(flags & XFS_PICK_LOWSPACE)) { flags |= XFS_PICK_LOWSPACE; continue; } /* * Take the AG with the most free space, regardless of whether * it's already in use by another filestream. */ if (max_ag != NULLAGNUMBER) { xfs_filestream_get_ag(mp, max_ag); TRACE_AG_PICK1(mp, max_ag, maxfree); streams = max_streams; free = maxfree; *agp = max_ag; break; } /* take AG 0 if none matched */ TRACE_AG_PICK1(mp, max_ag, maxfree); *agp = 0; return 0; } TRACE_AG_PICK2(mp, startag, *agp, streams, free, nscan, flags); return 0; } /* * Set the allocation group number for a file or a directory, updating inode * references and per-AG references as appropriate. */ static int _xfs_filestream_update_ag( xfs_inode_t *ip, xfs_inode_t *pip, xfs_agnumber_t ag) { int err = 0; xfs_mount_t *mp; xfs_mru_cache_t *cache; fstrm_item_t *item; xfs_agnumber_t old_ag; xfs_inode_t *old_pip; /* * Either ip is a regular file and pip is a directory, or ip is a * directory and pip is NULL. */ ASSERT(ip && (((ip->i_d.di_mode & S_IFREG) && pip && (pip->i_d.di_mode & S_IFDIR)) || ((ip->i_d.di_mode & S_IFDIR) && !pip))); mp = ip->i_mount; cache = mp->m_filestream; item = xfs_mru_cache_lookup(cache, ip->i_ino); if (item) { ASSERT(item->ip == ip); old_ag = item->ag; item->ag = ag; old_pip = item->pip; item->pip = pip; xfs_mru_cache_done(cache); /* * If the AG has changed, drop the old ref and take a new one, * effectively transferring the reference from old to new AG. */ if (ag != old_ag) { xfs_filestream_put_ag(mp, old_ag); xfs_filestream_get_ag(mp, ag); } /* * If ip is a file and its pip has changed, drop the old ref and * take a new one. */ if (pip && pip != old_pip) { IRELE(old_pip); IHOLD(pip); } TRACE_UPDATE(mp, ip, old_ag, xfs_filestream_peek_ag(mp, old_ag), ag, xfs_filestream_peek_ag(mp, ag)); return 0; } item = kmem_zone_zalloc(item_zone, KM_MAYFAIL); if (!item) return ENOMEM; item->ag = ag; item->ip = ip; item->pip = pip; err = xfs_mru_cache_insert(cache, ip->i_ino, item); if (err) { kmem_zone_free(item_zone, item); return err; } /* Take a reference on the AG. */ xfs_filestream_get_ag(mp, ag); /* * Take a reference on the inode itself regardless of whether it's a * regular file or a directory. */ IHOLD(ip); /* * In the case of a regular file, take a reference on the parent inode * as well to ensure it remains in-core. */ if (pip) IHOLD(pip); TRACE_UPDATE(mp, ip, ag, xfs_filestream_peek_ag(mp, ag), ag, xfs_filestream_peek_ag(mp, ag)); return 0; } /* xfs_fstrm_free_func(): callback for freeing cached stream items. */ STATIC void xfs_fstrm_free_func( unsigned long ino, void *data) { fstrm_item_t *item = (fstrm_item_t *)data; xfs_inode_t *ip = item->ip; int ref; ASSERT(ip->i_ino == ino); xfs_iflags_clear(ip, XFS_IFILESTREAM); /* Drop the reference taken on the AG when the item was added. */ ref = xfs_filestream_put_ag(ip->i_mount, item->ag); ASSERT(ref >= 0); TRACE_FREE(ip->i_mount, ip, item->pip, item->ag, xfs_filestream_peek_ag(ip->i_mount, item->ag)); /* * _xfs_filestream_update_ag() always takes a reference on the inode * itself, whether it's a file or a directory. Release it here. * This can result in the inode being freed and so we must * not hold any inode locks when freeing filesstreams objects * otherwise we can deadlock here. */ IRELE(ip); /* * In the case of a regular file, _xfs_filestream_update_ag() also * takes a ref on the parent inode to keep it in-core. Release that * too. */ if (item->pip) IRELE(item->pip); /* Finally, free the memory allocated for the item. */ kmem_zone_free(item_zone, item); } /* * xfs_filestream_init() is called at xfs initialisation time to set up the * memory zone that will be used for filestream data structure allocation. */ int xfs_filestream_init(void) { item_zone = kmem_zone_init(sizeof(fstrm_item_t), "fstrm_item"); if (!item_zone) return -ENOMEM; return 0; } /* * xfs_filestream_uninit() is called at xfs termination time to destroy the * memory zone that was used for filestream data structure allocation. */ void xfs_filestream_uninit(void) { kmem_zone_destroy(item_zone); } /* * xfs_filestream_mount() is called when a file system is mounted with the * filestream option. It is responsible for allocating the data structures * needed to track the new file system's file