*/
#include "xfs.h"
#include "xfs_fs.h"
-#include "xfs_bit.h"
#include "xfs_log.h"
-#include "xfs_inum.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_trans.h"
}
/*
- * This routine is called to handle zeroing any space in the last
- * block of the file that is beyond the EOF. We do this since the
- * size is being increased without writing anything to that block
- * and we don't want anyone to read the garbage on the disk.
+ * This routine is called to handle zeroing any space in the last block of the
+ * file that is beyond the EOF. We do this since the size is being increased
+ * without writing anything to that block and we don't want to read the
+ * garbage on the disk.
*/
STATIC int /* error (positive) */
xfs_zero_last_block(
- xfs_inode_t *ip,
- xfs_fsize_t offset,
- xfs_fsize_t isize)
+ struct xfs_inode *ip,
+ xfs_fsize_t offset,
+ xfs_fsize_t isize)
{
- xfs_fileoff_t last_fsb;
- xfs_mount_t *mp = ip->i_mount;
- int nimaps;
- int zero_offset;
- int zero_len;
- int error = 0;
- xfs_bmbt_irec_t imap;
-
- ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
-
- zero_offset = XFS_B_FSB_OFFSET(mp, isize);
- if (zero_offset == 0) {
- /*
- * There are no extra bytes in the last block on disk to
- * zero, so return.
- */
- return 0;
- }
+ struct xfs_mount *mp = ip->i_mount;
+ xfs_fileoff_t last_fsb = XFS_B_TO_FSBT(mp, isize);
+ int zero_offset = XFS_B_FSB_OFFSET(mp, isize);
+ int zero_len;
+ int nimaps = 1;
+ int error = 0;
+ struct xfs_bmbt_irec imap;
- last_fsb = XFS_B_TO_FSBT(mp, isize);
- nimaps = 1;
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
error = xfs_bmapi_read(ip, last_fsb, 1, &imap, &nimaps, 0);
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
if (error)
return error;
+
ASSERT(nimaps > 0);
+
/*
* If the block underlying isize is just a hole, then there
* is nothing to zero.
*/
- if (imap.br_startblock == HOLESTARTBLOCK) {
+ if (imap.br_startblock == HOLESTARTBLOCK)
return 0;
- }
- /*
- * Zero the part of the last block beyond the EOF, and write it
- * out sync. We need to drop the ilock while we do this so we
- * don't deadlock when the buffer cache calls back to us.
- */
- xfs_iunlock(ip, XFS_ILOCK_EXCL);
zero_len = mp->m_sb.sb_blocksize - zero_offset;
if (isize + zero_len > offset)
zero_len = offset - isize;
- error = xfs_iozero(ip, isize, zero_len);
-
- xfs_ilock(ip, XFS_ILOCK_EXCL);
- ASSERT(error >= 0);
- return error;
+ return xfs_iozero(ip, isize, zero_len);
}
/*
- * Zero any on disk space between the current EOF and the new,
- * larger EOF. This handles the normal case of zeroing the remainder
- * of the last block in the file and the unusual case of zeroing blocks
- * out beyond the size of the file. This second case only happens
- * with fixed size extents and when the system crashes before the inode
- * size was updated but after blocks were allocated. If fill is set,
- * then any holes in the range are filled and zeroed. If not, the holes
- * are left alone as holes.
+ * Zero any on disk space between the current EOF and the new, larger EOF.
+ *
+ * This handles the normal case of zeroing the remainder of the last block in
+ * the file and the unusual case of zeroing blocks out beyond the size of the
+ * file. This second case only happens with fixed size extents and when the
+ * system crashes before the inode size was updated but after blocks were
+ * allocated.
+ *
+ * Expects the iolock to be held exclusive, and will take the ilock internally.
*/
-
int /* error (positive) */
xfs_zero_eof(
- xfs_inode_t *ip,
- xfs_off_t offset, /* starting I/O offset */
- xfs_fsize_t isize) /* current inode size */
+ struct xfs_inode *ip,
+ xfs_off_t offset, /* starting I/O offset */
+ xfs_fsize_t isize) /* current inode size */
{
- xfs_mount_t *mp = ip->i_mount;
- xfs_fileoff_t start_zero_fsb;
- xfs_fileoff_t end_zero_fsb;
- xfs_fileoff_t zero_count_fsb;
- xfs_fileoff_t last_fsb;
- xfs_fileoff_t zero_off;
- xfs_fsize_t zero_len;
- int nimaps;
- int error = 0;
- xfs_bmbt_irec_t imap;
-
- ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL));
+ struct xfs_mount *mp = ip->i_mount;
+ xfs_fileoff_t start_zero_fsb;
+ xfs_fileoff_t end_zero_fsb;
+ xfs_fileoff_t zero_count_fsb;
+ xfs_fileoff_t last_fsb;
+ xfs_fileoff_t zero_off;
+ xfs_fsize_t zero_len;
+ int nimaps;
+ int error = 0;
+ struct xfs_bmbt_irec imap;
+
+ ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
ASSERT(offset > isize);
/*
* First handle zeroing the block on which isize resides.
