/* * Copyright (c) 2000-2005 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_fs.h" #include "xfs_types.h" #include "xfs_bit.h" #include "xfs_log.h" #include "xfs_inum.h" #include "xfs_trans.h" #include "xfs_sb.h" #include "xfs_ag.h" #include "xfs_dir2.h" #include "xfs_dmapi.h" #include "xfs_mount.h" #include "xfs_bmap_btree.h" #include "xfs_alloc_btree.h" #include "xfs_ialloc_btree.h" #include "xfs_dir2_sf.h" #include "xfs_attr_sf.h" #include "xfs_dinode.h" #include "xfs_inode.h" #include "xfs_btree.h" #include "xfs_ialloc.h" #include "xfs_alloc.h" #include "xfs_rtalloc.h" #include "xfs_bmap.h" #include "xfs_error.h" #include "xfs_rw.h" #include "xfs_quota.h" #include "xfs_fsops.h" STATIC void xfs_mount_log_sbunit(xfs_mount_t *, __int64_t); STATIC int xfs_uuid_mount(xfs_mount_t *); STATIC void xfs_uuid_unmount(xfs_mount_t *mp); STATIC void xfs_unmountfs_wait(xfs_mount_t *); #ifdef HAVE_PERCPU_SB STATIC void xfs_icsb_destroy_counters(xfs_mount_t *); STATIC void xfs_icsb_balance_counter(xfs_mount_t *, xfs_sb_field_t, int, int); STATIC void xfs_icsb_sync_counters(xfs_mount_t *); STATIC int xfs_icsb_modify_counters(xfs_mount_t *, xfs_sb_field_t, int64_t, int); STATIC int xfs_icsb_disable_counter(xfs_mount_t *, xfs_sb_field_t); #else #define xfs_icsb_destroy_counters(mp) do { } while (0) #define xfs_icsb_balance_counter(mp, a, b, c) do { } while (0) #define xfs_icsb_sync_counters(mp) do { } while (0) #define xfs_icsb_modify_counters(mp, a, b, c) do { } while (0) #endif static const struct { short offset; short type; /* 0 = integer * 1 = binary / string (no translation) */ } xfs_sb_info[] = { { offsetof(xfs_sb_t, sb_magicnum), 0 }, { offsetof(xfs_sb_t, sb_blocksize), 0 }, { offsetof(xfs_sb_t, sb_dblocks), 0 }, { offsetof(xfs_sb_t, sb_rblocks), 0 }, { offsetof(xfs_sb_t, sb_rextents), 0 }, { offsetof(xfs_sb_t, sb_uuid), 1 }, { offsetof(xfs_sb_t, sb_logstart), 0 }, { offsetof(xfs_sb_t, sb_rootino), 0 }, { offsetof(xfs_sb_t, sb_rbmino), 0 }, { offsetof(xfs_sb_t, sb_rsumino), 0 }, { offsetof(xfs_sb_t, sb_rextsize), 0 }, { offsetof(xfs_sb_t, sb_agblocks), 0 }, { offsetof(xfs_sb_t, sb_agcount), 0 }, { offsetof(xfs_sb_t, sb_rbmblocks), 0 }, { offsetof(xfs_sb_t, sb_logblocks), 0 }, { offsetof(xfs_sb_t, sb_versionnum), 0 }, { offsetof(xfs_sb_t, sb_sectsize), 0 }, { offsetof(xfs_sb_t, sb_inodesize), 0 }, { offsetof(xfs_sb_t, sb_inopblock), 0 }, { offsetof(xfs_sb_t, sb_fname[0]), 1 }, { offsetof(xfs_sb_t, sb_blocklog), 0 }, { offsetof(xfs_sb_t, sb_sectlog), 0 }, { offsetof(xfs_sb_t, sb_inodelog), 0 }, { offsetof(xfs_sb_t, sb_inopblog), 0 }, { offsetof(xfs_sb_t, sb_agblklog), 0 }, { offsetof(xfs_sb_t, sb_rextslog), 0 }, { offsetof(xfs_sb_t, sb_inprogress), 0 }, { offsetof(xfs_sb_t, sb_imax_pct), 0 }, { offsetof(xfs_sb_t, sb_icount), 0 }, { offsetof(xfs_sb_t, sb_ifree), 0 }, { offsetof(xfs_sb_t, sb_fdblocks), 0 }, { offsetof(xfs_sb_t, sb_frextents), 0 }, { offsetof(xfs_sb_t, sb_uquotino), 0 }, { offsetof(xfs_sb_t, sb_gquotino), 0 }, { offsetof(xfs_sb_t, sb_qflags), 0 }, { offsetof(xfs_sb_t, sb_flags), 0 }, { offsetof(xfs_sb_t, sb_shared_vn), 0 }, { offsetof(xfs_sb_t, sb_inoalignmt), 0 }, { offsetof(xfs_sb_t, sb_unit), 0 }, { offsetof(xfs_sb_t, sb_width), 0 }, { offsetof(xfs_sb_t, sb_dirblklog), 0 }, { offsetof(xfs_sb_t, sb_logsectlog), 0 }, { offsetof(xfs_sb_t, sb_logsectsize),0 }, { offsetof(xfs_sb_t, sb_logsunit), 0 }, { offsetof(xfs_sb_t, sb_features2), 0 }, { sizeof(xfs_sb_t), 0 } }; /* * Return a pointer to an initialized xfs_mount structure. */ xfs_mount_t * xfs_mount_init(void) { xfs_mount_t *mp; mp = kmem_zalloc(sizeof(xfs_mount_t), KM_SLEEP); if (xfs_icsb_init_counters(mp)) { mp->m_flags |= XFS_MOUNT_NO_PERCPU_SB; } AIL_LOCKINIT(&mp->m_ail_lock, "xfs_ail"); spinlock_init(&mp->m_sb_lock, "xfs_sb"); mutex_init(&mp->m_ilock); initnsema(&mp->m_growlock, 1, "xfs_grow"); /* * Initialize the AIL. */ xfs_trans_ail_init(mp); atomic_set(&mp->m_active_trans, 0); return mp; } /* * Free up the resources associated with a mount structure. Assume that * the structure was initially zeroed, so we can tell which fields got * initialized. */ void xfs_mount_free( xfs_mount_t *mp) { if (mp->m_perag) { int agno; for (agno = 0; agno < mp->m_maxagi; agno++) if (mp->m_perag[agno].pagb_list) kmem_free(mp->m_perag[agno].pagb_list, sizeof(xfs_perag_busy_t) * XFS_PAGB_NUM_SLOTS); kmem_free(mp->m_perag, sizeof(xfs_perag_t) * mp->m_sb.sb_agcount); } AIL_LOCK_DESTROY(&mp->m_ail_lock); spinlock_destroy(&mp->m_sb_lock); mutex_destroy(&mp->m_ilock); freesema(&mp->m_growlock); if (mp->m_quotainfo) XFS_QM_DONE(mp); if (mp->m_fsname != NULL) kmem_free(mp->m_fsname, mp->m_fsname_len); if (mp->m_rtname != NULL) kmem_free(mp->m_rtname, strlen(mp->m_rtname) + 1); if (mp->m_logname != NULL) kmem_free(mp->m_logname, strlen(mp->m_logname) + 1); xfs_icsb_destroy_counters(mp); } /* * Check size of device based on the (data/realtime) block count. * Note: this check is used by the growfs code as well as mount. */ int xfs_sb_validate_fsb_count( xfs_sb_t *sbp, __uint64_t nblocks) { ASSERT(PAGE_SHIFT >= sbp->sb_blocklog); ASSERT(sbp->sb_blocklog >= BBSHIFT); #if XFS_BIG_BLKNOS /* Limited by ULONG_MAX of page cache index */ if (nblocks >> (PAGE_CACHE_SHIFT - sbp->sb_blocklog) > ULONG_MAX) return E2BIG; #else /* Limited by UINT_MAX of sectors */ if (nblocks << (sbp->sb_blocklog - BBSHIFT) > UINT_MAX) return E2BIG; #endif return 0; } /* * Check the validity of the SB found. */ STATIC int xfs_mount_validate_sb( xfs_mount_t *mp, xfs_sb_t *sbp, int flags) { /* * If the log device and data device have the * same device number, the log is internal. * Consequently, the sb_logstart should be non-zero. If * we have a zero sb_logstart in this case, we may be trying to mount * a volume filesystem in a non-volume manner. */ if (sbp->sb_magicnum != XFS_SB_MAGIC) { xfs_fs_mount_cmn_err(flags, "bad magic number"); return XFS_ERROR(EWRONGFS); } if (!XFS_SB_GOOD_VERSION(sbp)) { xfs_fs_mount_cmn_err(flags, "bad version"); return XFS_ERROR(EWRONGFS); } if (unlikely( sbp->sb_logstart == 0 && mp->m_logdev_targp == mp->m_ddev_targp)) { xfs_fs_mount_cmn_err(flags, "filesystem is marked as having an external log; " "specify logdev on the\nmount command line."); return XFS_ERROR(EINVAL); } if (unlikely( sbp->sb_logstart != 0 && mp->m_logdev_targp != mp->m_ddev_targp)) { xfs_fs_mount_cmn_err(flags, "filesystem is marked as having an internal log; " "do not specify logdev on\nthe mount command line."); return XFS_ERROR(EINVAL); } /* * More sanity checking. These were stolen directly from * xfs_repair. */ if (unlikely( sbp->sb_agcount <= 0 || sbp->sb_sectsize < XFS_MIN_SECTORSIZE || sbp->sb_sectsize > XFS_MAX_SECTORSIZE || sbp->sb_sectlog < XFS_MIN_SECTORSIZE_LOG || sbp->sb_sectlog > XFS_MAX_SECTORSIZE_LOG || sbp->sb_blocksize < XFS_MIN_BLOCKSIZE || sbp->sb_blocksize > XFS_MAX_BLOCKSIZE || sbp->sb_blocklog < XFS_MIN_BLOCKSIZE_LOG || sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG || sbp->sb_inodesize < XFS_DINODE_MIN_SIZE || sbp->sb_inodesize > XFS_DINODE_MAX_SIZE || sbp->sb_inodelog < XFS_DINODE_MIN_LOG || sbp->sb_inodelog > XFS_DINODE_MAX_LOG || (sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog) || (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE) || (sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE) || (sbp->sb_imax_pct > 100 /* zero sb_imax_pct is valid */))) { xfs_fs_mount_cmn_err(flags, "SB sanity check 1 failed"); return XFS_ERROR(EFSCORRUPTED); } /* * Sanity check AG count, size fields against data size field */ if (unlikely( sbp->sb_dblocks == 0 || sbp->sb_dblocks > (xfs_drfsbno_t)sbp->sb_agcount * sbp->sb_agblocks || sbp->sb_dblocks < (xfs_drfsbno_t)(sbp->sb_agcount - 1) * sbp->sb_agblocks + XFS_MIN_AG_BLOCKS)) { xfs_fs_mount_cmn_err(flags, "SB sanity check 2 failed"); return XFS_ERROR(EFSCORRUPTED); } if (xfs_sb_validate_fsb_count(sbp, sbp->sb_dblocks) || xfs_sb_validate_fsb_count(sbp, sbp->sb_rblocks)) { xfs_fs_mount_cmn_err(flags, "file system too large to be mounted on this system."); return XFS_ERROR(E2BIG); } if (unlikely(sbp->sb_inprogress)) { xfs_fs_mount_cmn_err(flags, "file system busy"); return XFS_ERROR(EFSCORRUPTED); } /* * Version 1 directory format has never worked on Linux. */ if (unlikely(!XFS_SB_VERSION_HASDIRV2(sbp))) { xfs_fs_mount_cmn_err(flags, "file system using version 1 directory format"); return XFS_ERROR(ENOSYS); } /* * Until this is fixed only page-sized or smaller data blocks work. */ if (unlikely(sbp->sb_blocksize > PAGE_SIZE)) { xfs_fs_mount_cmn_err(flags, "file system with blocksize %d bytes", sbp->sb_blocksize); xfs_fs_mount_cmn_err(flags, "only pagesize (%ld) or less will currently work.", PAGE_SIZE); return XFS_ERROR(ENOSYS); } return 0; } STATIC void xfs_initialize_perag_icache( xfs_perag_t *pag) { if (!pag->pag_ici_init) { rwlock_init(&pag->pag_ici_lock); INIT_RADIX_TREE(&pag->pag_ici_root, GFP_ATOMIC); pag->pag_ici_init = 1; } } xfs_agnumber_t xfs_initialize_perag( xfs_mount_t *mp, xfs_agnumber_t agcount) { xfs_agnumber_t index, max_metadata; xfs_perag_t *pag; xfs_agino_t agino; xfs_ino_t ino; xfs_sb_t *sbp = &mp->m_sb; xfs_ino_t max_inum = XFS_MAXINUMBER_32; /* Check to see if the filesystem can overflow 32 bit inodes */ agino = XFS_OFFBNO_TO_AGINO(mp, sbp->sb_agblocks - 1, 0); ino = XFS_AGINO_TO_INO(mp, agcount - 1, agino); /* Clear the mount flag if no inode can overflow 32 bits * on this filesystem, or if specifically requested.. */ if ((mp->m_flags & XFS_MOUNT_SMALL_INUMS) && ino > max_inum) { mp->m_flags |= XFS_MOUNT_32BITINODES; } else { mp->m_flags &= ~XFS_MOUNT_32BITINODES; } /* If we can overflow then setup the ag headers accordingly */ if (mp->m_flags & XFS_MOUNT_32BITINODES) { /* Calculate how much should be reserved for inodes to * meet the max inode percentage. */ if (mp->m_maxicount) { __uint64_t icount; icount = sbp->sb_dblocks * sbp->sb_imax_pct; do_div(icount, 100); icount += sbp->sb_agblocks - 1; do_div(icount, sbp->sb_agblocks); max_metadata = icount; } else { max_metadata = agcount; } for (index = 0; index < agcount; index++) { ino = XFS_AGINO_TO_INO(mp, index, agino); if (ino > max_inum) { index++; break; } /* This ag is preferred for inodes */ pag = &mp->m_perag[index]; pag->pagi_inodeok = 1; if (index < max_metadata) pag->pagf_metadata = 1; xfs_initialize_perag_icache(pag); } } else { /* Setup default behavior for smaller filesystems */ for (index = 0; index < agcount; index++) { pag = &mp->m_perag[index]; pag->pagi_inodeok = 1; xfs_initialize_perag_icache(pag); } } return index; } void xfs_sb_from_disk( xfs_sb_t *to, xfs_dsb_t *from) { to->sb_magicnum = be32_to_cpu(from->sb_magicnum); to->sb_blocksize = be32_to_cpu(from->sb_blocksize); to->sb_dblocks = be64_to_cpu(from->sb_dblocks); to->sb_rblocks = be64_to_cpu(from->sb_rblocks); to->sb_rextents = be64_to_cpu(from->sb_rextents); memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid)); to->sb_logstart = be64_to_cpu(from->sb_logstart); to->sb_rootino = be64_to_cpu(from->sb_rootino); to->sb_rbmino = be64_to_cpu(from->sb_rbmino); to->sb_rsumino = be64_to_cpu(from->sb_rsumino); to->sb_rextsize = be32_to_cpu(from->sb_rextsize); to->sb_agblocks = be32_to_cpu(from->sb_agblocks); to->sb_agcount = be32_to_cpu(from->sb_agcount); to->sb_rbmblocks = be32_to_cpu(from->sb_rbmblocks); to->sb_logblocks = be32_to_cpu(from->sb_logblocks); to->sb_versionnum = be16_to_cpu(from->sb_versionnum); to->sb_sectsize = be16_to_cpu(from->sb_sectsize); to->sb_inodesize = be16_to_cpu(from->sb_inodesize); to->sb_inopblock = be16_to_cpu(from->sb_inopblock); memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname)); to->sb_blocklog = from->sb_blocklog; to->sb_sectlog = from->sb_sectlog; to->sb_inodelog = from->sb_inodelog; to->sb_inopblog = from->sb_inopblog; to->sb_agblklog = from->sb_agblklog; to->sb_rextslog = from->sb_rextslog; to->sb_inprogress = from->sb_inprogress; to->sb_imax_pct = from->sb_imax_pct; to->sb_icount = be64_to_cpu(from->sb_icount); to->sb_ifree = be64_to_cpu(from->sb_ifree); to->sb_fdblocks = be64_to_cpu(from->sb_fdblocks); to->sb_frextents = be64_to_cpu(from->sb_frextents); to->sb_uquotino = be64_to_cpu(from->sb_uquotino); to->sb_gquotino = be64_to_cpu(from->sb_gquotino); to->sb_qflags = be16_to_cpu(from->sb_qflags); to->sb_flags = from->sb_flags; to->sb_shared_vn = from->sb_shared_vn; to->sb_inoalignmt = be32_to_cpu(from->sb_inoalignmt); to->sb_unit = be32_to_cpu(from->sb_unit); to->sb_width = be32_to_cpu(from->sb_width); to->sb_dirblklog = from->sb_dirblklog; to->sb_logsectlog = from->sb_logsectlog; to->sb_logsectsize = be16_to_cpu(from->sb_logsectsize); to->sb_logsunit = be32_to_cpu(from->sb_logsunit); to->sb_features2 = be32_to_cpu(from->sb_features2); } /* * Copy in core superblock to ondisk one. * * The fields argument is mask of superblock fields to copy. */ void xfs_sb_to_disk( xfs_dsb_t *to, xfs_sb_t *from, __int64_t fields) { xfs_caddr_t to_ptr = (xfs_caddr_t)to; xfs_caddr_t from_ptr = (xfs_caddr_t)from; xfs_sb_field_t f; int first; int size; ASSERT(fields); if (!fields) return; while (fields) { f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields); first = xfs_sb_info[f].offset; size = xfs_sb_info[f + 1].offset - first; ASSERT(xfs_sb_info[f].type == 0 || xfs_sb_info[f].type == 1); if (size == 1 || xfs_sb_info[f].type == 1) { memcpy(to_ptr + first, from_ptr + first, size); } else { switch (size) { case 2: *(__be16 *)(to_ptr + first) = cpu_to_be16(*(__u16 *)(from_ptr + first)); break; case 4: *(__be32 *)(to_ptr + first) = cpu_to_be32(*(__u32 *)(from_ptr + first)); break; case 8: *(__be64 *)(to_ptr + first) = cpu_to_be64(*(__u64 *)(from_ptr + first)); break; default: ASSERT(0); } } fields &= ~(1LL << f); } } /* * xfs_readsb * * Does the initial read of the superblock. */ int xfs_readsb(xfs_mount_t *mp, int flags) { unsigned int sector_size; unsigned int extra_flags; xfs_buf_t *bp; int error; ASSERT(mp->m_sb_bp == NULL); ASSERT(mp->m_ddev_targp != NULL); /* * Allocate a (locked) buffer to hold the superblock. * This will be kept around at all times to optimize * access to the superblock. */ sector_size = xfs_getsize_buftarg(mp->m_ddev_targp); extra_flags = XFS_BUF_LOCK | XFS_BUF_MANAGE | XFS_BUF_MAPPED; bp = xfs_buf_read_flags(mp->m_ddev_targp, XFS_SB_DADDR, BTOBB(sector_size), extra_flags); if (!bp || XFS_BUF_ISERROR(bp)) { xfs_fs_mount_cmn_err(flags, "SB read failed"); error = bp ? XFS_BUF_GETERROR(bp) : ENOMEM; goto fail; } ASSERT(XFS_BUF_ISBUSY(bp)); ASSERT(XFS_BUF_VALUSEMA(bp) <= 0); /* * Initialize the mount structure from the superblock. * But first do some basic consistency checking. */ xfs_sb_from_disk(&mp->m_sb, XFS_BUF_TO_SBP(bp)); error = xfs_mount_validate_sb(mp, &(mp->m_sb), flags); if (error) { xfs_fs_mount_cmn_err(flags, "SB validate failed"); goto fail; } /* * We must be able to do sector-sized and sector-aligned IO. */ if (sector_size > mp->m_sb.sb_sectsize) { xfs_fs_mount_cmn_err(flags, "device supports only %u byte sectors (not %u)", sector_size, mp->m_sb.sb_sectsize); error = ENOSYS; goto fail; } /* * If device sector size is smaller than the superblock size, * re-read the superblock so the buffer is