streams. */ int xfs_filestream_mount( xfs_mount_t *mp) { int err; unsigned int lifetime, grp_count; /* * The filestream timer tunable is currently fixed within the range of * one second to four minutes, with five seconds being the default. The * group count is somewhat arbitrary, but it'd be nice to adhere to the * timer tunable to within about 10 percent. This requires at least 10 * groups. */ lifetime = xfs_fstrm_centisecs * 10; grp_count = 10; err = xfs_mru_cache_create(&mp->m_filestream, lifetime, grp_count, xfs_fstrm_free_func); return err; } /* * xfs_filestream_unmount() is called when a file system that was mounted with * the filestream option is unmounted. It drains the data structures created * to track the file system's file streams and frees all the memory that was * allocated. */ void xfs_filestream_unmount( xfs_mount_t *mp) { xfs_mru_cache_destroy(mp->m_filestream); } /* * Return the AG of the filestream the file or directory belongs to, or * NULLAGNUMBER otherwise. */ xfs_agnumber_t xfs_filestream_lookup_ag( xfs_inode_t *ip) { xfs_mru_cache_t *cache; fstrm_item_t *item; xfs_agnumber_t ag; int ref; if (!(ip->i_d.di_mode & (S_IFREG | S_IFDIR))) { ASSERT(0); return NULLAGNUMBER; } cache = ip->i_mount->m_filestream; item = xfs_mru_cache_lookup(cache, ip->i_ino); if (!item) { TRACE_LOOKUP(ip->i_mount, ip, NULL, NULLAGNUMBER, 0); return NULLAGNUMBER; } ASSERT(ip == item->ip); ag = item->ag; ref = xfs_filestream_peek_ag(ip->i_mount, ag); xfs_mru_cache_done(cache); TRACE_LOOKUP(ip->i_mount, ip, item->pip, ag, ref); return ag; } /* * xfs_filestream_associate() should only be called to associate a regular file * with its parent directory. Calling it with a child directory isn't * appropriate because filestreams don't apply to entire directory hierarchies. * Creating a file in a child directory of an existing filestream directory * starts a new filestream with its own allocation group association. * * Returns < 0 on error, 0 if successful association occurred, > 0 if * we failed to get an association because of locking issues. */ int xfs_filestream_associate( xfs_inode_t *pip, xfs_inode_t *ip) { xfs_mount_t *mp; xfs_mru_cache_t *cache; fstrm_item_t *item; xfs_agnumber_t ag, rotorstep, startag; int err = 0; ASSERT(pip->i_d.di_mode & S_IFDIR); ASSERT(ip->i_d.di_mode & S_IFREG); if (!(pip->i_d.di_mode & S_IFDIR) || !(ip->i_d.di_mode & S_IFREG)) return -EINVAL; mp = pip->i_mount; cache = mp->m_filestream; /* * We have a problem, Houston. * * Taking the iolock here violates inode locking order - we already * hold the ilock. Hence if we block getting this lock we may never * wake. Unfortunately, that means if we can't get the lock, we're * screwed in terms of getting a stream association - we can't spin * waiting for the lock because someone else is waiting on the lock we * hold and we cannot drop that as we are in a transaction here. * * Lucky for us, this inversion is not a problem because it's a * directory inode that we are trying to lock here. * * So, if we can't get the iolock without sleeping then just give up */ if (!xfs_ilock_nowait(pip, XFS_IOLOCK_EXCL)) return 1; /* If the parent directory is already in the cache, use its AG. */ item = xfs_mru_cache_lookup(cache, pip->i_ino); if (item) { ASSERT(item->ip == pip); ag = item->ag; xfs_mru_cache_done(cache); TRACE_LOOKUP(mp, pip, pip, ag, xfs_filestream_peek_ag(mp, ag)); err = _xfs_filestream_update_ag(ip, pip, ag); goto exit; } /* * Set the starting AG using the rotor for inode32, otherwise * use the directory inode's AG. */ if (mp->m_flags & XFS_MOUNT_32BITINODES) { rotorstep = xfs_rotorstep; startag = (mp->m_agfrotor / rotorstep) % mp->m_sb.sb_agcount; mp->m_agfrotor = (mp->m_agfrotor + 1) % (mp->m_sb.sb_agcount * rotorstep); } else startag = XFS_INO_TO_AGNO(mp, pip->i_ino); /* Pick a new AG for the parent inode starting at startag. */ err = _xfs_filestream_pick_ag(mp, startag, &ag, 0, 0); if (err || ag == NULLAGNUMBER) goto exit_did_pick; /* Associate the parent inode with the AG. */ err = _xfs_filestream_update_ag(pip, NULL, ag); if (err) goto exit_did_pick; /* Associate the file inode with the AG. */ err = _xfs_filestream_update_ag(ip, pip, ag); if (err) goto