[02/11] xfs: add an ioctl to map free space into a file

Message ID	173568777900.2709794.4653807334110054797.stgit@frogsfrogsfrogs (mailing list archive)
State	New
Headers	show Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E135E1B0425 for <linux-xfs@vger.kernel.org>; Tue, 31 Dec 2024 23:45:22 +0000 (UTC) Date: Tue, 31 Dec 2024 15:45:21 -0800 Subject: [PATCH 02/11] xfs: add an ioctl to map free space into a file From: "Darrick J. Wong" <djwong@kernel.org> To: aalbersh@kernel.org, djwong@kernel.org Cc: linux-xfs@vger.kernel.org Message-ID: <173568777900.2709794.4653807334110054797.stgit@frogsfrogsfrogs> In-Reply-To: <173568777852.2709794.6356870909327619205.stgit@frogsfrogsfrogs> References: <173568777852.2709794.6356870909327619205.stgit@frogsfrogsfrogs> Precedence: bulk MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit
Series	[01/11] xfs_io: display rtgroup number in verbose fsrefs output \| expand [01/11] xfs_io: display rtgroup number in verbose fsrefs output [02/11] xfs: add an ioctl to map free space into a file [03/11] xfs_io: support using XFS_IOC_MAP_FREESP to map free space [04/11] xfs_db: get and put blocks on the AGFL [05/11] xfs_spaceman: implement clearing free space [06/11] spaceman: physically move a regular inode [07/11] spaceman: find owners of space in an AG [08/11] xfs_spaceman: wrap radix tree accesses in find_owner.c [09/11] xfs_spaceman: port relocation structure to 32-bit systems [10/11] spaceman: relocate the contents of an AG [11/11] spaceman: move inodes with hardlinks

diff --git a/include/xfs_trace.h b/include/xfs_trace.h index 7778366c5e3319..178497c8770d37 100644 --- a/include/xfs_trace.h +++ b/include/xfs_trace.h @@ -26,6 +26,8 @@ #define trace_xfs_alloc_exact_done(a) ((void) 0) #define trace_xfs_alloc_exact_notfound(a) ((void) 0) #define trace_xfs_alloc_exact_error(a) ((void) 0) +#define trace_xfs_alloc_find_freesp(...) ((void) 0) +#define trace_xfs_alloc_find_freesp_done(...) ((void) 0) #define trace_xfs_alloc_near_first(a) ((void) 0) #define trace_xfs_alloc_near_greater(a) ((void) 0) #define trace_xfs_alloc_near_lesser(a) ((void) 0) @@ -197,6 +199,8 @@ #define trace_xfs_bmap_pre_update(a,b,c,d) ((void) 0) #define trace_xfs_bmap_post_update(a,b,c,d) ((void) 0) +#define trace_xfs_bmapi_freesp(...) ((void) 0) +#define trace_xfs_bmapi_freesp_done(...) ((void) 0) #define trace_xfs_bunmap(a,b,c,d,e) ((void) 0) #define trace_xfs_read_extent(a,b,c,d) ((void) 0) diff --git a/libxfs/libxfs_priv.h b/libxfs/libxfs_priv.h index ac2f64a9a75d82..932a45d734d460 100644 --- a/libxfs/libxfs_priv.h +++ b/libxfs/libxfs_priv.h @@ -446,6 +446,15 @@ xfs_buf_readahead( #define xfs_filestream_new_ag(ip,ag) (0) #define xfs_filestream_select_ag(...) (-ENOSYS) +struct xfs_trans; + +static inline int +xfs_rtallocate_extent(struct xfs_trans *tp, xfs_rtxnum_t start, + xfs_rtxlen_t maxlen, xfs_rtxlen_t *len, xfs_rtxnum_t *rtx) +{ + return -EOPNOTSUPP; +} + #define xfs_trans_inode_buf(tp, bp) ((void) 0) /* quota bits */ diff --git a/libxfs/xfs_alloc.c b/libxfs/xfs_alloc.c index 