correctly sized. */ if (sector_size < mp->m_sb.sb_sectsize) { XFS_BUF_UNMANAGE(bp); xfs_buf_relse(bp); sector_size = mp->m_sb.sb_sectsize; bp = xfs_buf_read_flags(mp->m_ddev_targp, XFS_SB_DADDR, BTOBB(sector_size), extra_flags); if (!bp || XFS_BUF_ISERROR(bp)) { xfs_fs_mount_cmn_err(flags, "SB re-read failed"); error = bp ? XFS_BUF_GETERROR(bp) : ENOMEM; goto fail; } ASSERT(XFS_BUF_ISBUSY(bp)); ASSERT(XFS_BUF_VALUSEMA(bp) <= 0); } /* Initialize per-cpu counters */ xfs_icsb_reinit_counters(mp); mp->m_sb_bp = bp; xfs_buf_relse(bp); ASSERT(XFS_BUF_VALUSEMA(bp) > 0); return 0; fail: if (bp) { XFS_BUF_UNMANAGE(bp); xfs_buf_relse(bp); } return error; } /* * xfs_mount_common * * Mount initialization code establishing various mount * fields from the superblock associated with the given * mount structure */ STATIC void xfs_mount_common(xfs_mount_t *mp, xfs_sb_t *sbp) { int i; mp->m_agfrotor = mp->m_agirotor = 0; spinlock_init(&mp->m_agirotor_lock, "m_agirotor_lock"); mp->m_maxagi = mp->m_sb.sb_agcount; mp->m_blkbit_log = sbp->sb_blocklog + XFS_NBBYLOG; mp->m_blkbb_log = sbp->sb_blocklog - BBSHIFT; mp->m_sectbb_log = sbp->sb_sectlog - BBSHIFT; mp->m_agno_log = xfs_highbit32(sbp->sb_agcount - 1) + 1; mp->m_agino_log = sbp->sb_inopblog + sbp->sb_agblklog; mp->m_litino = sbp->sb_inodesize - ((uint)sizeof(xfs_dinode_core_t) + (uint)sizeof(xfs_agino_t)); mp->m_blockmask = sbp->sb_blocksize - 1; mp->m_blockwsize = sbp->sb_blocksize >> XFS_WORDLOG; mp->m_blockwmask = mp->m_blockwsize - 1; INIT_LIST_HEAD(&mp->m_del_inodes); /* * Setup for attributes, in case they get created. * This value is for inodes getting attributes for the first time, * the per-inode value is for old attribute values. */ ASSERT(sbp->sb_inodesize >= 256 && sbp->sb_inodesize <= 2048); switch (sbp->sb_inodesize) { case 256: mp->m_attroffset = XFS_LITINO(mp) - XFS_BMDR_SPACE_CALC(MINABTPTRS); break; case 512: case 1024: case 2048: mp->m_attroffset = XFS_BMDR_SPACE_CALC(6 * MINABTPTRS); break; default: ASSERT(0); } ASSERT(mp->m_attroffset < XFS_LITINO(mp)); for (i = 0; i < 2; i++) { mp->m_alloc_mxr[i] = XFS_BTREE_BLOCK_MAXRECS(sbp->sb_blocksize, xfs_alloc, i == 0); mp->m_alloc_mnr[i] = XFS_BTREE_BLOCK_MINRECS(sbp->sb_blocksize, xfs_alloc, i == 0); } for (i = 0; i < 2; i++) { mp->m_bmap_dmxr[i] = XFS_BTREE_BLOCK_MAXRECS(sbp->sb_blocksize, xfs_bmbt, i == 0); mp->m_bmap_dmnr[i] = XFS_BTREE_BLOCK_MINRECS(sbp->sb_blocksize, xfs_bmbt, i == 0); } for (i = 0; i < 2; i++) { mp->m_inobt_mxr[i] = XFS_BTREE_BLOCK_MAXRECS(sbp->sb_blocksize, xfs_inobt, i == 0); mp->m_inobt_mnr[i] = XFS_BTREE_BLOCK_MINRECS(sbp->sb_blocksize, xfs_inobt, i == 0); } mp->m_bsize = XFS_FSB_TO_BB(mp, 1); mp->m_ialloc_inos = (int)MAX((__uint16_t)XFS_INODES_PER_CHUNK, sbp->sb_inopblock); mp->m_ialloc_blks = mp->m_ialloc_inos >> sbp->sb_inopblog; } /* * xfs_initialize_perag_data * * Read in each per-ag structure so we can count up the number of * allocated inodes, free inodes and used filesystem blocks as this * information is no longer persistent in the superblock. Once we have * this information, write it into the in-core superblock structure. */ STATIC int xfs_initialize_perag_data(xfs_mount_t *mp, xfs_agnumber_t agcount) { xfs_agnumber_t index; xfs_perag_t *pag; xfs_sb_t *sbp = &mp->m_sb; uint64_t ifree = 0; uint64_t ialloc = 0; uint64_t bfree = 0; uint64_t bfreelst = 0; uint64_t btree = 0; int error; int s; for (index = 0; index < agcount; index++) { /* * read the agf, then the agi. This gets us * all the inforamtion we need and populates the * per-ag structures for us. */ error = xfs_alloc_pagf_init(mp, NULL, index, 0); if (error) return error; error = xfs_ialloc_pagi_init(mp, NULL, index); if (error) return error; pag = &mp->m_perag[index]; ifree += pag->pagi_freecount; ialloc += pag->pagi_count; bfree += pag->pagf_freeblks; bfreelst += pag->pagf_flcount; btree += pag->pagf_btreeblks; } /* * Overwrite incore superblock counters with just-read data */ s = XFS_SB_LOCK(mp); sbp->sb_ifree = ifree; sbp->sb_icount = ialloc; sbp->sb_fdblocks = bfree + bfreelst + btree; XFS_SB_UNLOCK(mp, s); /* Fixup the per-cpu counters as well. */ xfs_icsb_reinit_counters(mp); return 0; } /* * xfs_mountfs * * This function does the following on an initial mount of a file system: * - reads the superblock from disk and init the mount struct * - if we're a 32-bit kernel, do a size check on the superblock * so we don't mount terabyte filesystems * - init mount struct realtime fields * - allocate inode hash table for fs * - init directory manager * - perform recovery and init the log manager */ int xfs_mountfs( xfs_mount_t *mp, int mfsi_flags) { xfs_buf_t *bp; xfs_sb_t *sbp = &(mp->m_sb); xfs_inode_t *rip; bhv_vnode_t *rvp = NULL; int readio_log, writeio_log; xfs_daddr_t d; __uint64_t resblks; __int64_t update_flags; uint quotamount, quotaflags; int agno; int uuid_mounted = 0; int error = 0; if (mp->m_sb_bp == NULL) { if ((error = xfs_readsb(mp, mfsi_flags))) { return error; } } xfs_mount_common(mp, sbp); /* * Check if sb_agblocks is aligned at stripe boundary * If sb_agblocks is NOT aligned turn off m_dalign since * allocator alignment is within an ag, therefore ag has * to be aligned at stripe boundary. */ update_flags = 0LL; if (mp->m_dalign && !(mfsi_flags & XFS_MFSI_SECOND)) { /* * If stripe unit and stripe width are not multiples * of the fs blocksize turn off alignment. */ if ((BBTOB(mp->m_dalign) & mp->m_blockmask) || (BBTOB(mp->m_swidth) & mp->m_blockmask)) { if (mp->m_flags & XFS_MOUNT_RETERR) { cmn_err(CE_WARN, "XFS: alignment check 1 failed"); error = XFS_ERROR(EINVAL); goto error1; } mp->m_dalign = mp->m_swidth = 0; } else { /* * Convert the stripe unit and width to FSBs. */ mp->m_dalign = XFS_BB_TO_FSBT(mp, mp->m_dalign); if (mp->m_dalign && (sbp->sb_agblocks % mp->m_dalign)) { if (mp->m_flags & XFS_MOUNT_RETERR) { error = XFS_ERROR(EINVAL); goto error1; } xfs_fs_cmn_err(CE_WARN, mp, "stripe alignment turned off: sunit(%d)/swidth(%d) incompatible with agsize(%d)", mp->m_dalign, mp->m_swidth, sbp->sb_agblocks); mp->m_dalign = 0; mp->m_swidth = 0; } else if (mp->m_dalign) { mp->m_swidth = XFS_BB_TO_FSBT(mp, mp->m_swidth); } else { if (mp->m_flags & XFS_MOUNT_RETERR) { xfs_fs_cmn_err(CE_WARN, mp, "stripe alignment turned off: sunit(%d) less than bsize(%d)", mp->m_dalign, mp->m_blockmask +1); error = XFS_ERROR(EINVAL); goto error1; } mp->m_swidth = 0; } } /* * Update superblock with new values * and log changes */ if (XFS_SB_VERSION_HASDALIGN(sbp)) { if (sbp->sb_unit != mp->m_dalign) { sbp->sb_unit = mp->m_dalign; update_flags |= XFS_SB_UNIT; } if (sbp->sb_width != mp->m_swidth) { sbp->sb_width = mp->m_swidth; update_flags |= XFS_SB_WIDTH; } } } else if ((mp->m_flags & XFS_MOUNT_NOALIGN) != XFS_MOUNT_NOALIGN && XFS_SB_VERSION_HASDALIGN(&mp->m_sb)) { mp->m_dalign = sbp->sb_unit; mp->m_swidth = sbp->sb_width; } xfs_alloc_compute_maxlevels(mp); xfs_bmap_compute_maxlevels(mp, XFS_DATA_FORK); xfs_bmap_compute_maxlevels(mp, XFS_ATTR_FORK); xfs_ialloc_compute_maxlevels(mp); if (sbp->sb_imax_pct) { __uint64_t icount; /* Make sure the maximum inode count is a multiple of the * units we allocate inodes in. */ icount = sbp->sb_dblocks * sbp->sb_imax_pct; do_div(icount, 100); do_div(icount, mp->m_ialloc_blks); mp->m_maxicount = (icount * mp->m_ialloc_blks) << sbp->sb_inopblog; } else mp->m_maxicount = 0; mp->m_maxioffset = xfs_max_file_offset(sbp->sb_blocklog); /* * XFS uses the uuid from the superblock as the unique * identifier for fsid. We can not use the uuid from the volume * since a single partition filesystem is identical to a single * partition volume/filesystem. */ if ((mfsi_flags & XFS_MFSI_SECOND) == 0 && (mp->m_flags & XFS_MOUNT_NOUUID) == 0) { if (xfs_uuid_mount(mp)) { error = XFS_ERROR(EINVAL); goto error1; } uuid_mounted=1; } /* * Set the default minimum read and write sizes unless * already specified in a mount option. * We use smaller I/O sizes when the file system * is being used for NFS service (wsync mount option). */ if (!