exit_did_pick; TRACE_ASSOCIATE(mp, ip, pip, ag, xfs_filestream_peek_ag(mp, ag)); exit_did_pick: /* * If _xfs_filestream_pick_ag() returned a valid AG, remove the * reference it took on it, since the file and directory will have taken * their own now if they were successfully cached. */ if (ag != NULLAGNUMBER) xfs_filestream_put_ag(mp, ag); exit: xfs_iunlock(pip, XFS_IOLOCK_EXCL); return -err; } /* * Pick a new allocation group for the current file and its file stream. This * function is called by xfs_bmap_filestreams() with the mount point's per-ag * lock held. */ int xfs_filestream_new_ag( xfs_bmalloca_t *ap, xfs_agnumber_t *agp) { int flags, err; xfs_inode_t *ip, *pip = NULL; xfs_mount_t *mp; xfs_mru_cache_t *cache; xfs_extlen_t minlen; fstrm_item_t *dir, *file; xfs_agnumber_t ag = NULLAGNUMBER; ip = ap->ip; mp = ip->i_mount; cache = mp->m_filestream; minlen = ap->alen; *agp = NULLAGNUMBER; /* * Look for the file in the cache, removing it if it's found. Doing * this allows it to be held across the dir lookup that follows. */ file = xfs_mru_cache_remove(cache, ip->i_ino); if (file) { ASSERT(ip == file->ip); /* Save the file's parent inode and old AG number for later. */ pip = file->pip; ag = file->ag; /* Look for the file's directory in the cache. */ dir = xfs_mru_cache_lookup(cache, pip->i_ino); if (dir) { ASSERT(pip == dir->ip); /* * If the directory has already moved on to a new AG, * use that AG as the new AG for the file. Don't * forget to twiddle the AG refcounts to match the * movement. */ if (dir->ag != file->ag) { xfs_filestream_put_ag(mp, file->ag); xfs_filestream_get_ag(mp, dir->ag); *agp = file->ag = dir->ag; } xfs_mru_cache_done(cache); } /* * Put the file back in the cache. If this fails, the free * function needs to be called to tidy up in the same way as if * the item had simply expired from the cache. */ err = xfs_mru_cache_insert(cache, ip->i_ino, file); if (err) { xfs_fstrm_free_func(ip->i_ino, file); return err; } /* * If the file's AG was moved to the directory's new AG, there's * nothing more to be done. */ if (*agp != NULLAGNUMBER) { TRACE_MOVEAG(mp, ip, pip, ag, xfs_filestream_peek_ag(mp, ag), *agp, xfs_filestream_peek_ag(mp, *agp)); return 0; } } /* * If the file's parent directory is known, take its iolock in exclusive * mode to prevent two sibling files from racing each other to migrate * themselves and their parent to different AGs. */ if (pip) xfs_ilock(pip, XFS_IOLOCK_EXCL); /* * A new AG needs to be found for the file. If the file's parent * directory is also known, it will be moved to the new AG as well to * ensure that files created inside it in future use the new AG. */ ag = (ag == NULLAGNUMBER) ? 0 : (ag + 1) % mp->m_sb.sb_agcount; flags = (ap->userdata ? XFS_PICK_USERDATA : 0) | (ap->low ? XFS_PICK_LOWSPACE : 0); err = _xfs_filestream_pick_ag(mp, ag, agp, flags, minlen); if (err || *agp == NULLAGNUMBER) goto exit; /* * If the file wasn't found in the file cache, then its parent directory * inode isn't known. For this to have happened, the file must either * be pre-existing, or it was created long enough ago that its cache * entry has expired. This isn't the sort of usage that the filestreams * allocator is trying to optimise, so there's no point trying to track * its new AG somehow in the filestream data structures. */ if (!pip) { TRACE_ORPHAN(mp, ip, *agp); goto exit; } /* Associate the parent inode with the AG. */ err = _xfs_filestream_update_ag(pip, NULL, *agp); if (err) goto exit; /* Associate the file inode with the AG. */ err = _xfs_filestream_update_ag(ip, pip, *agp); if (err) goto exit; TRACE_MOVEAG(mp, ip, pip, NULLAGNUMBER, 0, *agp, xfs_filestream_peek_ag(mp, *agp)); exit: /* * If _xfs_filestream_pick_ag() returned a valid AG, remove the * reference it took on it, since the file and directory will have taken * their own now if they were successfully cached. */ if (*agp != NULLAGNUMBER) xfs_filestream_put_ag(mp, *agp); else *agp = 0; if (pip) xfs_iunlock(pip, XFS_IOLOCK_EXCL); return err; } /* * Remove an association between an inode and a filestream object. * Typically this is done on last close of an unlinked file. */ void xfs_filestream_deassociate( xfs_inode_t *ip) { xfs_mru_cache_t *cache = ip->i_mount->m_filestream; xfs_mru_cache_delete(cache, ip->i_ino); }