+ *
* We only zero a part of that block so it is handled specially.
*/
- error = xfs_zero_last_block(ip, offset, isize);
- if (error) {
- ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL));
- return error;
+ if (XFS_B_FSB_OFFSET(mp, isize) != 0) {
+ error = xfs_zero_last_block(ip, offset, isize);
+ if (error)
+ return error;
}
/*
- * Calculate the range between the new size and the old
- * where blocks needing to be zeroed may exist. To get the
- * block where the last byte in the file currently resides,
- * we need to subtract one from the size and truncate back
- * to a block boundary. We subtract 1 in case the size is
- * exactly on a block boundary.
+ * Calculate the range between the new size and the old where blocks
+ * needing to be zeroed may exist.
+ *
+ * To get the block where the last byte in the file currently resides,
+ * we need to subtract one from the size and truncate back to a block
+ * boundary. We subtract 1 in case the size is exactly on a block
+ * boundary.
*/
last_fsb = isize ? XFS_B_TO_FSBT(mp, isize - 1) : (xfs_fileoff_t)-1;
start_zero_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize);
while (start_zero_fsb <= end_zero_fsb) {
nimaps = 1;
zero_count_fsb = end_zero_fsb - start_zero_fsb + 1;
+
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
error = xfs_bmapi_read(ip, start_zero_fsb, zero_count_fsb,
&imap, &nimaps, 0);
- if (error) {
- ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL));
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ if (error)
return error;
- }
+
ASSERT(nimaps > 0);
if (imap.br_state == XFS_EXT_UNWRITTEN ||
imap.br_startblock == HOLESTARTBLOCK) {
- /*
- * This loop handles initializing pages that were
- * partially initialized by the code below this
- * loop. It basically zeroes the part of the page
- * that sits on a hole and sets the page as P_HOLE
- * and calls remapf if it is a mapped file.
- */
start_zero_fsb = imap.br_startoff + imap.br_blockcount;
ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
continue;
/*
* There are blocks we need to zero.
- * Drop the inode lock while we're doing the I/O.
- * We'll still have the iolock to protect us.
*/
- xfs_iunlock(ip, XFS_ILOCK_EXCL);
-
zero_off = XFS_FSB_TO_B(mp, start_zero_fsb);
zero_len = XFS_FSB_TO_B(mp, imap.br_blockcount);
zero_len = offset - zero_off;
error = xfs_iozero(ip, zero_off, zero_len);
- if (error) {
- goto out_lock;
- }
+ if (error)
+ return error;
start_zero_fsb = imap.br_startoff + imap.br_blockcount;
ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
-
- xfs_ilock(ip, XFS_ILOCK_EXCL);
}
return 0;
-
-out_lock:
- xfs_ilock(ip, XFS_ILOCK_EXCL);
- ASSERT(error >= 0);
- return error;
}
/*
struct xfs_inode *ip = XFS_I(inode);
int error = 0;
- xfs_rw_ilock(ip, XFS_ILOCK_EXCL);
restart:
error = generic_write_checks(file, pos, count, S_ISBLK(inode->i_mode));
- if (error) {
- xfs_rw_iunlock(ip, XFS_ILOCK_EXCL);
+ if (error)
return error;
- }
/*
* If the offset is beyond the size of the file, we need to zero any
* blocks that fall between the existing EOF and the start of this
* write. If zeroing is needed and we are currently holding the
- * iolock shared, we need to update it to exclusive which involves
- * dropping all locks and relocking to maintain correct locking order.
- * If we do this, restart the function to ensure all checks and values
- * are still valid.
+ * iolock shared, we need to update it to exclusive which implies
+ * having to redo all checks before.
*/
if (*pos > i_size_read(inode)) {
if (*iolock == XFS_IOLOCK_SHARED) {
- xfs_rw_iunlock(ip, XFS_ILOCK_EXCL | *iolock);
+ xfs_rw_iunlock(ip, *iolock);
*iolock = XFS_IOLOCK_EXCL;
- xfs_rw_ilock(ip, XFS_ILOCK_EXCL | *iolock);
+ xfs_rw_ilock(ip, *iolock);
goto restart;
}
error = -xfs_zero_eof(ip, *pos, i_size_read(inode));
+ if (error)
+ return error;
}
- xfs_rw_iunlock(ip, XFS_ILOCK_EXCL);
- if (error)
- return error;
/*
* Updating the timestamps will grab the ilock again from
* lock above. Eventually we should look into a way to avoid
* the pointless lock roundtrip.