(mp->m_flags & XFS_MOUNT_DFLT_IOSIZE)) { if (mp->m_flags & XFS_MOUNT_WSYNC) { readio_log = XFS_WSYNC_READIO_LOG; writeio_log = XFS_WSYNC_WRITEIO_LOG; } else { readio_log = XFS_READIO_LOG_LARGE; writeio_log = XFS_WRITEIO_LOG_LARGE; } } else { readio_log = mp->m_readio_log; writeio_log = mp->m_writeio_log; } if (sbp->sb_blocklog > readio_log) { mp->m_readio_log = sbp->sb_blocklog; } else { mp->m_readio_log = readio_log; } mp->m_readio_blocks = 1 << (mp->m_readio_log - sbp->sb_blocklog); if (sbp->sb_blocklog > writeio_log) { mp->m_writeio_log = sbp->sb_blocklog; } else { mp->m_writeio_log = writeio_log; } mp->m_writeio_blocks = 1 << (mp->m_writeio_log - sbp->sb_blocklog); /* * Set the inode cluster size. * This may still be overridden by the file system * block size if it is larger than the chosen cluster size. */ mp->m_inode_cluster_size = XFS_INODE_BIG_CLUSTER_SIZE; /* * Set whether we're using inode alignment. */ if (XFS_SB_VERSION_HASALIGN(&mp->m_sb) && mp->m_sb.sb_inoalignmt >= XFS_B_TO_FSBT(mp, mp->m_inode_cluster_size)) mp->m_inoalign_mask = mp->m_sb.sb_inoalignmt - 1; else mp->m_inoalign_mask = 0; /* * If we are using stripe alignment, check whether * the stripe unit is a multiple of the inode alignment */ if (mp->m_dalign && mp->m_inoalign_mask && !(mp->m_dalign & mp->m_inoalign_mask)) mp->m_sinoalign = mp->m_dalign; else mp->m_sinoalign = 0; /* * Check that the data (and log if separate) are an ok size. */ d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks); if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_dblocks) { cmn_err(CE_WARN, "XFS: size check 1 failed"); error = XFS_ERROR(E2BIG); goto error1; } error = xfs_read_buf(mp, mp->m_ddev_targp, d - XFS_FSS_TO_BB(mp, 1), XFS_FSS_TO_BB(mp, 1), 0, &bp); if (!error) { xfs_buf_relse(bp); } else { cmn_err(CE_WARN, "XFS: size check 2 failed"); if (error == ENOSPC) { error = XFS_ERROR(E2BIG); } goto error1; } if (((mfsi_flags & XFS_MFSI_CLIENT) == 0) && mp->m_logdev_targp != mp->m_ddev_targp) { d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_logblocks); if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_logblocks) { cmn_err(CE_WARN, "XFS: size check 3 failed"); error = XFS_ERROR(E2BIG); goto error1; } error = xfs_read_buf(mp, mp->m_logdev_targp, d - XFS_FSB_TO_BB(mp, 1), XFS_FSB_TO_BB(mp, 1), 0, &bp); if (!error) { xfs_buf_relse(bp); } else { cmn_err(CE_WARN, "XFS: size check 3 failed"); if (error == ENOSPC) { error = XFS_ERROR(E2BIG); } goto error1; } } /* * Initialize realtime fields in the mount structure */ if ((error = xfs_rtmount_init(mp))) { cmn_err(CE_WARN, "XFS: RT mount failed"); goto error1; } /* * For client case we are done now */ if (mfsi_flags & XFS_MFSI_CLIENT) { return 0; } /* * Copies the low order bits of the timestamp and the randomly * set "sequence" number out of a UUID. */ uuid_getnodeuniq(&sbp->sb_uuid, mp->m_fixedfsid); mp->m_dmevmask = 0; /* not persistent; set after each mount */ xfs_dir_mount(mp); /* * Initialize the attribute manager's entries. */ mp->m_attr_magicpct = (mp->m_sb.sb_blocksize * 37) / 100; /* * Initialize the precomputed transaction reservations values. */ xfs_trans_init(mp); /* * Allocate and initialize the per-ag data. */ init_rwsem(&mp->m_peraglock); mp->m_perag = kmem_zalloc(sbp->sb_agcount * sizeof(xfs_perag_t), KM_SLEEP); mp->m_maxagi = xfs_initialize_perag(mp, sbp->sb_agcount); /* * log's mount-time initialization. Perform 1st part recovery if needed */ if (likely(sbp->sb_logblocks > 0)) { /* check for volume case */ error = xfs_log_mount(mp, mp->m_logdev_targp, XFS_FSB_TO_DADDR(mp, sbp->sb_logstart), XFS_FSB_TO_BB(mp, sbp->sb_logblocks)); if (error) { cmn_err(CE_WARN, "XFS: log mount failed"); goto error2; } } else { /* No log has been defined */ cmn_err(CE_WARN, "XFS: no log defined"); XFS_ERROR_REPORT("xfs_mountfs_int(1)", XFS_ERRLEVEL_LOW, mp); error = XFS_ERROR(EFSCORRUPTED); goto error2; } /* * Now the log is mounted, we know if it was an unclean shutdown or * not. If it was, with the first phase of recovery has completed, we * have consistent AG blocks on disk. We have not recovered EFIs yet, * but they are recovered transactionally in the second recovery phase * later. * * Hence we can safely re-initialise incore superblock counters from * the per-ag data. These may not be correct if the filesystem was not * cleanly unmounted, so we need to wait for recovery to finish before * doing this. * * If the filesystem was cleanly unmounted, then we can trust the * values in the superblock to be correct and we don't need to do * anything here. * * If we are currently making the filesystem, the initialisation will * fail as the perag data is in an undefined state. */ if (xfs_sb_version_haslazysbcount(&mp->m_sb) && !XFS_LAST_UNMOUNT_WAS_CLEAN(mp) && !mp->m_sb.sb_inprogress) { error = xfs_initialize_perag_data(mp, sbp->sb_agcount); if (error) { goto error2; } } /* * Get and sanity-check the root inode. * Save the pointer to it in the mount structure. */ error = xfs_iget(mp, NULL, sbp->sb_rootino, 0, XFS_ILOCK_EXCL, &rip, 0); if (error) { cmn_err(CE_WARN, "XFS: failed to read root inode"); goto error3; } ASSERT(rip != NULL); rvp = XFS_ITOV(rip); if (unlikely((rip->i_d.di_mode & S_IFMT) != S_IFDIR)) { cmn_err(CE_WARN, "XFS: corrupted root inode"); cmn_err(CE_WARN, "Device %s - root %llu is not a directory", XFS_BUFTARG_NAME(mp->m_ddev_targp), (unsigned long long)rip->i_ino); xfs_iunlock(rip, XFS_ILOCK_EXCL); XFS_ERROR_REPORT("xfs_mountfs_int(2)", XFS_ERRLEVEL_LOW, mp); error = XFS_ERROR(EFSCORRUPTED); goto error4; } mp->m_rootip = rip; /* save it */ xfs_iunlock(rip, XFS_ILOCK_EXCL); /* * Initialize realtime inode pointers in the mount structure */ if ((error = xfs_rtmount_inodes(mp))) { /* * Free up the root inode. */ cmn_err(CE_WARN, "XFS: failed to read RT inodes"); goto error4; } /* * If fs is not mounted readonly, then update the superblock * unit and width changes. */ if (update_flags && !(mp->m_flags & XFS_MOUNT_RDONLY)) xfs_mount_log_sbunit(mp, update_flags); /* * Initialise the XFS quota management subsystem for this mount */ if ((error = XFS_QM_INIT(mp, "amount, "aflags))) goto error4; /* * Finish recovering the file system. This part needed to be * delayed until after the root and real-time bitmap inodes * were consistently read in. */ error = xfs_log_mount_finish(mp, mfsi_flags); if (error) { cmn_err(CE_WARN, "XFS: log mount finish failed"); goto error4; } /* * Complete the quota initialisation, post-log-replay component. */ if ((error = XFS_QM_MOUNT(mp, quotamount, quotaflags, mfsi_flags))) goto error4; /* * Now we are mounted, reserve a small amount of unused space for * privileged transactions. This is needed so that transaction * space required for critical operations can dip into this pool * when at ENOSPC. This is needed for operations like create with * attr, unwritten extent conversion at ENOSPC, etc. Data allocations * are not allowed to use this reserved space. * * We default to 5% or 1024 fsbs of space reserved, whichever is smaller. * This may drive us straight to ENOSPC on mount, but that implies * we were already there on the last