diff options
Diffstat (limited to 'fs/xfs/libxfs/xfs_attr_remote.c')
-rw-r--r-- | fs/xfs/libxfs/xfs_attr_remote.c | 712 |
1 files changed, 712 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_attr_remote.c b/fs/xfs/libxfs/xfs_attr_remote.c new file mode 100644 index 0000000000..d440393b40 --- /dev/null +++ b/fs/xfs/libxfs/xfs_attr_remote.c @@ -0,0 +1,712 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2000-2005 Silicon Graphics, Inc. + * Copyright (c) 2013 Red Hat, Inc. + * All Rights Reserved. + */ +#include "xfs.h" +#include "xfs_fs.h" +#include "xfs_shared.h" +#include "xfs_format.h" +#include "xfs_log_format.h" +#include "xfs_trans_resv.h" +#include "xfs_bit.h" +#include "xfs_mount.h" +#include "xfs_defer.h" +#include "xfs_da_format.h" +#include "xfs_da_btree.h" +#include "xfs_inode.h" +#include "xfs_trans.h" +#include "xfs_bmap.h" +#include "xfs_attr.h" +#include "xfs_attr_remote.h" +#include "xfs_trace.h" +#include "xfs_error.h" + +#define ATTR_RMTVALUE_MAPSIZE 1 /* # of map entries at once */ + +/* + * Remote Attribute Values + * ======================= + * + * Remote extended attribute values are conceptually simple -- they're written + * to data blocks mapped by an inode's attribute fork, and they have an upper + * size limit of 64k. Setting a value does not involve the XFS log. + * + * However, on a v5 filesystem, maximally sized remote attr values require one + * block more than 64k worth of space to hold both the remote attribute value + * header (64 bytes). On a 4k block filesystem this results in a 68k buffer; + * on a 64k block filesystem, this would be a 128k buffer. Note that the log + * format can only handle a dirty buffer of XFS_MAX_BLOCKSIZE length (64k). + * Therefore, we /must/ ensure that remote attribute value buffers never touch + * the logging system and therefore never have a log item. + */ + +/* + * Each contiguous block has a header, so it is not just a simple attribute + * length to FSB conversion. + */ +int +xfs_attr3_rmt_blocks( + struct xfs_mount *mp, + int attrlen) +{ + if (xfs_has_crc(mp)) { + int buflen = XFS_ATTR3_RMT_BUF_SPACE(mp, mp->m_sb.sb_blocksize); + return (attrlen + buflen - 1) / buflen; + } + return XFS_B_TO_FSB(mp, attrlen); +} + +/* + * Checking of the remote attribute header is split into two parts. The verifier + * does CRC, location and bounds checking, the unpacking function checks the + * attribute parameters and owner. + */ +static xfs_failaddr_t +xfs_attr3_rmt_hdr_ok( + void *ptr, + xfs_ino_t ino, + uint32_t offset, + uint32_t size, + xfs_daddr_t bno) +{ + struct xfs_attr3_rmt_hdr *rmt = ptr; + + if (bno != be64_to_cpu(rmt->rm_blkno)) + return __this_address; + if (offset != be32_to_cpu(rmt->rm_offset)) + return __this_address; + if (size != be32_to_cpu(rmt->rm_bytes)) + return __this_address; + if (ino != be64_to_cpu(rmt->rm_owner)) + return __this_address; + + /* ok */ + return NULL; +} + +static xfs_failaddr_t +xfs_attr3_rmt_verify( + struct xfs_mount *mp, + struct xfs_buf *bp, + void *ptr, + int fsbsize, + xfs_daddr_t bno) +{ + struct xfs_attr3_rmt_hdr *rmt = ptr; + + if (!xfs_verify_magic(bp, rmt->rm_magic)) + return __this_address; + if (!uuid_equal(&rmt->rm_uuid, &mp->m_sb.sb_meta_uuid)) + return __this_address; + if (be64_to_cpu(rmt->rm_blkno) != bno) + return __this_address; + if (be32_to_cpu(rmt->rm_bytes) > fsbsize - sizeof(*rmt)) + return __this_address; + if (be32_to_cpu(rmt->rm_offset) + + be32_to_cpu(rmt->rm_bytes) > XFS_XATTR_SIZE_MAX) + return __this_address; + if (rmt->rm_owner == 0) + return __this_address; + + return NULL; +} + +static int +__xfs_attr3_rmt_read_verify( + struct xfs_buf *bp, + bool check_crc, + xfs_failaddr_t *failaddr) +{ + struct xfs_mount *mp = bp->b_mount; + char *ptr; + int len; + xfs_daddr_t bno; + int blksize = mp->m_attr_geo->blksize; + + /* no verification of non-crc buffers */ + if (!xfs_has_crc(mp)) + return 0; + + ptr = bp->b_addr; + bno = xfs_buf_daddr(bp); + len = BBTOB(bp->b_length); + ASSERT(len >= blksize); + + while (len > 0) { + if (check_crc && + !xfs_verify_cksum(ptr, blksize, XFS_ATTR3_RMT_CRC_OFF)) { + *failaddr = __this_address; + return -EFSBADCRC; + } + *failaddr = xfs_attr3_rmt_verify(mp, bp, ptr, blksize, bno); + if (*failaddr) + return -EFSCORRUPTED; + len -= blksize; + ptr += blksize; + bno += BTOBB(blksize); + } + + if (len != 0) { + *failaddr = __this_address; + return -EFSCORRUPTED; + } + + return 0; +} + +static void +xfs_attr3_rmt_read_verify( + struct xfs_buf *bp) +{ + xfs_failaddr_t fa; + int error; + + error = __xfs_attr3_rmt_read_verify(bp, true, &fa); + if (error) + xfs_verifier_error(bp, error, fa); +} + +static xfs_failaddr_t +xfs_attr3_rmt_verify_struct( + struct xfs_buf *bp) +{ + xfs_failaddr_t fa; + int error; + + error = __xfs_attr3_rmt_read_verify(bp, false, &fa); + return error ? fa : NULL; +} + +static void +xfs_attr3_rmt_write_verify( + struct xfs_buf *bp) +{ + struct xfs_mount *mp = bp->b_mount; + xfs_failaddr_t fa; + int blksize = mp->m_attr_geo->blksize; + char *ptr; + int len; + xfs_daddr_t bno; + + /* no verification of non-crc buffers */ + if (!xfs_has_crc(mp)) + return; + + ptr = bp->b_addr; + bno = xfs_buf_daddr(bp); + len = BBTOB(bp->b_length); + ASSERT(len >= blksize); + + while (len > 0) { + struct xfs_attr3_rmt_hdr *rmt = (struct xfs_attr3_rmt_hdr *)ptr; + + fa = xfs_attr3_rmt_verify(mp, bp, ptr, blksize, bno); + if (fa) { + xfs_verifier_error(bp, -EFSCORRUPTED, fa); + return; + } + + /* + * Ensure we aren't writing bogus LSNs to disk. See + * xfs_attr3_rmt_hdr_set() for the explanation. + */ + if (rmt->rm_lsn != cpu_to_be64(NULLCOMMITLSN)) { + xfs_verifier_error(bp, -EFSCORRUPTED, __this_address); + return; + } + xfs_update_cksum(ptr, blksize, XFS_ATTR3_RMT_CRC_OFF); + + len -= blksize; + ptr += blksize; + bno += BTOBB(blksize); + } + + if (len != 0) + xfs_verifier_error(bp, -EFSCORRUPTED, __this_address); +} + +const struct xfs_buf_ops xfs_attr3_rmt_buf_ops = { + .name = "xfs_attr3_rmt", + .magic = { 0, cpu_to_be32(XFS_ATTR3_RMT_MAGIC) }, + .verify_read = xfs_attr3_rmt_read_verify, + .verify_write = xfs_attr3_rmt_write_verify, + .verify_struct = xfs_attr3_rmt_verify_struct, +}; + +STATIC int +xfs_attr3_rmt_hdr_set( + struct xfs_mount *mp, + void *ptr, + xfs_ino_t ino, + uint32_t offset, + uint32_t size, + xfs_daddr_t bno) +{ + struct xfs_attr3_rmt_hdr *rmt = ptr; + + if (!xfs_has_crc(mp)) + return 0; + + rmt->rm_magic = cpu_to_be32(XFS_ATTR3_RMT_MAGIC); + rmt->rm_offset = cpu_to_be32(offset); + rmt->rm_bytes = cpu_to_be32(size); + uuid_copy(&rmt->rm_uuid, &mp->m_sb.sb_meta_uuid); + rmt->rm_owner = cpu_to_be64(ino); + rmt->rm_blkno = cpu_to_be64(bno); + + /* + * Remote attribute blocks are written synchronously, so we don't + * have an LSN that we can stamp in them that makes any sense to log + * recovery. To ensure that log recovery handles overwrites of these + * blocks sanely (i.e. once they've been freed and reallocated as some + * other type of metadata) we need to ensure that the LSN has a value + * that tells log recovery to ignore the LSN and overwrite the buffer + * with whatever is in it's log. To do this, we use the magic + * NULLCOMMITLSN to indicate that the LSN is invalid. + */ + rmt->rm_lsn = cpu_to_be64(NULLCOMMITLSN); + + return sizeof(struct xfs_attr3_rmt_hdr); +} + +/* + * Helper functions to copy attribute data in and out of the one disk extents + */ +STATIC int +xfs_attr_rmtval_copyout( + struct xfs_mount *mp, + struct xfs_buf *bp, + xfs_ino_t ino, + int *offset, + int *valuelen, + uint8_t **dst) +{ + char *src = bp->b_addr; + xfs_daddr_t bno = xfs_buf_daddr(bp); + int len = BBTOB(bp->b_length); + int blksize = mp->m_attr_geo->blksize; + + ASSERT(len >= blksize); + + while (len > 0 && *valuelen > 0) { + int hdr_size = 0; + int byte_cnt = XFS_ATTR3_RMT_BUF_SPACE(mp, blksize); + + byte_cnt = min(*valuelen, byte_cnt); + + if (xfs_has_crc(mp)) { + if (xfs_attr3_rmt_hdr_ok(src, ino, *offset, + byte_cnt, bno)) { + xfs_alert(mp, +"remote attribute header mismatch bno/off/len/owner (0x%llx/0x%x/Ox%x/0x%llx)", + bno, *offset, byte_cnt, ino); + return -EFSCORRUPTED; + } + hdr_size = sizeof(struct xfs_attr3_rmt_hdr); + } + + memcpy(*dst, src + hdr_size, byte_cnt); + + /* roll buffer forwards */ + len -= blksize; + src += blksize; + bno += BTOBB(blksize); + + /* roll attribute data forwards */ + *valuelen -= byte_cnt; + *dst += byte_cnt; + *offset += byte_cnt; + } + return 0; +} + +STATIC void +xfs_attr_rmtval_copyin( + struct xfs_mount *mp, + struct xfs_buf *bp, + xfs_ino_t ino, + int *offset, + int *valuelen, + uint8_t **src) +{ + char *dst = bp->b_addr; + xfs_daddr_t bno = xfs_buf_daddr(bp); + int len = BBTOB(bp->b_length); + int blksize = mp->m_attr_geo->blksize; + + ASSERT(len >= blksize); + + while (len > 0 && *valuelen > 0) { + int hdr_size; + int byte_cnt = XFS_ATTR3_RMT_BUF_SPACE(mp, blksize); + + byte_cnt = min(*valuelen, byte_cnt); + hdr_size = xfs_attr3_rmt_hdr_set(mp, dst, ino, *offset, + byte_cnt, bno); + + memcpy(dst + hdr_size, *src, byte_cnt); + + /* + * If this is the last block, zero the remainder of it. + * Check that we are actually the last block, too. + */ + if (byte_cnt + hdr_size < blksize) { + ASSERT(*valuelen - byte_cnt == 0); + ASSERT(len == blksize); + memset(dst + hdr_size + byte_cnt, 0, + blksize - hdr_size - byte_cnt); + } + + /* roll buffer forwards */ + len -= blksize; + dst += blksize; + bno += BTOBB(blksize); + + /* roll attribute data forwards */ + *valuelen -= byte_cnt; + *src += byte_cnt; + *offset += byte_cnt; + } +} + +/* + * Read the value associated with an attribute from the out-of-line buffer + * that we stored it in. + * + * Returns 0 on successful retrieval, otherwise an error. + */ +int +xfs_attr_rmtval_get( + struct xfs_da_args *args) +{ + struct xfs_bmbt_irec map[ATTR_RMTVALUE_MAPSIZE]; + struct xfs_mount *mp = args->dp->i_mount; + struct xfs_buf *bp; + xfs_dablk_t lblkno = args->rmtblkno; + uint8_t *dst = args->value; + int valuelen; + int nmap; + int error; + int blkcnt = args->rmtblkcnt; + int i; + int offset = 0; + + trace_xfs_attr_rmtval_get(args); + + ASSERT(args->valuelen != 0); + ASSERT(args->rmtvaluelen == args->valuelen); + + valuelen = args->rmtvaluelen; + while (valuelen > 0) { + nmap = ATTR_RMTVALUE_MAPSIZE; + error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno, + blkcnt, map, &nmap, + XFS_BMAPI_ATTRFORK); + if (error) + return error; + ASSERT(nmap >= 1); + + for (i = 0; (i < nmap) && (valuelen > 0); i++) { + xfs_daddr_t dblkno; + int dblkcnt; + + ASSERT((map[i].br_startblock != DELAYSTARTBLOCK) && + (map[i].br_startblock != HOLESTARTBLOCK)); + dblkno = XFS_FSB_TO_DADDR(mp, map[i].br_startblock); + dblkcnt = XFS_FSB_TO_BB(mp, map[i].br_blockcount); + error = xfs_buf_read(mp->m_ddev_targp, dblkno, dblkcnt, + 0, &bp, &xfs_attr3_rmt_buf_ops); + if (error) + return error; + + error = xfs_attr_rmtval_copyout(mp, bp, args->dp->i_ino, + &offset, &valuelen, + &dst); + xfs_buf_relse(bp); + if (error) + return error; + + /* roll attribute extent map forwards */ + lblkno += map[i].br_blockcount; + blkcnt -= map[i].br_blockcount; + } + } + ASSERT(valuelen == 0); + return 0; +} + +/* + * Find a "hole" in the attribute address space large enough for us to drop the + * new attributes value into + */ +int +xfs_attr_rmt_find_hole( + struct xfs_da_args *args) +{ + struct xfs_inode *dp = args->dp; + struct xfs_mount *mp = dp->i_mount; + int error; + int blkcnt; + xfs_fileoff_t lfileoff = 0; + + /* + * Because CRC enable attributes have headers, we can't just do a + * straight byte to FSB conversion and have to take the header space + * into account. + */ + blkcnt = xfs_attr3_rmt_blocks(mp, args->rmtvaluelen); + error = xfs_bmap_first_unused(args->trans, args->dp, blkcnt, &lfileoff, + XFS_ATTR_FORK); + if (error) + return error; + + args->rmtblkno = (xfs_dablk_t)lfileoff; + args->rmtblkcnt = blkcnt; + + return 0; +} + +int +xfs_attr_rmtval_set_value( + struct xfs_da_args *args) +{ + struct xfs_inode *dp = args->dp; + struct xfs_mount *mp = dp->i_mount; + struct xfs_bmbt_irec map; + xfs_dablk_t lblkno; + uint8_t *src = args->value; + int blkcnt; + int valuelen; + int nmap; + int error; + int offset = 0; + + /* + * Roll through the "value", copying the attribute value to the + * already-allocated blocks. Blocks are written synchronously + * so that we can know they are all on disk before we turn off + * the INCOMPLETE flag. + */ + lblkno = args->rmtblkno; + blkcnt = args->rmtblkcnt; + valuelen = args->rmtvaluelen; + while (valuelen > 0) { + struct xfs_buf *bp; + xfs_daddr_t dblkno; + int dblkcnt; + + ASSERT(blkcnt > 0); + + nmap = 1; + error = xfs_bmapi_read(dp, (xfs_fileoff_t)lblkno, + blkcnt, &map, &nmap, + XFS_BMAPI_ATTRFORK); + if (error) + return error; + ASSERT(nmap == 1); + ASSERT((map.br_startblock != DELAYSTARTBLOCK) && + (map.br_startblock != HOLESTARTBLOCK)); + + dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock), + dblkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount); + + error = xfs_buf_get(mp->m_ddev_targp, dblkno, dblkcnt, &bp); + if (error) + return error; + bp->b_ops = &xfs_attr3_rmt_buf_ops; + + xfs_attr_rmtval_copyin(mp, bp, args->dp->i_ino, &offset, + &valuelen, &src); + + error = xfs_bwrite(bp); /* GROT: NOTE: synchronous write */ + xfs_buf_relse(bp); + if (error) + return error; + + + /* roll attribute extent map forwards */ + lblkno += map.br_blockcount; + blkcnt -= map.br_blockcount; + } + ASSERT(valuelen == 0); + return 0; +} + +/* Mark stale any incore buffers for the remote value. */ +int +xfs_attr_rmtval_stale( + struct xfs_inode *ip, + struct xfs_bmbt_irec *map, + xfs_buf_flags_t incore_flags) +{ + struct xfs_mount *mp = ip->i_mount; + struct xfs_buf *bp; + int error; + + ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL)); + + if (XFS_IS_CORRUPT(mp, map->br_startblock == DELAYSTARTBLOCK) || + XFS_IS_CORRUPT(mp, map->br_startblock == HOLESTARTBLOCK)) + return -EFSCORRUPTED; + + error = xfs_buf_incore(mp->m_ddev_targp, + XFS_FSB_TO_DADDR(mp, map->br_startblock), + XFS_FSB_TO_BB(mp, map->br_blockcount), + incore_flags, &bp); + if (error) { + if (error == -ENOENT) + return 0; + return error; + } + + xfs_buf_stale(bp); + xfs_buf_relse(bp); + return 0; +} + +/* + * Find a hole for the attr and store it in the delayed attr context. This + * initializes the context to roll through allocating an attr extent for a + * delayed attr operation + */ +int +xfs_attr_rmtval_find_space( + struct xfs_attr_intent *attr) +{ + struct xfs_da_args *args = attr->xattri_da_args; + struct xfs_bmbt_irec *map = &attr->xattri_map; + int error; + + attr->xattri_lblkno = 0; + attr->xattri_blkcnt = 0; + args->rmtblkcnt = 0; + args->rmtblkno = 0; + memset(map, 0, sizeof(struct xfs_bmbt_irec)); + + error = xfs_attr_rmt_find_hole(args); + if (error) + return error; + + attr->xattri_blkcnt = args->rmtblkcnt; + attr->xattri_lblkno = args->rmtblkno; + + return 0; +} + +/* + * Write one block of the value associated with an attribute into the + * out-of-line buffer that we have defined for it. This is similar to a subset + * of xfs_attr_rmtval_set, but records the current block to the delayed attr + * context, and leaves transaction handling to the caller. + */ +int +xfs_attr_rmtval_set_blk( + struct xfs_attr_intent *attr) +{ + struct xfs_da_args *args = attr->xattri_da_args; + struct xfs_inode *dp = args->dp; + struct xfs_bmbt_irec *map = &attr->xattri_map; + int nmap; + int error; + + nmap = 1; + error = xfs_bmapi_write(args->trans, dp, + (xfs_fileoff_t)attr->xattri_lblkno, + attr->xattri_blkcnt, XFS_BMAPI_ATTRFORK, args->total, + map, &nmap); + if (error) + return error; + + ASSERT(nmap == 1); + ASSERT((map->br_startblock != DELAYSTARTBLOCK) && + (map->br_startblock != HOLESTARTBLOCK)); + + /* roll attribute extent map forwards */ + attr->xattri_lblkno += map->br_blockcount; + attr->xattri_blkcnt -= map->br_blockcount; + + return 0; +} + +/* + * Remove the value associated with an attribute by deleting the + * out-of-line buffer that it is stored on. + */ +int +xfs_attr_rmtval_invalidate( + struct xfs_da_args *args) +{ + xfs_dablk_t lblkno; + int blkcnt; + int error; + + /* + * Roll through the "value", invalidating the attribute value's blocks. + */ + lblkno = args->rmtblkno; + blkcnt = args->rmtblkcnt; + while (blkcnt > 0) { + struct xfs_bmbt_irec map; + int nmap; + + /* + * Try to remember where we decided to put the value. + */ + nmap = 1; + error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno, + blkcnt, &map, &nmap, XFS_BMAPI_ATTRFORK); + if (error) + return error; + if (XFS_IS_CORRUPT(args->dp->i_mount, nmap != 1)) + return -EFSCORRUPTED; + error = xfs_attr_rmtval_stale(args->dp, &map, XBF_TRYLOCK); + if (error) + return error; + + lblkno += map.br_blockcount; + blkcnt -= map.br_blockcount; + } + return 0; +} + +/* + * Remove the value associated with an attribute by deleting the out-of-line + * buffer that it is stored on. Returns -EAGAIN for the caller to refresh the + * transaction and re-call the function. Callers should keep calling this + * routine until it returns something other than -EAGAIN. + */ +int +xfs_attr_rmtval_remove( + struct xfs_attr_intent *attr) +{ + struct xfs_da_args *args = attr->xattri_da_args; + int error, done; + + /* + * Unmap value blocks for this attr. + */ + error = xfs_bunmapi(args->trans, args->dp, args->rmtblkno, + args->rmtblkcnt, XFS_BMAPI_ATTRFORK, 1, &done); + if (error) + return error; + + /* + * We don't need an explicit state here to pick up where we left off. We + * can figure it out using the !done return code. The actual value of + * attr->xattri_dela_state may be some value reminiscent of the calling + * function, but it's value is irrelevant with in the context of this + * function. Once we are done here, the next state is set as needed by + * the parent + */ + if (!done) { + trace_xfs_attr_rmtval_remove_return(attr->xattri_dela_state, + args->dp); + return -EAGAIN; + } + + args->rmtblkno = 0; + args->rmtblkcnt = 0; + return 0; +} |