*/
- if (likely(!(file->f_mode & FMODE_NOCMTIME)))
- file_update_time(file);
+ if (likely(!(file->f_mode & FMODE_NOCMTIME))) {
+ error = file_update_time(file);
+ if (error)
+ return error;
+ }
/*
* If we're writing the file then make sure to clear the setuid and
* people from modifying setuid and setgid binaries.
*/
return file_remove_suid(file);
-
}
/*
return block_page_mkwrite(vma, vmf, xfs_get_blocks);
}
+STATIC loff_t
+xfs_seek_data(
+ struct file *file,
+ loff_t start,
+ u32 type)
+{
+ struct inode *inode = file->f_mapping->host;
+ struct xfs_inode *ip = XFS_I(inode);
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_bmbt_irec map[2];
+ int nmap = 2;
+ loff_t uninitialized_var(offset);
+ xfs_fsize_t isize;
+ xfs_fileoff_t fsbno;
+ xfs_filblks_t end;
+ uint lock;
+ int error;
+
+ lock = xfs_ilock_map_shared(ip);
+
+ isize = i_size_read(inode);
+ if (start >= isize) {
+ error = ENXIO;
+ goto out_unlock;
+ }
+
+ fsbno = XFS_B_TO_FSBT(mp, start);
+
+ /*
+ * Try to read extents from the first block indicated
+ * by fsbno to the end block of the file.
+ */
+ end = XFS_B_TO_FSB(mp, isize);
+
+ error = xfs_bmapi_read(ip, fsbno, end - fsbno, map, &nmap,
+ XFS_BMAPI_ENTIRE);
+ if (error)
+ goto out_unlock;
+
+ /*
+ * Treat unwritten extent as data extent since it might
+ * contains dirty data in page cache.
+ */
+ if (map[0].br_startblock != HOLESTARTBLOCK) {
+ offset = max_t(loff_t, start,
+ XFS_FSB_TO_B(mp, map[0].br_startoff));
+ } else {
+ if (nmap == 1) {
+ error = ENXIO;
+ goto out_unlock;
+ }
+
+ offset = max_t(loff_t, start,
+ XFS_FSB_TO_B(mp, map[1].br_startoff));
+ }
+
+ if (offset != file->f_pos)
+ file->f_pos = offset;
+
+out_unlock:
+ xfs_iunlock_map_shared(ip, lock);
+
+ if (error)
+ return -error;
+ return offset;
+}
+
+STATIC loff_t
+xfs_seek_hole(
+ struct file *file,
+ loff_t start,
+ u32 type)
+{
+ struct inode *inode = file->f_mapping->host;
+ struct xfs_inode *ip = XFS_I(inode);
+ struct xfs_mount *mp = ip->i_mount;
+ loff_t uninitialized_var(offset);
+ loff_t holeoff;
+ xfs_fsize_t isize;
+ xfs_fileoff_t fsbno;
+ uint lock;
+ int error;
+
+ if (XFS_FORCED_SHUTDOWN(mp))
+ return -XFS_ERROR(EIO);
+
+ lock = xfs_ilock_map_shared(ip);
+
+ isize = i_size_read(inode);
+ if (start >= isize) {
+ error = ENXIO;
+ goto out_unlock;
+ }
+
+ fsbno = XFS_B_TO_FSBT(mp, start);
+ error = xfs_bmap_first_unused(NULL, ip, 1, &fsbno, XFS_DATA_FORK);
+ if (error)
+ goto out_unlock;
+
+ holeoff = XFS_FSB_TO_B(mp, fsbno);
+ if (holeoff <= start)
+ offset = start;
+ else {
+ /*
+ * xfs_bmap_first_unused() could return a value bigger than
+ * isize if there are no more holes past the supplied offset.
+ */
+ offset = min_t(loff_t, holeoff, isize);
+ }
+
+ if (offset != file->f_pos)
+ file->f_pos = offset;
+
+out_unlock:
+ xfs_iunlock_map_shared(ip, lock);
+
+ if (error)
+ return -error;
+ return offset;
+}
+
+STATIC loff_t
+xfs_file_llseek(
+ struct file *file,
+ loff_t offset,
+ int origin)
+{
+ switch (origin) {
+ case SEEK_END:
+ case SEEK_CUR:
+ case SEEK_SET:
+ return generic_file_llseek(file, offset, origin);
+ case SEEK_DATA:
+ return xfs_seek_data(file, offset, origin);
+ case SEEK_HOLE:
+ return xfs_seek_hole(file, offset, origin);
+ default:
+ return -EINVAL;
+ }
+}
+
const struct file_operations xfs_file_operations = {
- .llseek = generic_file_llseek,
+ .llseek = xfs_file_llseek,
.read = do_sync_read,
.write = do_sync_write,
.aio_read = xfs_file_aio_read,
projects / ~andy / linux / blobdiff