unmount. */ resblks = mp->m_sb.sb_dblocks; do_div(resblks, 20); resblks = min_t(__uint64_t, resblks, 1024); xfs_reserve_blocks(mp, &resblks, NULL); return 0; error4: /* * Free up the root inode. */ VN_RELE(rvp); error3: xfs_log_unmount_dealloc(mp); error2: for (agno = 0; agno < sbp->sb_agcount; agno++) if (mp->m_perag[agno].pagb_list) kmem_free(mp->m_perag[agno].pagb_list, sizeof(xfs_perag_busy_t) * XFS_PAGB_NUM_SLOTS); kmem_free(mp->m_perag, sbp->sb_agcount * sizeof(xfs_perag_t)); mp->m_perag = NULL; /* FALLTHROUGH */ error1: if (uuid_mounted) xfs_uuid_unmount(mp); xfs_freesb(mp); return error; } /* * xfs_unmountfs * * This flushes out the inodes,dquots and the superblock, unmounts the * log and makes sure that incore structures are freed. */ int xfs_unmountfs(xfs_mount_t *mp, struct cred *cr) { __uint64_t resblks; /* * We can potentially deadlock here if we have an inode cluster * that has been freed has it's buffer still pinned in memory because * the transaction is still sitting in a iclog. The stale inodes * on that buffer will have their flush locks held until the * transaction hits the disk and the callbacks run. the inode * flush takes the flush lock unconditionally and with nothing to * push out the iclog we will never get that unlocked. hence we * need to force the log first. */ xfs_log_force(mp, (xfs_lsn_t)0, XFS_LOG_FORCE | XFS_LOG_SYNC); xfs_iflush_all(mp); XFS_QM_DQPURGEALL(mp, XFS_QMOPT_QUOTALL | XFS_QMOPT_UMOUNTING); /* * Flush out the log synchronously so that we know for sure * that nothing is pinned. This is important because bflush() * will skip pinned buffers. */ xfs_log_force(mp, (xfs_lsn_t)0, XFS_LOG_FORCE | XFS_LOG_SYNC); xfs_binval(mp->m_ddev_targp); if (mp->m_rtdev_targp) { xfs_binval(mp->m_rtdev_targp); } /* * Unreserve any blocks we have so that when we unmount we don't account * the reserved free space as used. This is really only necessary for * lazy superblock counting because it trusts the incore superblock * counters to be aboslutely correct on clean unmount. * * We don't bother correcting this elsewhere for lazy superblock * counting because on mount of an unclean filesystem we reconstruct the * correct counter value and this is irrelevant. * * For non-lazy counter filesystems, this doesn't matter at all because * we only every apply deltas to the superblock and hence the incore * value does not matter.... */ resblks = 0; xfs_reserve_blocks(mp, &resblks, NULL); xfs_log_sbcount(mp, 1); xfs_unmountfs_writesb(mp); xfs_unmountfs_wait(mp); /* wait for async bufs */ xfs_log_unmount(mp); /* Done! No more fs ops. */ xfs_freesb(mp); /* * All inodes from this mount point should be freed. */ ASSERT(mp->m_inodes == NULL); xfs_unmountfs_close(mp, cr); if ((mp->m_flags & XFS_MOUNT_NOUUID) == 0) xfs_uuid_unmount(mp); #if defined(DEBUG) || defined(INDUCE_IO_ERROR) xfs_errortag_clearall(mp, 0); #endif XFS_IODONE(mp); xfs_mount_free(mp); return 0; } void xfs_unmountfs_close(xfs_mount_t *mp, struct cred *cr) { if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp) xfs_free_buftarg(mp->m_logdev_targp, 1); if (mp->m_rtdev_targp) xfs_free_buftarg(mp->m_rtdev_targp, 1); xfs_free_buftarg(mp->m_ddev_targp, 0); } STATIC void xfs_unmountfs_wait(xfs_mount_t *mp) { if (mp->m_logdev_targp != mp->m_ddev_targp) xfs_wait_buftarg(mp->m_logdev_targp); if (mp->m_rtdev_targp) xfs_wait_buftarg(mp->m_rtdev_targp); xfs_wait_buftarg(mp->m_ddev_targp); } int xfs_fs_writable(xfs_mount_t *mp) { return !(xfs_test_for_freeze(mp) || XFS_FORCED_SHUTDOWN(mp) || (mp->m_flags & XFS_MOUNT_RDONLY)); } /* * xfs_log_sbcount * * Called either periodically to keep the on disk superblock values * roughly up to date or from unmount to make sure the values are * correct on a clean unmount. * * Note this code can be called during the process of freezing, so * we may need to use the transaction allocator which does not not * block when the transaction subsystem is in its frozen state. */ int xfs_log_sbcount( xfs_mount_t *mp, uint sync) { xfs_trans_t *tp; int error; if (!xfs_fs_writable(mp)) return 0; xfs_icsb_sync_counters(mp); /* * we don't need to do this if we are updating the superblock * counters on every modification. */ if (!xfs_sb_version_haslazysbcount(&mp->m_sb)) return 0; tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_COUNT); error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0, XFS_DEFAULT_LOG_COUNT); if (error) { xfs_trans_cancel(tp, 0); return error; } xfs_mod_sb(tp, XFS_SB_IFREE | XFS_SB_ICOUNT | XFS_SB_FDBLOCKS); if (sync) xfs_trans_set_sync(tp); xfs_trans_commit(tp, 0); return 0; } STATIC void xfs_mark_shared_ro( xfs_mount_t *mp, xfs_buf_t *bp) { xfs_dsb_t *sb = XFS_BUF_TO_SBP(bp); __uint16_t version; if (!(sb->sb_flags & XFS_SBF_READONLY)) sb->sb_flags |= XFS_SBF_READONLY; version = be16_to_cpu(sb->sb_versionnum); if ((version & XFS_SB_VERSION_NUMBITS) != XFS_SB_VERSION_4 || !(version & XFS_SB_VERSION_SHAREDBIT)) version |= XFS_SB_VERSION_SHAREDBIT; sb->sb_versionnum = cpu_to_be16(version); } int xfs_unmountfs_writesb(xfs_mount_t *mp) { xfs_buf_t *sbp; int error = 0; /* * skip superblock write if fs is read-only, or * if we are doing a forced umount. */ if (!((mp->m_flags & XFS_MOUNT_RDONLY) || XFS_FORCED_SHUTDOWN(mp))) { sbp = xfs_getsb(mp, 0); /* * mark shared-readonly if desired */ if (mp->m_mk_sharedro) xfs_mark_shared_ro(mp, sbp); XFS_BUF_UNDONE(sbp); XFS_BUF_UNREAD(sbp); XFS_BUF_UNDELAYWRITE(sbp); XFS_BUF_WRITE(sbp); XFS_BUF_UNASYNC(sbp); ASSERT(XFS_BUF_TARGET(sbp) == mp->m_ddev_targp); xfsbdstrat(mp, sbp); /* Nevermind errors we might get here. */ error = xfs_iowait(sbp); if (error) xfs_ioerror_alert("xfs_unmountfs_writesb", mp, sbp, XFS_BUF_ADDR(sbp)); if (error && mp->m_mk_sharedro) xfs_fs_cmn_err(CE_ALERT, mp, "Superblock write error detected while unmounting. Filesystem may not be marked shared readonly"); xfs_buf_relse(sbp); } return error; } /* * xfs_mod_sb() can be used to copy arbitrary changes to the * in-core superblock into the superblock buffer to be logged. * It does not provide the higher level of locking that is * needed to protect the in-core superblock from concurrent * access. */ void xfs_mod_sb(xfs_trans_t *tp, __int64_t fields) { xfs_buf_t *bp; int first; int last; xfs_mount_t *mp; xfs_sb_field_t f; ASSERT(fields); if (!fields) return; mp = tp->t_mountp; bp = xfs_trans_getsb(tp, mp, 0); first = sizeof(xfs_sb_t); last = 0; /* translate/copy */ xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb, fields); /* find modified range */ f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields); ASSERT((1LL << f) & XFS_SB_MOD_BITS); first = xfs_sb_info[f].offset; f = (xfs_sb_field_t)xfs_highbit64((__uint64_t)fields); ASSERT((1LL << f) & XFS_SB_MOD_BITS); last = xfs_sb_info[f + 1].offset - 1; xfs_trans_log_buf(tp, bp, first, last); } /* * xfs_mod_incore_sb_unlocked() is a utility routine common used to apply * a delta to a specified field in the in-core superblock. Simply * switch on the field indicated and apply the delta to that field. * Fields are not allowed to dip below zero, so if the delta would * do this do not apply it and return EINVAL. * * The SB_LOCK must be held when this routine is called. */ int xfs_mod_incore_sb_unlocked( xfs_mount_t *mp, xfs_sb_field_t field, int64_t delta, int rsvd) { int scounter; /* short counter for 32 bit fields */ long long lcounter; /* long counter for 64 bit fields */ long long res_used, rem; /* * With the in-core superblock spin lock held, switch * on the indicated field. Apply the delta to the * proper field. If the fields value