9aebe7227a6148..e21b694420e309 100644 --- a/libxfs/xfs_alloc.c +++ b/libxfs/xfs_alloc.c @@ -4164,3 +4164,91 @@ xfs_extfree_intent_destroy_cache(void) kmem_cache_destroy(xfs_extfree_item_cache); xfs_extfree_item_cache = NULL; } + +/* + * Find the next chunk of free space in @pag starting at @agbno and going no + * higher than @end_agbno. Set @agbno and @len to whatever free space we find, + * or to @end_agbno if we find no space. + */ +int +xfs_alloc_find_freesp( + struct xfs_trans *tp, + struct xfs_perag *pag, + xfs_agblock_t *agbno, + xfs_agblock_t end_agbno, + xfs_extlen_t *len) +{ + struct xfs_mount *mp = pag_mount(pag); + struct xfs_btree_cur *cur; + struct xfs_buf *agf_bp = NULL; + xfs_agblock_t found_agbno; + xfs_extlen_t found_len; + int found; + int error; + + trace_xfs_alloc_find_freesp(pag_group(pag), *agbno, + end_agbno - *agbno); + + error = xfs_alloc_read_agf(pag, tp, 0, &agf_bp); + if (error) + return error; + + cur = xfs_bnobt_init_cursor(mp, tp, agf_bp, pag); + + /* Try to find a free extent that starts before here. */ + error = xfs_alloc_lookup_le(cur, *agbno, 0, &found); + if (error) + goto out_cur; + if (found) { + error = xfs_alloc_get_rec(cur, &found_agbno, &found_len, + &found); + if (error) + goto out_cur; + if (XFS_IS_CORRUPT(mp, !found)) { + xfs_btree_mark_sick(cur); + error = -EFSCORRUPTED; + goto out_cur; + } + + if (found_agbno + found_len > *agbno) + goto found; + } + + /* Examine the next record if free extent not in range. */ + error = xfs_btree_increment(cur, 0, &found); + if (error) + goto out_cur; + if (!found) + goto next_ag; + + error = xfs_alloc_get_rec(cur, &found_agbno, &found_len, &found); + if (error) + goto out_cur; + if (XFS_IS_CORRUPT(mp, !found)) { + xfs_btree_mark_sick(cur); + error = -EFSCORRUPTED; + goto out_cur; + } + + if (found_agbno >= end_agbno) + goto next_ag; + +found: + /* Found something, so update the mapping. */ + trace_xfs_alloc_find_freesp_done(pag_group(pag), found_agbno, + found_len); + if (found_agbno < *agbno) { + found_len -= *agbno - found_agbno; + found_agbno = *agbno; + } + *len = found_len; + *agbno = found_agbno; + goto out_cur; +next_ag: + /* Found nothing, so advance the cursor beyond the end of the range. */ + *agbno = end_agbno; + *len = 0; +out_cur: + xfs_btree_del_cursor(cur, error); + return error; +} diff --git a/libxfs/xfs_alloc.h b/libxfs/xfs_alloc.h index 50ef79a1ed41a1..069077d9ad2f8c 100644 --- a/libxfs/xfs_alloc.h +++ b/libxfs/xfs_alloc.h @@ -286,5 +286,8 @@ void xfs_extfree_intent_destroy_cache(void); xfs_failaddr_t xfs_validate_ag_length(struct xfs_buf *bp, uint32_t seqno, uint32_t length); +int xfs_alloc_find_freesp(struct xfs_trans *tp, struct xfs_perag *pag, + xfs_agblock_t *agbno, xfs_agblock_t end_agbno, + xfs_extlen_t *len); #endif /* __XFS_ALLOC_H__ */ diff --git a/libxfs/xfs_fs.h b/libxfs/xfs_fs.h index 936f719236944f..f4128dbdf3b9a2 100644 --- a/libxfs/xfs_fs.h +++ b/libxfs/xfs_fs.h @@ -1087,6 +1087,19 @@ xfs_getfsrefs_advance( /* fcr_flags values - returned for each non-header segment */ #define FCR_OF_LAST (1U << 0) /* last record in the dataset */ +/* map free space to file */ + +/* + * XFS_IOC_MAP_FREESP maps all the free physical space in the filesystem into + * the file at the same offsets. This ioctl requires CAP_SYS_ADMIN. + */ +struct xfs_map_freesp { + __s64 offset; /* disk address to map, in bytes */ + __s64 len; /* length in bytes */ + __u64 flags; /* must be zero */ + __u64 pad; /* must be zero */ +}; + /* * ioctl commands that are used by Linux filesystems */ @@ -1127,6 +1140,7 @@ xfs_getfsrefs_advance( #define XFS_IOC_SCRUBV_METADATA _IOWR('X', 64, struct xfs_scrub_vec_head) #define XFS_IOC_RTGROUP_GEOMETRY _IOWR('X', 65, struct xfs_rtgroup_geometry) #define XFS_IOC_GETFSREFCOUNTS _IOWR('X', 66, struct xfs_getfsrefs_head) +#define XFS_IOC_MAP_FREESP _IOW ('X', 67, struct xfs_map_freesp) /* * ioctl commands that replace IRIX syssgi()'s diff --git a/man/man2/ioctl_xfs_map_freesp.2 b/man/man2/ioctl_xfs_map_freesp.2 new file mode 100644 index 00000000000000..ecd2d08f3fdeee --- /dev/null +++ b/man/man2/ioctl_xfs_map_freesp.2 @@ -0,0 +1,76 @@ +.\" Copyright (c) 2023-2025 Oracle. All rights reserved. +.\" +.\" %%%LICENSE_START(GPLv2+_DOC_FULL) +.\" SPDX-License-Identifier: GPL-2.0-or-later +.\" %%%LICENSE_END +.TH IOCTL-XFS-MAP-FREESP 2 2023-11-17 "XFS" +.SH NAME +ioctl_xfs_map_freesp \- map free space into a file +.SH SYNOPSIS +.br +.B #include <xfs/xfs_fs.h> +.PP +.BI "int ioctl(int " fd ", XFS_IOC_MAP_FREESP, struct xfs_map_freesp *" arg ); +.SH DESCRIPTION +Maps free space into the sparse ranges of a regular file. +This ioctl uses +.B struct xfs_map_freesp +to specify the range of free space to be mapped: +.PP +.in +4n +.nf +struct xfs_map_freesp { + __s64 offset; + __s64 len; + __s64 flags; + __s64 pad; +}; +.fi +.in +.PP +.I offset +is the physical disk address, in bytes, of the start of the range to scan. +Each free space extent in this range will be mapped to the file if the +corresponding range of the file is sparse. +.PP +.I len +is the number of bytes in the range to scan. +.PP +.I flags +must be zero; there are no flags defined yet. +.PP +.I pad +must be zero. +.SH RETURN VALUE +On error, \-1 is returned, and +.I errno +is set to indicate the error. +.PP +.SH ERRORS +Error codes can be one of, but are not limited to, the following: +.TP +.B EFAULT +The kernel was not able to copy into the userspace buffer. +.TP +.B EFSBADCRC +Metadata checksum validation failed while performing the query. +.TP +.B EFSCORRUPTED +Metadata corruption was encountered while performing the query. +.TP +.B EINVAL +One of the arguments was not valid, +or the file was not sparse. +.TP +.B EIO +An I/O error was encountered while performing the query. +.TP +.B ENOMEM +There was insufficient memory to perform the query. +.TP +.B ENOSPC +There was insufficient disk space to commit the space mappings. +.SH CONFORMING TO +This API is specific to XFS filesystem on the Linux kernel. +.SH SEE ALSO +.BR ioctl (2)

[02/11] xfs: add an ioctl to map free space into a file

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