would dip below * 0, then do not apply the delta and return EINVAL. */ switch (field) { case XFS_SBS_ICOUNT: lcounter = (long long)mp->m_sb.sb_icount; lcounter += delta; if (lcounter < 0) { ASSERT(0); return XFS_ERROR(EINVAL); } mp->m_sb.sb_icount = lcounter; return 0; case XFS_SBS_IFREE: lcounter = (long long)mp->m_sb.sb_ifree; lcounter += delta; if (lcounter < 0) { ASSERT(0); return XFS_ERROR(EINVAL); } mp->m_sb.sb_ifree = lcounter; return 0; case XFS_SBS_FDBLOCKS: lcounter = (long long) mp->m_sb.sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp); res_used = (long long)(mp->m_resblks - mp->m_resblks_avail); if (delta > 0) { /* Putting blocks back */ if (res_used > delta) { mp->m_resblks_avail += delta; } else { rem = delta - res_used; mp->m_resblks_avail = mp->m_resblks; lcounter += rem; } } else { /* Taking blocks away */ lcounter += delta; /* * If were out of blocks, use any available reserved blocks if * were allowed to. */ if (lcounter < 0) { if (rsvd) { lcounter = (long long)mp->m_resblks_avail + delta; if (lcounter < 0) { return XFS_ERROR(ENOSPC); } mp->m_resblks_avail = lcounter; return 0; } else { /* not reserved */ return XFS_ERROR(ENOSPC); } } } mp->m_sb.sb_fdblocks = lcounter + XFS_ALLOC_SET_ASIDE(mp); return 0; case XFS_SBS_FREXTENTS: lcounter = (long long)mp->m_sb.sb_frextents; lcounter += delta; if (lcounter < 0) { return XFS_ERROR(ENOSPC); } mp->m_sb.sb_frextents = lcounter; return 0; case XFS_SBS_DBLOCKS: lcounter = (long long)mp->m_sb.sb_dblocks; lcounter += delta; if (lcounter < 0) { ASSERT(0); return XFS_ERROR(EINVAL); } mp->m_sb.sb_dblocks = lcounter; return 0; case XFS_SBS_AGCOUNT: scounter = mp->m_sb.sb_agcount; scounter += delta; if (scounter < 0) { ASSERT(0); return XFS_ERROR(EINVAL); } mp->m_sb.sb_agcount = scounter; return 0; case XFS_SBS_IMAX_PCT: scounter = mp->m_sb.sb_imax_pct; scounter += delta; if (scounter < 0) { ASSERT(0); return XFS_ERROR(EINVAL); } mp->m_sb.sb_imax_pct = scounter; return 0; case XFS_SBS_REXTSIZE: scounter = mp->m_sb.sb_rextsize; scounter += delta; if (scounter < 0) { ASSERT(0); return XFS_ERROR(EINVAL); } mp->m_sb.sb_rextsize = scounter; return 0; case XFS_SBS_RBMBLOCKS: scounter = mp->m_sb.sb_rbmblocks; scounter += delta; if (scounter < 0) { ASSERT(0); return XFS_ERROR(EINVAL); } mp->m_sb.sb_rbmblocks = scounter; return 0; case XFS_SBS_RBLOCKS: lcounter = (long long)mp->m_sb.sb_rblocks; lcounter += delta; if (lcounter < 0) { ASSERT(0); return XFS_ERROR(EINVAL); } mp->m_sb.sb_rblocks = lcounter; return 0; case XFS_SBS_REXTENTS: lcounter = (long long)mp->m_sb.sb_rextents; lcounter += delta; if (lcounter < 0) { ASSERT(0); return XFS_ERROR(EINVAL); } mp->m_sb.sb_rextents = lcounter; return 0; case XFS_SBS_REXTSLOG: scounter = mp->m_sb.sb_rextslog; scounter += delta; if (scounter < 0) { ASSERT(0); return XFS_ERROR(EINVAL); } mp->m_sb.sb_rextslog = scounter; return 0; default: ASSERT(0); return XFS_ERROR(EINVAL); } } /* * xfs_mod_incore_sb() is used to change a field in the in-core * superblock structure by the specified delta. This modification * is protected by the SB_LOCK. Just use the xfs_mod_incore_sb_unlocked() * routine to do the work. */ int xfs_mod_incore_sb( xfs_mount_t *mp, xfs_sb_field_t field, int64_t delta, int rsvd) { unsigned long s; int status; /* check for per-cpu counters */ switch (field) { #ifdef HAVE_PERCPU_SB case XFS_SBS_ICOUNT: case XFS_SBS_IFREE: case XFS_SBS_FDBLOCKS: if (!(mp->m_flags & XFS_MOUNT_NO_PERCPU_SB)) { status = xfs_icsb_modify_counters(mp, field, delta, rsvd); break; } /* FALLTHROUGH */ #endif default: s = XFS_SB_LOCK(mp); status = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd); XFS_SB_UNLOCK(mp, s); break; } return status; } /* * xfs_mod_incore_sb_batch() is used to change more than one field * in the in-core superblock structure at a time. This modification * is protected by a lock internal to this module. The fields and * changes to those fields are specified in the array of xfs_mod_sb * structures passed in. * * Either all of the specified deltas will be applied or none of * them will. If any modified field dips below 0, then all modifications * will be backed out and EINVAL will be returned. */ int xfs_mod_incore_sb_batch(xfs_mount_t *mp, xfs_mod_sb_t *msb, uint nmsb, int rsvd) { unsigned long s; int status=0; xfs_mod_sb_t *msbp; /* * Loop through the array of mod structures and apply each * individually. If any fail, then back out all those * which have already been applied. Do all of this within * the scope of the SB_LOCK so that all of the changes will * be atomic. */ s = XFS_SB_LOCK(mp); msbp = &msb[0]; for (msbp = &msbp[0]; msbp < (msb + nmsb); msbp++) { /* * Apply the delta at index n. If it fails, break * from the loop so we'll fall into the undo loop * below. */ switch (msbp->msb_field) { #ifdef HAVE_PERCPU_SB case XFS_SBS_ICOUNT: case XFS_SBS_IFREE: case XFS_SBS_FDBLOCKS: if (!(mp->m_flags & XFS_MOUNT_NO_PERCPU_SB)) { XFS_SB_UNLOCK(mp, s); status = xfs_icsb_modify_counters(mp, msbp->msb_field, msbp->msb_delta, rsvd); s = XFS_SB_LOCK(mp); break; } /* FALLTHROUGH */ #endif default: status = xfs_mod_incore_sb_unlocked(mp, msbp->msb_field, msbp->msb_delta, rsvd); break; } if (status != 0) { break; } } /* * If we didn't complete the loop above, then back out * any changes made to the superblock. If you add code * between the loop above and here, make sure that you * preserve the value of status. Loop back until * we step below the beginning of the array. Make sure * we don't touch anything back there. */ if (status != 0) { msbp--; while (msbp >= msb) { switch (msbp->msb_field) { #ifdef HAVE_PERCPU_SB case XFS_SBS_ICOUNT: case XFS_SBS_IFREE: case XFS_SBS_FDBLOCKS: if (!(mp->m_flags & XFS_MOUNT_NO_PERCPU_SB)) { XFS_SB_UNLOCK(mp, s); status = xfs_icsb_modify_counters(mp, msbp->msb_field, -(msbp->msb_delta), rsvd); s = XFS_SB_LOCK(mp); break; } /* FALLTHROUGH */ #endif default: status = xfs_mod_incore_sb_unlocked(mp, msbp->msb_field, -(msbp->msb_delta), rsvd); break; } ASSERT(status == 0); msbp--; } } XFS_SB_UNLOCK(mp, s); return status; } /* * xfs_getsb() is called to obtain the buffer for the superblock. * The buffer is returned locked and read in from disk. * The buffer should be released with a call to xfs_brelse(). * * If the flags parameter is BUF_TRYLOCK, then we'll only return * the superblock buffer if it can be locked without sleeping. * If it can't then we'll return NULL. */ xfs_buf_t * xfs_getsb( xfs_mount_t *mp, int flags) { xfs_buf_t *bp; ASSERT(mp->m_sb_bp != NULL); bp = mp->m_sb_bp; if (flags & XFS_BUF_TRYLOCK) { if (!XFS_BUF_CPSEMA(bp)) { return NULL; } } else { XFS_BUF_PSEMA(bp, PRIBIO); } XFS_BUF_HOLD(bp); ASSERT(XFS_BUF_ISDONE(bp)); return bp; } /* * Used to free the superblock along various error paths. */ void xfs_freesb( xfs_mount_t *mp) { xfs_buf_t *bp; /* * Use xfs_getsb() so that the buffer will be locked * when we call xfs_buf_relse(). */ bp = xfs_getsb(mp, 0); XFS_BUF_UNMANAGE(bp); xfs_buf_relse(bp); mp->m_sb_bp = NULL; } /* * See if the UUID is unique among mounted XFS filesystems. * Mount fails if UUID is nil or a FS with the same UUID is already mounted. */ STATIC int xfs_uuid_mount( xfs_mount_t *mp) { if (uuid_is_nil(&mp->m_sb.sb_uuid)) { cmn_err(CE_WARN, "XFS: Filesystem %s has nil UUID - can't mount", mp->m_fsname); return -1; } if (!uuid_table_insert(&mp->m_sb.sb_uuid)) { cmn_err(CE_WARN, "XFS: Filesystem %s has duplicate UUID - can't mount", mp->m_fsname); return -1; } return 0; } /* * Remove filesystem from the UUID table. */ STATIC void xfs_uuid_unmount( xfs_mount_t *mp) { uuid_table_remove(&mp->m_sb.sb_uuid); } /* * Used to log changes to the superblock unit and width fields which could * be altered by the mount options. Only the first superblock is updated. */ STATIC void xfs_mount_log_sbunit( xfs_mount_t *mp, __int64_t fields) { xfs_trans_t *tp; ASSERT(fields & (XFS_SB_UNIT|XFS_SB_WIDTH|XFS_SB_UUID)); tp = xfs_trans_alloc(mp, XFS_TRANS_SB_UNIT); if (xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0, XFS_DEFAULT_LOG_COUNT)) { xfs_trans_cancel(tp, 0); return; } xfs_mod_sb(tp, fields); xfs_trans_commit(tp, 0); } #ifdef HAVE_PERCPU_SB /* * Per-cpu incore superblock counters * * Simple concept, difficult implementation * * Basically, replace the incore superblock counters with a distributed per cpu * counter for contended fields (e.g. free block count). * * Difficulties arise in that the incore sb is used for ENOSPC checking, and * hence needs to be accurately read when we are running low on space. Hence * there is a method to enable and disable the per-cpu counters based on how * much "stuff" is available in them. * * Basically, a counter is enabled if there is enough free resource to justify * running a per-cpu fast-path. If the per-cpu counter runs out (i.e. a local * ENOSPC), then we disable the counters to synchronise all callers and * re-distribute the available resources. * * If, once we redistributed the available resources, we still get a failure, * we disable the per-cpu counter and go through the slow path. * * The slow path is the current xfs_mod_incore_sb() function. This means that * when we disable a per-cpu counter, we need to drain it's resources back to * the global superblock. We do this after disabling the counter to prevent * more threads from queueing up on the counter. * * Essentially, this means that we still need a lock in the fast path to enable * synchronisation between the global counters and the per-cpu counters. This * is not a problem because the lock will be local to a CPU almost all the time * and have little contention except when we get to ENOSPC conditions. * * Basically, this lock becomes a barrier that enables us to lock out the fast * path while we do things like enabling and disabling counters and * synchronising the counters. * * Locking rules: * * 1. XFS_SB_LOCK() before picking up per-cpu locks * 2. per-cpu locks always picked up via for_each_online_cpu() order * 3. accurate counter sync requires XFS_SB_LOCK + per cpu locks * 4. modifying per-cpu counters requires holding per-cpu lock * 5. modifying global counters requires holding XFS_SB_LOCK * 6. enabling or disabling a counter requires holding the XFS_SB_LOCK * and _none_ of the per-cpu locks. * * Disabled counters are only ever re-enabled by a balance operation * that results in more free resources per CPU than a given threshold. * To ensure counters don't remain disabled, they are rebalanced when * the global resource goes above a higher threshold (i.e. some hysteresis * is present to prevent thrashing). */ #ifdef CONFIG_HOTPLUG_CPU /* * hot-plug CPU notifier support. * * We need a notifier per filesystem as we need to be able to identify * the filesystem to balance the counters out. This is achieved by * having a notifier block embedded in the xfs_mount_t and doing pointer * magic to get the mount pointer from the notifier block address. */ STATIC int xfs_icsb_cpu_notify( struct notifier_block *nfb, unsigned long action, void *hcpu) { xfs_icsb_cnts_t *cntp; xfs_mount_t *mp; int s; mp = (xfs_mount_t *)container_of(nfb, xfs_mount_t, m_icsb_notifier); cntp = (xfs_icsb_cnts_t *) per_cpu_ptr(mp->m_sb_cnts, (unsigned long)hcpu); switch (action) { case CPU_UP_PREPARE: case CPU_UP_PREPARE_FROZEN: /* Easy Case - initialize the area and locks, and * then rebalance when online does everything else for us. */ memset(cntp, 0, sizeof(xfs_icsb_cnts_t)); break; case CPU_ONLINE: case CPU_ONLINE_FROZEN: xfs_icsb_lock(mp); xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0, 0); xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0, 0); xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0, 0); xfs_icsb_unlock(mp); break; case CPU_DEAD: case CPU_DEAD_FROZEN: /* Disable all the counters, then fold the dead cpu's * count into the total on the global superblock and * re-enable the counters. */ xfs_icsb_lock(mp); s = XFS_SB_LOCK(mp); xfs_icsb_disable_counter(mp, XFS_SBS_ICOUNT); xfs_icsb_disable_counter(mp, XFS_SBS_IFREE); xfs_icsb_disable_counter(mp, XFS_SBS_FDBLOCKS); mp->m_sb.sb_icount += cntp->icsb_icount; mp->m_sb.sb_ifree += cntp->icsb_ifree; mp->m_sb.sb_fdblocks += cntp->icsb_fdblocks; memset(cntp, 0, sizeof(xfs_icsb_cnts_t)); xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, XFS_ICSB_SB_LOCKED, 0); xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, XFS_ICSB_SB_LOCKED, 0); xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, XFS_ICSB_SB_LOCKED, 0); XFS_SB_UNLOCK(mp, s); xfs_icsb_unlock(mp); break; } return NOTIFY_OK; } #endif /* CONFIG_HOTPLUG_CPU */ int xfs_icsb_init_counters( xfs_mount_t *mp) { xfs_icsb_cnts_t *cntp; int i; mp->m_sb_cnts = alloc_percpu(xfs_icsb_cnts_t); if (mp->m_sb_cnts == NULL) return -ENOMEM; #ifdef CONFIG_HOTPLUG_CPU mp->m_icsb_notifier.notifier_call = xfs_icsb_cpu_notify; mp->m_icsb_notifier.priority = 0; register_hotcpu_notifier(&mp->m_icsb_notifier); #endif /* CONFIG_HOTPLUG_CPU */ for_each_online_cpu(i) { cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i); memset(cntp, 0, sizeof(xfs_icsb_cnts_t)); } mutex_init(&mp->m_icsb_mutex); /* * start with all counters disabled so that the * initial balance kicks us off correctly */ mp->m_icsb_counters = -1; return 0; } void xfs_icsb_reinit_counters( xfs_mount_t *mp) { xfs_icsb_lock(mp); /* * start with all counters disabled so that the * initial balance kicks us off correctly */ mp->m_icsb_counters = -1; xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0, 0); xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0, 0); xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0, 0); xfs_icsb_unlock(mp); } STATIC void xfs_icsb_destroy_counters( xfs_mount_t *mp) { if (mp->m_sb_cnts) { unregister_hotcpu_notifier(&mp->m_icsb_notifier); free_percpu(mp->m_sb_cnts); } mutex_destroy(&mp->m_icsb_mutex); } STATIC_INLINE void xfs_icsb_lock_cntr( xfs_icsb_cnts_t *icsbp) { while (test_and_set_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags)) { ndelay(1000); } } STATIC_INLINE void xfs_icsb_unlock_cntr( xfs_icsb_cnts_t *icsbp) { clear_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags); } STATIC_INLINE void xfs_icsb_lock_all_counters( xfs_mount_t *mp) { xfs_icsb_cnts_t *cntp; int i; for_each_online_cpu(i) { cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i); xfs_icsb_lock_cntr(cntp); } } STATIC_INLINE void xfs_icsb_unlock_all_counters( xfs_mount_t *mp) { xfs_icsb_cnts_t *cntp; int i; for_each_online_cpu(i) { cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i); xfs_icsb_unlock_cntr(cntp); } } STATIC void xfs_icsb_count( xfs_mount_t *mp, xfs_icsb_cnts_t *cnt, int flags) { xfs_icsb_cnts_t *cntp; int i; memset(cnt, 0, sizeof(xfs_icsb_cnts_t)); if (!(flags & XFS_ICSB_LAZY_COUNT)) xfs_icsb_lock_all_counters(mp); for_each_online_cpu(i) { cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i); cnt->icsb_icount += cntp->icsb_icount; cnt->icsb_ifree += cntp->icsb_ifree; cnt->icsb_fdblocks += cntp->icsb_fdblocks; } if (!(flags & XFS_ICSB_LAZY_COUNT)) xfs_icsb_unlock_all_counters(mp); } STATIC int xfs_icsb_counter_disabled( xfs_mount_t *mp, xfs_sb_field_t field) { ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS)); return test_bit(field, &mp->m_icsb_counters); } STATIC int xfs_icsb_disable_counter( xfs_mount_t *mp, xfs_sb_field_t field) { xfs_icsb_cnts_t cnt; ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS)); /* * If we are already disabled, then there is nothing to do * here. We check before locking all the counters to avoid * the expensive lock operation when being called in the * slow path and the counter is already disabled. This is * safe because the only time we set or clear this state is under * the m_icsb_mutex. */ if (xfs_icsb_counter_disabled(mp, field)) return 0; xfs_icsb_lock_all_counters(mp); if (!test_and_set_bit(field, &mp->m_icsb_counters)) { /* drain back to superblock */ xfs_icsb_count(mp, &cnt, XFS_ICSB_SB_LOCKED|XFS_ICSB_LAZY_COUNT); switch(field) { case XFS_SBS_ICOUNT: mp->m_sb.sb_icount = cnt.icsb_icount; break; case XFS_SBS_IFREE: mp->m_sb.sb_ifree = cnt.icsb_ifree; break; case XFS_SBS_FDBLOCKS: mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks; break; default: BUG(); } } xfs_icsb_unlock_all_counters(mp); return 0; } STATIC void xfs_icsb_enable_counter( xfs_mount_t *mp, xfs_sb_field_t field, uint64_t count, uint64_t resid) { xfs_icsb_cnts_t *cntp; int i; ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS)); xfs_icsb_lock_all_counters(mp); for_each_online_cpu(i) { cntp = per_cpu_ptr(mp->m_sb_cnts, i); switch (field) { case XFS_SBS_ICOUNT: cntp->icsb_icount = count + resid; break; case XFS_SBS_IFREE: cntp->icsb_ifree = count + resid; break; case XFS_SBS_FDBLOCKS: cntp->icsb_fdblocks = count + resid; break; default: BUG(); break; } resid = 0; } clear_bit(field, &mp->m_icsb_counters); xfs_icsb_unlock_all_counters(mp); } void xfs_icsb_sync_counters_flags( xfs_mount_t *mp, int flags) { xfs_icsb_cnts_t cnt; int s; /* Pass 1: lock all counters */ if ((flags & XFS_ICSB_SB_LOCKED) == 0) s = XFS_SB_LOCK(mp); xfs_icsb_count(mp, &cnt, flags); /* Step 3: update mp->m_sb fields */ if (!xfs_icsb_counter_disabled(mp, XFS_SBS_ICOUNT)) mp->m_sb.sb_icount = cnt.icsb_icount; if (!xfs_icsb_counter_disabled(mp, XFS_SBS_IFREE)) mp->m_sb.sb_ifree = cnt.icsb_ifree; if (!xfs_icsb_counter_disabled(mp, XFS_SBS_FDBLOCKS)) mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks; if ((flags & XFS_ICSB_SB_LOCKED) == 0) XFS_SB_UNLOCK(mp, s); } /* * Accurate update of per-cpu counters to incore superblock */ STATIC void xfs_icsb_sync_counters( xfs_mount_t *mp) { xfs_icsb_sync_counters_flags(mp, 0); } /* * Balance and enable/disable counters as necessary. * * Thresholds for re-enabling counters are somewhat magic. inode counts are * chosen to be the same number as single on disk allocation chunk per CPU, and * free blocks is something far enough zero that we aren't going thrash when we * get near ENOSPC. We also need to supply a minimum we require per cpu to * prevent looping endlessly when xfs_alloc_space asks for more than will * be distributed to a single CPU but each CPU has enough blocks to be * reenabled. * * Note that we can be called when counters are already disabled. * xfs_icsb_disable_counter() optimises the counter locking in this case to * prevent locking every per-cpu counter needlessly. */ #define XFS_ICSB_INO_CNTR_REENABLE (uint64_t)64 #define XFS_ICSB_FDBLK_CNTR_REENABLE(mp) \ (uint64_t)(512 + XFS_ALLOC_SET_ASIDE(mp)) STATIC void xfs_icsb_balance_counter( xfs_mount_t *mp, xfs_sb_field_t field, int flags, int min_per_cpu) { uint64_t count, resid; int weight = num_online_cpus(); int s; uint64_t min = (uint64_t)min_per_cpu; if (!(flags & XFS_ICSB_SB_LOCKED)) s = XFS_SB_LOCK(mp); /* disable counter and sync counter */ xfs_icsb_disable_counter(mp, field); /* update counters - first CPU gets residual*/ switch (field) { case XFS_SBS_ICOUNT: count = mp->m_sb.sb_icount; resid = do_div(count, weight); if (count < max(min, XFS_ICSB_INO_CNTR_REENABLE)) goto out; break; case XFS_SBS_IFREE: count = mp->m_sb.sb_ifree; resid = do_div(count, weight); if (count < max(min, XFS_ICSB_INO_CNTR_REENABLE)) goto out; break; case XFS_SBS_FDBLOCKS: count = mp->m_sb.sb_fdblocks; resid = do_div(count, weight); if (count < max(min, XFS_ICSB_FDBLK_CNTR_REENABLE(mp))) goto out; break; default: BUG(); count = resid = 0; /* quiet, gcc */ break; } xfs_icsb_enable_counter(mp, field, count, resid); out: if (!(flags & XFS_ICSB_SB_LOCKED)) XFS_SB_UNLOCK(mp, s); } int xfs_icsb_modify_counters( xfs_mount_t *mp, xfs_sb_field_t field, int64_t delta, int rsvd) { xfs_icsb_cnts_t *icsbp; long long lcounter; /* long counter for 64 bit fields */ int cpu, ret = 0, s; might_sleep(); again: cpu = get_cpu(); icsbp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, cpu); /* * if the counter is disabled, go to slow path */ if (unlikely(xfs_icsb_counter_disabled(mp, field))) goto slow_path; xfs_icsb_lock_cntr(icsbp); if (unlikely(xfs_icsb_counter_disabled(mp, field))) { xfs_icsb_unlock_cntr(icsbp); goto slow_path; } switch (field) { case XFS_SBS_ICOUNT: lcounter = icsbp->icsb_icount; lcounter += delta; if (unlikely(lcounter < 0)) goto balance_counter; icsbp->icsb_icount = lcounter; break; case XFS_SBS_IFREE: lcounter = icsbp->icsb_ifree; lcounter += delta; if (unlikely(lcounter < 0)) goto balance_counter; icsbp->icsb_ifree = lcounter; break; case XFS_SBS_FDBLOCKS: BUG_ON((mp->m_resblks - mp->m_resblks_avail) != 0); lcounter = icsbp->icsb_fdblocks - XFS_ALLOC_SET_ASIDE(mp); lcounter += delta; if (unlikely(lcounter < 0)) goto balance_counter; icsbp->icsb_fdblocks = lcounter + XFS_ALLOC_SET_ASIDE(mp); break; default: BUG(); break; } xfs_icsb_unlock_cntr(icsbp); put_cpu(); return 0; slow_path: put_cpu(); /* * serialise with a mutex so we don't burn lots of cpu on * the superblock lock. We still need to hold the superblock * lock, however, when we modify the global structures. */ xfs_icsb_lock(mp); /* * Now running atomically. * * If the counter is enabled, someone has beaten us to rebalancing. * Drop the lock and try again in the fast path.... */ if (!(xfs_icsb_counter_disabled(mp, field))) { xfs_icsb_unlock(mp); goto again; } /* * The counter is currently disabled. Because we are * running atomically here, we know a rebalance cannot * be in progress. Hence we can go straight to operating * on the global superblock. We do not call xfs_mod_incore_sb() * here even though we need to get the SB_LOCK. Doing so * will cause us to re-enter this function and deadlock. * Hence we get the SB_LOCK ourselves and then call * xfs_mod_incore_sb_unlocked() as the unlocked path operates * directly on the global counters. */ s = XFS_SB_LOCK(mp); ret = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd); XFS_SB_UNLOCK(mp, s); /* * Now that we've modified the global superblock, we * may be able to re-enable the distributed counters * (e.g. lots of space just got freed). After that * we are done. */ if (ret != ENOSPC) xfs_icsb_balance_counter(mp, field, 0, 0); xfs_icsb_unlock(mp); return ret; balance_counter: xfs_icsb_unlock_cntr(icsbp); put_cpu(); /* * We may have multiple threads here if multiple per-cpu * counters run dry at the same time. This will mean we can * do more balances than strictly necessary but it is not * the common slowpath case. */ xfs_icsb_lock(mp); /* * running atomically. * * This will leave the counter in the correct state for future * accesses. After the rebalance, we simply try again and our retry * will either succeed through the fast path or slow path without * another balance operation being required. */ xfs_icsb_balance_counter(mp, field, 0, delta); xfs_icsb_unlock(mp); goto again; } #endif